This study was carried out to improve the rearing methods of endoparasiteHyposoter didymator(Thunberg) for biological control release. The growth and the development ofH. didymatoron the first, second, and third instars ofSpodoptera littoralis(Boisduval) andHelicoverpa armigera(Hübner) under laboratory conditions were investigated. Results indicated thatS. littoraliswas a suitable host for the rearing of H. didymator The development time of the parasite on the second instar of both hosts was almost the same (∼17 d). The age of the female parasite affected the percentage of adult emergence, pupal mortality, and females in the offspring reared onS. littoralishost. The best copulation period ofH. didymatorfemales and males was 36 h that resulted in 51.8% of females in the offspring. The male to female ratio during copulation period, as well as the presence of males after copulation, and the number of host larvae for each parasite female had no effect on parasitism. Results suggested thatS. littoralissecond instar is a suitable host for mass rearing ofH. didymatorparasite, which may improve the use ofH. didymatoras a biocontrol agent.
The study was done in the laboratories of Bollworms, Leafworm and piercing & sucking Research Departments of Plant Protection Research Institute during 2010. The tested pests and the biocide, Protecto were exposed to gamma irradiation doses at National Center for Radiation Research and Technology, Egypt. Three tested insects were tested includes: pink bollworm, Pectinophora gossypiella (Saund.) newly hatched and fourth instar larvae, cotton leafworm, Spodoptera littoralis (Boisd.) 4 th instar larvae and the nymph & adult of cowpea aphid, Aphis craccivora (Koch). Insects were exposed to three doses of gamma irradiation, 150, 250 & 350 Gy. Also, the biocide compound, Protecto (Bacillus thuringiensis, Kurs.) was applied on the same pests to assess the insecticidal activity of Protecto in three combinations (Protecto +150 Gy, Protecto +250 Gy and Protecto +350 Gy). Data showed that the tested γ-irradiation doses of 150, 250and 350 Gy increased the newly hatched larval mortality of P. gossypiella to 52, 65 and 85% at zero day, respectively. While, it was reached to 100% kill at third day for 350 Gy and fifth day for 150 and 250 Gy. Larval mortality of P. gossypiella fourth instar was reached to 100% at eight and tenth days after radiation. Also, the larval mortality of S. littoralis fourth instar larvae was reached to 100% at tenth and twelfth days after treatment, respectively.While, A. craccivora adults and nymphs mortality was reached to 100% at zero day just after treatment. Generally, LC 50 , s on subjected insects treated with Protecto and exposed to gamma doses were lower than untreated Protecto.The aim of present work was to evaluate the insecticidal activity of the biocide Protecto in combination with γ-irradiation exposure against three key insect pests in laboratory.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.