Zur Parasitierung der Pfennigminiermotte, Leucoptera malifoliella (Costa), (Lep., Lyonetiidae) im Havelländischen Obstbaugebiet

Abstract

On the parasitization of the Pear Leaf Blister Moth, Leucoptera malifoliella (Costa) (Lep., Lyonetiidae) in the fruit‐growing area Havelländisches Obstbaugebiet A total of 16 parasitoid species had been reared from larvae and pupae of the leafmining host. They belong to the families Eulophidae (11), Pteromalidae (2) and Braconidae (2). The species are listed in systematical order. Additional informations about bionomics and rearing experiences are included. Chrysocharis nitetis Walk. is the most frequent parasitoid of the larvae. The parasitization had been investigated in sprayed and unsprayed orchards as well as in abandoned localities, distributed over the whole region. The percent parasitism rate was very low at all sites in the first generation. In contrast to the summer time the parasitoid induced mortality reached high values in the second generation, often exceeding 50%. These alternating levels of parasitization between the generations turned out to be stable during 3 successive years of the research period. In sprayed orchards the parasitization of the host populations remained generally low during all the time. All the identified species are polyphagous parasitoids, and thus not restricted to single habitats. Consequently, the host — parasitoid interaction must be considered on a much wider spatial scale, including landscape elements outside the orchards. Zusammenfassung Der Parasitoidenkomplex der Pfennigminiermotte Leucoptera malifoliella Costa umfaßte im Havelländischen Obstbaugebiet im Untersuchungszeitraum 16 Arten der Ordnung Hymenoptera. Davon waren die Eulophidae mit 11 Arten vertreten. Wichtigster Larvenparasitoid war Chrysocharis nitetis Walk. Mit Phänologiediagrammen der häufigsten Arten werden die Schlupf‐ und Flugzeiten dargestellt. Die Parasitierung der Larven und Puppen war in der 1. Generation sehr gering. In der 2. Generation wurden Werte über 50 % an Standorten ohne Pestizideinstz erreicht. Dieser alternierende Wechsel blieb im Untersuchungszeitraum über 3 Jahre erhalten. In den Intensivanlagen war die Parasitierung ständig sehr gering und stellte einen völlig unbedeutenden Mortalitätsfaktor dar. Da die Parasitoide überwiegend polyphage Arten sind und eine geringe Habitatbindung besitzen, muß das Parasitierungsgeschehen in größeren räumlichen Dimensionen als bisher betrachtet werden, um zu einem kausalen Verständnis zu gelangen.

Temporal and spatial variations in the parasitoid complex of the horse chestnut leafminer during its invasion of Europe

“…Native leafminers are often heavily attacked by parasitoids, and parasitism rates of more than 50% are common (e.g., Askew and Shaw 1979;Cornell and Hawkins 1993;Mey 1993). In this survey, maximum parasitism rates of little more than 30% have been observed only occasionally and our study's average parasitism rate of 6.2% corresponds to previously recorded parasitism rates of C. ohridella (Freise et al 2002;Girardoz et al 2006;Grabenweger and Lethmayer 1999;Volter and Kenis 2006).…”

Impact of poor host-parasitoid synchronisation on the parasitism of Cameraria ohridella (Lepidoptera: Gracillariidae)

“…Miller, 1973;Askew & Shaw, 1979;Cornell & Hawkins, 1993;Mey, 1993). In contrast, parasitism of Cameraria ohridella is very low, parasitism levels of more than 5% are rarely recorded in Central Europe (Freise & Heitland, 2004).…”

Parasitoid complex of Phyllonorycter robiniella (Clemens, 1859) (Lepidoptera, Gracillariidae) in Serbia

“…Its parasitoids are broadly polyphagous species; in addition to Ph. robiniella, they also develop on other species of leaf miners as solitary or gregarious; primary; primary and secondary; or primary, secondary, and tertiary parasitoids (Boucˇek and Askew 1968;Graham 1969Graham , 1987Graham , 1991Pschorn-Walcher 1980;Mey 1991Mey , 1993Zverova 1992;Stojanovic´and Markovic´2004). Certain species of the parasitoids of Ph.…”