Insect Identification And Effect Of Some Factors To Attracting Insects On Solar Light Trap In Tobacco Filed

Insect light trap is an important measure of physical control and there are many factors affecting the attraction of insects. In this research the basin type and electrified-net type of solar light trap were selected, and used in tobacco fields in Sangzhi, Ningxiang, Guiyang, Liuyang and Leiyang in Hunan province in China during the year2010to2011. Geographical environment, distance, wavelength and other factors were studied and suggestions put forward for improvement on the design and use of solar light trap.1. A list of insects in7orders,52families and208genus were obtained through a survey in samples. There were67species of non-phototactic insects, accounting for32.21%,141species of phototactic insects, accounting for67.79%and10insects were newly recorded in Hunan province:Diaperis lewisi intersecta Gebein, Heterotarsus carinula Marseul, H. pustulifer Fairmaire, Euhemicera sakishimensis (Chujo), Leiochrinus sp., Ancylopus phungi Pic, Sinocymbachus humerosus (Mader), Aulacochilus luniferus (Guerin-Meneville), A. sibiricus (Reitter) and Clerus sinae (Chapin).12insects were newly discovered as potential tobacco pests: Hoplosternus chinensis (Guerin-Meneville), Megistophylla grandicornis (Fairmaire), Holotrichia szechuanensis Chang, Anomala aulax Wiedeman, A. coxalis Bates, A.viridicostata Nonfried, A. virens Lin, Gonocephalum coriaceum Motschulsky, Heterotarsus carinula Marseul, H. pustulifer Fairmaire, Agrypnus davidi (Fairmaire), Aeoloderma agnate (Candeze).2. The species of insects in five samples were156,89,64,57and37respectively. There were118species of insects attracted by the basin type solar light trap and95species of insects attracted by the electrified-net type solar light trap,72species insects were attracted by both of them. The more fine the environment, the more insects attracted.3. Pests of tobacco were mainly Gryllotalpa orientalis Burmeister and scarabaeid. In scarabaeid, Anomala corpulenta Motschulsky and A. coxalis Bates were the most, the followed were A. aulax Wiedeman and Megistophylla grandicornis (Fairmaire). Natural enemies were mainly Carabidae, Staphylinidae, Cicindelidae and Reduviidae. The neutral insects were mainly Hydrophilidae, Stenelmis, Heterocerus and Scarabaeinae.4. There were two distances of the basin type solar light trap set in tobacco fileds at120m and180m, the weight of phototactic insects and the number of Gryllotalpa orientalis and Agrotis ypsilon of the former were more than the latter, the number of Helicoverpa assulta was no significant difference between the two, all of them were not significant (P<0.05). 5. Total weight of phototactic insects of20electrified-net type solar light traps in different wavelengths. The numbers of Gryllotalpa orientalis, Anomala corpulenta, A. coxalis, Exolontha serrulata, Sirthenea flavipes, Cicindelidae, Onitis falcatus, and Hydrophilidae were compared. Short-wavelength traps attracted insects more than long-wavelength traps. The linear regression results showed that the trapping volume and the wavelength was inversely proportional to the level, total average weight and number of Anomala coxalis were very significant (P<0.01). The number of Anomala corpulenta and Onitis falcatus were significant (P<0.05) but the rest were not significant (P>0.05).6. The time of insect flying to lights before midnight was observed in the summer. Most insects flew towards the lights within a time of30min to1.5hr after lights were put on. Most Gryllotalpa orientalis flew towards the lights from20o’clock to21o’clock, most Agrotis ypsilon flew towards lights from21o’clock to23o’clock and Helicoverpa assulta had no significant difference in its preferred time of moving towards the light.