Studies On The Occurrence And Chemical Control Of Pealius Spina In Xiamen

Pealius spina (Singh)(Homoptera:Aleyrodidae) is an important whitefly pest on bodhi tree(Ficus religiosa Linn.), which was originally found in India and invaded into Taipei City of Taiwan, China in1988. At present there is no research reports on P. spina in mainland China. This work dealt with the outbreak regularity and spatial distribution, investigation of parasitic wasps, and screening of pestisides for P. spina in order to find out the effective measures to control the damage and spread of P. spina pest in Xiamen City of Fujian Province. The results were as follows:1. The population dynamic of the nymphs and eggs of P. spina were consistent between Hu Ming Road and Bai Luzhoug Rroad, which had about4peak of occurrence, and August, September and October were the serious injury stage. P. spina developed about5generations a year, of which the fourth generation had the highest population, and started into overwinter in mid December in Xiamen City.2. The spatial distribution of nymphs of P. spina belonged to the aggregated distribution on both leaf surface and back, and its basic element of distribution was individual clusters which increased with the nymph density. The nymph and egg number of P. spina at Hu Ming Road and Bai Luzhoug Road were difference. The individual clusters of nymphs of P. spina on the leaf surface in Bai Luzhoug Road was more than that at Hu Ming Road, while the similar of the eggs.3. Through the survey and identification, we found5species of parasitoids of P. spina in Xiamen City, which respectively belong to Encarsia (2species) and Eretmocerus (1species) in Aphelinidae, Baeoentedon (1species) in Eulophidae, and Amitus (1species) in Platygasteridae. But so far the predatory natural enemies have not been found.4. By comparison with the toxicity test on Cyhalothrin, Emamectin benzoate, Acetamiprid, Endosulfan and Thiazine methidathion, the toxicity to P. spina shown that: Emamectin benzoate> Acetamiprid> Thiazine methidathion> Endosulfan> Cyhalothrin.1.14%Emamectin benzoate and6%Acetamiprid had good poison effect for P. spina, So we recommend1.14%Emamectin benzoate (effective ingredients dosage4.56mg/L) with2500times and6%Acetamiprid (effective ingredients dosage24.00mg/L) with2500times to control P. spina.