柑桔吸果夜蛾的头部内骨骼、肌肉系统和口器构造与成虫取食习性的关系

吸果夜蛾的取食习性与头部内骨骼、肌肉和口器构造的特点有如下的关系:1.嗜食健果类型:幕骨强大,为着生肌肉提供较大的面积。头部肌肉发达。口器强角质化,端部具有适于穿刺果皮的附属物。2.兼食性类型:幕骨强大,头部肌肉发达程度常界于第一和第三类型之间。口器端部锐利,角质比较强。3.间接取食类型:幕骨不发达,着生肌肉的面积较小。头部肌肉较纤细。口器端部钝或膜质状,角质化程度弱。此外,下颚茎节外形及颊宽的特征,可以将嗜食健果类型的夜蛾与其他两类型的夜蛾区分开来。

STUDIES ON THE CEPHALIC ENDOSKELETON, MUSCULATURE AND PROBOSCIS OF CITRUS FRUIT-PIERCING NOCTUID MOTHS IN RELATION TO THEIR FEEDING HABITS

The fruit-piercing noctuid moths are important insect pests of citrus in China. According to their feeding habits, they may be divided into the following three groups: the first pierce directly the fruits and prefer intact fruits to the damaged ones, the second pierce both intact and damaged fruits, and the third feed only on the damaged fruits. The cephalic endoskelaton, musculature, and proboscis of the moths associated with different feeding habits are described and differences may be summarized as follows :In the moths piercing directly intact fruits, the anterior tentorial arms are very strong and arched and thus provide larger area for the attachment of the muscles. The refractor of proboscis, cranial adductor and cibarial dilator are highly developed. The widths of gena and outer condyle of stripe are larger than those of the other groups. The proboscis is strong and possesses sharp and stout outgrowths on the outer side for piercing fruits. In the moths piercing both intact and damaged fruits, the anterior tentorial arms are strong. The cephalic muscles are usually better developed than those of the third group, but weaker than those of the first group. The proboscis is strong and provided with rigid spines and hairs. In the moths feeding on damaged fruits only, the anterior tentorial arms and cephalic muscles are poorly developed as compared with those of the other groups. The tip of proboscis is blunt or membraneous, unsuitable for piercing fruits with rigid pericarp. The outer condyle of stripe is rather unconspicuous.