Study on different methods of ovarian induction in diapausing female adults of the sunn pest Eurygaster integriceps
Sara hkodahemmati1, Morteza Allahyari2 and Mohammad Hadi loghmanisarvestani3
1- Beijing Universiry Of Tecnology, PhD Student, 2- Fars agricultural and natural resource research center, plant protection department, 3- Beijing Universiry Of Tecnology
Sunn pest lives nine months of a year in a reproduction diapause and this leads to survival of pest populations until next year. Thus realizing diapause mechanisms can help to develop new control methods. In this research some experiments performed to induce ovarian development in diapausing females including different juvenoids treatments, corpora allatum transplantation, destruction some regions of brain and maintaining of diapausing adults in incubator to pass diapause. Results showed that applying 400 ppm pyriperoxyfen led to laying viable eggs. Also topical application of 20 ppm fenoxycarb (AI) led to ovarian development and egg formation whereas Metoprene (AI) application had no effect. In addition higher doses of fenoxycarb had lethal effect so the LD50 for male and females were 29.626 and 31.634 ppm respectively. Also Corpora allatum transplantation and destruction a region of brain led to development of ovary and egg formation. So a brain factor may be involved in diapasue maintenance in females. Adults obtained from rearing of nymphs that were maintained in an 14ºC dark incubator for two months and then in an 4ºC dark incubator for three month, mate and laid viable eggs after transfer to an incubator adjusted to 27ºC and 14:10 photoperiod.
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