Chair of Animal Ecology II, University of Bayreuth, P.B. 10 12 51, D-8580, Bayreuth, Germany.
J Chem Ecol. 1993 Jul;19(7):1337-54. doi: 10.1007/BF00984880.
The abdominal glands of three bark-inhabiting larvae of generaBolitochara, Leptusa (Staphylinidae), andHypophloeus (Tenebrionidae) were studied chemically and morphologically. Behavior of the larvae indicated that secretion is emitted only after severe disturbance of the larvae. These mechanical contacts may also occur incidentally with coinhabiting nonpredatory arthropods when the beetle larvae move within small interstices under bark. Depending on the species, the secretions contained 1,4-benzoquinone derivatives and three 6-alkyl-naphthoquinones dissolved within various alkanes, alkenes, ethyl-, isopropyl-, and isoamylesters. More erratically distributed gland constituents also detected were acetophenone, benzyl propionate, and methyl hydroxybenzoate. In the laboratory, synthetic quinone-containing solutions simulating those found inLeptusa andBolitochara larvae acted as strong topical irritants and caused further damage to last-stageCalliphora vomitoria larvae if hydrocarbons or esters were used as solvents. The natural secretions ofHypophloeus versipellis elicited considerable mortality in two subcortical sciarid larvae cooccurring with tenebrionid larvae. Bioassay and secretion chemistry of the Staphylinidae/Tenebrionidae larval secretions indicated that they are typical defensive secretions that act topically. Morphological data characterized Bolitocharini larvae as possessing protuberant abdominal tergites supplied with an interiorly situated gland reservoir. After mechanical contact, the defensive secretion is topically applied to other arthropods by dabbing this tergal protuberance on targets. The defensive gland ofHypophloeus versipellis is unusual in possessing a movable reservoir opening situated at the anterior border of tergite IX. By this peculiar gland morphologyHypophloeus larvae are capable of shooting secretion droplets frontally from their slightly depressed dorsal abdominal surface without bending their abdominal tips dorsally. This seems an adaptation to the interstitial habitat of the larvae. The types of defensive glands and their phylogenetic value in Aleocharinae/Tenebrionidae larvae are discussed.
对三种栖息于树皮的幼虫（步甲科的 Bolitochara 和 Leptusa，拟步甲科的 Hypophloeus）的腹部腺体进行了化学和形态学研究。幼虫的行为表明，只有在受到严重干扰时才会分泌分泌物。当甲虫幼虫在树皮下的小缝隙中移动时，这些机械接触也可能偶然与同栖的非捕食性节肢动物发生。根据物种的不同，分泌物中含有 1,4-苯醌衍生物和三种溶解在各种烷烃、烯烃、乙酯、异丙酯和异戊酯中的 6-烷基萘醌。还检测到分布更不规则的腺体成分有苯乙酮、丙酸苄酯和羟基苯甲酸甲酯。在实验室中，模拟 Leptusa 和 Bolitochara 幼虫中发现的含有醌的合成溶液作为强烈的局部刺激物，如果使用碳氢化合物或酯作为溶剂，会对最后阶段的 Calliphora vomitoria 幼虫造成进一步的损害。Hypophloeus versipellis 的天然分泌物会引起与拟步甲科幼虫共同发生的两种皮层下蕈蚊幼虫的相当高死亡率。步甲科/拟步甲科幼虫分泌物的生物测定和分泌化学表明，它们是典型的防御性分泌物，具有局部作用。形态学数据将 Bolitocharini 幼虫的特征描述为具有突出的腹部背板，内部设有一个腺体储库。在机械接触后，防御性分泌物通过将这个背板突起擦拭到目标上，局部应用于其他节肢动物。Hypophloeus versipellis 的防御腺的独特之处在于，它有一个可移动的储液室开口，位于第九背板的前缘。通过这种特殊的腺体形态，Hypophloeus 幼虫能够从略微凹陷的背部腹部表面向前喷射分泌液滴，而无需将腹部尖端向上弯曲。这似乎是对幼虫间室栖息地的一种适应。讨论了 Aleocharinae/Tenebrionidae 幼虫中防御腺的类型及其在系统发育上的价值。
