《环境昆虫学报》

栗等鳃金龟Exolontha castanea Chang是甘蔗上重要的地下害虫。本研究通过室内饲养和田间调查，系统研究了栗等鳃金龟的外部形态、胚后发育特征、发育历期、年生活史和生活习性。结果表明，栗等鳃金龟雌雄幼虫肛腹片上的短刺毛数量存在差异，雌虫显著多于雄虫。蛹和成虫腹部存在明显的性别分化特征，易于辨别，并且在体长、体宽和体重上均表现出“雌大雄小”现象。不同日龄的卵、幼虫和蛹发育特性变化明显，卵长轴和短轴发育趋势符合Logistic模型。幼虫共3个龄期，头宽随着龄期增加显著增大。26℃条件下，卵期10.12 d，幼虫期309.54 d。雌、雄蛹期分别为17.54 d和17.80 d，雌、雄成虫寿命分别为45.27 d和40.00 d。该虫在广西1年发生1代，以老熟幼虫在土中越冬，3月中旬开始陆续化蛹，4下旬至6月下旬为成虫出土活动期，5月中下旬为出土活动盛期。成虫出土后不取食植物，能吸食少量水分，单雌产卵量为38.43粒。幼虫6月上旬出现，9-11月是危害盛期。幼虫是危害甘蔗的主要阶段，雌成虫具有较强的繁殖能力和趋光特性，建议在初孵幼虫期和成虫出土活动期进行有效防控。

英文摘要:

Exolontha castanea Chang is a significant subterranean pest affecting sugarcane. Its morphological characteristics, postembryonic developmental characteristics, developmental durations, annual life history, and living habits were studied systematically through field investigations and indoor feeding observations. The results showed that there was a significant difference in the number of short hairs on the posterior end of female and male larvae of E. castanea. There were obvious gender differentiation characteristics in the abdomen of pupae and adults with the phenomenon of "larger females and smaller males" in body length, width, and weight, which were easy to distinguish. Furthermore, the developmental characteristics of eggs, larvae, and pupae vary notably at different developmental ages. The relationship between the long-axis and short-axis developmental of eggs and their age conforms to the “Logistic” model. The larva undergoes three instars, with a significant increase in head width as it progresses through each instar. At a temperature of 26 ℃, the developmental durations of egg, larva, female and male pupa were 10.12 d, 309.54d, 17.54 d and 17.80 d, respectively. The lifespans of female and male adults were 45.27 d and 40.00 d, respectively. E. castanea occurs annually in Guangxi, overwintering as mature larvae in the soil. It began to pupate gradually in mid-March. Adult emergence activity spanned from late April to late June, with peak emergence occurring from mid to late May. Upon emergence, adults can absorb a small amount of water without feeding on plants. Female adults laid an average of 38.43 eggs each. Larvae emerged in early June, and the peak period of damage was from September to November. Larvae are the main stage causing damage to sugarcane and female adults exhibit strong reproductive ability and phototaxis. It is recommended that control measures be implemented during the initial larval hatching stage and the adult emergence stage.

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