Abstract: Based on the investigation data of oriental migratory locust occurrence and corresponding meteorological records, a comprehensive analysis was made on the relationships between the occurrence of the locusts and the climate factors in coastal and low-lying locust areas around Bohai Bay. The difference in the locust occurrence between these two areas was mainly due to the effects of climate factors, and air temperature was the main one. The air temperature in March and April was 02 ℃〖KG-*2〗-〖KG-*7〗04 ℃ lower in coastal than in low-lying locust area, resulting in 2〖KG-*2〗-〖KG-*7〗3 days delay of the occurrence of summer locust nymphs before third phase in coastal locust area. In other months, the air temperature in coastal locust area was higher, and due to the accumulative effect of air temperature, the occurrence of summer locust nymphs after third phase took place earlier. The occurrence of autumn locusts had a smaller variation than that of summer locusts, which was corresponded to the small change of air temperature in summer. The different change pattern of air temperature in the coastal and low-lying locust areas around Bohai Bay since the 1990s was the main cause for the variations of locust phase, and the summer locust occurrence happened sooner or later was closely related with the air temperature in March and April.

Key words: Pig manure, Heavy metal, Earthworm, Acute toxicity