| 1. The time-series dynamics and spatial pattern of Spider mites, Tydeus sp. and Euseius finlandicus population in apple tree garden were analyzed by calculating five indices of aggregation and parameters of Iwao model.The results as following.1.1 Spider mites were main prey of E.finlandicus. Peak periods of the number of spider mites population was July 1st in natural apple tree garden which kept active jamming in lower. The number of spider mites population was decrased with increasing of E.finlandicus population from the middle ten days of July to the middle ten days of October. The spatial pattern of spider mites population in apple tree garden belonged to an aggregated distribution pattern and distributed with basic component of individual colony. Its aggregation intensity decrased from July to September, and then increased from September 1st to the middle ten days of October.1.2 Tydeus sp. were main supplement prey of E.finlandicus.The number of Tydeus population was rapidly increased from July 1st to August 1st. Peak periods of Tydeus population was August 1st. The number of Tydeus population decreased from September 1st to the middle ten days of October. the reason was the number of spider mites population decreased and predation of E.finlandicus on Tydeus sp. The spatial pattern of Tydeus in apple tree garden belonged to an aggregated distribution pattern except lower crown which belonged to an uniform distribution pattern. The population distributed with basic component of individual colony. Its aggregation intensity kept in a certain level from July 1st to October 1st, and then increased in lower, east, north crown from October 1st to the middle ten days of October.1.3 Peak periods of E.finlandicus population was the middle ten days of July to the middle ten days of August. The number of E.finlandicus population was inferior to the population of spider mites and Tydeus sp. in July 1st, and then mainly increased with the number of spider mites and Tydeus population after the middle ten days of July. The number of three mites population kept in balance relatively from September 1st to October 1st. The population repelled each other in the upper, north and inner crown of apple tree. The population attracted each other and distributed with basic component of individual colony in the middle, lower, east, south and west crown of apple tree. The spatial pattern of E.finlandicus in apple tree garden belonged to an aggregated distribution pattern. Its aggregation intensity was decreased from from July to October, and then gradually increased from October 1st to the middle ten days of October.1.4 The number of spider mites population was decreased, Tydeus sp. population was increased initiatly, and E.finlandicus population was decreased compared with former period in the first ten days of July. Peak period of the number of Tydeus and E.finlandicus population was August 1st, and the number of Spider mites population was decreased continued. The number of E.finlandicus population was decreased with decreasing of the number of Tydeus sp. and spider mites population after the middle ten days of August. The number of three mites population kept in lower balance level in September 1st, and then decreased in minimum in the middle ten days of October account for they turned into overwintering period. The variation of E.finlandicus population aggregation intensity was connected with the variation of Tydeus sp. population aggregation intensity.2 .The predation of E.finlandicus female on Aleuroglyphus ovatus female, Tydeus sp. female and Tetranychus truncates (Ehara) female was examined at (25±0.5)℃temperatures under the RH85%.The results showed that predatory function to prey density can be imitated by Holling typeⅡ. Predation ability that E.finlandicus on Aleuroglyphus ovatus was maximum, Tydeus secondly and T.truncates (Ehara) was minimum. With a fixed number of prey available, predation rate per predatory decreased with the increase of predator density.3. The predation of A.barkeri (Hughes)female on T.truncates (Ehara) at three stages (adult female, nymph and egg) was examined at five constant temperatures (16, 20, 24, 28 and 32℃) under the RH85%.The results showed that predatory function to prey density in above temperatures can be imitated by Holling typeⅡ. At each temperature predation ability that A.barkeri (Hughes) on egg was maximum, nymph secondly and adult female was minimum. At the range of 16～28 temperatures, a/Th value is increased with increasing temperature. Pick period was 28℃, and then decreased above 28℃.With a fixed number of prey available, predation rate per predatory decreased with the increase of predator density. |
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