食木性隐尾蠊属的触角感器特征及分类意义探究（蜚蠊目：隐尾蠊科）

利用扫描电镜观察了3种食木性蜚蠊:滇南隐尾蠊、哈巴隐尾蠊和长白隐尾蠊的触角感器。在本文中对上述3种隐尾蠊的触角形态进行了详细的描述,3种隐尾蠊触角无明显差异。观察并测量了6种主要的感器类型:刺形感器、毛形感器、锥形感器、腔锥形感器、钟形感器和小头感器。结果发现,在3种隐尾蠊触角上毛形感器是最丰富的感器。统计表明感器在3种隐尾蠊种间和两性间存在一些差异。与其他蜚蠊和白蚁进行了比较,并讨论了它们在生活习性上的差异。综上所述,感器的形态描述和统计分析不足以对3种隐尾蠊进行分类鉴别,不宜作为种级单元分类特征。     

Initial reproductive investment and parental body size in Cryptocercus punctulatus (Dictyoptera: Cryptocercidae)

Abstract. Females of the subsocial woodroach Cryptocercus punctulatus Scudder generally have a single oviposition period during which they produce one to four oöthecae. Monogamous pairs and their recently deposited oöthecae were collected in the field, and measured, weighed and analysed for nitrogen in the laboratory. Females put 9.8 ± 2.4% (mean ± SD) of their dry weight and 11.6 ±0.5% of their body nitrogen into oöthecae. The total nitrogen and dry weight of the brood were positively related to the post-oviposition total nitrogen and dry weight of the mother. A female's investment, on a per nymph basis, averaged 0.06% of her post-oviposition dry weight. Females may be able to recover up to 58.7% of the nitrogen invested into a brood by consuming the egg cases after hatch. Overall, there was little variation in the width of head capsules of adults in this species, and this parameter was not significantly different between the sexes. Females were heavier than males (dry weight) (P = 0.06). Within pairs, the weights and nitrogen contents of males and females were positively correlated, probably because they feed together in the same log for nearly a year prior to reproduction.     

Age-related changes in foraging in the German cockroach (Dictyoptera: Blattellidae)

The dynamics of exploitation of standard experimental food sources by the German cockroach, Blattella germanicaL. (Blattellidae), were analyzed in an urban habitat in relation to developmental stage. The data presented here stress differences in foraging capacities between small (first-and second-instar) larvae and animals of other developmental stages. The first animals to arrive in a food patch presented a developmental-stage distribution significantly different from that of the general population. Adults and large larvae (fifth and sixth instars) were the first to find food sources and, in particular, before small larvae. Significant differences appeared between developmental stages concerning givingup time and the time animals left a patch. Small larvae were significantly underrepresented in a patch just before food exhaustion but they were significantly more numerous than expected just after depletion. Small larvae remained in the vicinity of a depleted food dish longer than animals of other developmental stages. Adults left patches as soon as these were depleted, long before small larvae did. Developmental stage influenced rate of departure. These observations indicate that cockroaches improve their foraging performance as they grow larger.     

Calling behavior of the female german cockroach,Blattella germanica (Dictyoptera: Blattellidae)

Virgin German cockroach females, Blattella germanica(L.), were observed, for the first time, to exhibit a characteristic calling behavior during which females emit a volatile sex pheromone. Under a photoperiod of 12L12D, the percentage of 7-day-old virgin females that exhibited this behavior peaked before the end of the scotophase in a similar pattern to the diel periodicity of mating. A clear relationship was evident between calling and stages of sexual receptivity during successive gonotrophic cycles. Females initiated calling 5–6 days after the imaginal molt, when their basal oocytes were 1.6 mm long. If not mated, females continued to exhibit bouts of calling during the next 3–4 days until 24 h before ovulation. Calling was completely suppressed by mating as well as the presence of an egg case in the genital atrium in both virgin and mated gravid females. We suggest that calling and the emission of a volatile sex pheromone serve to attract males from a distance as well as to potentiate responses to contact sex pheromone in aggregations.     

Evolution of host- and habitat association in the wood-feeding cockroach, Cryptocercus

Members of the cockroach genus Cryptocercus are subsocial insects that live in temperate forests and feed on decomposing logs. At present, seven species are recognized worldwide: four in the eastern USA, one in the western USA, and one each in Russia and China. Genetic variation within and among the Nearctic species has been characterized extensively in previous studies. However, whether there has been a corresponding divergence in the host and habitat association of Cryptocercus species is not known. Here, we report on differences in host and habitat association among six of the seven Cryptocercus species, estimated from field observations, elevation data, and land cover data. Our results indicated that the eastern and western USA species differ from one another in their distribution patterns, abundance, and habitat association. The eastern USA species are associated largely with deciduous forests, whereas the western USA and the Russian species are associated with evergreen forests. Thus, the eastern USA species, which are evolutionarily the most recent ones, have adapted to a different set of tree species relative to the basal species. There were also differences in the habitat association of the various species. Specifically, in the eastern USA, Cryptocercus darwini , evolutionarily the most recent species, occupied a habitat that is predominantly at low elevation [<400 m above sea level (ASL)] while all the other Nearctic species and the Russian species occupied a habitat that is at relatively higher elevations (>400 m ASL). Mapping of the above traits on a phylogenetic tree revealed that the evolutionary trend in Cryptocercus with regard to host and habitat association has been toward the utilization of low elevation habitats dominated by deciduous forests. © 2002 The Linnean Society of London, Biological Journal of the Linnean Society , 2002, 75 , 163–172.     

Genetic studies of a behavioral mutant,glucose aversion,in the German cockroach (Dictyoptera: Blattellidae)

Glucose aversion(Glu) is a naturally occurring behavioral mutant of the German cockroach,Blattella germanica. Earlier work suggested thatGlu is a semidominant autosomal trait. Further study was undertaken to place the mutant gene in the linkage map of the species and expand the information on its genetic basis. Linkage was investigated in test crosses with morphologic markers for 7 of the 11 autosomal linkage groups. Assays for amounts of glucose ingested per individual confirmed the expected low consumption ofGlu heterozygotes(Glu/+) and that continuous selection pressure on the parental strain had resulted in near- and probably complete homozygosity forGlu. Glu genotypes were identified by means of a discriminating ingestion that separated heterozygotes from wild type(Glu+). Variations in expression indicate that genetic factors influence food consumption inB. germanica. Positive results were obtained in linkage tests ofGlu with ruby eye(ru), indicating that theGlu locus lies in linkage group VIII (chromosome 9), a group notable for mutants that apparently result in the expression of latent, highly primitive development pathways.     

Circadian calling behavior of the adult female brown-banded cockroach,Supella longipalpa (F.) (Dictyoptera: Blattellidae)

The diel pattern of pheromone-releasing behavior (calling) of the adult female brown-banded cockroach, Supella longipalpa (F.),was examined. Calling occurs discontinuously throughout most of the scotophase in a 12L: 12D photoperiodic regime. Females exhibited a free-running calling rhythm after transfer to continuous light or dark conditions. Shifts in the temporal pattern of calling following changes in the timing of the photoperiodic cues indicated that lights-off is the Zeitgeber. Studies of insects under long- and short-day conditions suggest that, although insects within a population may call synchronously or asynchronously, respectively, the duration of an individual's calling bout is innately limited.     

Uplift-driven diversification revealed by the historical biogeography of the cockroach Cryptocercus Scudder (Blattodea: Cryptocercidae) in eastern Asia

Cryptocercus Scudder is a genus of wingless cockroaches, which spend their lives feeding within rotting wood in old-growth montane forests. Their dispersal capability is likely to be limited because they depend on the succession of temperate forests, but their distribution exhibits intercontinental disjunctions. Although the natural history and conservation biology of the North American species of the genus have received much attention, the evolution of the eastern Asian lineages remains enigmatic. To resolve the geographic patterns and evolutionary history of Cryptocercus in eastern Asia, we analysed genetic data of species from China (27 species), Korea (one species) and the Russian Far East (one species). We performed phylogenetic analyses of seven genes to infer the evolutionary relationships among species of Asian Cryptocercus. We then used Bayesian molecular dating to estimate the evolutionary timescale of the genus. Ancestral geographic distributions were reconstructed in rasp using statistical dispersal-vicariance analysis and statistical dispersal-extinction-cladogenesis. Our maximum-likelihood and Bayesian phylogenetic trees supported four major lineages of Cryptocercus, revealing a clear geographical pattern. The divergence of American and Asian lineages was inferred to have occurred 74.8 Ma (95% credibility interval: 51.1–103.8 Ma), with the diversification of Asian taxa beginning at 30.7 Ma (95% credibility interval: 22.9–40.3 Ma). The most recent common ancestor of Asian Cryptocercus taxa was inferred to have had a broad distribution in Asia. The uplift of the Qinghai-Tibet Plateau in the Palaeogene and Neogene, along with climatic oscillations in the Quaternary, probably had substantial effects on the formation of the disjunction pattern in the Cryptocercus lineages found in the Hengduan Mountains and Qin-Daba Mountains of China. We propose that the distribution of Cryptocercus has been strongly influenced by habitat fragmentation and subsequent allopatric speciation.     

'Candidatus Rhabdochlamydia crassificans', an intracellular bacterial pathogen of the cockroach Blatta orientalis (Insecta: Blattodea)

The genus Rickettsiella comprises various intracellular bacterial pathogens of arthropods, exhibiting a chlamydia-like developmental cycle. Species may be divided into two main groups, the R. popilliae-R. grylli group and the R. chironomi group. Previous phylogenetic studies based on the 16S ribosomal RNA encoding gene showed that two Rickettsiella species, one from each group, belong in reality to two distantly related lineages, the gamma-Proteobacteria (R. grylli) and the Chlamydiales ('Candidatus Rhabdochlamydia porcellionis', a pathogen of terrestrial isopods). In the present work, the 16S rDNA sequence of another Rickettsiella-like species, causing abdominal swelling to its cockroach host Blatta orientalis, was determined and phylogenetic analysis performed. Identical 16S rDNA sequences of 1495 nucleotides were obtained from fat body and ovary tissues of both healthy and diseased cockroach individuals. The sequence shared only 73% of similarity with R. grylli, but 82-87% with most Chlamydiales, and even 96.3% with 'Candidatus Rhabdochlamydia porcellionis'. Phylogenetic analyses confirmed the affiliation of the cockroach pathogen within the order Chlamydiales, and based on ultrastructural characteristics and genetic analyses, we propose its inclusion in the 'Candidatus Rhabdochlamydia' as a distinct taxon, 'Candidatus Rhabdochlamydia crassificans'. These results extend our knowledge of the phylogenetic diversity of the Chlamydiales.     

Inheritance and diversification of symbiotic trichonymphid flagellates from a common ancestor of termites and the cockroach Cryptocercus

Cryptocercus cockroaches and lower termites harbour obligate, diverse and unique symbiotic cellulolytic flagellates in their hindgut that are considered critical in the development of social behaviour in their hosts. However, there has been controversy concerning the origin of these symbiotic flagellates. Here, molecular sequences encoding small subunit rRNA and glyceraldehyde-3-phosphate dehydrogenase were identified in the symbiotic flagellates of the order Trichonymphida (phylum Parabasalia) in the gut of Cryptocercus punctulatus and compared phylogenetically to the corresponding species in termites. In each of the monophyletic lineages that represent family-level groups in Trichonymphida, the symbionts of Cryptocercus were robustly sister to those of termites. Together with the recent evidence for the sister-group relationship of the host insects, this first comprehensive study comparing symbiont molecular phylogeny strongly suggests that a set of symbiotic flagellates representative of extant diversity was already established in an ancestor common to Cryptocercus and termites, was vertically transmitted to their offspring, and subsequently became diversified to distinct levels, depending on both the host and the symbiont lineages.     

Colony composition,social behavior and some ecological characteristics of the Korean wood-feeding cockroach (Cryptocercus kyebangensis)

Korean populations of the genus Cryptocercus occur in forested mountains throughout South Korea. They live in monogamous associations in which parents care for their young in complex woody galleries. Single paired adults (23.2%) and one or both parents with their offspring (28.1%) were found most frequently in the field. Among single-parent families adult females (6.7%) were observed more frequently than adult males (1.4%). In families with single or both parents, the mean brood size was 21.6+/-9.4. Oothecae were observed from mid-June to the late July. Oothecae were found in the galleries of only paired adults and never found in families with nymphs. The mean number of eggs per female was 73.7+/-29.8. Most of neonates grew to the third or fourth instar prior to the winter. During the winter, C. kyebangensis in the field remained almost frozen in their galleries, but ones kept in the laboratory continued to grow during winter. Some characteristics of proctodeal feeding behavior are also described based on laboratory observations. We propose that the cold temperate climate, especially of the winter season, is one of the most important causes for the evolution of unusual life history of Cryptocercus including delayed development of nymphs.     

Water composition and loss by body color and form mutants of the German cockroach (Dictyoptera: Blattellidae)

Body water composition and rates of water loss were determined for adult males of five body color or form mutants of the German cockroach, Blattella germanica (L.). Body water content ranged from 68.4% for a yellow body strain to 74.7% for the balloon wing strain. Dark body strains (black and black×orange) contained less water than lighter color strains (orange and yellow). There were no differences in whole-body lipid content among the strains. Cuticular permeability at 30°C ranged from 18.44 to 24.8 μg cm^-2 h^-1 mmHg^-1 for black body and balloon wing strains, respectively; dark body strains had lower cuticular permeabilities than light body strains. Brief, whole-body extraction with hexane increased cuticular permeability from 5.6-fold for the balloon strain to 8.3-fold for the orange body strain. Cuticular permeabilities of hexane-extracted dark body strains again had lower cuticular permeabilities than those of light body strains, indicating that differences in permeability were due to the cuticle itself and not differences in the amount or composition of epicuticular lipids. Measurements of cuticle water content indicated that light body strains contained significantly more water than dark body strains. Rate of percent original mass and percentage of total body water lost increased linearly with time. Implications of cuticular water content to cuticular permeability are discussed.     

Thermal requirements for the embryonic development of Periplaneta americana (L.) (Dictyoptera: Blattidae) with potential application in mass-rearing of egg parasitoids

The embryonic development of oothecae of Periplaneta americana was evaluated under four different constant temperatures (5, 10, 15, 20, 25, 30, and 35 °C) and also at different exposure times at <5 °C. Their suitability as hosts after the treatment for the parasitoids Evania appendigaster and Aprostocetus hagenowii was also assessed. Temperatures of 5, 10, 15, and 35 °C adversely affected the development of the cockroaches, and exposure times to <5 °C longer than 5 days sufficed to kill all the embryos in the oothecae. The lower thermal threshold for complete development of P. americana was estimated to be 6.8 °C, with a required total amount of 900.9 degree-days. Cold-killed oothecae were still fit for the development of parasitoids. Parasitism rates of A. hagenowii were higher than those of E. appendigaster, although with lower emergence rates. Our results can be useful in aiding mass-rearing of these parasitoids for biological control programmes of P. americana, and may help forecast the time of emergence of nymphs of American cockroaches in infested areas.     

Interspecific variation in floral fragrances within the genus Narcissus (Amaryllidaceae)

To improve our understanding of the floral biology, pollination, and systematics of the genus Narcissus, a comparative study was made of flower volatiles from nine species native to southern Spain using headspace collection and GC-MS analysis. The species fell into three fragrance types based on the identity of their major volatiles. In all but one species the fragrances consisted mainly of monoterpene isoprenoids mixed with benzenoids: in six species trans-ß-ocimene occurred in high proportions, in two others it was lacking; the last species had a fragrance dominated by fatty acid derivatives, mixed with terpenoids. Two of the species showed marked intraspecific variation in many of their volatiles. When the volatile data matrix of all species was subjected to cluster analyses and the resulting phenetic trees compared with currently recognized taxonomic groups, there was no congruence at the subgeneric level. However, there was considerable agreement at the sectional level, although in most sections we studied only a single species. This apparent agreement was stronger when the volatiles were analyzed according to shared biosynthetic pathways rather than treated individually, pointing to the higher value of using biosynthetic pathways for uncovering and confirming phenetic, and probable evolutionary, relationships among species. In terms of possible selective pressures from pollinators in shaping fragrance chemistry, available information on the pollination of our species suggested an association between fragrance and types of pollinators. Two pollinator-fragrance groups were apparent: (1) species pollinated by insects that include butterflies and moths displayed fragrances containing volatiles typical of moth-pollinated flowers, most particularly indole combined with high amounts of esters, and (2) species visited exclusively by insects other than butterflies and moths, especially by bees and flies, had fragrances lacking this combination of volatiles. Narcissus assoanus was unusual among our species in having both fragrance chemotypes. Future pollination studies of Narcissus in the field are needed to test the reliability and predictability of the proposed fragrance-pollinator associations.     

Stictis s. lat. (Ostropales, Ascomycota) in northern Scandinavia, with a key and notes on morphological variation in relation to lifestyle

The closely related genera Carestiella, Schizoxylon and Stictis (Stictidaceae, Ostropales, Ascomycota) are revised in northern Scandinavia, and a revised phylogenetic hypothesis, including all seven species of this group in the area, is presented. A key to the species of Stictis s. lat. (including Carestiella, Schizoxylon and Stictis) in Northern Scandinavia is presented. S. albescens and S. confusum are described as new to science, and the new name S. brunnescens is introduced for S. mollis ssp. populorum, when treated as a distinct species. C. socia and S. albescens are the only representatives of their genera in northern Scandinavia, but a total of five species of Stictis are present in the area (S. brunnescens, S. confusum, S. mollis, S. populorum and S. radiata). Substantial within-species variation in ascoma morphology and wall pigmentation is revealed and discussed, and found to correlate with fungal lifestyles; optional lichenization apparently affects several details in fungal anatomy and morphology.