Jn 3003, a cecidogenous aphid - PDF document

Jn 3003, a cecidogenous aphid )= )L.) showed outbreaks in Ulmus glabra Iuds. at some localities in Noravia. For example, in a riparian and accompanying stand along the Tvitava river, it attacked about 50% leaves in the area between Crno-Obřany and the Tvratka river in Crno-Jundrov and Crno-Pisárky were damaged even more )85%). Uhe outbreak of the aphid was used to study its occurrence, development, natural Jn the Czech Sepublic )CS), is one of the most abundant representatives of a developmentally advanced and economically important family of Pemphigidae )= Friosomatidae) in elms. Uhe family includes about 350 species. According to OLNAO and JOUFSA )2:88), about 50 species occur in the CS. Uheir amphigonic in digestive system. Jn apterous parthenogenetic forms, well-developed wax glands producing wax dust, �bres etc. occur very often. Uheir antennae are relatively short, 7-segment, in winged individuals mostly with narrowly annular secondary rhinaria. Tiphunculi and cauda are not marked or are missing, anal plate is rounded. Jn the course of the year, great majority of species migrates from primary )main) host plants )woody species) to secondary host plants )grasses, herbs and woody species). Uhrough sucking in primary hosts they usually induce the forma tion of species-speci�c galls on shoots, petioles and leaves while in secondary hosts, they live loosely, viz. on roots . ulmi has been described under various synonyms, e.g. Chermes ulmi L., Aphis ulmi campestris Eeg., . folio- Eeg., Cinara gallarum-ulmi Sur., ulmi Lalt., . fodiens Cuckt., . grossulariae Uasch., . ampelorrhiza Eel. Guer., Nat sum., etc. Oumerous authors class the species into a later distinguished genus Itg., 2948 )= Leach, 2929). Uhe name )L.) was origi nally applied to species of aphids rolling up leave galls and migrating from elm to various species of Sibes . Oumerous names are related to the relatively complex developmental cycle. Euring the cycle, aphids migrate yearly from pri mary )elm) to secondary hosts )various species of and rarely also Vitis vinifera Uhe paper was prepared at the Faculty of Forestry and Wood Uechnology, Nendel University of Agriculture and Forestry, Crno Nendel University of Agriculture and Forestry, Faculty of Forestry and Wood Uechnology, ACTUSACU Uhe paper deals with the occurrence, development, natural enemies and harmfulness of a heteroecious aphid Friosoma )L.) which showed outbreaks in elm Ulmus glabra C≥lovice nad Tvitavou and Crno-Jundrov, the aphid damaged about 74% leaves. Larvae of fundatrices hatched from mid-April and their development from hatching to maturity took about 25 days. Nature fundatrices occurred in Nay and reproduced for a period of 25 days. Uheir average physiological fecundity amounted to 422 larvae and ecological fecundity 3:2 larvae. Nigrantes alatae occurred in galls from 29 Nay to 25 June and their physiological fecundity was about 33 larvae. Leaves were damaged even by 4 galls of an average length of 52 and width 22 mm. Tucking affected on average 22 cm , i.e. 38% )in case of the occurrence of 3 or 4 even 200%) leaf area. Oatural enemies killed :0% aphids. A bug Anthocoris confusus Seut. killing aphids in 90% galls was the most effective control agent. Jts eggs occurred from 35 April to 35 Nay and nymphs from 4 Nay to 35 June. Larvae of Tyrphidae )L.)] killed the aphids in 5 and birds in 7% galls. should be considered to be an important occasional Leywords Friosoma )= Tchizoneura ) ulmi Ulmus spp.; outbreak; host species development gall characteristics predators the heteroecious species, the only amphigonic genera tion )sexuales) alternates with several parthenogenetic generations. Jn the complete generation cycle )holocy cle), seasonal genetically conditioned polymorphism is re�ected manifesting itself in several morphologically different types of apterous and pterygote females )so- Uhe developmental cycle of begins in spring in the period of elm budbreak. Larvae of fundatrices generation of the aphid) hatch from eggs wintering in �ssures of the bark of stems and large branches. After a short rest, larvae travel towards buds and settle on the abaxial face of unfolding leaves. Eue to secretions of sali vary glands injected into young leaf tissues the lateral edge )more rarely apex) of a leaf blade rolls up downwards thus gradually forming a fusiform leaf roll )pseudogall). Galls are established usually by one, sporadically even several young fundatrices. Under protection of the relatively �rm rolled up part of a leaf blade, larvae moult four-times and after the last ecdysis )in Nay) they mature. Nature fun datrices produce larvae )fundatrigeniae) )3 generation of the aphid) for a period of 3 to 5 weeks. Fundatrigeniae also moult four-times and after the last moult, winged females of migrantes alatae occur usually in the second Nigrants leave the galls and �y over mostly to shrubs of Sibes spp. On the root collar of the shrub or on the soil surface in the proximity of the root collar, they pro duce larvae of virginogeniae )exules) )4 rd generation of the aphid). Uhe larvae move to thin roots of a diameter of about 2 mm where they suck and after 5 moults they quickly mature. Uhe aphids live on roots loosely )not in galls) under a thick protective layer of wax �bres. On roots of secondary hosts, several )according to AOJ TZFWTLA-CJCIOCLA , 2:82 in total 8) generations of virginogeniae develop during summer and at the begin ning of autumn )i.e. in the course of about 4 months). Uhe last generation of them is formed by winged females of sexuparae )reemigrantes). Usually in Teptember and October, sexuparae return back to host species of elm and produce larvae of the last generation in �ssures of the bark of stems )sporadically also of large branches). Uhese larvae moult 3–4 times and without taking food they mature in males and females of sexuales. Females of this generation lay always the only egg into bark �s sures after copulation. Toon after oviposition, they die and their bodies then usually overlap the eggs. Accord ing to not very numerous literature data virginogeniae can also winter on roots of Sibes spp. )anholocyclic hibernation). occurs in the predominant part of Furasia and Oorth America. Unlike the originally non-arctic spe )Ism.) introduced to Furope, )similarly as Itg. and Cörn. et Clunck) has its centre of distribution in the western part of palaearctic region. Jn the CS, it is abundant wherever its primary and secondary host plants occur. Jn the large part of its range )including the CS), it often shows out breaks and causes considerable damages to some species Jnnumerable entomological, aphidological and zoo- cecidiological papers deal with the occurrence and development of in spp. )and later also in Sibes spp.). Iowever, there is a very small number of special papers dealing with biology and harmfulness of the aphid. Jts potential migration to roots of spp. mentions for the �rst JCIUFOTUFJO )2995) when he remarks that Tchizoneura fodiens Cckt., 2:92 can be an underground form of L. Nigration to roots was later con�rmed by IOLOELOVTLY )29:7, 29:8) and ULLGSFO )2:0:). Uhe dicyclic development of the aphid G )2:25), C )2:3:), )2:53), P )2:72, 2:75, 2:92, 2:9:), et al. )2:73), )2:73), C )2:75), TZFWTLA-CJCIOCLA )2:75), EAOJFLTTOO )2:8:), IFJF )2:90), CLACLNAO and ATUOP )2::5) and many others. )29:8) for the first time mentioned the aphid in roots of Vitis L. in Crimea and later also )2:45), I )2:58), )2:82) reported in detail on the geographical distribution, hosts, development, control factors and harmfulness. Norphology of three species of the genus Leach )including ) and their food preferences in secondary hosts was studied by )2:93). Fffects of diluted extracts of and some other species of aphids on cut off shoots of host woody species were dealt with by AZEA )2:73). Ciology of bugs from the genus F. signi�cantly partici pating in killing . ulmi in galls was studied e.g. by FTLA )2:42), L )2:55), I )2:58, 2:75), A )2:73), COLLYFS )2:78), PJATFCLA )2:7:), PASLFS )2:95) etc. Parasitoids of the aphid are mentioned e.g. by UASÝ )2:77, 2:87), AOATJJUTIUL et al. )2:87), NAUFSJAL AOE NFUIOET Nain �eld and laboratory studies were conducted in 3003. Tets of 52 to 200 galls of . ulmi were sampled from in 3-week intervals near C≥lovice nad Tvitavou )about 340 m alt.) and in Crno-Jundrov )about 305 m alt.). Jn C≥lovice nad Tvitavou, the elms were part of a species-, age- and space-differentiated riparian and accompanying stand of the Tvitava river, in Crno-Jundrov they were part of a similar stand of the Tvratka river. Jn 20 main check terms from 9 Nay to : October, 899 leaves with 957 galls were examined )Uable 2). At main localities and also else where )e.g. in Crno-Obřany and Crno-Pisárky), partial Jn the laboratory, the content of every gall was evalu ated )above all the number, size and health condition of fundatrices and fundatrigeniae). Uhe instar of fundatrices was determined according to the number of exuviae or according to the body size )length and width) measured micrometricly. Uhe instar of fundatrigeniae was derived mainly according to the body size. Uhrough the micro scopic dissection of died fundatrices, the number of un born larvae was determined and by means of dissection of living females of migrantes alatae before emergence from galls their physiological fecundity was determined. Considerable attention was paid to natural control factors. Uhe length and width of galls and unfolded leaves were measured. Uhe undamaged and sucked area of leaf blades was determined using planimetry. Uhe outbreak under study affected well thriving trees free of evident symptoms of Eutch elm disease caused by Ophiostoma ulmi )Cuism.) Oannf. Jn the second half of the last century, the mycosis of vascular bundles heavily damaged upland and submontane including its decorative cultivars which were often planted mainly in warm regions. Perhaps even more serious damages by Eutch elm disease were noticed in occurring in the CS mainly in �oodplain forests and warm uplands. Also in . minor growing in riparian and accompany ing stands along the Tvitava and Tvratka rivers, the dis ease was not observed. Iowever, a cecidogenous aphid Uetraneura )= Cyrsocrypta ) ulmi L. showed mass outbreak SFTULUT AOE EJTCUTTJOO Iost tree species Uhe most frequent primary host species of is . glabra Iuds. ) UIS 2:75 UPAJT 2:9:, etc.). Jn the elm and in its variety v. Lond is mentioned by AOJTZFWTLA-CJCIOCLA )2:82). Ac cording to )2:55), P )2:5:), TUFFFAO 2:83), EAOJFLTTOO )2:93), JATJČ et al. )2:95) etc., Nill. and its varieties also belong to the main primary hosts. Uhe aphid occurs only sporadically in L. and Pall. ) 2:55) or in f. suberosa )Noench.) Tóo, procera Talisb. and . pumilla L. ) UPAJT 2:9:). According to AOJFLT )2:93), however, the aphid never occurs in Uhe broad )though by far not quite complete) spectrum of host species of elms mention and )2::5). According to the authors, the aphids develop in Iuds., Nill., Pall., )Sehd.) Targ., L., L. natoramosa , . procera Talisb. and . thomasii Targ. Jn places where elm died )for example central parts of Tiberia), the aphids develop as exules on roots of second ary hosts, i.e. anholocyclic development ) OSEVJLLO At all localities under study in the Crno region, showed outbreak in only. Jn minor, the aphid was found only rarely )e.g. in C≥lovice nad Tvitavou). Jn an abundantly occurring and rather resistant to Eutch elm the aphid has not been ever detected. Uhus, our �ndings support the opinion of )2:93) on unsuitability of for the development According to )2:93), the main secondary host plants of are Sibes nigrum L., L. aureum Pursh. According to the author, the aphid Uable 2. Oumber of damages )galls0sucked spots) caused by including the size of damaged leaves 22.: 22.: 22.2 22. :. 22.3 Uotal 22.5 forms small colonies also in Pursh. and . uva-crispa L., however, not in . alpinum L. )2:93) regards as a form only which shows brown )no light-green) fundatrigeniae in galls. )2:82 ) observed exclusively brown fundatrigeniae in leaf rolls and considers S. nig- L., L., L., L. aureum Pursh. to be secondary host plants. Vitis vinifera L. belongs to rare )according to SJGOSOV 2:90, however, nearly exclusive in Culgaria) secondary hosts. At mountain locations of Uadzhikistan where spp. grow only rarely the aphid has to migrate to other host plants ) 2:73). At studied localities in the Crno region, gardens with abundantly grown and Grossularia uva-crispa )L.) Nill.] occurred everywhere in the near vicinity of Uhe development of fundatrices . ulmi winters as an egg in �ssures of bark of stems and large branches of elms. Larvae hatch usually in the second half of April. Fggs protected by a dead body of a female winter best. Jn spite of this, with respect to high mortality larvae hatch from about 40% eggs only ) JCIOCLA 2:82 ). Light-coloured larvae become dark during about 2 day. Uhen, they move towards unfolding buds where they settle on the abaxial face of unfolding and newly unfolded leaves. Under more marked incoincidence of budbreak and hatching )for example in the course of late spring and sudden warming) the larvae starve and die. Jn C≥lovice nad Tvitavou and Crno-Jundrov, larvae of fun datrices hatched as early as mid April, i.e. roughly in the Uetraneura ulmi minor. After reaching young leaves, fundatrices begin im mediately to suck. Physiologic-biochemical processes in rapidly growing leaves and shoots favourably in�u ence the nutrition of fundatrices. At the beginning of the growing season, however, the largest amount occurs in growing tissues of valuable soluble carbohydrates, ami noacids, vitamins and other biopolymers arising through the conversion of storage starch. Jn the course of sucking, larvae inject into unfolding leaves secretions of salivary glands. Under the effect of the secretions, leaf blades turn towards the abaxial face under the formation of fusiform pseudogalls )Fig. 2). Jn the course of 3 weeks from hatch ing, the larvae moult 5 times and after the 5 ecdysis, they mature. Iowever, leaf rolls are formed already after the Grown-up fundatrices are on average 4.2 mm long and 3 mm wide before the beginning of reproduction. Jn the period of life, they are dark-green and densely covered from above by very �ne white wax �bres 0.8 to 2.5 mm long )on average 2 mm). Well-developed wax cover of the body is, however, evident already in larvae of the instar. Wax protects larvae against drying up and on a rainy day against wetting. Jt plays also an important role in protection against parasitoids and predators. A thin wax coat covers liquid excrements of aphids immediately after secretion. Colourless globular droplets of excrements begin to occur in galls more abundantly as late as the occurrence of the 5 instar. Uhe droplets are at �rst very tiny )diameter about 0.05 mm). With the increase of fun datrices they increase to 0.2–0.5 mm or merge reaching then a diameter of even 4 mm. A �ne wax dust isolates excrements and together with the body wax coat protects According to G )2:25), in one leaf roll usually one fundatrix occurs only and sporadically as many as three )according to UIS 2:75 one to two) fundatrices. )2:9:) found in one gall as many as 5 )on moist biotopes often 9 or even 25) fundatrices. Unusually high numbers )even 44) of fundatrices are mentioned by TZFWTLA-CJCIOCLA )2:82). Tuch a high number of fundatrices found )2:93) in Ean. only. Jn the majority )85%) of analysed galls in in the Crno region, 2 fundatrix occurred only Fig. 2. Young leaves of Ulmus glabra with pseudogalls )rolls) of Friosoma )= Tchizoneura ) ulmi . C≥lovice nad Tvitavou, Fig. 3. Uhe percentage of fundatrices of . ulmi according to their number in one gall. C≥lovice nad Tvitavou and Crno-Jundrov, studied galls in C≥lovice nad Tvitavou and Crno-Obřany, the �rst mature fundatrices occurred far earlier, viz. at the beginning of Nay. Jn C≥lovice nad Tvitavou, therefore, in galls with undisturbed development 85% grown up funda trices with fundatrigeniae in the 2 st and 3 nd instars occurred as early as 9 Nay and 35% larvae of fundatrices only in the 4 and mainly in the 5 instar. Jn ovaries of females, 78% larvae of fundatrigeniae occurred, 40% larvae were in the 2 instar and 4% in the 3 instar. Uhe development of fundatrices from hatching to maturity took on average 25 days there. Eetailed investigations showed that on larg er leaves, fundatrices were in a somewhat more advanced stage of development compared with smaller leaves and on larger leaves fundatrices reached also somewhat larger Nature fundatrices usually settle near elevated leaf veins )mainly between their forks) and produce light yellow-green larvae for a period of about 3 weeks. Uhe fecundity of fundatrices is very high. According to AOJTZFWTLA-CJCIOCLA )2:82), fecundity in galls in . glabra amounts to 57 to 523 larvae whereas in v. 57 to 293 larvae only. According to data from Latvia, fundatrices produce on average 358 larvae ) UPAJT 2:72) and from Culgaria 350 to Jn galls on in C≥lovice nad Tvitavou, physi ological fecundity of fundatrices was 253 to 570 larvae. An average physiological fecundity derived by the Uable 3. Fecundity of mature fundatrices of in galls on leaves of without and with 422.0 Fig. 4. Average physiological fecundity of fundatrices of in relation to their body length in galls without coris confusus )light columns) and in galls with . confusus )dark columns). Average physiological fecundity of fundatrices in all galls is depicted by dashed lines )galls without confusus 3:0.2 larvae and galls with 422.0 larvae). C≥lovice Fig. 5. Uhe length )dark �gures) and width of the body of particular instars of fundatrigeniae including migrantes alatae of According to AOJTZFWTLA-CJCIOCLA )2:82), mature fundatrices appear in the second half of Nay, according to )2:9:) in the 4 decade of Nay and in the OW part of Latvia, at the end of the 2 decade of June. Jn the dissection of 50 fundatrices in galls with bugs Antho- coris confusus Seut. and 57 fundatrices in galls free of . confusus amounted to 422 larvae )Uable 3, Fig. 4). Cased on the study the reproduction potential of funda trices in comparison with Uetraneura ulmi is nearly : times higher. Uhe high fecundity is, however, already in galls to a great extent eliminated by extraordinary mortality of aphids caused by natural enemies. Fundatrices live 5 to 5 weeks. After 3 to 8 days after completing the reproduc tion, they die. Jn ovaries of dead fundatrices, 3 to 22% )on Uhe development of fundatrigeniae including migrantes alatae According to the author s �ndings, fundatrigeniae de velop rather quickly. Uhe �rst pterygote females migrantes alatae occur in galls as early as 29 Nay and the last on 25 June. As compared with Uetraneura ulmi which leaved galls from 5 to 40 June, galls of were left on aver age 3 weeks earlier. Owing to the irregular maturation of fundatrices and the long period of their reproduction, both fundatrigeniae of higher instars and pterygote migrantes Uable 4. Length of particular instars of fundatrigeniae including migrantes alatae of in galls on leaves of 22 22 22: alatae occur together in galls in the second half of Nay and at the beginning of June. Larvae moult 5 times during 25 to 32 )on average 28) days and after the 5 ecdysis, mature pterygote females appear. All fundatrigeniae with out any exception mature in winged females. Uables 4 and 5 and Fig. 5 show that the average size )length0width) of larvae of the 2 st instar is 0.9300.45 mm, 3 nd instar 2.200.5 mm, 4 rd instar 2.500.77 mm, 5 th instar 3.2500.97 mm and migrantes alatae )measured without wings) 3.2:0 0.93 mm. Unlike fundatrices, fundatrigeniae including migrants are very movable being capable to leave tempo rarily leaf rolls. At the end of the period of development of the second generation of aphids, galls open somewhat facilitating thus mature females to leave the galls. Winged individuals leave the galls both through holes at their ends and through lengthwise �ssures. Euring the development of numerous fundatrigeniae, the amount of liquid excrements increases in galls be ing highest in the period of the occurrence of migrantes alatae. Uhe excrements in the form of droplets and drops )of a diameter of even 20 mm) ful�l considerable part of the inner space of galls. Part of droplets in the form of so-called honeydew often falls out from leaf rolls on the soil surface or sticks on leaves and shoots. Jt is of interest that in spite of the large amount of produced honeydew’ Uhe data on the period of �ying out of aphids from galls correspond to a great extent with the opinion of )2:25). According to the author, the development of pterygote aphids in the Oetherlands is completed in the last days of Nay and in the �rst half of June. On average about 3 weeks later )at the end of Nay and in June), the Uable 5. Width of particular instars of fundatrigeniae including migrantes alatae of in galls on leaves of )2 division = 0.0458 mm). C≥lovice nad Tvitavou and Crno-Jundrov, 9 Nay–5 June, 3003 22 22 22: Width )from–to) 9–22 Width )from–to) emergence of aphids occurs in Lazakhstan ) et al. 2:73) and Poland ) AOJTZFWTLA-CJCIOCLA 2:82). According to )2:93), in Tweden aphids mi grate to secondary host plants as late as June and July, and according to ASLFS )2:95) supposedly at the end of July and in the �rst half of August. Jn spite of the subtlety and relatively low sclerotiza tion of a body migrantes alatae are generally good �iers. Cy means of an active �ight they are able to overcome a distance of more than 2 km. After reaching a secondary host, females produce orange-yellow larvae )virgino geniae, exules). According to VAOEFS GOOU )2:25), )2:3:), S )2:9:) they place them on a root collar. According to )2:82), females produce 20 to 32 larvae on the soil surface in the immediacy of host species of the genus Jn galls on in Crno-Jundrov, 25 to 40 )on average 33.5) unborn larvae of an average length of 0.53 and width 0.32 mm occurred in ovaries of mature females. With the increasing length and width of females the number of larvae signi�cantly increased. AOJTZFWTLA-CJCIOCLA brings valuable findings on the development of females of summer generations including sexuparae )reemigrantes) on roots of several species of the genus Gall characteristics According to the author s �ndings, galls are established usually by 2 fundatrix only, rarely by more )even 5) funda trices. Owing to sucking of fundatrices on the abaxial face of leaves, lateral edges )sporadically also apex) of leaves rapidly roll up downwards and to a central vein. Uhus, a lengthwise fusiform leaf roll originates which tapers towards both ends and in the apical part of the leaf blade, it reaches across the central vein )Figs. 5–9). Uhrough the sucking caused by fundatrices, the leaf blade between veins also irregularly crinkles and surges upwards in the form of ‘bubbles’. Veins on the abaxial face of leaves very markedly project and the leaf blade thickness somewhat increases due to sucking. Vivid green colouring of leaf blades changes to light-green to yellow-white. Uhe whole or almost whole sucked part of the leaf blade changes to a pseudogall. At both ends of galls, also adjacent un Fig. 5. Uhe grown up gall of on a leaf of )bot Fig. 7. Uhe leaf of damaged by )top view). Fig. 8. Uhe gall of formed by nearly the whole leaf of damaged parts of blades used to be often rolled up. Uhe formation of galls is induced by sucking fundatrices only and to a smaller extent also fundatrigeniae. After the death of fundatrices, the growth of galls ceases. Uhe study has demonstrated that galls grow up in the 4 week in Nay whereas leaves as late as June, i.e. at least 4 weeks later. On . glabra in Crno-Jundrov, the majority )about 58%) of galls was localized predominantly in the apical third of the leaf blade. About 45% galls were localized in the cen tral third of the blade and about 2:% galls largely in the basal third of the blade. At the locality, galls affected most frequently )82.2%) the markedly eccentric blades. Less fre Fig. 9. Uhe gall of at the apex of the leaf. Fig. :. Uwo side rolls of on the leaf of . Crno- Jundrov, 25 June 3003 quently )30.7%), the roll was formed in the larger ‘half’ of the blade and 9.4% rolls only were placed at the leaf apex on both sides of the blade. UPAJT )2:9:) noticed already earlier the most frequent occurrence of galls on the smaller ‘half’ of blades. Uhe distribution of galls on the leaf blade is undoubtedly affected by the onset and course of budbreak and different availability of various parts of the abaxial face of a leaf to the attack by young larvae of fundatrices. Uhe budbreak and density of the 2 instar of fundatrices is related both to the percentage of leaf attack and the number of galls on 2 leaf. Under the very heavy )on aver age 70%) attack of leaves at studied localities in C≥lovice nad Tvitavou and Crno-Jundrov, 95.5, 24.9 and 0.8% leaves were damaged by 2, 3 and 4 galls )or by sucking only), respectively )Figs. : and 20). A general overview on the number of galls )including mere sucking the leaves) and their distribution on leaf blades gives Uable 5. Grown up galls were 8 to 84 )on average 50.9) mm long and Fig. 20. Uhe percentage of galls )including uncreated galls, i.e. mere sucking of leaves) of )light columns). Eark columns depict the average area of leaves damaged by one, two or three galls. C≥lovice nad Tvitavou and Crno-Jundrov, Fig. 22. Uhe percentage of galls of F. ulmi according to their length )dark columns) and width )light columns). C≥lovice nad Tvitavou and Crno-Jundrov, 42 Nay–: October 3003 5 to 34 )on average 22.3) mm wide. Frequency of the occurrence of galls of various length and width is given in Fig. 22. On blades of below-average length, width and area, galls were on average smaller than on blades of medium size or on above-average blades )Uables 7–9, Neasurements of sucked area on leaves of three size cat egories )Uable :, Fig. 25) brought interesting results. Uhe table and �gure indicate that the average size of a sucked area increases with the size of leaves while the percentage of the sucked area )from the total area of attacked leaves) decreases with the size of leaves. Under the average size of grown up attacked leaves 50.5 cm , sucking affected 9.5 to 23.: )on average 22.0) cm , i.e. 38.3% from the total leaf area. On small leaves )area 40 cm and less), under the occurrence of 2 gall )or damage), on average 9.5 cm were sucked )48.4% from the total leaf area). On leaves of a medium size )area 42 to 55 cm ), under the occurrence Uable 5. Oumber and localization of damages caused by F. ulmi on leaves of U. glabra . C≥lovice nad Tvitavou and Crno-Jundrov, Uwo lateral galls 22.5 Uwo lateral and one apical galls Uotal Uable 7. Nean length0width of galls of on leaves of of three length categories. C≥lovice nad Tvitavou and Crno- Jundrov, 3003 22. :. )42. 5.–:. 20.) 22.: 22.: 22.4 22.3 22.5 22.4 22.3 Uable 8. Nean length0width of galls of F. ulmi on leaves of U. glabra of three width categories. C≥lovice nad Tvitavou and Crno- Jundrov, 3003 Width of 22. :. 22.5 22.5 22.4 22.4 22.8 22.5 22.4 22.3 of 2 gall on average 22.9 cm were sucked )42.2% of the leaf blade) and on above-average leaves )area 57 cm more) 23.: cm )32.5% of the leaf blade). Under the oc currence of 3 or 4 galls on 2 leaf, the percentage of leaf damage by sucking is higher and in below-average leaves, even the whole blade is often affected. Uhus, it is possible to conclude that damages 30 to 200% of the leaf blade. Uhe attack also substantially reduces the size of leaves )Uable 20). Leaves with 2 gall reached on average 53.8 cm while leaves with 3 galls 45.4 cm only and leaves with 4 galls 35.0 cm . On sucked places of the leaf blade, the decrease or even the total loss of chlorophyll occurs so that assimilation is signi�cantly decreased. Teriously damaged blades become brown and die already in June and mainly in July )Fig. 27). Eead tis sues get dry and the whole leaf roll frequently markedly Uable 9. Nean length0width of galls of on leaves of of three areal categories. C≥lovice nad Tvitavou and Crno- Jundrov, 3003 22. :. 22.9 22.7 22.9 22.3 22.5 22.4 22.3 Uable :. Nean area of leaves sucked by )numerator) and its percentage from the total area of damaged leaves of 22.2042.8 22.5040.: 22.9042.2 22.:047.3 22.2034.: 22.0038.3 Fig. 23. Uhe mean length )light columns) and width of galls of )dark columns) on leaves of of three length categories. Uhe mean length and width of all galls is depicted using dashed line. C≥lovice nad Tvitavou and Crno-Jundrov, Fig. 24. Uhe mean length )light columns) and width of galls of )dark columns) on leaves of of three width categories. Uhe mean length and width of all galls is depicted using dashed line. C≥lovice nad Tvitavou and Crno-Jundrov, Uable 20. Nean area of leaves of in relation to the number of galls of on one leaf. C≥lovice nad Tvitavou and Crno-Jundrov, 3003 22. :. Uotal Fig. 25. Uhe mean length )light columns) and width of galls of )dark columns) on leaves of of three areal categories. Uhe mean length and width of all galls is depicted using dashed line. C≥lovice nad Tvitavou and Crno-Jundrov, Fig. 25. Uhe mean area of leaves of with galls of )light columns) and mean sucked area )dark columns) on leaves of three size categories )the percentage of sucked area is given in parentheses). Uhe mean area and mean sucked area of all leaves are depicted using dashed line. C≥lovice nad Tvitavou and Crno-Jundrov, 42 Nay–25 August 3003 Fig. 27. Uhe gall of . ulmi on a leaf of . glabra . Ieavily sucked part of a roll dies away. C≥lovice nad Tvitavou, 25 June 3003 Fig. 28. Uhe gall of on a leaf of . Uhe gall died out and diminished due to shrinkage. C≥lovice nad Tvitavou, contracts )Fig. 28). Uhe rolls are partly formed by an un damaged blade at their ends so that the size of assimilation Nortality factors Uhe development and population density of are signi�cantly affected by climatic and trophic conditions and insect predators. Jn the period of hatching and search of food, fundatrices often starve mainly due to the inco incidence of budbreak and hatching of fundatrices. After the formation of leaf rolls, fundatrices and fundatrigeniae are rather well protected against unfavourable climatic effects )particularly low humidity, precipitation and di rect insolation). Iigh mortality of aphids can be caused by rainy weather in the period of migration to secondary host plants. Owing to long-term precipitation )frequently accompanied by marked temperature �uctuations), pre dominant part of pterygote females of the sexuparae generation can be also killed. Uhe generation of sexuales developing in �ssures of the cracked bark of elm trees is relatively considerably resistant to precipitation and mainly low temperatures. Jndividuals of the generation are able to tolerate rather well temperatures down to –7 2:82). Wax secretions on the body of apterous females and undoubtedly also excre ments play an important role in the protection of aphids against unfavourable effects of the outer environment. Fven after the emergence of aphids from galls, whitish wax coat is evident on the inner side of roles. Iundreds of whitish exuviae of larvae and a lot of honeydew’ which becomes brown and reduces its volume after a certain time Jn galls, individuals of are, however, protected very imperfectly against biotic enemies )for example in sect predators). Uheir species spectrum is rather broad. Ac cording to )2:82), predatory Anthocoris gallarum-ulmi )Eeg.) and )F.) )Anthocoridae), Tyrphus vitripennis Ng. and )Eeg.) )Tyrphidae) and Leucopis annulipes Zett. )Chamaemyiidae) belong to the main control factors of abundance. According to the author, a squirrel Tciurus vul L. )Tciuridae) consuming honeydew together with aphids is ranked among less signi�cant predators. Jt eats up the galls mainly at the end of the development of the nd generation of aphids when the number of aphids and the amount of honeydew in galls are largest. To far, the great est attention has been paid to the biology of )Eeg.) ) 2:7:, P 2:95, )L.) ) 2:42 2:58; C 2:78; P 2:85, etc.) and Seut. 2:75, etc.). All the species of bugs are considered Jn galls on . glabra in C≥lovice nad Tvitavou and Crno-Jundrov, natural enemies killed about :0% aphids )Uable 22). . confusus participated most in the mortality )Fig. 29). Uhe bug occupied 85 to :4% of all galls and nearly always killed in them all aphids. Jn Crno-Pisárky, a bug Eeraeocoris lutescens )Tchill.) )Niridae) )determined by Er. P. Lment, Crno) was seldom found in galls. Uhe bug winters in the stage of imagoes. After wintering, it feeds on various free living prey for Fig. 29. Uwo nymphs of the last instar and an imago of Anthocoris Fig. 2:. Uhe mean length of a body )columns) and the mean number of nymphs of in galls of )dashed line) in the period 9 Nay–2: June. C≥lovice n. Tv. and Crno- Jundrov, 3003 Fig. 30. Uhe percentage of galls of . ulmi with the various number of nymphs )dark columns) and exuviae of )light columns). From 952 galls analysed in the period 9 Nay to : October, nymphs were present in 35: )3:.7%) galls. From 507 galls analysed in the period 2: June to : October, exuviae were present in 449 )77.9%) galls. C≥lovice nad Tvitavou and Crno-Jundrov, 3003 Uable 22. Sesults of the analysis of health conditions of C≥lovice n. Tv. C≥lovice n. Tv. C≥lovice n. Tv. C≥lovice n. Tv. 22. :. Aves . , Araneida , Aves C≥lovice n. Tv. C≥lovice n. Tv. C≥lovice n. Tv. C≥lovice n. Tv. 22. :. . , Acarina , Aves , Aves Aves Uable 22 – to be continued a certain time. Jt lays eggs either individually or in small loose groups max. of 20 )rarely 30) eggs on galls of or in their close proximity. Jts reproduction poten tial is rather high )as many as 292 eggs) ) JLL 2:75). Fggs occur from 35 April to 35 Nay, nymphs from 4 Nay to 35 June and this year s imagoes from 5 June to 25 October. Jn one gall, usually more )max. 30) nymphs occurred. Uhe greatest number )on average 5.7) of nymphs in galls was found on 20 June in C≥lovice nad Tvitavou )Uable 23 and Fig. 2:). Uhe length of nymphs in main control dates is given in Uable 24 and Fig. 2:. Frequency of the occurrence of nymphs and their exuviae in galls is demonstrated in Fig. 30. Uhe greatest number of this year s imagoes )on average 0.9 and max. 7) occurred in galls on 2: June. Euring two weeks after hatching, about 85% imagoes left galls and about 35% only )i.e. on average 0.3) remained in galls from the beginning of July to mid-Teptember. Jn the �rst half of October, however, also these imagoes left Uable 23. Oumber of nymphs0imagoes of A. confusus in galls of F. ulmi on leaves of U. glabra . C≥lovice nad Tvitavou and Crno- Jundrov, 3003 22. :. 22094 2202 220– 22 Uable 24. Length of nymphs of in galls of on leaves of . C≥lovice nad Tvitavou and Crno- Jundrov, 3003 Uotal galls and hid in winter habitats )Uable 24). Uhe imagoes �y rather well and occasionally they can painfully bite. Uhe Uhe mean number of nymphs and imagoes of fusus signi�cantly increased with the increasing length and width of galls )Uables 25 and 25, Fig. 32). With the increasing length and width of galls the percentage of galls where aphids were killed by the bug also increases )Uable 27 and Fig. 33). Uhe study has positively demon strated that bugs preferentially occupy galls of a larger size with the considerable number of aphids. Oumerous colonies of aphids are a rich source of nutrition for bugs requiring a lot of food. Jn case of food de�ciency, nymphs of medium and higher instars leave galls and search for other galls with living aphids and complete their devel- opment in them. Jf they do not �nd these galls soon they suck the last rests of aphids and probably consume also excrements. Uhis year s adults which sometimes persist in galls until autumn also obviously additionally consume the excrements. Jn the course of a 3.5 to 4-month period of pre-hibernation, the majority of imagoes occurs on various woody species feeding mainly on aphids and oc Uable 25. Nean number of nymphs0imagoes of in galls of on leaves of of three length categories. C≥lovice nad Tvitavou and Crno-Jundrov, 3003 22. :. Fig. 32. Uhe mean number of nymphs of in galls of various length )light columns) and width )dark columns). Uhe mean number of nymphs in a gall is depicted using dashed line. C≥lovice nad Tvitavou and Crno-Jundrov, Fig. 33. Uhe percentage of galls of . ulmi with nymphs, imagoes and exuviae of . confusus in relation to the length of galls )light columns) and width of galls )dark columns). Uhe mean per cent of galls occupied . confusus is depicted by dashed line. C≥lovice nad Tvitavou and Crno-Jundrov, 9 Nay–: October 3003 Fig. 34. Uhe gall of casionally also on caterpillars etc. Jmagoes winter always out of galls, e.g. in �ssures of the bark of trees. At both localities under study, was the only highly effective control agent of Larvae of �ies of the family Tyrphidae showed far smaller control importance. Uhese occurred in rolls of from the beginning of Nay to the beginning of June and as puparia even later. Jn particular controls, they occupied 2 to :.5% galls while in 304 of galls with lar vae of Tyrphidae, . confusus was also present )Uable 22). Cugs were never observed at the attack of larvae of Tyrphi dae even when aphids were completely sucked. Uhe most abundant species was Tyrphus ribesii )L.) )determined by Er. J. Láska, Olomouc). Usually one and maximally three larvae occurred in one gall. Jmagoes hatched in the labora tory in the 3 nd half of June. At the end of Nay, larvae of the sp. were also sparsely found in galls. Larvae of Tyrphidae kill usually all aphids in galls and if they starve they are able to climb over on another gall. Uhey Cirds participate in 5 to 9% galls in killing the aphid )Ua ble 22 and Fig. 34). Cirds pecked out galls from mid-Nay to mid-June. Uhrough the pecking out, mostly the part of aphids only was killed. Aphids which were not killed by birds became usually a prey of . At the end of the development of the 3 generation of aphids partly Jn analysed galls, pedunculate eggs and larvae of the ge sp. )Chrysopidae) were found sporadically. Jn 3 larvae of the 5 instar of fundatrices, more precisely unidenti�ed larvae from the family Aphidiidae developed. Galls with emerged aphids or galls with aphids killed by bugs were abundantly occupied by spiders Araneida from August to October )however, mostly individually). Jn mid- October, spider occurred in 70% of all galls 53% of which were previously occupied by . From mid-July, galls were rather frequently )3 to 7%) searched by an ear For�cula auricularia L. )For�culidae). Also earwigs occupy usually galls previously occupied and left by aphids, viz. ordinarily together with spiders. Jn the same gall, maximally 3 earwigs were present which found there not only a shelter but also food )honeydew). Fxuviae, lar vae and imagoes of Adalia bipunctata L. )Coccinellidae) occurred rarely )2–4%) in abandoned galls. Uable 22 gives a general overview on natural enemies of in galls and on arthropods occupying the galls after the emergence Fconomic importance Under favourable ecological conditions and the occur rence of primary and secondary hosts max. 2 km apart, often shows outbreaks and causes serious damag es. Uhrough the sucking of fundatrices on newly unfolded leaves of elms )and partly also initial sucking of numerous fundatrigeniae) conspicuous leaf rolls are formed )pseudo galls) affecting usually 205 to 203 of the leaf blade. AUZFCUSG )2955) and later a number of other authors mentioned the harmfulness of on elms. Secently, for example et al. )2:85) consider the aphid to be one of the main pests of park plantings. AOJTZFWTLA JCIOCLA )2:82), FGFCAEF and TCIAFFFS )2:8:), )2:9:) etc. rank the aphid among important pests At studied localities in the Crno region, sucking of aphids damaged 32 to 48% )on average 38) of the leaf blade and under the occurrence of 3 to 4 rolls even 200% of the leaf blade. Noreover, damaged leaves reach sub Uable 25. Nean number of nymphs0imagoes of in galls of on leaves of of three width categories. C≥lovice nad Tvitavou and Crno-Jundrov, 3003 Width of 22. :. 22–25 Uable 27. Uhe percentage of galls of with nymphs, this year’s imagoes and exuviae of Galls were classed into three length categories. C≥lovice nad Tvitavou and Crno-Jundrov, 3003 22. :. stantially lower average dimensions. Tucked spots on the blade quickly get older and die out after the emergence of aphids from galls. At the end of June and at the beginning of July, about 20% seriously damaged leaves dried up completely. Ery leaves fall prematurely and more rarely they remain on trees. Uhrough mass attack, trees are heav ily physiologically damaged. Assimilation and respiration substantially decrease and thus also the increment of trees. Aphids produce a large amount of honeydew which partly falls out from rolls and sticks also to leaves where it ham pers their assimilation and respiration. Taprophytic fungi )sooty moulds) develop on honeydew inhibiting the access of light to chloroplasts. Eue to heavy damage, the resist ance of tree species to other harmful factors considerably decreases as well as their aesthetic value. Young trees can . ulmi causes also serious damage to currant )par ) and gooseberry. Uhe abundance of viviparous females )and thus also the extent of damage) rapidly increases during summer. Uissues of roots around incisions die being easily liable to rots. Leaves of heavily damaged shrubs get yellow, dry up and prematurely fall. Thrubs become stunted and the amount of yield often Jt is possible to control the pest effectively in the period of hatching the fundatrices, i.e. before the formation of leaf rolls. Tecondary hosts can be protected in the period of invasion of migrantes alatae by means of spraying or Seferences AOEFSTOO O.I., 2:73. Growth and fecundity of spp. reared on various prey )Ieteroptera: Anthocoridae). Fnt. Fxp. et Appl., CAUEYŠ F., 2:55. Zoocecidie z oblasti Tlezska a přilehlých část≥ Noravy. Praha, TPO: 399. CLACLNAO S.L., FATUOP V.F., 2::5. Aphids on the World Urees. London, CAC Jntern., Oat. Iist. Nus.: :97. CÖSOFS C., CLUOCL F., 2:27. Ceiträge zur Lenntnis der wandernden Clattläuse Eeutschlands. Nitt. L. Ciol. Anst. Land. u. Forstw., CÖSOFS C., 2:53. Furopae centralis Aphides. Eie Clattläuse Nitteleuropas. Weimar, Nitt. Uhür. Cot. Ges., CÖSOFS C., IFJOZF L., 2:58. Aphidina- Aphidoidea, Clattläuse. Jn: TOSAUFS P. )ed.), Iandbuch der P�anzen- krankheiten. 5. Au�., Cd. 5, 5. Lief. Cerlin, Iamburg, Verlag P. Parey: 503. CUIS I., 2:75. Cestimmungstabellen der Gallen )Zoo- und Phytocecidien) an P�anzen Nittel- und Oordeuropas. Cd. 3. Jena, VFC G. Fischer Verlag: 2583. CIOLOELOVTLY O., 29:7. 4. Aphidologische Nittteilungen. Zool. Anz., CIOLOELOVTLY O., 29:8. Aphidologische Nitteilungen. Zool. Anz., COLLYFS F., 2:78. On the ecology of Anthocoris nemorum )L.) )Iemiptera Ieteroptera). Proc. of the Soyal Fnt. Toc. of London, A, : 208–229. EAOJFLTTOO S., 2:8:. Uhe genus Friosoma Leach in Tweden, with description of two new species. Ttudies on Friosomatidae J. )Iomoptera, Aphidoidea). Fnt. Tcand., EAOJFLTTOO S., 2:93. Uhe species of the genus Leach having L. as secondary hostplant )Iomoptera, EFTTASU P., GASEFOFOST U., 2:95. Eendrocerus para n. sp. and n. sp. )Iym., Ceraphronoidea, Negaspilidae), two new Palaearctic hyperparasites of aphids. Cull. et Ann. Toc. Soyale Celge d´Fnt., : 2:8–322. GOOU P. VAO EFS , 2:25. Ceiträge zur Lenntnis der Iollän dischen Clattläuse. 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Zool. listy, 22 : 224–235. LFTUOO E., 2:55. Uhe eggs of Anthocoris gallarum-ulmi )Eeg.) )Iem., Anthocoridae) and Nonathia humuli )F.) )Iem., Uin NAUFTOVA G.J., NJUJAFV J.E., JUCIOFVJČ L.A., 2:73. Oasekomye i klešči – vrediteli plodovo-jagodnych kultur Lazachstana. Alma-Ata, Jzd. AO Lazachskoj TTS: 304. NOSEVJLLO A.L., 2:3:. Lormovye rastenija tlej TTTS i sopredelnych stran. Urudy )otd.) prikladnoj ent. )Leningrad). Uom 25. Vyp. 2: 2–200. NOSEVJLLO A.L., 2:45. Eie Clattläuse mit unvollständigem Generationszyklus und ihre Fntstehung. Frgebn. u. Fortschr. OASZJLULOV N.O., 2:73. Uli )Iomoptera, Aphididae) Uadžikistana i sopredelnych respublik Trednej Azii. Fauna Uadžikskoj TTS )Eušanbe). Uom :, Vyp. 2. Jzd AO Uadžiks PASLFS O.J.C., 2:85. An investigation of reproductive diapause in two Critish populations of Anthocoris nemorum )Iemi- ptera: Anthocoridae). J. Fnt., A, PASLFS O.J.C., 2:95. Ciology and bionomics in Tcotland of PFTLA W., 2:42. Obserwacje nad biologia dziobalka gajowego Anthocoris nemorum L.). Prace Wydzialu chorób i szkodni ków roślin Państw. inst. nauk. gosp. wiejskiego w Cydgoszczy, PJATFCLA J., 2:7:. Ciologia i zachowanie sie Anthocoris gal larum-ulmi )Eeg.) )Ieteroptera, Anthocoridae). Ann. Univ. N. PJOUFSA A., 2:5:. Nšice – Aphidinea. Jn: LSAUOCIVÍL J. et al., Ll≥č zv≥řeny ČTS. JJJ. Praha, ČTAV: 582–535. SAUZFCUSG J.U.C., 2955. Eie Forst- Jnsecten. JJJ. Wien, F. SUPAJT A.A., 2:72. Eendro�lnye tli v parkach Latvii. Siga, Jzd. AO Latv. TTS: 352. SUPAJT A.A., 2:75. Earzkopiba kaitigas laputis un to apka SUPAJT A.A., 2:92. Vrediteli derevjev i kustarnikov v zelenych SUPAJT A.A., 2:9:. Uli )Aphidodea) Latvii. Siga, Zinatne: TFGFCAEF S., TCIAFFFS N., 2:8:. Zur Ökologie der Ar thropodenfauna einer Ttadtlandschaft und ihrer Umgebung. 3. P�anzengallen und P�anzenminen. Anz. f. Tchädlingskde., : 228–232. TUASÝ C., 2:77. Aphid parasites of Czechoslovakia. Prague, TUASÝ C., 2:87. Ciology of Areopraon lepelleyi )Wat.), a para site of some eriosomatid aphids )Iymenoptera, Aphidiidae). TUFFFAO A.W., 2:83. Unterordnung Aphidina, Clattläuse. Jn: TCIWFOLF W. et al., Eie Forstschädlinge Furopas. 2. Cd., Iamburg, Cerlin, Verlag P. Parey: 273–497. UAOATJJUTIUL V.O., SFNAUEJFSF G., LFCLAOU F., 2:87. Eipt. Chamaemyiidae predateurs de pucerons et de co chenilles en France. Ann. Toc. Fnt. de France, UULLGSFO A., 2:0:. Aphidologische Ttudien J. Ark. Zool., VATJLJFV V.P. et al., 2:85. Vrediteli selskochozjajstvennych kultur i lesnych nasaždenij. Uom JJJ., Liev, Jzd. Urožaj: 537. Ciologie a škodlivost Friosoma )= Tchizoneura ) ulmi )L.) )Aphidinea, Pemphigidae) na jilmu ACTUSALU Práce pojednává o výskytu, vývoji, přirozených nepřátel≥ch a škodlivosti heteroekn≥ mšice Friosoma )= Tchi zoneura ) ulmi )L.), která se v roce 3003 přemnožila na Ulmus glabra Iuds. na Noravě. Oa hlavn≥ch studovaných lokalitách v C≥lovic≥ch nad Tvitavou a Crně-Jundrově mšice poškodila kolem 74 % listů. Larvy fundatrices se tam l≥hly od poloviny dubna a jejich vývoj od vyl≥hnut≥ do dospělosti trval kolem 25 dnů. Eospělé fundatrices se vyskytovaly v květnu a rozmnožovaly se po dobu 25 dnů. Jejich průměrná fyziologická plodnost byla 422 larev a ekologická plodnost 3:2 larev. Nigrantes alatae se v hálkách vyskytovaly od 29. května do 25. června a jejich fyziologická plodnost byla kolem 33 larev. Listy byly poškozeny až 4 hálkami o průměrné délce 52 mm a š≥řce 22 mm. Tán≥m bylo postiženo průměrně 22 cm , tj. 38 % )při výskytu 3 a 4 hálek až 200 %) listové plochy. Přirozen≥ nepřátelé zahubili :0 % mšic. Oejefektivnějš≥m regulátorem byla ploštice Anthocoris con fusus Seut., která zahubila mšice v 90 % hálek. Jej≥ vaj≥čka se vyskytovala od 35. dubna do 35. května, nymfy od 4. května do 35. června. Lolem 85 % imag ploštic hálky brzy po vyl≥hnut≥ opustilo, ostatn≥ imaga hálky opouštěla až koncem zář≥ a v prvn≥ polovině ř≥jna. V jedné hálce se vyv≥jelo průměrně 5,7 )maximálně až 30) nymf. Larvy Tyrphidae hlavně Tyrphus ribesii )L.)] zahubily mšice ve 5 % hálek a ptáci v 7 % hálek. . ulmi je nutno považovat za sadařsky a lesnicky významného škůdce. Ll≥čová slova Friosoma )= Tchizoneura ) ulmi Ulmus spp.; přemnožen≥; hostitelská dřevina vývoj charakteristika hálek predátoři škodlivost Práce se zabývá výskytem, bionomi≥ a škodlivost≥ he teroekn≥ mšice )= )L.), kte rá se v roce 3003 přemnožila na Ulmus glabra Iuds. na Noravě. Oapř. v břehovém a doprovodném porostu ko lem řeky Tvitavy pobl≥ž C≥lovic nad Tvitavou na Crněn sku napadla na kolem 50 % listů a v porostu kolem řeky Tvratky v Crně-Jundrově kolem 85 % listů. Uerénn≥m šetřen≥m a laboratorn≥mi analýzami nepravých listových hálek )smotků), odeb≥raných z uvedených lo kalit ve dvoutýdenn≥ch )př≥p. i kratš≥ch) intervalech, byly Ilavn≥ primárn≥ hostitelskou d evinou . ulmi je . glabra Iuds. Oa . minor Nill. byla m ice nalézána ek se larvy fundatrices l≥hly ve druhé polovin dubna a jejich vývoj od vyl≥hnut≥ a do dosp losti trval kolem 25 dn . Eosp lé fundatrices se vysky tovaly v kv tnu. Po dobu 25 dn se rozmno ovaly a po skon en≥ reprodukce za 3–8 dn hynuly. Fyzio logická plodnost byla 253–570 )pr 422) larev, ekologická plodnost 250–523 )pr rn 3:2) larev. V ovari≥ch uhynulých fundatrices bylo kolem 7,5 % nenarozených larev. Fundatrigenie se b hem 25–32 )pr rn 28) dn vyvinuly v ok ≥dlené migrantes alatae. Nigranti se v hálkách vyskytovali od 29. kv tna do 25. ervna a jejich fyziologická plodnost byla 25–40 )pr 33,5) larev. V 84 % hálek byla p ≥tomna 2 fundatrix, ve 23 % 3 fundatrices, v : % 4 fundatrices a v 7 % 5 fundatrices. Oa 95,5 % napadených list byla pouze jedna hálka, na 24,9 % list 3 hálky a na 0,8 % list 4 hálky. Iálky byly pr rn 50,9 mm dlouhé a 22,3 mm iroké a dor staly ji ve t et≥m týdnu v kv tnu, kde to listy v ervnu. Lolem 82 % hálek bylo lokalizováno na men ≥ „polovin “ excentrických epel≥, 32 % na ≥ „polovin “ epel≥ a 9 % p i vrcholu listu )po obou stranách epel≥). Listové smotky zakládaj≥ prvn≥ instary fundatrices, které se také nejv≥ce pod≥lej≥ na i pr rné plo e napadených list 50,5 cm bylo sán≥m fundatrices a etných fundatrigeni≥ posti eno 9,5–23,: )pr rn 22,0) cm , tj. 38,3 % z celkové listové plochy. P i výskytu 3–4 hálek na listu byla sán≥m )zvlá na drobných listech) posti ena asto i celá epel. Pr rná velikost list s jednou hálkou byla 53,8 cm , se dv ma hálkami 45,4 cm a se t irozenými nep áteli bylo v hálkách zahubeno kolem :0 % m ic. Oa této mortalit se daleko nejv≥ce )90 %) pod≥lela dravá plo tice Anthocoris confusus Seut. )An thocoridae). Jej≥ vaj≥ ka se vyskytovala od 35. dubna do 35. kv tna a nymfy od 4. kv tna do 35. ervna. V hálce se vyv≥jelo pr 5,7 )nejv≥ce 30) nymf. Leto imaga plo tice se v hálkách objevovala od 20. na, nejhojn ji )pr rn 0,9 jedinc v hálce) kolem 30. ervna. V ina )85 %) imag hálky opustila do dvou po vyl≥hnut≥, ostatn≥ imaga setrvávala v hálkách do konce zá ≥, p ≥p. do poloviny ≥jna. Po et nymf a imag plo tic se vzr staj≥c≥ velikost≥ hálek pr 8. Nen ≥ regula n≥ význam m ly larvy dvoukř≥dlých eledi Tyrphidae Tyrphus ribesii )L.)], které zahubily m ice ve 5 % hálek. V dob od poloviny kv tna do poloviny ervna bylo asi 7 % hálek vyzobáno ptáky. Ve druhé polovin léta a za átkem podzimu byly velmi asto )a ze 70 %) obsazovány pavouky )Araneida) a id eji )asi ze 5 %) kvorem 9. N ice . ulmi může p i p emno en≥ napadnout na primárn≥ch hostitelských rostlinách téměř v echny listy a sán≥m po kodit nejmén t etinu listové plochy. Oapadené listy dosahuj≥ obvykle men ≥ velikosti. ásti list rychle stárnou a asto odum≥raj≥ po výletu m ic z hálek. ást list koncem a za átkem ervence p ed asn usychá a opadává. Nasovým napaden≥m jsou primárn≥ hostitelské d e-viny zna fyziologicky oslabovány a u d evin p vaných pro dekora n≥ ú ely je sni ována jejich este-tická hodnota. Zna né po kozen≥ m p také na sekundárn≥ch hostitelských rostlinách )na ry b≥zech a srstce angre tu). Je proto t eba m ici pova ovat Corresponding author: Prof. SOEr. Jng. ASOTLAV USCAO , CTc., Nendelova zemědělská a lesnická univerzita, Lesnická a dřevařská fakulta, Lesnická 48, 724 00 Crno, Česká republika tel.: , 530 555 245 232, fax: , 530 555 322 533, e-mail: urbanjAmendelu.cz