Investigation On Natural Enemy Resources And Predatory Function Of Citrus Psylla In Ganzhou City

Diaphorina citri Kuwayama is a worldwide pest that can harm Citrus reticulata Blanco,Citrus medica,Clausena lansium,Murraya exotica and other rutaceous plants.In this study,the natural enemy insect resources of citrus psyllid were systematically investigated in citrus main areas,the information of natural enemy insect resources of citrus psyllid was analyzed,the dominant species of citrus psyllid were identified,and the dominant species were evaluated,and the pest control effects of natural enemies and local dominant species of psyllid were studied.The results are as follows:1.There are abundant natural enemies of citrus psyllidincluding the Coccinella septempunctata,Menochilus s exmaculata,Tamarixia radiate,Denopie chinensis,Harmonia axyridis,Coelophora biplagiata,Chrysoperla sinica.2.Coccinella septempunctata has obvious predatory ability to young nymphs of Citrus psylla,and its predatory ability to young nymphs of Citrus Psylla is better than that to older nymphs.There was a negative acceleration curve between the quantity of citrus psyllid and the density of citrus psyllid.The maximum daily predation of female adult ladybugs on the young and old nymphs of citrus psyllid were 336.7 and 265.3,respectively.The maximum daily predation of male adults on the young and old nymphs of citrus psyllid were 256.4 and 194.6,respectively.The maximum daily predation of female and male adults on citrus psyllid adults was 40.2 and 39.6,respectively.In terms of feeding time and instantaneous attack rate,the female of ladybug was superior to the male.3.The developmental duration of Menochilus sexmaculata was 2.82 d,1.35 d,1.17 d,1.32d,2.68d,2.55d,respectively.The average predation amount of Menochilus sexmaculata increased with the increase of prey density.The average daily predation amount of Menochilus sexmaculata of 1st,2nd,3rd and 4th instar larvae,female adult and male adult were 11.8,29.0,65.4,135.0,142.2 and 118.8,respectively,when the maximum prey density was set.The attack coefficient of the fourth instar larvae is the highest,which is 1.192.The maximum daily predation of female adults was 290.6.The instantaneous attack rate,processing time and daily maximum predation of Menochilus sexmaculata at different ages were compared comprehensively.