摘要
旨在明确番茄潜叶蛾(Tuta absoluta)不同发育阶段的抗寒能力,为番茄潜叶蛾的越冬条件确定和准确预测预报提供依据.利用昆虫过冷却点测定仪分别测定番茄潜叶蛾不同发育阶段的过冷却点和结冰点.结果表明,番茄潜叶蛾1龄幼虫的平均过冷却点最低,为-21.63 ℃,而3龄幼虫的平均过冷却点最高,为-15.97 ℃,其余虫态平均过冷却点依次为-21.40 ℃(成虫)＜-19.98 ℃(4龄幼虫)＜-19.37 ℃(蛹)＜-17.96 ℃(2龄幼虫);成虫的平均结冰点最低,为-19.37 ℃,3龄幼虫的平均结冰点最高,为-12.60 ℃,其余发育阶段平均结冰点依次为-18.93 ℃(1龄幼虫)＜-16.32 ℃(4龄幼虫)＜-16.16 ℃(蛹)＜-14.24 ℃(2龄幼虫).可见:番茄潜叶蛾1龄幼虫和成虫的抗寒能力相对较强,3龄幼虫的抗寒能力较弱.该虫在宁夏冬季露地上难以越冬,温室可以为其在不利的气候条件下提供庇护环境,限制1龄幼虫及成虫的虫口密度是维护早春茬作物产量与品质的关键.
Abstract
This study aimed to investigate the cold tolerance of Tuta absoluta at different developmen-tal stages,providing a basis for establishing overwintering conditions and forecasting the pest's sur-vival in differing climates.The supercooling and freezing points of larvae,pupae and adults of T.abso-luta were measureed using an insect supercooling point tester.The results showed that the average supercooling point was lowest in first-instar larvae(-21.63 ℃)and highest in third-instar larvae(-15.97 ℃),while values for other stages followed in descending order:adults(-21.40 ℃)＜fourth-instar larvae(-19.98 ℃)＜pupae(-19.37 ℃)＜second-instar larvae(-17.96 ℃).The average freezing point was lowest in adults(-19.37 ℃)and highest in third-instar larvae(-12.60 ℃),with other developmental stages ordered as follows:first-instar larvae(-18.93 ℃)＜fourth-instar larvae(-16.32 ℃)＜pupae(-16.16 ℃)＜second-instar larvae(-14.24 ℃).These findings indicate that first-instar larvae and adults of T.absoluta exhibit a high cold resistance,where-as the third-instar larvae display relatively lower tolerance.T.absoluta is unlikely to overwinter in open field conditions in Ningxia,although the greenhouse may provide protective environments for survival under adverse climates.Controlling the population density of is critical for preserving the yield and quality of early spring crops.
维普
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