اثر گونه های میزبان روی برخی از ویژگی‌های زیستی Compsilura concinnata (Diptera: Tachinidae)

Dipteran parasitoids are the second most crucial group of parasitoid insects, which are far less studied than hymenopterans due to their relatively low species number. The Tachinidae is the largest and most important family of dipteran parasitoids that comprises approximately 1500 valid genera and more than 8500 described species in the world. Compsilura concinnata (Meigen) (Diptera: Tachinidae) is a larval, gregarious, polyphagous, and endoparasitoid of Lepidoptera, Hymenoptera, and Coleoptera which is recorded on about 289 host species. The biology and ecology of C. concinnata have received little attention; therefore, the current experiment aimed at the acceptance and suitability of four key insect pests including, the small white butterfly Pieris rapae (L.)(Lepidoptera: Pieridae), the tobacco caterpillar Spodoptera litura (Fabricius)(Lepidoptera: Noctuidae), the Colorado potato beetle Leptinotarsa decemlineata (Say)(Coleoptera: Chrysomelidae), and the elm leaf beetle Pyrrhalta luteola (Muller)(Coleoptera: Chrysomelidae) as host species for C. concinnata. For each host species, 10 last instars of host larvae (preferred stage) were exposed daily to a pair of parasitoids for 2 hours inside the ventilated Plexiglas cage (45×35×35 cm) until the parasitoid died. The experiment was performed at a standard environmental condition (26±1 °C, 65±5% RH, and 16:8 L:D photoperiod) with 20 pairs of adult parasitoids per host species. Different parameters of C. concinnata, including larval and pupal development period, adult longevity, adult emergence (%), puparium weight (female), sex ratio (female-based), host larval mortality (%), percent parasitism, and fecundity (larvae/female) were evaluated. Our results showed that C. concinnata cannot parasitize larval stages of L. decemlineata and P. luteola. In biological traits of the parasitoid, a significant difference was observed in percent parasitism and host larval mortality. The biological parameters of C. concinnata on P. rapae and S. litura were estimated as 10.3 ± 0.33 and 11.2 ± 0.32 (day) for larval development period, 11.45 ± 0.29 and 12.25 ± 0.30 (day) for pupal development period, 13.9 ± 0.67 and 12.7 ± 0.65 (day) for adult longevity, 93.3 ± 0.44 and 92.13 ± 0.47% for adult emergence, 46.27 ± 0.13 and 45.97 ± 0.27 (mg) for female puparium weight, 52.21 ± 0.56 and 54.08 ± 0.76% for sex ratio (females), 62.26 ± 0.88 and 65.82 ± 1.46% for host larval mortality, 54.21 ± 0.84 and 58.37 ± 1.19% for percent parasitism, and 111.95 ± 8.95 and 105.7 ± 8.96 for fecundity (larvae/female), respectively. This finding indicates that C. concinnata could effectively contribute to lowering the population size of P. rapae and S. litura; however, Further studies must be done in field conditions to apply C. concinnata successfully in biological control programs against these two key pests. Moreover, the current result demonstrates the possible benefits of using P. rapae and S. litura as the rearing hosts for C. concinnata.