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The present paper deals with the status of the hibernated larvae (L5) of Euproctis melania Staud. inside their nests which are formed of the rolled leaves of oak trees; the main host plant of this pest. The number of larvae per nest varied considerably; being 49.7 larvae on the average. These hibernated larvae harbour Apanteles parasite as mature larvae inside their bodies. Just the larva of Euproctis starts its activity in spring, the parasitic larva soonly leaves its host and spins its cocoon. The prepupal and pupal stages of this parasite average one and 10 d, respectively at 20.6 °C and 48.4 % R. H. Emergence of the parasite occurs after 11.7 and 12.7 d of cocoon formation, for males and females, respectively. The percentage of parasitism by Apanteles averaged 10.8 %. This braconid parasite is hyperparasitised by the eulophid, Pediobius pyrgo Wlk, but in a very low percentage. The pteromalid, Habrocytus sp. near dispar group was also obtained from only three closed nests. Zusammenfassung Untersuchungen uber die uberwinternden Larven von Euproctis melania Staud. (Lymantriidae, Lep.) im Irak Euproctis melania uberwintert als L5 in zusammengerollten Blattern von Eiche, der Hauptnahrungspflanze des Schadlings. Die Zahl uberwinternder Raupen/Nest variierte betrachtlich, mit einem Mittel von 49.7. Die Uberwinterer sind z. T. parasitiert von Apanteles. Wenn die Euproctis-Raupe im Fruhjahr aktiv wird, verlast die Parasitenlarve ihren Wirt und spinnt ihren Kokon. Das Prapuppen- bzw. Puppenstadium des Parasiten dauert 1 bzw. 10 d. Nach i. M. 11.7 (♂) und 12.7 (♀) d verlassen die Schlupfwespen den Kokon. Die Parasitierungsquote durch Apanteles betrug i. M 10.8 %. Als Hyperparasit trat in geringer Anzahl die eulophile Pediobius pyrgo auf. In 3 Nestern wurde auch die Pteromalide Habrocytus sp. nahe dispar gefunden.

Summary The browntail moth (Euproctis chrysorrhoea L.) fairly frequently completely defoliates oak trees in the part of the country South of the river Waal and in the “Achterhoek”, and buck thorn in the dunes region along the coast. In the “Veluwe” defoliation has been observed as an exception only. In the Northern provinces the species in question never caused important damage. In appears, therefore, that the North limit of the area in which outbreaks of the browntail moth occur, runs from West to East through the Netherlands. From time to time the limit moves to the North, and back again after a few years. An hypothesis was advanced according to which the increase of the damage and the movement of the limit of the outbreak region to the north would be caused by changes in the quality of the food, resulting from changes in weather conditions. In order to find out whether there is any likelihood of the nature of the food affecting the population dynamics of the brown tail moth in our country, two series of experiments were carried out. a. Field experiments with colonies placed in oak, hawthorn, apple and birch by the experimentor. It appeared that there were considerable differences in the development of the caterpillars on the different plant species and in the different localities. b. Laboratory experiments in which oak, hawthorn and apple leaves were fed to the caterpillars showed that they thrived best on hawthorn, less well on apple and least on oak. It is, therefore, concluded that an influence of the nature of the food on the population dynamics of the brown tail moth may be decisive. Further experiments are in progress.

Zusammenfassung Die hier beschriebene Arbeit vom Einflus der Nahrung auf die Populationsdichte des Goldafters (Euproctis chrysorrhoea L. = Nygmia phaeorrhoea Don.) ist eine Fortsetzung von fruher veroffentlichten Untersuchungen. Als neues Element wird in der vorliegenden Veroffentlichung der Einflus ungleichwertiger Nahrung aus verschiedenen Teilen der Baumkrone gepruft. Die Raupen wurden mit Eichen- und Weisdornblattern aus verschiedenen Orten der Provinzen Nordbrabant und Gelderland gezuchtet. Von jedem Fundort wurde Material des Wipfels sowie der Nord- und Sudseite der Krone der Raupen in verschiedenen Zuchten verfuttert. Ebenso wie 1957 gediehen 1958 die Raupen mit Weisdorn besser als mit Eiche. Die Zuchten erbrachten deutliche Unterschiede in der Eignung der Nahrung der genannten Teile der Baumkrone. Dabei waren die mit Blattern der Nordseite gezuchteten Tiere am schwachsten. Bei den mit Eichenblattern gefutterten Tieren war die Zahl der auf Blattmaterial vom Wipfel produzierten Eier ca. funfmal so gros wie auf Material von der Nordseite (Schattenblatter). Regionale Unterschiede der Eignung zur Nahrung fur die Raupen des Goldafters traten in diesen Ergebnissen nicht deutlich ans Licht. Summary The investigations on the influence of the quality of the food on the population-density of the browntail moth (Euproctis chrysorrhoea L. = Nygmia phaeorrhoea Don.) described in this paper are a continuation of some introductary investigations published before. In this study the possibility was tested that the different parts of the crown of the tree would not have the same value as food for the caterpillars. The caterpillars were reared on the leaves of hawthorn and oak, which were collected in different localities in the provinces of Noordbrabant and Gelderland. At every locality material of these species from the top, the south- and northside of the crown was collected separately. This year, as the year before, the caterpillars developped better on hawthorn than on oak. Marked differences were found between caterpillars reared on material from the parts of the crown allready mentioned. So caterpillars reared on leaves from the north side were allways less vigorous than those reared on leaves from the top and the south side. As regards oak leaves, butterflies from caterpillars reared on leaves taken from the top of the crown produced about 5 times as many eggs as those from caterpillars reared on leaves from the north side. In these data, no pronounced regional differences were found in the suitability of the leaves as food for the caterpillars.

Candan, S., Suludere, Z. and Bayrakdar, F. 2007. Surface morphology of eggs of Euproctis chrysorrhoea (Linnaeus, 1758). —Acta Zoologica (Stockholm) 88: 000–000. Filaments covering the egg batches and chorion structure were studied both by light and scanning electron microscopy in the brown-tailed moth Euproctis chrysorrhoea (Linnaeus, 1758). Females lay eggs in masses on the underside of apple leaves. The egg batches are covered with brown hairs derived from the bodies of the female. Each female lays about 200–400 eggs. The spherical eggs are about 0.84 mm long and 0.47 mm wide. Newly deposited eggs are golden-yellow and darken after the onset of embryonic development. The micropylar area appears somewhat depressed and has a circular outline. The region is surrounded by a rosette of 10–12 petal-shaped primary cells, which are completely surrounded by a series of secondary and tertiary cells. The remainder of the egg is largely smooth, but shows aeropyles. These are located in the corners of ill-defined polygons.

Analysis of nestling food in four species of Parus and one species of Ficedula using the 'Halsringmethode' showed a high quota of adults and caterpillars of the important forest pests: Tortrix viridana, Euproctis chrysorrhoea, Diprion pini, and Lymantria dispar. These four major pest species amounted in the nestling food of Parus major to 50 %, P. coeruleus to 52.6 %, P. ater to 40.9 %, and Ficedula hypoleuca to 30.2 %.

Two EAG-active compounds were found in the solvent extract of abdominal tips of virgin females of the tussock moth Euproctis pulverea (Leech) (Lepidoptera: Lymantriidae), and identified as (Z,Z,Z)-11,14,17-icosatrienyl isobutyrate and (Z,Z,Z)-11,14,17-icosatrieny14-methylvalerate at 190 and 80 ng female -1 , respectively, by means of GC-MS analyses and chemical derivatization. Esters of n-butyric acid, n-valeric acid, n-hexanoic acid and a methylheptanoic acid were also found at 3, 2, 0.4 and 9 ng female -1 as minor EAG-inactive compounds. Two active compounds were also detected in the hexane extract of female anal tufts at 17 and 6 ng female -1 , respectively. In Okinawa, the binary blend of the synthetic compounds attracted male moths to the sticky traps, but single compounds did not. The significance of these findings in relation to parasitism by Telenomus euproctidis (Hymenoptera: Scelionidae) is discussed.

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.

Summary Observations regarding outbreaks of Euproctis chrysorrhoea L. have been recorded in the Netherlands since 1940 by the Forest Insect Survey of the Itbon: 1. Usually, damage by the caterpillars only occurred in the southern and western parts of the country, but during very heavy outbreaks also further north. 2. The number of host species appeared to increase with the seriousness of the outbreak. 3. Apparently, in most cases, outbreaks resulted from the development of the endemic population. 4. The woody species were attacked in a definite order. 5. It is considered likely that this order is that in which the different species become suitable as food, as the result of different weather conditions.

Summary. Studies on the effect of Catharanthus roseus alkaloids on the biology of Euproctis fraterna showed that at a dose of 10 ppm, only 19.25% fertile eggs were laid. The hatchability was totally suppressed at higher doses. There was a considerable reduction in total carbohydrate and protein content in treated larvae. The activity of digestive enzymes were also found to be inhibited.

The distribution of microsporidian infections of browntail moth (Euproctis chrysorrhoea L.) populations in Bulgaria was studied. Of the 72 browntail moth populations in the regions of Balkan, Sredna Gora, Sakar Mountains, and Rodope Mountains, 21 were infected by Microsporidia. The Microsporidia belong to two genera – Nosema (Dihaplophasea, Nosematidae) and Endoreticulatus (Haplophasea, Encephalitozoonidae). Microsporidial infections caused by a Nosema were found in 14 populations, by an Endoreticulatus in 8 populations, and mixed infections of Nosema and Endoreticulatus were recorded from 3 populations. Endoreticulatus was present in Balkan, Sredna Gora, and the Sakar Mountains. Nosema infections were found in Sakar Mountains and Rodope, and mixed infections were recorded only from the Sakar Mountain populations.

A field trial of a naturally occurring nuclear polyhedrosis virus as a bioinsecticide for control of the Brown-tail moth, Euproctis chrysorrhoea, is described. The trial was carried out in the autumn on a non-outbreak population of second instar larvae on Rubus sp. bushes in southern England. Despite erratic droplet coverage generated by a hand held, fan assisted ULV sprayer (Turbair Fox), a series of doses produced a clearly defined primary infection response peaking at ca. 70% at 1 times 109 PIBs/ml. The development of these infections was slow and most mortality occurred during or shortly after winter diapause. Secondary infection peaks in the spring were unpredictable, but occurred in many plots across the dose range. The data suggest that the virus would be a useful, environmentally acceptable insecticide for control of this insect in sensitive areas during pest outbreaks. Zusammenfassung Freilandversuche zum Einsatz eines Kernpolyedervirus gegen den Gemeinen Goldafter, Euproctis chrysorrhoea (L.) (Lep., Lymantriidae) Es wird uber einen Freilandversuch zur Bekampfung des Gemeinen Goldafters, Euproctis chrysorrhoea mit einem naturlich vorkommenden Kernpolyedervirus berichtet. Der Versuch wurde im Herbst im zweiten Larvenstadium durchgefuhrt. Die an Rubus sp. fressende Population befand sich in der Latenzphase. Trotz der unregelmasigen Tropfchenverteilung bei der Ausbringung mit einer Handspritze, unterstutzt durch ein ULV-Spruhgerat (Turbair Fox), ergab sich bei den verschiedenen Dosierungen eine deutliche primare Infektionsreaktion mit einem Maximum von ca. 70% bei 1 × 109 PIBs/ml. Die Infektionsentwicklungen waren langsam, die Mortalitat trat uberwiegend wahrend oder kurz nach der Winterdiapause ein. Ein zweiter Infektionszyklus im Fruhjahr war nicht kalkulierbar, aber in vielen Versuchsparzellen bei allen Konzentrationen zu beobachten. Die Ergebnisse zeigen, das das Virus ein geeignetes und aus Umweltschutzgrunden akzeptables Bioinsektizid ist, um bei Kalamitaten den Goldafter in bewohnten Gebieten zu bekampfen.

The transmission of a nuclear polyhedrosis virus was investigated within a single generation of the Brown-tail moth, Euproctis chrysorrhoea (L.). Larvae infected with a lethal dose of virus were introduced onto bramble bushes naturally infested with the host, in separate studies in the spring and autumn. The course of infection was followed and clearly showed the development of a secondary infection peak in the spring. The presence of a secondary peak in the autumn was also suggested. These peaks are considered to have resulted from the passage of the virus from the primary infected larvae into further larvae. Virus dispersal was more widespread in the spring than in the autumn reflecting differences in larval dispersal. Zusammenfassung Uher das Auftreten sekundarer Infektionszahlen nach Anwendung eines Kernpolyeder-Virus gegen eine Population des Goldafters, Euproctis chrysorrhoea (L.) (Lep., Lymantriidae) Es wurde die Ubertragung eines nuklearen Polyeder-Virus in einer Generation des Goldafters, Euproctis chrysorrhoea (L.) untersucht. Die Raupen wurden mit einer letalen Dosis des Virus infiziert und dann in Brombeerstrauchern freigelassen, die naturlicherweise mit Goldafter-Raupen besetzt waren. Die Untersuchung wurde zweimal, im Fruhling und Herbst, durchgefuhrt. Der Verlauf der Infektion wurde verfolgt, und die Infektionskurve zeigte klar die Entwicklung einer sekundaren Spitze im Fruhjahr. Moglicherweise existierte auch noch eine sekundare Spitze im Herbst. Diese Spitzen stammen vermutlich aus einer Ubertragung des Virus von den primar infizierten Raupen auf weitere Raupen. Der Virus verbreitete sich im Fruhjahr weiter als im Herbst, vermutlich wegen unterschiedlicher Wanderlust der Raupen.