Comparision In Insect Communities And Abundances Of Main Species In Paddy Fields Between Two Solar-Energy Powered Light Traps

This study was to compare two light traps differed in light wavelength—570-630 nm (orange-yellow light trap) and 400-470 nm (blue-purple light trap) in their catching insect communities in paddy fields. The survey was made from July 7 through to September 9,2013 in the paddy field under organic management, Yangzhong city, north Jiangsu. Insects caught by the two light traps were identified as species and recorded as individuals. Following results and conclusions are reached.1. Insect communities caught in different wavelength traps in paddy fieldThe orange-yellow light trap caught 10,252 individuals, belonging to 58 families in 7orders, among which Hemiptera was most abundant (5,542). The blue-purple light trap caught 150 individuals, belonging to 52 families in 6 orders, among which Coleoptera was most abundant (10,003). The two light traps collected a total of 62 species from 33 families in 7 orders, including 25 beneficial,8 neutral and 29 pest species. The blue-purple light caught 17 beneficial,8 neutral and 27 pest species, the orange-yellow light caught 25 beneficial,8 neutral and 29 pest species.Species diversity parameters were 1.8959 in Shannon diversity,0.2935 in Simpson dominance,52 in species richness, and 0.5010 in Pielou evenness, for insect communities in the orange-yellow light trap; they were 2.4902 in Shannon diversity,0.1214 in Simpson dominance,58 in species richness, and 0.6652 in Pielou evenness, for insect communities in the blue-purple light trap.2. Abundances for dominant and economic insect species in different wavelength traps in paddy fieldThe dominant species in the blue-purple light trap included Eusphalerum sp. (Coleopterous:Staphylinid), Corixa substtiata (Heteroptera:Corixidae) and Microvelia douglasi (Hemiptera:Gerridae). The dominant insects in the orange-yellow light trap comprised Lissorhoptrus oryzophilus (Coleoptera:Curculionidae), Erythroneura apicalis (Hemiptera:Cicadellidae), Nymphula responsalis (Lepidoptera: Pyralididae), Microvelia douglasi (Hemiptera:Gerridae), and Telmatoscopus albipunctata (Diptera:Psychodidae). The orange-yellow light trap caught four abundant insect species:320 individuals in Lisstorhoptrus oryzophius (Coleoptera:Curculionidae),277 in E. apicalis (Hemiptera:Cicadellidae),182 in Cnaphalocrocis medinalis (Lepidoptera: Pyralididae), and 188 in Naranga aenesc (Lepidoptera:Pyralididae), and the blue-purple light trap captured 1,201,1,521,125, and 146 in these species, respectively.The study comes to the conclusion that the orange-yellow light trap can catch more pests and less beneficial insects than can the blue-purple light trap, and therefore be more useful in pest control practices.