锦天牛属阳茎内囊结构

采用显微解剖和冰冻组织切片方法研究锦天牛属Acalolepta三种天牛阳茎内囊的结构,发现内囊骨化结构物,尤其端部骨化结构物,及其控制内囊伸缩的加厚侧带和有聚集精子作用的射精管壶腹结构,在探讨天牛科分类和系统发育上均具有重要意义。     

Abaristophora sachalinensis Michailovskaya (Diptera: Phoridae) representing genitalic affinities with the genus Borophaga Enderlein

Abaristophora sachalinensis Michailovskaya is reviewed based on Japanese materials. Its male genitalia are compared with those of the genus Borophaga, which is a genus in a group of the related genera, the Borophaga subgroup. A synapomorphic character of the Borophaga subgroup including Abaristophora, the left flattened arm derived from the posterodorsal margin of the hypandrium being broadened at the base, is confirmed in A. sachalinensis. Morphology of the aedeagus in A. sachalinensis is complex and extremely asymmetric, and very similar to that of species of the genus Borophaga, but the characters observed in this study are not regarded as synapomorphic for the Borophaga subgroup.     

Revision of the genus Stichillus Enderlein of Japan (Diptera: Phoridae)

The genus Stichillus in Japan is revised. Three species are recognized: S. japonicus (Matsumura), S. spinosus Liu and Chou and S. cylindratus sp. nov. Stichillus brunneicornis Beyer is excluded from the Japanese fauna. These Japanese species are described and keyed. The male genitalia and the female terminalia are illustrated. Some unique characters of the male genitalia in the genus are reported, and morphology of the male genitalia and the female terminalia is discussed.     

柑橘大实蝇雄性外生殖器超显微结构及其性选择权

柑橘大实蝇Bactrocera minax（Enderlein）,是柑橘的重要害虫。本研究基于光学、扫描电镜、X射线CT,对其雄虫外生殖器的形态结构、阳茎长度和雌虫泄殖腔到受精囊的长度、以及雌雄虫交配过程中的夹持状态和雄虫阳茎冠到达雌虫阴道位置的观察和测量。结果表明,柑橘大实蝇雄性外生殖器是由阳茎（阳茎管和阳茎冠）、生殖突（阳茎内突和生殖环）和抱握器（背刺突和抱器）这3个部分组成。阳茎管是长而弯曲的双套管结构（向腹面卷曲）,外管即阳茎管,内含1条输精管（内管）,阳茎管腹面褶皱,骨化程度低,背面平坦（中间有沟）,骨化程度较高,既可以弯曲折叠又可以变直。休息时,阳茎蜷曲,大部分隐藏在第5腹节内。阳茎冠由生殖杆、阳茎冠体（基囊、喇叭口、裂口和骨化体）组成,精子出口位于阳茎冠顶部喇叭口内和基囊前端的阳茎冠体上的裂口内。成虫交配时,雄虫抱握器夹持住雌虫产卵针背片端部,阳茎能够到达的最远处为雌虫布氏交配囊。雌虫从泄殖腔口至受精囊长度（21.64 ± 0.59 mm）远大于雄虫阳茎的长度（9.21 ± 0.25 mm）,表明雄虫的阳茎不能到达雌虫的受精囊,雌性可以通过控制精子是否进入受精囊来控制受精。因此,雌成虫拥有最终的授精控制权。这些结构或组织经过进化,从而适应其阳茎的运动、交配等行为活动。为理解昆虫繁殖生理、进化和多样性,昆虫交配、阳茎运动等行为机制提供理论基础。     

The genetics of primary and secondary sexual character trade-offs in a horned beetle

When structures compete for shared resources, this may lead to acquisition and allocation trade-offs so that the enlargement of one structure occurs at the expense of another. Among the studies of morphological trade-offs, their importance has been demonstrated primarily through experimental manipulations and comparative analyses. Relatively, a few studies have investigated the underlying genetic basis of phenotypic patterns. Here, we use a half-sibling breeding design to determine the genetic underpinnings of the phenotypic trade-off between head horns and the male copulatory organ or aedeagus that has been found in the dung beetle Onthophagus taurus. Instead of the predicted negative genetic covariance among characters that trade-off, we find positive genetic covariance between absolute horn and aedeagus length and zero genetic covariance between relative horn and aedeagus length. Therefore, although the genetic covariance between absolute horn and aedeagus length would constrain the independent evolution of primary and secondary sexual characters in this population, there was no evidence of a trade-off. We discuss alternative hypotheses for the observed patterns of genetic correlation between traits that compete for resources and the implications that these have for selection and the evolution of such traits.     

Possible coevolution of male and female genital form and function in a calopterygid damselfly

In this paper some evolutionary changes of genitalia in the damselfly Calopteryx haemorrhoidalis are investigated by determining their current and past function. Calopteryx haemorrhoidalis males stimulate females by aedeagal frictioning on a set of vaginal sensilla. The aedeagus is considerably variable and positively correlates with volumes of ejected sperm from the spermatheca. Interestingly, females show a significantly reduced sensillum number compared with other family members. Here I explore whether there existed directional selection for aedeagal width at its evolutionary onset; and whether the sensillum reduction evolved to make sperm ejection less effective. Using C. haemorrhoidalis aedeagi in females whose species retained the ancestral conditions (no stimulatory ability and large sensillum numbers), Hetaerina cruentata and C. xanthostoma, my results corroborated these assumptions: variation in aedeagal width inversely correlated with sperm ejection rate while sperm ejection was higher in species with high sensillum numbers. A suggested coevolutionary interpretation of these results in C. haemorrhoidalis is that aedeagal width was favoured which was followed by a sensillum reduction.     

Systematic and morphological studies of the genus Chaetopleurophora Schmitz (Diptera: Phoridae) occurring in Japan

Japanese species of the genus Chaetopleurophora are reviewed. All belong to the C. erythronota group. The following three species from Japan are described: C. rhomboidea sp. nov., C. pygidialis Schmitz and C. dividua sp. nov. The male and female genitalia are studied and further examples of unique characters of the genus including asymmetric features are added. The male aedeagus of the genus is illustrated for the first time. The aedeagus of the species treated in this study consists of only two components, the inner core plate and the outer jacket plate. The jacket plate wraps sinistrally around the core plate. The combination of the core plate and the jacket plate forms complex, asymmetric features of the aedeagus in the Phoridae. The structure around the genital opening in the female genitalia protrudes posteriorly under the segment IX + X, and shows asymmetric features in C. rhomboidea sp. nov. with a bilaterally different degree of sclerotization, shifted genital opening to the right side and a membranous ribbon just on the left side. In addition, C. dividua sp. nov. is different from most of the species in the C. erythronota group, and very closely related to C. multiseriata (known in North America) in the male and female genitalia, wing venation and bristle formation on the scutellum. It is suggested that C. dividua sp. nov. forms a monophyletic group with C. multiseriata and the related species.