New parasitoids of<Emphasis Type="Italic"> Saperda populnea</Emphasis> (L.) (Col. Cerambycidae) in Bulgaria

The parasitoid complex of Saperda populnea (L.) (Col., Cerambycidae) was studied during the period 2002–2003 at different sites in Bulgaria. Galls containing cerambycid larvae were collected on branches of aspen (Populus tremula L.), goat willow (Salix caprea L.) and hybrid poplars and were studied under laboratory conditions. As a result, four new species for the parasitoid complex of S. populnea in Bulgaria were recorded: Dolichomitus tuberculatus (Geoffroy), Xylophrurus lancifer (Gravenhorst), Gelis ornatulus (Thomson) (Hym., Ichneumonidae) and Dendrocerus serricornis (Boheman) (Hym., Megaspilidae). D. serricornis and G. ornatulus are new species for Bulgarian fauna. D. tuberculatus and X. lancifer were found as primary parasitoids, and G. ornatulus and D. serricornis as hyperparasitoids. The primary parasitoids developed solitarily in the host larvae. D. serricornis was reared gregariously from a puparium of Billaea irrorata (Meig.) (Dipt., Tachinidae). The host of G. ornatulus was not identified, but the hyperparasitid could be connected with Iphiaulax impostor (Scop.) (Hym., Braconidae). The mortality of S. populnea caused by the parasitoids was 2.0–6.3%.     

New and little-known lepidopteran (Lepidoptera) phytophages on the poplars (Populus spp.) in Bulgaria

Investigations were carried out during the period 1997-1999 on lepidopteran entomofauna deleterious to poplars (Populus spp.) in Bulgaria. The phytophages were collected in larval and pupal stage and were reared under laboratory con-ditions to the adult stage. In two regions of Bulgaria, Sofia and Montana, 18 new and little-known phytophages in seven families were established on the trees in Populus genus: Limenitis populi (L.) (Nymphalidae); Anacampsis populefia (Cl.), Gelechia turpella (Den. & Schiff.) (Gelechiidae); Synanthedon melliniformis (Lasp.) (Sesiidae); Euproctis similis (Fuessl.) (Lymantriidae); Drymonia velitaris (Hufn.), Notodonta tritophus (Den. & Schiff.) (Notodontidae); Amphipyra pyramidea (L.), Catocala nupta (L.), Cosmia trapezina (L.), Enargia paleacea (Esp.), Eupsilia transversa (Hufn.), Ipomorpha subtusa (Den. & Schiff.), Parastichtis ypsilon (Den. & Schiff.), Scoliopteryx libatrix (L.) (Noctuidae); Gastropacha quercifolia (L.), Phyllodesma tremulifolia (Hb.) and Poecilocampa populi (L.) (Lasiocampidae). G. turpella and S. melliniformis are new records for Bulgaria and D. velitaris was found for the first time in Northern Bulgaria. Thirteen species (L. populi, E. similis, D. velltaris, N. tritophus, A. pyramidea, C. nupta, C. trapezina, E. transversa, I. subtusa, P. ypsilon, G. quercifolia, P. tremulifolia and P. populi) were established for the first time in Bulgaria to have a trophic relationship with poplars. G. turpella and L subtusa were occurred in the highest population densities – up to 1.6 larvae/m and up to 1.1 larvae/m respectively. The remaining species occurred in low population densities in the studied habitats and were not considered to be pests on the poplars.     

Parasitoids of Saperda populnea (L.) (Coleoptera: Cerambycidae) on aspen (Populus tremula L.) in Bulgaria

The parasitoids of Saperda populnea (L.) (Col.: Cerambycidae) were studied in Bulgaria during the period 1997?–?2001. Galls with pest larvae were collected from young aspen trees at eight locations (Sofia, Kokaliane, Plana, Churek, Gorni Lom, Gintzi, Dolno Kamartzi and Klisura) and examined under laboratory conditions. Four species were reared from 1118 galls containing overwintering pest larvae: Iphiaulax impostor (Scop.) (Hym.: Braconidae), Dolichomitus populneus (Ratz.), Schreineria populnea (Gir.) (Hym.: Ichneumonidae) and Billaea irrorata (Meig.) (Dipt.: Tachinidae). All of the parasitoids were solitary. Schreineria populnea was found as a new parasitoid of the host in Bulgaria. B. irrorata emerged mainly from late-stage S. populnea larvae; the remaining species from both early- and mid-stage larvae. In the parasitoid complex of S. populnea, the most numerous were B. irrorata (59.8?%) and D. populneus (29.4?%). The percentage of host larval parasitism varied from 2.4 to 33.3, with an average of 9.7?%. B. irrorata was the most important in reducing the pest number. The average mortality of S. populnea caused by the tachinid was 5.8?%, and the highest mortality observed in individual study was 20.2?%.     

Physiologische und parasitologische Untersuchungen an Lachnellula flavovirens (Bres.) Dennis

Studies on the physiology and parasitism of Lachnellula flavovirens (Bres.) Dennis. From laboratory and field studies L. flavovirens was identified as a facultative parasite on several alpine conifer species (Pinus cembra, P. montana, Larix decidua). In the course of the work, factors affecting its development were investigated, especially with regard to temperature and nutrients.     

Bioecological characteristics of Bracon intercessor Nees (Hymenoptera: Braconidae) as a parasitoid of the poplar clearwing moth, Paranthrene tabaniformis (Rott.) (Lepidoptera: Sesiidae) in Bulgaria

The major bioecological characteristics of Bracon intercessor Nees (Hymenoptera: Braconidae), a parasitoid of the poplar clearwing moth, Paranthrene tabaniformis (Rott.) (Lepidoptera: Sesiidae), were studied from 1987 to 2003. Poplar shoots infested with P. tabaniformis larvae were collected in 11 localities in Bulgaria and examined in the laboratory, and infestations were also studied in the field. B. intercessor was recorded in seven localities and was found to be a gregarious external larval parasitoid of P. tabaniformis. Two generations of the parasitoid developed on the host. The first (summer) generation was associated with early and mid-stage (up to third instar) host larvae, and the second (overwintering) generation with third- to fifth-instar larvae. The average number of parasitoid individuals feeding on a host was 4.5 and 12.4 in summer and overwintering generations, respectively. The maximum number recorded was 25 individuals per host in the overwintering generation. B. intercessor overwintered as a mature larva on the host and completed its development in early spring. The adults from the overwintering generation appeared in April, about 1 month prior to emergence of P. tabaniformis. The life cycle of B. intercessor was not in close synchrony with the development of P. tabaniformis in the spring, but the parasitoid adults which fed on honey-sugar solution lived for up to 31 days (males) and 86 days (females), respectively. This suggests that, in the field, B. intercessor females eclosing in the spring could survive until the host larvae appear if nectar is available. Adults of the summer generation emerge from July to September when sufficient suitable host larvae are available. B. intercessor was responsible for 1.5% of the average mortality of the P. tabaniformis overwintering larvae. The host mortality caused by the summer generation of the parasitoid ranged from 3.2% to 5.8%.     

Population growth of <Emphasis Type="Italic">Pieris brassicae</Emphasis> (L.) (Lepidoptera: Pieridae) on different cole crops under laboratory conditions

The effect of different host plants including cabbage, cauliflower, mustard, radish, and broccoli on biological parameters of Pieris brassicae (L.) was studied in the laboratory at 28°C, 65 ± 5% RH and 12L:12D photoperiod. Duration of each life stage, longevity, the intrinsic rate of natural increase (r _m), net reproductive rate (R ₀), mean generation time (T), doubling time (DT), and finite rate of increase (λ) of the cabbage white butterfly on the different cole crops were estimated. Differences in fertility life table parameters of the P. brassicae among host plants were analyzed using pseudo-values, which were produced by Jackknife re-sampling. The results indicating that cabbage might be the most suitable food for P. brassicae due to the shorter development time (16 days), longer adult longevity (12 and 9 days for female and male, respectively), higher fecundity (281 eggs/female), higher intrinsic rate of natural increase (0.1156 females/female/day), lower doubling time (6.00), lower larval mortality (70.33%), and higher yield of adult (30%). Therefore, it can be concluded from the present study that P. brassicae prefers cabbage for fast and healthy development with low larval mortality and highest number of adult yield than other cole crops.     

Zur Synchronisation der Entwicklung vonEpiblema tedella Cl. (Lep. Tortricidae) und ihres ParasitenLissonota dubia Hgn. (Hym. Ichneumonidae)

Zusammenfassung Lissonota dubia verbringt als biophager Endoparasit neun Monate in der Leibeshöhle der Larve seines WirtsEpiblema tedella. Die Larvenentwicklung von Wirt und Parasit verläuft nicht synchron, da während der vier bis fünf Monate währenden Winterruhe die Wirtslarve sich schon im Vorpuppenstadium, der Parasit dagegen erst im 2. Larvenstadium befindet. Die Weiterentwicklung zur Vollwüchsigkeit vollzieht dieLissonota-Larve nach der Überwinterung sehr schnell, so daß die Parasitimagines nur etwa drei Wochen später erscheinen als die Wirtsimagines.Die erwachsenenEpiblema-Larven treten im Herbst in Diapause, die jedoch offensichtlich schon im Februar in einen Quieszenz-Zustand übergeht. Im Gegensatz dazu begibt sich ein großer Teil derLissonota-Larven im Herbst nicht in Diapause, sondern nur in Quieszenz, und kann deshalb jederzeit unter geeigneten Temperaturbedingungen die Entwicklung fortsetzen. Ein anderer Teil derLissonota-Larven weist allem Anschein nach im Herbst eine festere Arretierung der Entwicklung auf und verhält sich ähnlich wieEpiblema. Diese physiologische Heterogenität derLissonota-Population könnte als eine zusätzliche Sicherung der zeitlichen Koinzidenz angesehen werden, da sie eine weitere Streuung der imaginalen Schlüpfzeiten zur Folge haben kann. Ein solcher Sachverhalt muß fürLissonota von Vorteil sein, zumal die zeitliche Koinzidenz der Parasitenweibchen mit dam 1.Wirtslarvenstadium nicht durch einen hormonalen Synchronisationsmechanismus, sondern nur durch die Temperatur der Bodenstreu gesteuert zu werden scheint.

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Summary Lissonota dubia Hgn., a biophagous endoparasite ofEpiblema (= Epinotia) tedella Cl., stays for nine months in the body cavity of its host larva. The development of the larvae of host and parasite do not proceed simultanously, since theLissonota larva is still in the second stage, when the host larva has reached the prepupal instar at the time it enters the litter for hibernation (Fig. 1). Although after hibernation the development of host and parasite stars from very different instars, the adult ofLissonota appears only three weeks after theEpiblema moth.Under laboratory conditions the interval between the emergence of the host and the parasite depends on the duration of natural hibernation temperatures before laboratory treatment. If suitable feeding conditions are given continuously during autumn to the fullgrown host larvae, the larvae ofLissonota partly develop to adults without any diapause, while the development of the host is blocked, except for some specimens, which emerge some time afterLissonota (Fig. 2 Tab. 1 and 2). As Figure 3 demonstrates, the posthibernation development ofLissonota is not accelerated after cold treatment by temporary exposure to low hibernation temperatures, but inEpiblema a dependence is evident.From these results it can be concluded that the fullgrown host larvae have a diapause, which seems to change into a quiescence state in February. A great number ofLissonota larvea (orLissonota hosts) stay only in quiescence and are able to continue the development at any time, when suitable temperatures occur. The otherLissonota larvea seem to be retarded in their further development during the first weeks of the hibernation period and therefore to react similar toEpiblema.This physiological heterogeneity of theLissonota population could provide additional security to the temporal coincidence, because it can prolong the emergence period of the parasite. It must be a useful principle, since the temporal coincidence for the parasitization ofEpiblema byLissonota is not controlled by a hormonal mechanism — as it seemed earlier, but mainly (perhaps only) by the soil temperatures in spring.

     

Biological and ecological studies onDiadegma semiclausum Hellen (Hym., Ichneumonidae), a larval parasite of the Diamond-Back Moth,Plutella xylostella (L.) (Lep., Plutellidae) in Egypt

Diadegma semiclausum was reared in the laboratory on 2nd and 3rd instar larvae ofPlutella xylostella. At 25°C, the incubation period of the parasite's egg was 38h; the following stages lasted 5.4 days (5 instars), 33h (pre-pupa), and 5.9 days (pupa). Superparasitism occurred but only one parasite developed from one host larva. Sex ratio inD. semiclausum was found to be 11 in nature as well as in laboratory. The daily and total rate of eggs deposited per female were 13.6 and 164.2, respectively. The parasite male and female, fed on honey, lived for 11.2 and 14.6 days, respectively. Laboratory trials failed to rearD. semiclausum on certain lepidopterous larvae other thanP. xylostella. Percentages of parasitism byD. semiclausum inP. xylostella larvae collected from cabbage fields during 1982 ranged between 0 and 66%.

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Zusammenfassung Diadegma semiclausum wurde im Labor in L2- und L3-Raupen vonPlutella xylostella gezüchtet. Bei 25°C dauerte die Entwicklung 1,6 (Ei), 5,4 (L1–L5), 1,4 (Präpuppe) und 5,9 (Puppe) Tage. Superparasitismus kam vor, doch entwickelte sich nur jeweils eine Parasitenlarve. Das Geschlechterverhältnis vonD. semiclausum betrug im Freiland und im Labor 11. Die tägliche und die Gesamtzahl an abgelegten Eiern betrugen 13,6 und 164,2. Bei Fütterung mit Honig lebten die männlichen Parasiten i.M. 11,2, die weiblichen i. M. 14,6 Tage. Die Laborversuche zeigten, daßD. semiclausum sich ausschließlich ausP. xylostella-Raupen ziehen ließ. Die Parasitierungsquoten vonD. semiclausum inP. xylostella variierten bei Raupen von Kohlfeldern aus verschiedenen Landesteilen 1982 zwischen 0 und 66%.

     

Studies on the parasitoids of Gelechia senticetella (Stgr.) (Lepidoptera: Gelechiidae) in Bulgaria

The parasitoids of Gelechia senticetella (Stgr.) (Lepid.: Gelechiidae), a pest of Juniperus excelsa M.?B., were studied in the “Tissata” reserve in Bulgaria. They were reared in laboratory conditions from pest larvae and pupae collected in 1991, 1992 and 2000. As a result of this study, 16 species of parasitoids of G. senticetella were recorded: Habrobracon stabilis Wesm., Hormius moniliatus (Nees), Phanerotoma tritoma Marsh. (Hym.: Braconidae), Diadegma consumptor (Grav.), Liotryphon cydiae (Perk.), Scambus pomorum (Ratz.), Scambus foliae (Cush.), Pimpla turionellae (L.), Eudelus simillimus (Tasch.), Mesochorus sp. (Hym.: Ichneumonidae), Sympiesis acalle Walk., Aprostocetus sp. (Hym.: Eulophidae), Eupelmus urozonus Dalm. (Hym.: Eupelmidae), Copidosoma thompsoni Merc. (Hym.: Encyrtidae), Calliprymna bisetosa Grah., and Mesopolobus sp. (Hym.: Pteromalidae). H. stabilis and P. tritoma were discovered as new species for the fauna of Bulgaria. Three species (E. simillimus, Mesochorus sp. and Aprostocetus sp.) are hyperparasitoids, and the remaining species are primary parasitoids. Most of the parasitoid species attack the larvae of G. senticetella and kill the hosts before pupation. In the studied parasitoid complex, D. consumptor and H. moniliatus were the dominant species. In 1991, the level of total parasitism of the host in the “Tissata” reserve was 24.3?%, in 1992 – 57.9?% and in 2000 – 12.7?%. D. consumptor was the most important parasitoid destroying 26.6?% of the pest larvae in 1992.     

杨干象的发生规律及综合治理技术

杨干象是我国杨树的一种毁灭性蛀干害虫，先后三次被列入我国森林植物检疫对象名单。本文阐述了杨干象的分布、寄主、各虫态的形态特征、生活史、习性、传播途径、适生范围以及综合治理技术，为杨干象的有效控制提供了基础依据。     

Zur Kenntnis von Hyperodes bonariensis Kuschel (Col., Curculionidae) und seiner Feinde in Argentinien

On the knowledge of Hyperodes bonariensis Kuschel (Col., Curculionidae) and its antagonists in Argentina Studies were made on damage ofHyperodes bonariensis as a pest of pasture plants and on incidence of its parasites and predators. Among its natural enemies,Patasson atomarius (Breth.) (Mymaridae, parasitic on eggs) appeared to be polyphagous, having a good potential rate of increase and substantical ecological tolerance and seemed to be a promising parasite.Sericophanes obscuricornis Popp. (Miridae),Nabis punctipennis Blanch. (Nabidae),Philonthus sp. (Staphylinidae) (predaceous on eggs),Pterostichus aereus (Dej.),Pt. unistriatus (Dej.),Barypus clivinoides Curt.,Cnemalobus gavi Putz.,Metius blandus (Dej.) andM. malachiticus (Dej.) (Carabidae, predaceous on adult weevils) destroyed the host to some extent, but they are not of much importance in regulating the population of this pest.     

Species composition, structure and impact of larval parasitoids of poplar twig borer,Gypsonoma aceriana (Dup.) (Lepidoptera, Tortricidae), on poplar ornamental trees in Sofia

Studies on the species composition and structure of parasitoid complex of poplar twig borer,Gypsonoma aceriana (Dup.), on poplar ornamental trees in Sofia and their role in reducing the number of this pest have been conducted during the period 1990–1997. Six larval parasitoids—Bracon variator Nees,Orgilus obscurator (Nees),Microdus tumidulus Nees,Apanteles erevanicus Tob. (Braconidae),Pristomerus rufiabdominalis Ucida andPristomerus vulnerator (Panz.) (Ichneumonidae) were identified. Most numerous wereM. tumidulus (41.0%),A. erevanicus (30.6%) andP. rufiabdominalis (19.1%).A. erevanicus andM. tumidulus were dominating during the different years. The parasitoids ofG. aceriana were solitary, asB. variator is an ektoparasite, and the rest—endoparasites. They attack young host larvae and emerge at the end of the pupal stage. The life cycle of parasitoids, that have double generation, are well synchronised with the pest development. This was expressed in the high levels of parasitism, which in some cases reached 61.5%, and as a whole for the different generations they were 5.9–44.4%.A. erevanicus andM. tumidulus were the most important in reducing the number of the pest.     

Le Linospora ceuthocarpa (Fr.) Munk ex Morelet,parasite foliaire des peupliers

Linospora ceuthocarpa (Fr.) Munk ex Morelet, a parasite of poplar leaves. Linospora ceuthocarpa (Fr.) Munk ex Morelet and its conidial stage Titaeosporina tremulae (Lib.) v. Luyk are experimentally connected and described. The life history of the disease on poplar leaves is studied.     

Tree Mortality,Needle Biomass Recovery and Growth Losses in Scots Pine Following Defoliation by Diprion pini (L.) and Subsequent Attack by Tomicus piniperda (L.)

Tree mortality and growth losses following insect defoliation are poorly documented in Scandinavia. In 1990-1991, Diprion pini (L.) caused extensive defoliation to Scots pine in Lauhanvuori national park and surrounding areas in south-western Finland. Most trees lost all their foliage in 1990. In 1991, the outbreak area was sprayed with diflubenzuron (Dimilin®), except in the national park, where trees were severely defoliated again. No further defoliation occurred in 1992. In spring 1993, sprayed trees had ca 30% foliage, whereas unsprayed trees on average carried less than 10% of full foliage. The latter trees were susceptible to attack by Tomicus piniperda (L.), whereas the former largely escaped beetle attack. Beetle attacks peaked in 1993, and depletion of suitable host trees probably terminated the beetle outbreak in the area. Two years of severe defoliation resulted in substantial tree mortality and growth losses. In spring 1997, these unsprayed stands had suffered a ca. 50% loss in basal area which was mainly because of mortality, and about half of the dead trees had been attacked by T. piniperda. Surviving trees had ca 50% of full foliage, and radial growth had still not recovered. Basal area growth was reduced by 40-70%, depending on the amount of foliage left after the second year of defoliation. In contrast, tree mortality and beetle attack in the sprayed stands were negligible, and these trees had recovered full foliage and radial growth by spring 1997. Thus, one year of total defoliation resulted in an estimated loss in basal area growth of approximately 30% during ca. 5 yrs. In conclusion, the spraying operation was economically justified, as it prevented substantial tree mortality and reduced growth losses.     

Zur Lebensweise und Wirtsbindung des Distel-BlattkäfersLema cyanella L.(puncticollis Curt.) (Col. Chrysomelidae)

Summary L. cyanella L. is known to occur in Europe, Siberia, and Japan. A map showing personal records ofL. cyanella on creeping thistle(Cirsium arvense) is given in Figure 2. Our findings suggest thatL. cyanella is more common and more evenly distributed in the western parts of Europe (western France and southern England) than in central Europe (Switzerland, Germany, Austria), where only a very small proportion of the thistle stands examined yielded the beetle. There are no personal records from southern Europe. The hibernating adults ofL. cyanella appear in late April and May on the rosettes and young shoots ofC. arvense, where they start feeding and ovipositing. The larvae which are covered with their faeces feed on the lower side of the leaves ofC. arvense. Pupation takes place in the soil. In the laboratory the whole development from egg to adult lasted about 35 days. There is only one generation per annuum. All available field observations ofL. cyanella refer toC. arvense as host plant (one record fromCirsium vulgare). “Short-term feeding tests” with adults ofL. cyanella yielded feeding responses withCarduus,Cirsium spp. andSilybum. Test plants belonging to 17 other genera of the Compositae family were not accepted. As shown in Table 1 this “Carduus-Cirsium-Silybum pattern” has also been found in feeding experiments with other highly specialized thistle insects. Within its subfamily (Criocerinae)L. cyanella appears to have developed a unique host association, since to date no related species are known to feed on thistles or other Cynareae. Because of its high degree of host specifityL. cyanella may be a potential candidate insect for the biological control of creeping thistle in North America. Further feeding tests with larvae and investigations as to the reasons for the scarcity ofL. cyanella in central Europe should be made, before a definite decision about the usefulness ofL. cyanella as a biological control agent can be taken.      

A laboratory study on the activity of <Emphasis Type="Italic">Steinernema feltiae</Emphasis> (Rhabditida: Steinernematidae) Rioja strain against horticultural insect pests

The potential of the entomopathogenic nematode Steinernema feltiae (Filipjev) (Rhabditida: Steinernematidae) Rioja strain was assessed under laboratory conditions. Last instar larvae of Leptinotarsa decemlineata Say (Coleptera: Chrysomelidae), Spodoptera littoralis Boisdouval (Lepidoptera: Noctuidae) and Trichoplusia ni Hübner (Lepidoptera: Noctuidae) were exposed to infective juveniles (IJs) under laboratory conditions. Larval mortality, days to larval death, infection cycle length, and reproductive potential were recorded. Efficacy was assessed performing dose–response experiments. The results indicate that control of L. decemlineata with S. feltiae Rioja strain is not economically profitable (LC₅₀ = 99.61 IJs/cm²), whereas results obtained for T. ni (LC₅₀ = 0.27 IJs/cm²) are promising. Due to the life cycle of this insect, the efficacy needs to be investigated in foliar application studies. The effects on S. littoralis (LC₅₀ = 0.69 IJs/cm²) was considered the most suitable for development of the Rioja strain as a biocontrol agent for soil application.     

Parasitoid complex (Hymenoptera, Braconidae, Aphidiinae) of Aphis craccivora Koch (Hemiptera: Aphidoidea) in Iran

The parasitoids (Hymenoptera, Braconidae, Aphidiinae) of the cowpea aphid, Aphis craccivora Koch, were investigated throughout two far distant provinces, Tehran and Sistan-Baluchestan. Colonies of the cowpea aphid were collected from different host plants and reared under laboratory conditions until the parasitoids emerged. The aphids were parasitized by an expected range of parasitoids. The species were Aphidius colemani Viereck, Lysiphlebus fabarum (Marshall), Lysiphlebus confusus Tremblay and Eady, Lysiphlebus testaceipes (Cresson), Binodoxys acalephae (Marshall), Binodoxys angelicae (Haliday), Praon volucre (Haliday) and Ephedrus persicae Froggatt. L. testaceipes is reported here for the first time in Iran. The most common species was L. fabarum followed by B. acalephae and L. confusus. A key is provided for identification and host plant associations are considered.     

Beobachtungen am Schlehenspinner (Orgyia,antiqua L.) und seinen Parasiten

Zusammenfassung 1. Das erstmalige Massenauftreten des Schlehenspinners in Fichtenwäldern Süddeutschlands bot Gelegenheit, im Walde und Labor Beobachtungen an diesem seltenen Forstschädling und seinen Parasiten anzustellen. In warmen Gegenden und Jahren durchläuft er zwei Generationen (Bionomieformel: I = 67–78/ 9 + 9, II = 9,5–46/6 + 67).2. Die Altraupe hat Brennhaare. Längeres Arbeiten mit den Puppenkokons verursacht ein heftiges Nesselfieber (Urticaria).3. Gradationen des Schlehenspinners in mitteleuropäischen Forsten treten in 50–60jährigen Intervallen auf. Eine Standortgebundenheit ist nicht erkennbar. Die Altraupe verschont die Knospen, ein mehrjä hriger starker Fraß in denselben Beständen ist selten, er verursacht nur einen Zuwachsverlust. Die Gradation findet meist im Innern geschlossener Bestände statt.4. Im Untersuchungsgebiet, 7 km nördlich von Bad Wurzach, ermittelten wir an der 2. Generation des Jahres 1971 einen Weibchenanteil von 48,4% und eine Puppenmortalität von 4,4%. Die Zahl abgelegter Eier war im Zentrum geringfügig höher als im Randgebiet.5. Häufigste Parasiten waren der PuppenparasitCoccygomimus turionellae (L.), der LarvenparasitPhobocampe crassiuscula (Grav.) und der EiparasitTelenomus dalmanni Ratz. Die Besatzdichte der vorgenannten Schmarotzer wurde im Zentrum und Randgebiet untersucht.6. Systematische Stellung, Wirtsspektrum, Lebensdauer, Sexualindex und Parasitierungsverhalten vonTelenomus dalmanni Ratz. werden beschrieben.

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Summary 1. The first appearance in large numbers ofOrgyia antiqua in the spruce forest of Southern Germany offered the possibility of observing this insect pest and its parasitoides under field and laboratory conditions. In warm regions and years this insect has two generations (Bionomic data [Bionomieformel] I = 67–78/9 + 9, II = 9,5–46/6 + 67).2. The older larva has poisoned hairs. Extended handling with the cocoon causes a heavy kind of feaver (Urticaria).3. The outbreak ofOrgyia antiqua in middle-european forests occurs in intervals from 50 to 60 years. A preference of special areas could not be seen. The older larva doesn't attack the buds. A high population over several years in the same stands is very seldom. This high population density causes only a loss of increment. The outbreak mostly takes place in the center of closed forests.4. In the study area (about 7 km north of Bad Wurzbach, Baden-Württemberg) we found 48.4% females for the second generation. The mortality of the pupa was 4.4 %. The number of eggs laid was found to be higher in the center than in the peripheral zones.5. The most important parasitoides wereCoccygomimus turionellae (L.) (pupae),Phobocampe crassiuscula (Grav.) (larvae) andTelenomus dalmanni (Ratz.) (eggs). The density of population of these parasitoides has been studied in heavy infested areas as well as in scarcely poculated zones.6. Systematics, host-species, duration of life, sexual index and the behavoir of the parasitoidTelenomus dalmanni are described.

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Als Stipendiat der Alexander v. Humboldt-Stiftung am Institut für biologische Schädlingsbekämpfung tätig.     

Wechselseitige Beeinflussung des Entwicklungsablaufs bei entomophagen Parasiten und deren Wirten,erörtert am Beispiel vonColeophora-Arten(Lep., Coleophoridae) undUrophora-Arten(Dipt., Trypetidae)

Summary This study compares the host-parasite relation betweenColeophora ? alcyonipennella andAgathis sp., on the one hand, andUrophora spp. andEurytoma tibialis, on the other hand.Coleophora-Agathis is a striking example for a host-parasite relation where the larval development of the parasitoid is controlled by the endocrine system of the host, which results in an optimal synchronization between the life-cycles of the moth and its specialized Braconid parasite. Attempts to obtain adultAgathis during the winter season for the biological control ofColeophora in New Zealand have met with considerable difficulties because of the hormonal dependence of the parasite on the host. The rearing and the transfer of adult parasites was not possible until the diapause of the host could be ended experimentally. In the complexUrophora-E. tibialis the parasite larvae interferes with the hormonal system controlling the development of the host. In hibernating generations ofUrophora spp. the parasite induces a premature onset of the process of pupation of the host, but consumes the latter when it has formed its puparium. In both hosts the hormonal reactivation of the diapausing full-grown larva results in a change of the position of the larva in its case or gall, before the morphogenetic changes involved in pupation take place. The larvae ofAgathis as well asE. tibialis do not kill their hosts until the latter have reversed their position within the case or gall. In this way the emergence ofAgathis from the case ofColeophora and the emergence ofE. tibialis from the gall ofUrophora is facilitated.     

Studies on the parasitoid complex of Choristoneura murinana (Hbn.) (Lep.: Tortricidae) in Turkey

The parasitoid complex of Choristoneura murinana (Hbn.), a pest of Abies cilicica Carr., was studied in Isparta, Turkey. Shoots and needles of A. cilicica with C. murinana larvae and pupae were collected and examined under laboratory conditions in 2002 and 2003. As a result of this study, 14 parasitoid species of C. murinana were determined: Apanteles obscurus Nees. (Hym.: Braconidae), Brachymeria intermedia Nees (Hym.: Chalcididae), Mesopolobus mediterraneus Mayr, Mesopolobus dubius Walker, Pteromalus chrysos Walker, Pteromalus sp. (Hym.: Pteromalidae), Monodontomerus aereus Walker (Hym.: Torymidae), Itoplectis maculator (Fabricius), Apophua bipunctoria Thunberg, Triclistus globulipes Desvignes, Dirophanes maculicornis Stephens, Hyposoter sp., Dusona sp. (Hym.: Ichneumonidae) and Aprostocetus sp. (Hym.: Eulophidae). In the studied parasitoid complex, A. obscurus, B. intermedia and I. maculator were the most important in reducing pest numbers. The level of total parasitism of the C. murinana was 19.4% in 2002 and 22.3% in 2003.