温度对荔枝异形小卷蛾发育和繁殖的影响

Effect of temperature on the development and reproduction of Cryptophlebia ombrodelta (Lower) (Lepidoptera: Tortricidae)

荔枝异形小卷蛾的蛀梢为害是珍贵树种格木人工林健康发展的主要限制因子。依据其天然分布和潜在推广区的温度范围设置系列温度梯度,探讨温度对荔枝异形小卷蛾发育和繁殖的综合影响。结果显示,温度对荔枝异形小卷蛾各阶段的发育历期具有显著影响,在研究温度范围内,发育历期随温度升高呈显著地下降趋势,世代历期在18℃时为66.87 d,30℃时降至35.77 d。预蛹和蛹的存活率对温度的响应不敏感,而卵、幼虫、成虫的存活率和世代存活率以及产卵量均随温度升高表现为先上升后下降的变化趋势,且繁殖力对温度的反映较存活率敏感,其存活率和繁殖力在18℃时均最低,分别为41.20%和13.90粒,在27℃时发育最适,分别为83.80%和45.40粒,在30℃时虽有下降,分别为66.00%和32.40粒,但仍高于18℃时,即其对低温较高温敏感。荔枝异形小卷蛾完整世代发育起点温度为5.77℃,所需有效积温为876.76 d℃,其中幼虫发育所需有效积温最高,占整个历期的45.23%,发育速率与温度显著正相关。根据荔枝异形小卷蛾为害方式、发育和繁殖特征分析可知,在低温地区其幼虫期长,但世代数少、存活率和繁殖力低,对寄主植物受害部位的单次为害程度严重;在高温地区则幼虫期短,但世代数多、存活率和繁殖力高,对寄主植物受害部位的单次为害程度低,但更为频繁,持续为害程度高。研究结果对于不同地区选择荔枝异形小卷蛾的防治具有借鉴意义,同时有助于指导格木人工林的合理推广和健康发展。

The damage caused by Cryptophlebia ombrodelta(Lower)(Lepidoptera:Tortricidae)on the shoots Erythrophleum fordii,a precious species in south China,is the main restraint on this plant′s plantation promotion and healthy development.The comprehensive influence of temperature on the development and reproduction of C.ombrodelta were investigated using a series of temperature tests,which were based on the temperature range of E.fordii in a natural distribution and potential extension area.The results showed that the effect of temperature on the developmental stages of C.ombrodelta were significant within the temperature range.The developmental stages decreased significantly with an increase in temperature;generation duration was 66.87 d at 18℃and decreased to 35.77 d at 30℃.The survival rate of eggs,larvae,and adult generation and fecundity first significantly increased then decreased with an increase in temperature;the effects of temperature on pre-pupae and pupae were not significant,and fecundity,rather than survival rates,was more sensitive to temperature.The survival rates and fecundity,at 41.20%and 13.90 eggs,respectively,were the lowest at 18℃,and the survival rates and fecundity,at 83.80%and 45.40 eggs,respectively,reached the maximum at 27℃;this was the most appropriate developmental temperature for C.ombrodelta,since the survival rates and fecundity decreased to 66.00%and 32.43 eggs,respectively,at 30℃,but the survival rates and fecundity were higher at 18℃;therefore,the survival rate and fecundity were more sensitive to low temperatures than to high temperatures.The developmental temperature threshold and the effective accumulated temperature were 5.77℃and 876.76 d℃,respectively.The effective accumulated temperature of larvae was the highest among the developmental stages,and the proportion of the larval stage accounted for 45.23%of the whole generation.The developmental rates were positively correlated with temperature;eggs and pupae had the fastest developmental rates,followed by pupae and adults,and that of the larvae was the slowest.The stages with faster developmental rates were more sensitive to temperature.It can be deduced that when the larval duration of C.ombrodelta was longer,the generation time per year was less,and the survival rate and fecundity were lower.Therefore,the damage to the bored parts of the host plant,E.fordii,is more serious in low temperature regions.When the larval stage of C.ombrodelta was relatively shorter,the generation time per year was higher,and survival rate and fecundity were higher in high temperature regions;therefore,the degree of damage to the bored parts of host plant,E.fordii,is lower in every generation than which in low temperature regions,but the occurrence of damage is more frequent.These results provide a reference for the prevention and control of C.ombrodelta in different temperature regions,which could help guide the reasonable extension and healthy development of E.fordii plantations.