Biology of Parapodia sinaica (Lep.: Gelechiidae) in Qom province

Parapodia sinaica Frau. is among one of the important pests of tamarisk (Tamarix spp.) in Qom province. During 2000-2003, the biology of this pest was studied by periodic samplings of its different life stages every 15 days using light traps in natural tamarisk fields (Masileh region - Qom salt lake) and rearing some life stages in transparent dishes containing a tamarisk stem in laboratory conditions (50 ± 5% RH, 25 ± 1ºC and a photoperiod of 16L: 8D h.). P. sinaica overwinters as 4th or 5th larval instars in the galls. In early March, larvae change into pupa and the pupal period lasts 52 ± 5 and 44 ± 3 days in field and laboratory conditions, respectively. Flight peak of the adult moth took place in early May. The moth being fed on water and sugar survived 14 ± 3 days and preoviposition period lasted 2.3 ± 0.49 days. Average egg number deposited by a female in natural conditions was 32 ± 7. Oviposition period lasted 7.2 ± 0.83 days and incubation period of eggs was 29 ± 3 and 25 ± 2 days in the field and laboratory conditions, respectively. This insect has five larval instars and the mean developmental time of the first to the fifth larval instars were 63 ± 5, 46 ±.34, 44 ± 3.8, 50 ± 5.3 and 97 ± 6.2 days, respectively. The pest has one generation in a year. Larvae never feed on the wood but they feed on bark and cause die back of the branches in the end of the next year. Activity of this pest was also observed in Isfahan, Khuzestan, Qom and Yazd provinces.