Analyses of Numerical Responses and Main Life Parameters for Determining the Suppression of Amblyseius cucumeris on Panonychus citri

In this paper, the numeral response and main parameters of experimental population life table were analyzed for determining the suppressing ability of Amblyseius cucumeris on Panonychus citri. The result showed that: (1) Under 21-31°C and 1 - 9 prey densities/leaf fragment condition, the prey consumptions of A. cucumeris increased with the temperature or prey density; (2) In 1:3 predator-prey ratio treatment, the suppression of P. citri (Ro=34.0053; T=19.4369; t=3.8204) was rather weak, it was enhanced as the ratio over 5:30, and the populations of P. citri in these treatments can be fully controlled within 4-5 days; (3) Under 25±1°C, 80-85% RH and 15L: 9D illumination conditions, the net reproductive rate, mean generation duration and the time for population double increase of P. citri (Ro=34.0053; T=19.4369; t=3.8204) were higher than those of A. cucumeris (Ro=21.8750; T=16.8943; t=3.7954). While the intrinsic rate of increase and finite rate of increase of the former (rm=0.1814; λ=1.1989) were lower than those of the latter (rm=0.1826; λ=1.2004). These results indicated that A. cucumeris is a desirable bio-control agent to suppress P. citri at lower population stage in citrus orchard.

Integrated Control of Tetranychus cinnabarinus by Five Kinds of Pesticides Combined with Neoseiulus cucumeris

To find the method for the integrated control of Tetranychus cinnabarinus （carmine spider mite） and delay its resistance to pesticides, the joint actions of each of five commonly pesticides （abamectin, azadirachtin, matrine, pyrethrins and imidacloprid）, and Neoseiulus cucumeris （Oudemans）, the natural enemy of cotton red spider mite, were studied. N. cucumeris was released after application of pesticides for seven days （for 0,3% azadirachtin EC） or six days （for other pesticides）. The results showed that the combined action of 1.8% abamectin EW （1：8 000） and N. cucumeris had the best control efficacy of 96.63% at 20 days after N. cucumeris releasing. The control efficacies of N. cucumeds and 0.3% azadirachtin EC （1：250） were 59.7% and 90.1% after one day and 20 days, respectively, after N. cucumeris releasing. The control efficacy of N. cucumeris and 0.5% matrine AS （1：2 000） was 82.65% at 20 days after N. cucumeris releasing. The results provide options for sustainable control of T. cinnabarinus and for the delay of pesticides resistance.

Effect of Neoseiulus cucumeiris Carrying Paecilomyces fumosoroseus on the Prevention of Aphids and Spider Mites in Eggplant

Using predatory mites Neoseiulus cucumeris Oudermans dusted with en- tomopathgen Paecilomyces fumosoroseus （Wize） Brown ＆ Smith to control aphids and spider mites is a new idea of biological control. Some studies were conducted to confirm the feasibility of this idea. The germination condition of P. fumosoroseus conidia was determined by the method of different saturated salt solutions applying different humidity in small containers, and the pathogenicity test and the pot experi- ment were also conducted, under a suitable condition. There were 6 treatments for pot experiment as following： （1） CK; （2） releasing 50 N. cucumeds, （3） spraying 20 ml of 10^7 spores/ml conidial suspension; （4） releasing 50 N. cucumeris after spraying 20 ml of 10^7 spores/ml conidial suspension; （5） releasing 20 N. cucumeris dusted conidia of P. fumosoroseus; and （6） releasing 50 N. cucumeris dusted with conidia of P. fumosoroseus. The result showed that the germination condition of P. fu- mosoroseus conidia was 25-30 ℃ and 95%-100% RH, and under this condition, the 10s spores/ml conidia suspension caused a mortality of 86.52% in aphids and 41.78% in predatory mites after ten days. From the pot experiment, the numbers of aphids of treatment （3）, （4）, （6） were close to 0 at the 8th day. This study proved that the predatory mites N. cucumeris dusted with the entomogenous P. fu- mosoroseus could provide satisfactory control on both aphids and spider mites in potted eggplants under suitable temperature and humidity. The predatory mite vec- toring entomopathogen system could provide an economic and labor saving way for aphid control.

Investigation of Optimal Charcoal Concentration for Heterokaryon Formation of Rhizoctonia solani

Optimal charcoal concentrations were examined for tuff formation of SBIs （single-basidiospore isolates） obtained from Rhizoctonia solani AG-1 IC, AG-2-2 IV and AG-2-3, and SPIs （single-protoplast isolates） from AG-1 IA by using PDCA with different charcoal concentrations. The best charcoal concentration for SBIs from AG-1 IC was 0.5%, from AG-2-3 was 1%, and from AG-2-2 IV was 2%. The optimal concentration was 0% for SPIs from AG-1 IA. The optimal charcoal concentrations used for tuff formation between SBIs and between SPIs are quite varied, depending on the different AGs. The results of AFLP haplotypes suggest that tuff isolates formed between SBIs/SPIs are heterokaryon.

水稻3种重要病原真菌遗传多样性的研究进展

稻巨座壳菌(Magnaporthe oryzae)、瓜亡革菌(Thanatephorus cucumeris)和稻麦角菌(Claviceps virens)分别是引起稻瘟病、水稻纹枯病和稻曲病这3种重要水稻病害的病原真菌.文章简要介绍了真菌遗传多样性研究的意义,全面综述了近10年来这3种水稻重要病原真菌遗传多样性的国内外研究进展,并对该领域未来的研究方向进行了展望.