The Controlling Effect Of Eocanthecona Furcellata(hemiptera:pentatomidae)on Spodoptera Litura Population(lepidoptera: Noctuidae)on Dendrobium Officinale

The stink bug Cantheconidea furcellata(Wolff)is a potential insect pest controlling Lepidoptera,Coleoptera and Hemiptera pests.The use of stink bug to control the Spodoptera litura(Fabricius)on the Dendrobium officinale Kimura et Migo will help to reduce pesticide residues,protect the environment,and be safe for human and animal.In this paper,the biological characteristics of S.litura on D.candidum were observed;and the control effect of the stink bug on the population of D.candidum by using the life table was evaluated;the predation functional response of C.furcellata on S.litura larva were studied,with the method of three factors parabolic regression revolution design,the affecting factors were studued on predation rate.The main results are as follows1.In lab condition,the growth duration and feeding characteristics were observed.The average duration of the S.litura was 3 days,the average duration of the 1-2 instar larvae was 7.5 days,the average duration of the 3 instar larvae was 3.5 days,the average duration of the 4 instar larvae was 4 days,and the average duration of the 5 age larvae was 3.5 days and the average of 6-7 years was average.The calendar period is 10.5 days,and the average duration of the pupae is 12 days.At the age of 2,the larvae began to disperse as a pest,and the larvae fed on the leaves,tender stems and tender shoots of D.candidum.When the larvae were old,the larvae were drilled into the pre pupae,and after 2 to 3 days,the larvae pupated and 12 days turned into the adult fly out matrix.2.Using the life table of the S.litura to evaluate the control of the different ages of C.furcellata on S.litura larva.The results showed that the population trend index of S.litura in the control area was 9.274,which means that without any control measures the next generation of S.litura will be 9.274 times that of this generation.The population trend index of S.litura populations was 1.474,1.027 and 1.028 respectively in the nymph release area,female adult release area and male adult release area.The control indices for the interference of the S.litura were 0.159,0.111 and 0.111 in the treatment areas of the elderly nymph,female adult and male adult,indicating that the control effects of three treatments of old nymph,female adult and male adult were 84.1%,88.9% and 88.9%,respectively.The seedling protection effects of the 3 treatments were 17.2%,32.2% and 26.9%,respectively.That is,the order of seedling protection effect was: female adults > male adults > old nymphs.In the three treatments of older nymphs,female adults and male adults,the rate of decline of insect population before and after the calculation of the second release of the forked pupae was 46.3%,54.8% and 42.4%,respectively.It can be seen that releasing the prong can achieve better control effect.3.The relationship between the density of the S.litura the number of stink bugs and the density of D.officinale,and the three factors of the density of D.candidum were studied with three factor and two rotation design.The study showed that the three factors were not only positive or negative related to the search efficiency of the stink bug,and the interaction between factors also had a certain influence on the search efficiency,but none of them had a single factor.The results of two experiments on the elderly nymph and female adult of the advanced stink bug showed that the number of stink bug was the main factor affecting the search efficiency,while the density of the larvae of the S.litura,the density of the host plant,the density of the larva of the S.litura and the number of stink bugs of the S.litura could have a significant effect on the two treatments.