桑小头木虱Paurocephala sauteri Enderlein生物学特性研究

近年在海南各植桑区均发现桑小头木虱（Paurocephala sauteri Enderlein）严重为害,桑园被害株率达100%。在我国,该木虱仅记录于台湾省,为我国大陆新入侵害虫。本研究在实验室条件下(27±1)℃、RH (70±5)%、12L∶12D],采用45日龄桑树扦插苗和离体叶片饲养,对桑小头木虱的发育与繁殖特性及各虫态的形态特征开展观察。结果表明,桑小头木虱生活史包括卵、1~5龄若虫和成虫期。各龄期主要形态特征为：卵呈水滴形,带短的卵柄,端部具细长的端丝,初产时乳白色,待孵化时可见淡红色眼点;1龄若虫头、胸部乳白色,复眼和腹部橘黄色,无翅芽;2~5龄若虫黄绿色,随着龄期增加,体长增加,翅芽随之变化。2龄翅芽出现,稍突起;3龄翅芽较小,呈三角形;4龄和5龄翅芽长椭圆形,其中5龄超过腹部第1节。各龄若虫和初羽化成虫均可分泌白色球形蜡质。雌雄成虫以两性生殖方式繁殖后代,羽化3 d后体色由黄绿色逐渐变为黄褐色并开始交配,交配时间为0.5~3 h,结束交配18~21 h后开始产卵,产卵量为20~42粒。卵单个散产于叶片背面叶脉处,偶尔可见产于新抽嫩叶正面边缘,5~7 d后孵化,孵化率为98.19%,雌性百分率为70.44%。若虫期12~18 d,完成一代的时间为18~24 d。本研究将为桑小头木虱的准确识别与监测,以及防控策略的制定提供前提条件和理论依据。

Biological Characteristics of Paurocephala sauteri Enderlein (Hemiptera: Psylloidea: Psyllidae)

The terminal bud and tender leaf of mulberry in Hainan has been found to be seriously damaged by Paurocephala sauteri Enderlein in recent years. The reproductive mode, developmental duration, fecundity and morphological characteristics of various developmental stages of P. sauteri on the host mulberry were investigated under laboratory conditions temperature of (27±1)℃, RH (70±5)% and a photoperiod of 12L∶12D] in the life cycle of P. sauteri including egg, 1st-5th instar nymphs and adults (female and male). The egg was water drop shaped, with short egg pedicle and long terminal filament, milk white and transparent in appearance and had 2 red ocellus before hatching. The 1st instar nymph had milk white colour on the head and thorax, orange red in the compound eye and the abdomen, without wing bud. The instar nymphs of 2nd to 5th were yellow green in colour, the body length increased and the two pairs of wing pads developed as the instar increased. 2nd instar appeared wing pads with slightly bulged at apex. 3rd instar had wing pads more sharply triangular and pointed downward. 4th and 5th instar had wing pads directed backward, but extended beyond the first abdominal segment in 5th instar. Nymphs and adults could secret ball shaped white wax. P. sauteri produced offspring by sexual reproduction. Adults began mating after eclosion for 3 d, and became yellowish-brown in colour from yellow green of new eclosion. The mating behavior could continue 0.5 to 3 h. Then the female laid eggs after 18 to 21 h, with the number of eggs laid per female ranging from 20 to 42. The eggs were singly laid on both sides of the leaf vein underside of the leaf, and occasionally, some eggs also could be found at the upside edge of young leaves. The eggs hatched after 5 to 7 d with hatching percentage 98.19% and female percentage 70.44%. The developmental duration of the nymphs was 12 to 18 d, and that was 18 to 24 d from eggs to adults. The results would provides a theoretical basis and prerequisite for the management of P. sauteri.