Study On The Life History And Occurrence Of Blossome Midge (Contraina Sp.) In Carya Cathayensis,in Ningguo

Blossom midge (Contarinia sp.) (Diptera:Cecidomyiidae) is one of the important pests of Carya cathayensis, it's larvae damage the flowers of C. Cathayensis in early April and then cause a seriouly loss to the cathay hickory production. Recently, significant damage of the blossom midge to C. cathayensis have been reported in Ningguo, Anhui Province. It posed a serious threat to the healthy development of hickory industry in Ningguo. However, the biology knowledge on this midge was lacking now. Here, the morphology, life history, occurrence and monitor method of this blossom midge species were investigated.(1) Firstly, we described the morphological feature of this blossom midge, and especially, the pupa and larval cocoon were firstly reported.(2) Then, we demonstrated the life history of this blossom midge. In early April, adults emerge from the soil and take flight as soon as the wings dry. Then the eggs are laid in masses in the androecium of the flower buds and the larvae hatch and become full-fed within 5-7 days. In middle April, the blossom midge maggots feed inside unopened flower buds, causing deformed, discolored buds. In late April, when mature, or earlier if the flower becomes dry or otherwise unsuitable, they drop to the ground and enter the soil, where they over wintering and pupate until next spring.(3) Third, we developed two monitoring methods for this blossom midge, including the bubble chamber monitoring method and the nylon screen monitoring method. The nylon cage monitoring method was more practical for the field monitoring.(4) Fourth, the population dynamic of this blossom midge's adults in different sites were investigated. Adults emerged in early spring and the peak of midge flight came out around the late of March to the early of April in all of sites. This stage is the critical period for the control of this midge. There were showed an obvious gener-bias in the midge population, the number of male were significantly higher than the female.(5) At last, the volatiles of the cathay hickory's (Carya cathayensis) leaves and flowers, were analyzed by headspace sampling method, combined with gas chromatography - mass spectrometry (GC-MS) technique. These results laid the foundation of the development of attractant for the midge.