樟巢螟滞育诱导特性的研究

为探求诱导樟巢螟(Orthaga achatina Butler)滞育的临界光周期及敏感虫态(期),在室内25℃和28℃下观察不同光周期对樟巢螟滞育的影响,并利用不同长光照和短光照组合对樟巢螟幼虫的不同龄期进行处理,掌握樟巢螟的敏感虫态(期)。结果表明光周期为L∥D=12.0h∥12.0h,L∥D=12.5h∥11.5h,L∥D=13.0h∥11.0h时,在25℃下,樟巢螟的滞育率分别为100%,94.80%和97.60%;在28℃下,滞育率分别为98.55%,99.05%和83.50%。当光周期为L∥D=13.5h∥10.5h,在25℃和28℃下,樟巢螟的滞育率分别为42.38%和34.05%。樟巢螟属长日照发育型昆虫,在25℃时诱导滞育的临界光周期是13.565h,在28℃时是13.364h。25℃时樟巢螟对光照反应最敏感的时期是4～5龄期,1～3龄次之,卵期最不敏感。

Studies on diapause induction of Orthaga achatina

The critical photoperiod of diapause induction and the sensitive stage of Orthaga achatina Butler to photoperiod were investigated.The diapause reactions to different photoperiods were observed at 25 ℃ and 28 ℃ in the constant temperature incubator,and the sensitive stage was investigated by long and short photoperiod combination at different instars of this insect.When the photoperiods were L∥D=12.0 h∥12.0 h,L∥D=12.5 h∥11.5 h and L∥D=13.0 h∥11.0 h,the diapause rates of the insect were 100%,94.80% and 97.60% at 25 ℃ and 98.55%,99.05% and 83.50% at 28 ℃,respectively.At the same time,when photoperiod was L∥D =13.5 h∥10.5 h,the diapause rates were 42.38% at 25 ℃ and 34.05% at 28 ℃.The photoperiodic response curves in O.achatina showed that this insect was a long-day development species with a critical day length of 13.565 h at 25 ℃ and 13.364 h at 28 ℃.The sensitive stage to the short light(12 h) was the 4th-5th instars at 25 ℃,while the 1st-3rd instars were less sensitive,and the egg stage was the insensitive stage to short light.