Studies of chinch bug, Blissus leucopterus leucopterus (Say), in rice, Oryza sativa L.: An integrated pest management approach.

摘要

Experiments conducted from 1993 to 1996 under controlled conditions in a greenhouse and environmental chamber at the Texas A&M University Agricultural Research and Extension Center at Beaumont were designed to identify and quantify responses of young rice, Oryza sativa L., to chinch bug, Blissus leucopterus leucopterus (Say), attack and to evaluate control tactics in an integrated pest management (IPM) context.; In the first experiments, mortality was dependent on age of plants at the time of infestation, insect density, and duration of infestation. High mortality was observed for 6 day old or younger rice infested with one and two adult chinch bugs per plant for 12 and 5 days, respectively. For plants infested from nine to 18 days of age, mortality decreased markedly, and vegetative and reproductive characteristics were negatively affected. Plants infested at 28 days of age were unaffected.; In the second experiments, development of life stages was similar for chinch bugs reared on sorghum and rice. However, mean preoviposition time was 7 days longer for females reared on rice than sorghum, but mean number of eggs laid per female was similar for both hosts.; In the third experiments, higher numbers of chinch bugs and damage were observed in young rice growing on simulated levees than in simulated paddies. Insects did not prefer dry to flooded rice, yet higher mortality was observed for dry than flooded rice. When chinch bugs were restricted to feeding on culms and roots, mortality of young rice was 50% higher than when feeding was restricted to foliage.; In the fourth experiments, fipronil and imidacloprid applied to rice seeds; and acephate, chlorpyrifos, methyl parathion, lambda-cyhalothrin, carbaryl and fipronil applied early post-emergence provided excellent control of adult chinch bugs. Post-emergence applications of Beauveria bassiana (Balsamo) Vulleim were not as effective as carbaryl.; In the fifth experiments, gibberellic acid applied as a seed treatment did not reliably ameliorate mortality or damage caused by chinch bugs.; In the sixth experiments, mortality of young rice exposed to chinch bugs was dramatically increased by propanil (a grass herbicide) injury.