油茶象生物学初步研究

A Preliminary Study on The Biology of Curculio chinensis

油茶象(Curculio chinensis Chevrolat)是我国特有木本油料树种——油茶的专性蛀果害虫,常导致大量落果。为明确其基本的生物学特性,2014年在湖南省邵阳县小果油茶林采用震落法捕获油茶象成虫146头,实验室室温下饲养,记录日死亡数,并对其干重、喙长、体长和体宽进行了测量。用独立样本t检验(Independent—samples t test)分析雌雄成虫大小差异性,用线性拟合(Linear fit)分析成虫日死亡数与日最高气温的关系,并用Crosby生长法则对'多峰拟合'分龄结果进行了评价。结果表明:油茶象雌性多于雄性,性比为3.06:1;成虫具2种体色型,即黑色型和褐色型,黑色型为优势种群;成虫最长寿命>100天,7月下旬至8月初持续高温(日最高温度>35℃)导致成虫大量死亡,占55.8%,成虫日死亡数与日最高气温显著线性正相关(P<0.01)。Crosby指数均<10%,表明'多峰拟合'方法用于幼虫分龄合理可靠。本文明确了油茶象的一些基本生物学特性,并给出了卵、各龄幼虫及雌性成虫形态特征图。

Oil tea weevil(Curculio chinensis)is an important pest attacking the fruits of oil tea camellia(camellia spp.),special oil tree species in China,and often lead to a lot of fruit drop of its host plants.To clarify the basic biological characteristics,a total of 146 weevil adults were captured by shaking-off collection from the farm of Camellia meiocarpa in Shaoyang county of Hunan province in 2014.The adults were fed in laboratory at room temperature.The number of daily dead weevil adults was recorded,and then dry mass,rostrum length,body length and width of each dead adult were measured.Independent-samples t test was used to analysis the differences of adults size between female and male,linear fit was used to analysis the correlation between the number of daily dead weevil adults and the daily highest temperature,and the result of larval instar determination through"multiple peak fit"was evaluated using Crosby rule.The results indicated as follows.Females were more than males,and the sex ratio was 3.06:1.There were 2 types of body color,black one and brown one,and the former was the dominant population.The longest lifespan was more than 100 d,and adults were died largely(accounted for 55.8%of the tested weevils)when it was continuous in high temperature(daily highest temperature>35℃)in late July to early August,and the number of daily dead weevil adults was positive related to the daily highest temperature(P<0.01).All the Crosby ratios were more than 10%,it indicated that the method of multiple peak fit was robust to used to determine the weevil larval instars.In this paper,some basic biological characteristics of Curculio chinensis was revealed,and the figs of egg,all instars of larvae and adults of female and male were provided.