| Yellow-spined bamboo locust, Ceracris kiangsu Tsai（Orthoptera：Arcypteridae）is themost important defoliator of bamboos, and has been called the second largest forest insect pestin China. Recently, C. kiangsu broke out seriously in Guangdong, Zhejiang, Hunan, Nanjing,Chognqing etc., and caused huge economic losses and ecological disaster. It is urgent andnecessary to find out a safe, economical and effective strategy to control yellow-spinedbamboo locusts. C. kiangsu adults are known to prefer to human urine and sweat, which isespecially evident on hot summer days.This behavior is called ‘urine-puddling’, and itsmechanism is not clear so far. In addition, applying baits with human urine mixted withinsecticeds to kill C. kiangsu adults is a effective method to control yellow-spined bamboolocusts, but the method can not be widely practiced because human urine is unavailable whenthe C. kiangsu occurred. To understand the mechniam of urine-puddling behavior of C. kiangsuand achieve an effective attractant to C. kiangsu adults, we tested the behavioral andphysiological responses of C. kiangsu adults towards human urine fermented for different days,and compared the difference of the typology, number, and placement of antennal sensilla of C.kiangsu adults between female and male in present study. The results are summarized asfollows:(1) C. kiangsu adults were attracted by incubated human urine, and their behavioralresponses towards human urine were influenced by the length that human urine incubated.Compared with human urine that incubated for1day,4days,7days,15days and60days, theadults preferred significantly to the human urine incubated for30d. The filter papers treatedwith human urine incubated for30days was consumed significantly larger areas, visitedmarkedly more bounts and settled notaly more time by C. kiangsu adults than that incubatedfor1day,4days,7days,15days or60days. Incubation of human urine could enhance theattractiveness of the yellow-spined bamboo locust feeding on human urine. And the bait with 30d-incubated human urine mixed with insecticides bisultap attracted and killed much morelocust adults than that with human urine incubated for1day,4days,7days,15days or60daysin the field.(2) The EAG responses of C. kiangsu adults towards volatiles emitted from incubatedhuman urine was closely correlated with the fermentation length of urine and the sex as well.The female and males showed the strongest EAG responses to the volaties emitted from humanurine incubated for30days. And female and males adult showed a significiant differenct EAGresponse towards the volatiles emitted from the same urine sample. In addition, indole,ammonium bicarbonate and urea could trigger significant EAG response of C. kiangsu adults.(3) Sensilla of the yellow-spined bamboo locust were studied using scanning electronmicroscopy (SEM). The results showed that the antenna on both males and females were madeup of one scape, one pedicel and23flagellomeres. Totally, there were four types of sensillafound on the antenna. They were identified as sensilla trichodea, sensilla chaetica, sensillabasiconica and sensilla coeloconica. The sensilla trichodea and sensilla basiconica were of twotypes according to the morphology, respectively. Both the male and female had the same typesof antennal sensilla and similar distribution characteristics on the antenna. And males hadmuch more abundant sensilla basiconica and sensilla coeloconica than females.The behavioral responses towards human urine incubated for different days were firstlytested in present study, and the the results showed that incubation could enhance theattractiveness of C. kiangsu adults. The EAG responses to the vilatles emitted from humanurine implied the volatiles played a very important role in urine-puddling behavior of C.kiangsu. These results have provided important basic information of the mechanism ofurine-puddling of C. kiangsu and are helpful for effective deployments of attractants derivedfrom huanm urine. |
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