Exploiting diapause and cold tolerance to enhance the use of the green lacewing Chrysopa formosa for biological control

Publication date: Available online 28 August 2018Source: Biological ControlAuthor(s): Yuyan Li, Manzi Wang, Fei Gao, Hongzhi Zhang, Hongyin Chen, Mengqing Wang, Chenxi Liu, Lisheng ZhangAbstractKnowledge of environmental regulation of diapause in the green lacewing Chrysopa formosa, an important polyphagous predator against various pests, is essential for understanding seasonal adaptations of insects and for increasing the shelf-life and shipment of chrysopids used in biological control programs. In the present study, we identified environmental factors responsible for induction and termination of diapause and cold tolerance in this chrysopid. C. formosa exhibits a facultative, prepupal diapause within its cocoon. The free-living third instar larva is the stage most sensitive to photoperiodic stimuli. Photoperiod is the major factor governing the induction of prepupal diapause, and temperature exert a modulating effect. Photoperiodic response curves for C. formosa showed a typical long day response over a wide range of temperatures. Critical daylength for diapause induction was estimated to be 14.27 hours at 20°C, with a shift towards short daylengths at higher temperatures. The diapause response was maximal with a short daylength of 8L: 16D at 18°C or 20°C, and no diapause was induced under 16L: 8D at any temperature examined. Chilling temperature had a pronounced effect on the completion of diapause termination and post-diapause development. A chilling period of 60 days ...
Source: Biological Control - Category: Biology Source Type: research