The Study Of Molecular Identification And Occurrence Of Contarinia Sp.

Contarinia sp.is a serious pest of Carya cathayensis,which causing losses for forest farmer.At present,Contarinia sp.has not yet been named;Meanwhile,it is extremely difficult to identify because the pest has small size and the lack of fully intact specimens from field.In addition,the life cycle and occurrence of Contarinia sp.are remained to be explored.Identification of the pest is a prerequisite for sustainable C.cathayensis,production,and the knowledge about this pest's life cycle and occurrence is very important for its management.Here,we reported the morphological characteristics of Contarinia sp.,and developed the molecular identification method for this species based on mitochondrial DNA cytochrome oxidase subunit I(mt DNA COI)genes.At same time,the life cycle and the occurrence of Contarinia sp.also been studied.The results are as follows:(1)The morphological characteristics of the different life stages of this species were described.(2)Here,the mitochondrial CO I gene was employed to identify Contarinia sp.by using different stages and resource of Contarinia sp.A phylogenetic tree was constructed using sequences of mitochondrial CO I gene of several blossom midge species.The results show that Contarinia sp.from different stages and resource have the same gene sequence.Contarinia sp.might be a new species because of the unique sequence of mitochondrial CO I gene,however more data on morphological features are needed to support this conclusion.(3)The life cycle was studied by monitoring field screening and yellow sticky band.The results showed that adults emerge from the soil and lay egg around the late of March to the early of April;From mid April to late April,egg hatch and larvae emerge;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.(4)We found that Contarinia sp.activity peak was after 15;00,until 18:00 there are still a small amount of Contarinia sp.;The occurrence of Contarinia sp.is related with weather conditions such as soil temperature and humidity,sunshine,rainfall and so on;It's the optimum temperature and humidity for emergence that Soil temperature is around 17? and humidity is about 58%.There are no obvious relation between its emergence and location under the elevation of 400 m.