取食含不同植物源成分的饲料对香樟齿喙象幼虫生长发育及体内解毒酶活性的影响

【目的】明确取食含不同植物源成分的饲料对香樟齿喙象Pagiophloeus tsushimanus幼虫生长发育以及体内解毒酶活性的影响，以探究寄主植物对香樟齿喙象食性与抗性的作用。【方法】以3种樟科植物(香樟Cinnamomum camphora和浙江桂Cinnamomum chekiangensis和浙江楠Phoebe chekiangensis)枝条粉末为植物源成分，配制成半人工饲料。以半人工饲料进行室内饲养后，分别测定取食半人工饲料后香樟齿喙象幼虫的发育历期、体重、死亡率和化蛹率，以及饥饿12 h后取食含不同植物源成分的半人工饲料的4龄幼虫体内解毒酶(谷胱甘肽-S-转移酶、羧酸酯酶和乙酰胆碱酯酶)活性时序变化。【结果】香樟齿喙象幼虫的发育历期在取食含不同植物源成分的半人工饲料之间存在显著差异。取食含香樟成分的半人工饲料的幼虫发育历期最短(100.13 d)，取食含浙江楠成分的半人工饲料的幼虫发育历期最长(123.33 d)；整个幼虫期的死亡率以取食含浙江桂成分的半人工饲料的幼虫最高(41.67%)，以取食含香樟成分的半人工饲料的幼虫最低(10.00%)；化蛹率以取食含香樟成分的半人工饲料的最高(87.32%)；取食含香樟成分的半人工饲料的幼虫体重增长速率也明显高于取食含浙江桂或浙江楠成分的半人工饲料的幼虫。饥饿12 h后取食含不同植物源成分的半人工饲料的香樟齿喙象4龄幼虫体内GST和 AChE活性并无显著差异(P＞0.05)；而取食含香樟成分的半人工饲料的幼虫CarE活性在60 h时大幅度上升。【结论】说明香樟齿喙象对天然寄主香樟具有较强的生理适应性，这可能与其专食性密切相关；同时，也表明香樟齿喙象可以通过调节自身生长发育和解毒代谢功能来适应不同寄主植物。

Effects of feeding on diets containing components of different plants on the developmentand detoxifying enzyme activities inPagiophloeus tsushimanus(Coleptera: Curculionidae)larvae

【Aim】 This study aims to determine the effects of feeding on diets containingcomponents ofdifferent plants on the growth and development and detoxification enzyme activitiesof Pagiophloeustsushimanus larvae, so as to explore the roles of host plants on the feeding habits andresistance capabilities of P. tsushimanus.【Methods】 Three semi-artificial diets wereprepared separately by using twig powders of three plant species of Lauraceae (Cinnamomumcamphora, Cinnamomum chekiangensis, and Phoebe chekiangensis) as the plant components, andfed to P. tsushimanus larvae. The developmental duration, body weight, mortality rate, andpupation rate of the larvae fed on the semi-artificial diets were measured. After the 4thinstar larvae were subjected to starvation for 12 h and then fed on the threesemi-artificial diets, the temporal changes in the activities of detoxification enzymes［glutathione S-transferase (GST), carboxylesterase (CarE) and acetylcholinesterase (AChE)］ were measured. 【Results】 There were significant differences in the developmentalduration of P. tsushimanus larvae fed on the semi-artificial diets containing differentplant components. The developmental duration of P. tsushimanus larvae fed on thesemi-artificial diet containing C. camphora components was the shortest (100.13 d), whilethat of larvae fed on the semi-artificial diet containing P. chekiangensis components wasthe longest (123.33 d). In the larval stage, the mortality rate of P. tsushimanus larvaefed on the semi-artificial diet containing C. chekiangensis components was the highest(41.67%), while that of larvae fed on the semi-artificial diet containing C. camphoracomponents was the lowest (10.00%). The pupation rate of P. tsushimanus larvae fed on thesemi artificial diet containing C. camphora components was the highest (87.32%). Thegrowth rate of larvae fed on the semi-artificial diet containing C. camphora componentswas also significantly higher than that of larvae fed on the semi-artificial dietcontaining C. chekiangensis or P. chekiangensis components. Meanwhile, there was nosignificant difference in the activities of GST and AChE between the larvae fed on the semi-artificial diets containing different plant components after being subjected tostarvation for 12 h (P>0.05), while the CarE activity in the larvae fed on thesemi-artificial diet containing C. camphora components increased significantly at 60 hafter feeding. 【Conclusion】 The results suggest that P. tsushimanus has strongphysiological adaptability to its natural host plant C. camphora, which may be related toits host specificity. Meanwhile, P. tsushimanus can adapt to different host plants byadjusting its growth and metabolic detoxification.