Evaluation Of The Biology And Predation Of The Military Stink Bug Stethoconus Japonicus

Stethoconus japonicus Schumacher belongs to the Hemiptera Miridae,Stethoconus,and is a variety of agricultural and forestry bugs such as Stephanitis chinensis,S.nashi,S.pyriodes and Corythucha marata.One of the predatory natural enemies of pests,its biological control potential has important ecological value and economic significance for the development and utilization of predatory bugs.In this paper,the biological characteristics of S.japonicus were studied,observed S.japonicus on S.chinensis,predation of C.marata and C.cililiata designed to provide a scientific basis for biological control of pests lace bug quest.Thesis research results and conclusions obtained as follows:1.S.japonicus morphological description and annual life historyThe nymph stage of S.japonicus is divided into 5 instars.The female lays eggs in the veins or mesophyll of the plant,Infertile.S.japonicus eggs elongated oval,creamy white produced at first,the yellow-white gradation,bright red before hatching,also virgin females lay eggs,but not sterile.The main features of S.japonicus adults:scutellum microprojections,does not extend back to the top,with a pair of tan stripes,yellow-brown second antennal segment,the top one-third of its dark.S.japonicus occurred 3 to 4 generations in the previous year Guiyang Platanus acerifolia to eggs overwinter.2.Effects of temperature on the development and reproduction of S.japonicusWithin the constant temperatures ranging from 15 to 35?,the average duration of various developmental stages of S.japonicus shortened as the temperature rose gradually.S.japonicas needed 86.27 d to complete a life cycle at 15?,while needed21.35 d at 35?.The surviving rate of eggs,nymphs,egg-adults,pre-laying stage and generations of S.japonicus increased first and then decreased with increasing temperature.The survival rate was the highest at 25?.The development starting temperature of the whole generation of S.japonicus was 10.59?,and the effective accumulated temperature was 550.22 day-degree.With the increase in temperature,the life span of adults and female spawning period was gradually shortened.The life span of females is longer than that of males.With the increase in temperature,the life span of adults and female spawning period was gradually shortened.The life span of females was longer than that of males.The average egg production of eggs laid per female was the largest at 25?,218.36,and the lowest at 35?was 47.62.The highest population trend index of S.japonicus was I=18.01 at 25?,which was 2.05 times higher than20?,and 7.97 times higher than 30?,respectively.The optimal temperature for nymph development,survival,adult reproduction and population growth of S.japonicus is 25?.3.S.japonicus of three important lace bug pests prey preferencesNon-selective experiments showed that the 3^rd instar nymphs of S.japonicus had the largest daily predation on the younger nymphs of S.chinensis,C.cililiata and C.marata,which were 4.2 individuals/d and 3.8 individuals/d and 2.1 individuals/d,respectively.The females of S.japonicus have the largest daily predation on adults of S.chinensis,C.cililiata and C.marata,which are 3.8 individuals/d,4.2 individuals/d and 2.6 individuals/d,respectively.Selectivity tests showed,S.japonicus instar nymphs of 1^st,5^th instar nymphs and females prefer S.chinensis,C.cililiata,liking for the positive,negative for C.marata liking.4.S.japonicus predation of three kinds of lace bugs evaluationThe 3^rd,4^th,5^th instar and females of S.japonicus have predatory functional responses to S.chinensis,C.cililiata and C.marata,all conforming to the Holling-?model.The predation efficiency of S.japonicus 3^rd,4^th,5^th instar nymphs and female adults on the above three Tingidae species increased with the increase of insect instars.The predatory efficiency of different insects(instar)states were female adults>5^th instar nymph>4^th instar nymph>3^rd For young nymphs,the hunting effect gradually decreases with the increase of prey density,and it decreased linearly.