0622-B3

Yearly Life Cycle of Meteorus versicolor (Wesmael) on Euproctis chrysorrhoea (L.)

Prof.Dr. Mahmut EROĞLU 1


Abstract

The first generation of parasitoid pupae appeared 15-20 days after the host larvae has came out of over wintering, at the time host larvae were in the fifth and sixth instars. Pupation and longevity were 10.8 and 10.1; and 8.4 and 19.8 days in the first and second years, respectively. The effectiveness of this generation of parasitoid on the host was 6-7.5 %.

In the second generation of the parasitoid, the number of days between the peak of pupation and emergence periods of parasitoid and the host were about 15 and 25 days. Parasitoid pupae appeared in the two last instars of the host. The pupal periods of the parasitoid for the first, second and third years were 6.6, 6.6 and 7.2 days, and longevities were 5.8, 9.2 and 11.0 days, respectively. The larval stage of the parasitoid on the second generation lasted about 20 days. The effectiveness of the parasitoid was 23.5 %, on average.

The third generation of parasitoid pupae appeared when most of the host Larvae were pupae. Adult parasitoids which emerged 5-6 days after pupation and stayed alive 15-25 days, were active in the first and second instars of the new generation of the host.


Introduction

The brown tail moth, Euproctis chrysorrhoea (L.) (Lepidoptera: Lymantridae) which can be found over the large part of the world and as well as in Turkey, has a characteristic of population increases almost 3 or 4 years, causing important damages on orchard and broad-leaved forest trees (Schimitschek 1944, Nizamlıoglu 1953, Gürses 1975, Öncüer et al. 1977, Eroğlu 1992).

The natural distribution of the brown tail moth extends across the whole Europe, including Britain, southern Norway and Sweden and all the temperate areas of North Africa and Asia (Balachowsky and Mensil 1935, Sorauer et al. 1953, Schaefer 1986,1989). E.chrysorrhoea does not occur in Japan (Inoue 1957) or Korea (Nam and Kim 1981) but does apparently occur as far east as Yunnan Province, China (Chao 1978). Outbreaks occur periodically throughout most of this range.

E.chrysorrhoea was accidentally introduced into North America in 1897, after which it became a serious forest, shade and orchard tree pest that required control (Burges 1914; Burges and Crossman 1929; Metcalf and Flint 1951; Griffiths and Quednau 1983). It is also of public health interest due to the dermatitis and irritant in humans caused by the hairs from the caterpillars (Metcalf and Flint 1951; Öncüer et al. 1977; Sterling et al. 1988; Eroğlu 1992). This pest has continued to cause serious periodic damage in spite of almost continuous work to control it in Europe (Lipa et al. 1980; Eroğlu 1992; Sliwa 1993; Lipa 1996).

Laboratory breeding experiments suggest that, at least in some parts of Germany, M.versicolor may produce two generation a year, the first parasitic on larvae of Panolis flammea Schiiff., and the second on larvae of Denrolimus pini L. (Thalenhorst 1939). The parasitoid recovered from D.pini on Scots pine, Pinus sylvestris L. near Gomel, Belarus. (Emelyanov and Goncharenko 1991). M.versicolor is important parasitoid of larvae of L.salicis in Yugoslavia (Serafimovski 1954). Meteorus versicolor var. decoloratus Rutha., is a parasitoid of Thaumetopoea pityocampa (Schiff.) which also recovered from larvae of E.chrysorrhoea in Turkey (Öncüer et al. 1977). Parasitic attacks by this polyphagous larval parasitoid in the autumn are reported from many parts of Spain. Its effect may be important, but depends on the availability of secondary hosts for the summer generation. (Cadahia et al. 1967).

M.versicolor is a parasitoid of E.chrysorrhoea and Thaumetopoea processionea (L.) and has a potentiality for biological control. Describing observations during an outbreak of these oak defoliators in central East Germany, in the phase of decline, particularly where both pests occurred together, parasitization rates of up to 37 % in E.chrysorrhoea and ca. 20% in Th.Processionea were found (Frankhanel 1958). Long-term studies in Azerbaijan showed that 16 species of parasitoids were important in regulating the number of larvae or pupae of the orchard pest E.chrysorrhoea, one of the most widespread and effective being M.versicolor. (Mamedov 1988)

Studies on the biology and life cycle of M.versicolor connected with E.chrysorrhoea are limited. And also, the effects of the parasitoid on this host have not been studied in detailed due to the irritant in humans caused by the hairs from the caterpillars. M.versicolor produces two generation in a year, particularly where two of its hosts occurred together (Thalenhorst 1939; Frankhanel 1958), and parasitization rates of up to 37 %, where one of host is E.chrysorrhoea.

This compels to introduce control methods against the pest that has a lower negative impact on the environment. The aim of the present study was to bring about effective methods of such character. To this and, some biological data on the pest were first obtained (Eroğlu 1992). Later, the biology and mutual relationships of Meteorus versicolor (Wesmael, 1835) (Hymenoptera: Braconidae), which is the most important larvae parasitoid of the pest, have been investigated.

Material and Methods

The biologies and of and mutual relationships between the brown-tail moth, Euproctis chrysorrhoea (L.) and its one of the important larvae parasitoid, Meteorus versicolor (Wesm.) have been investigated in greater Trabzon, Turkey in the following three years.

The host Larvae were reared on Dog rose (Rose canina L.) branches dipped in glass bottles filled with water. Cages were placed in a room open to outdoor conditions in Trabzon, temperature of 20_2_C. Larval instars were determined by head capsule width, based on a frequency distribution of head capsule widths compiled from 960 E.chrysorrhoea larvae reared on R.canina.

Part of diapausing E.chrysorrhoea larvae were collected in late September in the overwintering webs and dissected to determine the presence of M.versicolor and its overwintering stage. The remainder were collected in early spring, and reared on R.cania until parasitoid emergence.

Egg masses containing an average of 300 eggs each, laid on waxed paper by females that had emerged from field-collected larvae between 20 and 30 June, were attached to the underside of leaves inside the cages. A total of 59 first generation adult parasitoids along with use laboratory originated host larvae were placed in a cage. Then, second generation pupae and adults of the parasitoid were recovered in 15 May-2 June and 22 May-9 June, respectively.

Results

About 2.5 days after the host larvae have stopped feeding, the second generation mature parasitoid larvae were recovered. These larvae became pupae in the cocoons spun in about 5-6 hours. The host larvae died on average 7.5 days after the parasitoid larvae have left, and they have not fed during this time.

A total of 526 parasitoid were recovered from 2516 host larvae which were collected in the first year. The parasitoid and the host pupae peaked on 2-4 June and 14-19 June 1988, respectively. Between the two peaks was 15 days. In the case of parasitoid and host adults, this period was 25 days.

A total of 59 first generation of parasitoid pupae and adults were recovered from 780 host larvae on 17-24 April and 29 April -2 May, in the second year, respectively. From 100 laboratory reared host larvae which were placed in the same cage as these adults, 72 parasitoid pupae were recovered on 15 May -2 June. The second larval period of parasitoid lasted about 20 days. The adults emerged on 22 May -4 June.

The larvae collected in the third year became active after 14-15 April. These larvae entered into fifth and sixth instars between 25 April -7 May. Of these larvae a total of 44 first generation parasitoid pupae were recovered on 30 April -5 May. From these pupae, adults were recovered on 8-14 May. From then on no M. versicolor was recovered. Starting on 14 - 17 May the larvae entered into sixth and seventh instars.

The pupal and adult periods of the first generation parasitoid were average 8.4 (7-9) days and 19.8 (1 6-24) days, respectively. The same periods for the year 1989 was 10.8 (8-1 2)days for pupae and 10.1 (9-11) days for the adult periods, respectively.

A total of 182 second generation pupae was recovered on 25 May -16 June from a total of 438 host larvae collected from an isolated area on the University Campus on 17- 18 May in the third year. The adults emerged on 2-22 June. Pupal and adult periods in this second generation were 7.1 (6-9) days and 10.5 (5-24) days, respectively.

In the mean time, a total of 138 second generation M.versicolor pupae were recovered on 25 May -5 June and parasitoid's adults on 3- 12 June from the cage in which 240 host larvae and 16 first generation parasitoid adults were present since 12 May. Pupal and adult periods in this generation were 7.3 (6-9) days and 11.5 (4-25) days, respectively.

The second generation pupal periods (in days) were 6.6, 6.6, and 7.1 and 7.3 in the first, second and third years, respectively. The differences in averages may be attributed to temperature variations f the days of month . The average temperatures in June in these three years were 20.0, 20.4 and 19.9 º C, and in the third year, the first period was 25 May -16 June and the second 25 May - 5 June.

The adult period of the first generation parasitoid was average10.1 days in the second year and 19.8 days in the third year. In the second year, all parasitoid adults were present with host larvae in the rearing cages. All adult parasitoids were fed syrup in the last year, which may explain the 10-days difference between longevities of these first generation adults.

A total of 3 third generation pupae were recovered on 20, 25, and 27 June from a total of 20 laboratory reared host larvae which were placed in the same cage as 10 second generation parasitoid adults in the first week of June in the second year. The adults emerged six days later, on average, and they lived until 6-7 July, at the time when host larvae were in the first instars.

In the third year, a total of 15 second generation of parasitoid adults emerged on 4-5 June were placed in a cage on 6 June with the rest of 70 fully grown larvae of the host larvae which were collected in overwintering webs and produced first generation parasitoids. Three third generation pupae and parasitoid adults were recovered from these host larvae. A third generation parasitoid adult was also recovered on 5 July from the cage where 9 parasitoid adults emerged on 5-13 June and 30 host larvae placed together on 13 June in the third year.

A total of 7 third generation pupae and adults were recovered from rest of host larvae which were collected on 17-18 May and produced second generation parasitoids. These third generation parasitoid adults emerged on 3-7 July and lived until 28 July, at the time when host larvae were in the first and second instars.

Discussion

The results confirm that M.versicolor overwintered as an egg or larva in larva of E.chrysorrhoea. Larvae of E.chrysorrhoea feed at least until the second-third (Skatulla 1978), fourth (Eroğlu 1992) or fifth (Gürses1975) larval instars before entering diapause in the fall. M.versicolor deposited the eggs host larvae before entering diapause until the fourth instar. It is likely that this parasitoid does not attack larvae once they have spun a hibernaculum. It was concluded that M.versicolor adjusted its life cycle to fit that of E.chrysorrhoea.

The peaks of pupa and adults of parasitoid and the host was the same as last year (i.e., 15-25 days). The life cycle of the pest ceased 10 days earlier than that of last year, indicating that the second generation of parasitoid depends on the biology of the host.

M.versicolor is a parasitoid of M.neustria, D.pini (Thalenhorst 1939; Emelyanov and Goncharenko 1991) L.salicis (Griffiths 1976), E.chrysorrhoea (Burges and Crossman 1929; Metcalf and Flint 1951; Frankhanel 1958; Griffiths and Quednau 1983; Mamedov 1988) and T.processionea (Frankhanel 1958) and has a potentiality for biological control of these pests .

In the spring, percentage parasitism of E.chrysorrhoea by the first generation of M.versicolor was 6.0 and 7.5% in the second and third years, respectively. In the second generation of M.versicolor, maximum parasitism on the host (23.5% in the firs year) was reached in May and June, at the time when host larvae were in the seventh and eighty instars. Totally 529 parasitoids were recovered from about 2500 host larvae in this year. The parasitism rose the rate of 41.5% in a partly isolated area where the host population were importantly reduced by the collectings during the three-years period. This result reflected that the parasitoid could deposit its eggs in higher proportions to the host larvae being in relatively lower population densities. In the second generations, the percentage parasitism was 72 and 57.5% in the rearing cages where the ratios of the parasitoids to host larvae were 0.7 and 0.1 in the second and third years, respectively.

The average longevity of the first generation parasitoids under laboratory conditions without sugar was 10 days and with sugar-water as food was 20 days. It is possible that with a diet including nutrients other than sugars, the adults could live for more than three weeks. It seems apparent that the presence of a suitable source of food increase the effectiveness of Orgilus obscurator (Ness) (Hymenoptera: Braconidae) to a level virtually able to eliminate the European pine shoot moth, Rhyacionia buoliana (Den. & Schiff.) (Lepdoptera: Tortricidae), populations (Syme 1977).

Conclusion

Based on the results were obtained, M.versicolor could produce three generation on the same larval populations of the brown tail moth in a year. The third generation parasitoid adults were lived at the time, when new generation larvae of E.chrysorrhoea were in first and second instars.

Combination of biotic agents may enhance the success of the classical approach to biological insect pest suppression. Strategically timed augmentative releases of adult M.versicolor reared in laboratory conditions should be made against the larval populations of these pests, in attempts to inoculate parasitoid populations within non defoliating host infestations and thereby reduce the temporal lag in parasite abundance.

Literature Cited

Balachowsky A and L., Mensil 1935. Lesinsectes nuisibles aux plantes cultivées. Tome preimer, Chapitre I; Insectes nuisibles aux Cultures. Fruitiéres, Paris, 624 pp.

Burges, A.F., 1914. The gypsy moth and the brown-tail moth. with suggestions for their control. US Department of Agriculture farm Bulletin 564, 24 pp.

Burgess, A.F., S.S., Crossman, 1929. Imported insect enemies of the gypsy moth and the brown-tail moth. US Department of Agriculture, Technical Bulletin 86, 147 pp.

Cadahia, D., G Demolin and E Biliotti,1967. Meteorus versicolor var. decoloratus Rutha., a new parasite of Thaumetopoea pityocampa. Entomophaga, Paris, 1967, 12 (4), 355-361

Chao, C.-L., 1978. Memoirs of Chinese economic entomology, vol. 12. Lepidoptera, Lymantriidae. Scientific Publ. Ctr., Peking, 121 pp.

Emelyanov, I.M. and G.G. Goncharenko, 1991. Enzyme-linked assay determination of the parasitic pine lappet caterpillars Dendrolimus pini L. Doklady, Biological Science (1991) 316 (1-6) 43-46.

Eroğlu, M.,1992. [Investigations on biology and damege of Euproctis chrysorrhoea (l.) (Lep., Lymantriidae)]. Proceedings of the Second Turkish National Congress of Entomolgy, January, 28-31 1992, Adana, pp. 425-431. (in Turkish), Entomoloji Derneği Yayınları, No: 5.

Frankhanel, H., 1958: Meteorus versicolor Wesm. als parasit von Euproctis chrysorrhoea L. und Thaumetopoea processionea und seine Einsatzmoglichkeiten. Transactions, First International Conference of Insect Pathology and Biological Control, Praha 1958, proceedings, 1959, 415-420.

Griffiths, K.J., 1976: The parasites of the gypsy moth: a review of the world literature with special application to Canada. Canadian Forestry Service Sault. Str. Marie. Ontario, Report 0-X-243, 92 pp.

Griffiths, K.J.and F.W., Quednau1, 983. Lymantria dispar (L.), gypsy moth (Lepidoptera: Lymantriidae).Kelleher, J.S., Hulsie, M.a. (eds.) In: Biological Control Programmes against Insects and Weeds in Canada 1969-1980. 303-310, CAB Commonwealth Agricultural Bureaux .

Gürses, A., 1975.: Trakya Bölgesinde Altın Kelebek (Euproctis chrysorrhoea L.)'in Biyo Ekolojisi ve Savaşı Üzerinde Araştırmalar. T.C. Tarım ve Orman Bakanlığı, Zirai Müc. Ve Zirai Karantina Gn. Md.lüğü, Araştırma Eserleri Serisi, Teknik Bülten No: 8, Ankara, 78 s.

Huddleston, T., 1980. A revision of the western palearctic (Hymenoptera: Braconidae) - Bulletin of the British Museum (Natural History). Vol. 41, No. 1, pp. 1-58.

Inoue, H.,1957: A revision of the Japanese Lymantriidae (ıı). Jap. Jour. Med. Sci. & Biol. 10: 187-219.

Lipa, J.J, J Ziemnicka and J. Bartkowski, 1980. [Collapse of the outbreak of brown tail moth due to epizotic of fungus Entomopthora aulicae (Reich.) in the south-western Poland]. Ochrona Roslin No. 1: 14-17 (in Polish).

Lipa, J.J.,1996. Present status of noxious Lymantriidae in Europe and Poland. Integrated Management of Forest Lymantriidae, Proceedings of International Conference, March 27-29, 1996, Warsaw-Sckocin, Poland, IBL, Bitwy Warszawskiej 1920r, no 3, 274 pp.

Mamedov, Z.M, 1988. [Parasitoids of the brown-tail moth (Euproctis chrysorrhoea L.) and the gypsy moth (Lymantria dispar L.) in orchards of Azerbaidzhan.] Izvestiyua Akademii Nauk Azerbaidzhanskol SSR, Biologicheskikh Nauk (1988) No. 4, 75-77.

Metcalf, C.L. and W.P. Flint, 1951. Destructive and useful insects. Mc Graw-Hill Book Company Inc., New York, 457 pp.

Nam, S.-H and C.-W. Kim, 1981. A synonymic list of tussock moths (Orgyidae: Lep.) in Korean. Entomological Research Bulletin 8:73-100.

Nizamlioglu, K., 1953. Euproctis chrysorrhoea L., (Altın tüylü kelebek)'nin İstanbul'da 1949 epidemisi, Tomurcuk, 2 (14) . 14-15.

Öncüer, C., E. Yalçın and E. Erkin, 1977. Ege Bölgesinde meyve ağaçlarında zarar yapan Euproctis chrysorrhoea L. (Lep.: Lymantriidae) larvalarının doğal düşmanları ve bunların etkililik durumları. Türkiye Bitki Kor. Dergisi, 1(1): 39-47.

Reardon, R.C., M.W Statler and W.H. McLane,., 1973. Rearing techniques and biology of five gypsy moth parasites. Environmental. Entomology, 2: 981-127.

Schaefer, P.W., 1986. Bibliography of the Browntail Moth, Euproctis chrysorrhoea (L.) (Lepidoptera: Lymantriidae) and its natural enemies. Agricultural Experiment Station, University of Delawaire Newark, Bulletin 464, 66 pp.

Schaefer, P.W., 1989. Diversity in form, function, behavior, and ecology: an overview of the Lymantriidae (Lepidoptera) pf the world. Pp. 1-19. In Proceedings, Lymantriidae: A Comparison of Features of New and Old World Tussock Moths (W.E. Wallner & K.A. McManus) (eds.). USDA,NEFS. Gen. Tech. Report NE-123, Broomal. 544 pp

Schimitschek, E., 1944. Forstinsekten der Türkei und ihre umwelt. Volk und Reich Verlag Prag. Amsterdam-Berlin-Wien, XVI+371 pp.

Serafimovskki, A., 1954. Ciklus razvica topoling gubara u okolini Beograda. Zast. Bilja No. 25, 18-41.

Skatulla, U., 1978. Euproctis Hbn., Porthesia Sthp. Pp. 368-375. In " Die Forstschaedlinge Europas. Band 3. Schmetterlinge" (W. Schwenke, ed.) Parey, Berlin und Hamburg.

Sliwa, E., 1993. [More Important Pests of Deciduous Trees] Swait, Warszawa, 79 pp. (in Polish).

Sorauer, P., O. Appel and H. Blunck,., 1953. Handbuch der pflanzenkrankheiten. Band IV, Paul Parey in Berlin und Hamburtg, 518 pp.

Sterling, P.H., P.M. Kelly, M.R. Speight and P.F. Entwistle, 1988. The generation of secondary infection cycles following population of the Brown-tail moth, Euproctis chrysorrhoea L. (Lep., Lymantriidae). Journal of Applied Entomology 106, 302-311.

Syme, P.D., 1977. Observations on the logevity and fecundity of Orgilus obscurator (Hymenoptera: Braconidae) and the effects of certain foods on longevity. Canadian Entomologist 109, 995-1000.

Thalenhorst, W., 1939. Ergebnisse einer Zucht von Meteorus versicolor Wesm. (Hymenoptera: Braconidae). Arb. physiol. angew. Ent. Berllin-dahlem, Band 6, 1939, (1) 73-75.


1 Karadeniz Technical University, Faculty of Forestry, 61080 Trabzon, Turkey
Tel: 05354712390,
E-mail: [email protected]