稻秆潜蝇的生物学与生态学特性研究

BIOLOGY AND ECOLOGY OF RICE STEM MAGGOT ( CHLOROPS ORYZAE )

稻秆潜蝇在重庆市已由次要害虫上升为主要害虫,该虫在重庆地区1年发生3代,以第3代幼虫越冬。越冬代幼虫在3月下旬化蛹,4月中旬至下旬为第1代成虫期,5月上旬为产卵期。5月上旬至6月上旬为第1代幼虫期,6月上旬至下旬为蛹期。第2代成虫期为6月下旬至7月中旬,7月上、中旬为产卵期,7月中旬至8月上旬为幼虫期,8月上旬至下旬为蛹期。第3代成虫期为9月上旬至下旬,并迁至越冬寄主上产卵,10月初至11月底孵化为幼虫进入越冬期。成虫羽化后l～2 h即可交配,但多数于羽化后1～3 d才交配。交足后越冬代于4～9 d,第2代于3～7 d后产卵,一般1叶仅产1卵,偶有数粒。单雌产卵量2～81粒不等。成虫寿命为20 d左右。

Three generations of rice stem maggot ( Chlorops oryzae), which has recently been become a dominant pest for rice crops in Chongqing) were found in the present investigation to occur in a year. The over- wintering generation is the third generation of the larvae, which pupate in late March. The first adult stage lasts from mid to late April and its laying stage lasts from early to mid May. The larval stage starts in early May and ends in early June to mid July with its pupal stage lasting from early to late June. The second adult stage lasts from late June to mid Jjuly and its laying stage lasts from early to mid July. The period from mid July to early August is the laval stage with its pupal stage lasting from early to late August. The thin] generation of the adult lasts from early to late September and then they get to the overwintering hosts and lay eggs in them. The larvae appear in eariy October to late November. Some adults start o copulation as early as 1 to 2 hours after emergence while most of them copulate 1 to 3 days later. The overwintering generation and the second generation lay eggs about 4 ~ 9 and 3-7 daysi respectively, after copulation . Usually only one egg is laid on a leaf, however, several eggs are occasionally found on one leaf. The number of eggs laid by a female ranges from 2 to 81. The longevity of the adults averages 20 days.