Life history of rice leaf aphid, Rhopalosiphum padi L. (Hemiptera: Aphididae) on wheat under laboratory conditions
عنوان دوره: دومین کنگره بین المللی حشره شناسی ایران
نویسندگان
چکیده
Rice leaf aphid, Rhopalosiphum padi L. is often considered as a major pest in cereals in temperate cereal crops. It is the principal vector of many viruses especially the barley yellow dwarf virus (BYDV). Life history of apterous morph of this aphid was studied in a laboratory condition with temperature of 20 ± 1˚C, 60-70% relative humidity, and a photoperiod of 16:8 (L:D) hours. The experiment was carried out by rearing 50 first instar aphid nymphs in leaf cages on wheat (Triticum aestivum cv. Mahdavi). Biological characteristics of the aphid were daily recorded and used for estimating population increase parameters according to Carey (1993). Mean nymphal developmental time of rice leaf aphid was obtained 9.67 ± 0.15 days. Mean longevity and fecundity were 32 ± 11 days and 37 ± 3.91 nymphs per female, respectively. Adults reproduced during most of their lifespan. Survival curve of R. padi on wheat was determined as Type І. Based on the age specific survival of aphid, it was clear that nymphs and young adults didn’t suffer high mortality which is similar to the development of herbivorous insects on susceptible host plants. The study on stable population parameters revealed that each female produced 36.56 female in next generation (R0). Intrinsic rate of increase (rm) was 0.231 female per female per day. Estimating the finite rate of increase (λ) was also indicated 26% increment in aphid population per day. In conclusion, results of studying demographic parameters of R. padi showed that population increase capability of the aphid on Mahdavi wheat cultivar was similar to that on susceptible ones.
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