Parasitoid assemblages reared from geometrid defoliators (lepidoptera: geometridae) of larch and fir in the alps

Abstract

1 Geometrid larvae were collected from larch and fir in the Swiss Alps in 1991-94. Eight geometrid species were found in sufficient numbers to rear out parasitoids: Agriopis aurantiaria, Bupalus piniarius, Epirrita autumnata, Eupithecia lariciata, Odontopera bidentata, Lycia isabellae and Semiothisa liturata were collected from larch, and Puengeleria capreolaria was obtained from fir. 2 Parasitoid species belonging to five different guilds and four families were obtained; however, the taxonomic status of some of these is not completely resolved. 3 The parasitoid complex of the larch-feeding species was totally different from that of Tortricidae and Tenthredinidae, which feed on the same host tree. In general, there was little overlap in the parasitoid complexes of the larch geometrids, with the most dominant parasitoid of each species reared from only one host. By contrast, many parasitoid species found during our study are also known to attack the same hosts or closely related hosts on different host tree species in different environments, suggesting that host specificity in geometrid parasitoids is more related to host taxonomy than to host plant or habitat.

How rapidly do invasive birch forest geometrids recruit larval parasitoids? Insights from comparison with a sympatric native geometrid

“…and various fruit trees]. The only relevant study for A. aurantiaria was Kenis et al (2005), dealing with parasitism of both A. aurantiaria and E. autumnata on European larch (Larix decidua Mill.) in Switzerland.…”

“…Therefore, we excluded parasitoid species which had not been reared in any of the studies we surveyed, but which some of the authors reported to have been encountered in earlier investigations within their study region. We also excluded parasitoids which had not been identified beyond the family level and which were ambiguous as to the number of species they represented [relevant only for about ten specimens in Kenis et al (2005)]. Finally, we excluded five parasitoid species which Wylie (1960) reported to have reared from a single O. brumata larva each, but which had not been recorded in any of the other studies.…”

“…The sample sizes of Kenis et al (2005) were a total of 6,258 A. aurantiaria larva and 2,498 E. autumnata larvae, sampled from seven and ten different locations, respectively. Ten different larval parasitoid species were reared from A. aurantiaria, including five ichneumonids, four braconids and one tachinid (Table 4).…”

“…(Autumnal moth), a native species; Operophtera brumata (L.) (Winter moth), an invader from the south that expanded its range into this system about a century ago [first recording near Tromsø (69°40 0 N) in 1892]; and Agriopis aurantiaria (Hübner) (Scarce umber moth), another southern species that invaded by range expansion only about 15 years ago [See Jepsen et al (2011) for details on geometrid invasions in this system]. Both O. brumata and A. aurantiaria are well known pests of broadleaved trees in their native ranges further south in Europe (Kenis et al 2005;Cross et al 1999), and their parasitoid complexes in these ranges have been surveyed as part of biological control programs and ecological studies. Thus, this three-species geometrid system offers an excellent opportunity to compare parasitism between native and invasive hosts within the invaded range, as well as between invasive hosts in their native and invaded ranges.…”

Homolobus (Phylacter) meridionalis van Achterberg, 1979 (Braconidae, Homolobinae) in Iran: the first record from Asia

“…The genus Homolobus Förster, 1862 is the largest genera of the subfamily with about 55 known species in the world and 20 species of it are known in the Palaearctic region (Yu et al, 2012). Members of Homolobus are solitary koinobiont endoparasitoids of Lepidopteran larvae (Shaw & Huddleston, 1991;Kenis et al, 2005), but has a final ectoparasitic phase (Allen, 1982). They are nocturnal parasitoids, usually attacking caterpillars various species of Geometridae and Noctuidae (Shaw & Huddleston, 1991).…”