萧氏松茎象幼虫龄数的估测

室内和林间调查的结果表明 ,萧氏松茎象HylobitelusxiaoiZhang幼虫期为 5～ 7龄。该虫在林间以老熟幼虫的前 1龄幼虫 ,即以第 4～ 6龄幼虫越冬 ,其中以 5～ 6龄幼虫为主 ,4龄幼虫仅占少数     

Intraspecific variability in number of larval instars in insects

The number of larval instars varies widely across insect species. Although instar number is frequently considered to be invariable within species, intraspecific variability in the number of instars is not an exceptional phenomenon. However, the knowledge has remained fragmentary, and there are no recent attempts to synthesize the results of relevant studies. Based on published case studies, we show that intraspecific variability in the number of larval instars is widespread across insect taxa, occurring in most major orders, in both hemimetabolous and holometabolous insects. We give an overview of various factors that have been observed to affect the number of instars. Temperature, photoperiod, food quality and quantity, humidity, rearing density, physical condition, inheritance, and sex are the most common factors influencing the number of instars. We discuss adaptive scenarios that may provide ultimate explanations for the plasticity in instar number. The data available largely support the compensation scenario, according to which instar number increases in adverse conditions when larvae fail to reach a species-specific threshold size for metamorphosis. However, in Orthoptera and Coleoptera, there are some exceptional species in which instar number is higher in favorable conditions. In more specific cases, the adaptive value of the variability in instar number may be in reaching or maintaining the developmental stage adapted to hibernation, producing additional generations in multivoltine species, or increasing the probability of surviving in long-lasting adverse conditions.     

Absence of outer caudal setae on all larval instars of Phlebotomus tobbi from the Ionian Greek islands

Larval instars 2, 3 and 4 of Phlebotomus tobbi Adler, Theodor & Lourie from the Greek islands of Corfu and Zakynthos were found to have two caudal setae instead of the four usually present on these instars of Phlebotomus larvae. In a scanning electron microscope comparison with larvae of P. papatasi (Scopoli), a sensillum was seen in place of each outer seta of P. tobbi larvae, suggesting secondary loss of the setae. As the larvae of less than a tenth of the species and subspecies of the genus Phlebotomus have been seen and described, it cannot be assumed that those of P. tobbi are unique in having only two caudal setae. However, four caudal setae in late instars can no longer be considered as a constant character of the genus Phlebotomus. Observations on the larvae of P. tobbi also raise the question of the unknown function of the caudal setae.     

Identification of instars and species in some larval Polypedilum (Polypedilum) (Diptera: Chironomidae)

Instars II and III of Polypedilum aviceps Townes, Polypedilum convictum (Walker), and Polypedilum illinoense (Malloch) can be identified to species by associating them with instar IV because key taxonomic characters remain relatively unchanged from instar to instar. Instars I cannot be identified to species or genus unless they are associated with older, identifiable larvae reared from the same egg masses. No single character evaluated on slide material can be used to clearly separate instars in all three species. Larvae of P. aviceps can be separated into instars based on any four of seven characters; P. convictum by either of two characters; and, P. illinoense by a combination of two characters. Changes in structures of instars II, III, and IV are described for all three species. Growth ratios for some structures are compared and discussed with regard to Dyar's Rule.     

External auditory structures in two species of neotropical notodontid moths

Summary Two species of neotropical moths,Antaea lichyi Franclemont andHapigia curvilinea Schaus (Notodontidae) from Panamá possess paired, cup-like extensions of their pleural segments, reminiscent of mammalian pinnae, that project laterally from the perimeter of the tympanic membrane. These cups are homologous with the post-spiracular abdominal hoods of typical noctuid moths, and may be related to the orientation of the notodontid ear, where the tympanic membrane faces ventrally toward the mid-line of the moth's body and potentially reduces the reception of incident sound energy.Removal of the cups did not alter the neurologically determined best frequencies of either species, nor did it affect the shape ofH. curvilinea's directional sensitivity or its spatial point of maximal sensitivity. Polar threshold curves to stimulus tones of 30 kHz, however, revealed a reduced overall directionality, and thus indicate that the cups may impart a degree of sound localization ability.Both removal and blockage of the external structures result in reduced sensitivities (i.e. increased thresholds) to frequencies higher than approximately 30 kHz. All individuals ofH. curvilinea tested became deaf to tones over 115 kHz when the cups were ablated or blocked.Neotropical moths are exposed to potentially heavy predation pressure from insectivorous bats that characteristically emit faint and/or high frequency echolocation signals, some in excess of 70 kHz (e.g., foliage-gleaning Phyllostomatidae). In certain notodontids, the development of external auditory adaptations that enhance the reception of faint, high frequency sounds may be an evolutionary response to predation pressures by these bats.     

Inter- and intra-specific differences in the number of larval instars in British populations of 24 species of stoneflies (Plecoptera)

1. Ontogenetic changes during the life cycle of aquatic insects are important not only in life‐history studies but also in evaluating food‐web structure. They require information on the growth and number of larval instars but such information is lacking for many species, including Plecoptera. Therefore, the chief objectives of the present study were to determine inter‐ and intra‐specific differences in the number of larval instars in British populations of 24 species of stoneflies, to test Dyar’s hypothesis that growth followed a geometric progression, and to synthesise this information with previously published values for four British species. 2. Larvae were reared at constant temperatures in the laboratory from eggs from 63 populations (one to six populations per species). First instars from each population were divided into three batches and each batch was reared at one of three constant temperatures. For each species, the rearing temperature and source population had no significant effect on the mean size of each larval instar. 3. The relationship between the geometric mean length of each instar and instar number was well described by an exponential equation (P < 0.001, r² > 0.9 for all species), thus supporting Dyar’s hypothesis. Only one species, Brachyptera risi, had the same number of instars for males and females (12–13). For the other 15 herbivorous species and the four smaller carnivorous ones, the number of instars was higher for females than males (range 11–16 for males, 12–17 for females). The larger size of the females was due to their additional instars, not a sex difference in growth rates. In contrast, there was a clear growth separation of the sexes after the 9th or 10th instar for the four largest carnivores. The number of larval instars was highest for these four species (range 16–19 for males, 18–23 for females), and females were much larger than males. 4. A multiple regression equation with data from the present and previous studies (n = 27) showed that variability in the mean length of the first instar and the maximum number of larval instars for each species accounted for 88% and 91% of the variability in the mean length of the final instar for males and females, respectively. 5. Values for Plecoptera in other countries were in general agreement with those in the present study, especially in the same families. Two old, but widely quoted, high values are doubtful. The present study and four previous ones provide a sound basis for ontogenetic studies on 28 species of Plecoptera and their role in aquatic ecosystems.     

Decrease of fluctuating asymmetry among larval instars in an aquatic, holometabolous insect

The use of fluctuating asymmetry (FA) to reveal environmental stress in natural populations has been investigated extensively over the past decade. In aquatic ecosystems, many investigations involve amphibiotic insects with larval development stages in freshwater. To explain the important variability in study results, we investigated the FA level of a natural Hydropsyche exocellata (Insecta: Trichoptera) population at four different stages, from first larval instar to adult. The level of FA decreased between larval stages, but remained constant between the last larval instar and the adult. The presence of a compensational growth mechanism and the elimination of asymmetric individuals by natural selection are two hypotheses that could explain this observation.     

眉斑并脊天牛幼虫龄数及各龄特征

测定头壳宽度室内观察结果表明,眉斑并脊天牛Glenea cantor(Fabricius)幼虫有4龄。1~4龄幼虫的头壳宽度分别为(0.66±0.20),(1.45±0.20),(2.22±0.23),(3.26±0.29)mm。其龄数(Y)与幼虫头壳宽(X)度符合关系式Y=0.2975+1.1606X。在25℃条件下,1~4龄幼虫的平均龄期分别为(5.25±0.60),(4.94±0.58),(5.98±0.63)d和(22.92±1.28)d,整个幼虫期为(39.09±2.14)d。还对眉斑并脊天牛各龄幼虫的形态特征作了描述。     

Bioassay of nucleopolyhedrosis virus against larval instars of Malacosoma neustria

The relative susceptibility of third- and fourth-instar Malacosoma neustria larvae to a nucleopolyhedrosis virus was studied by bioassay in the laboratory. Larval mortality increased with increased dosage, whereas the dosage-incubation relationship was reversed. Larval age inversely affected mortality and incubation. The computed LD₅₀'s for third- and fourth-instar larvae were 1,405 and 12,320 polyhedral inclusion bodies (PIB's)/larva. The median lethal doses calculated as number of PIB's/mg body weight showed that third-instar larvae were only twice more susceptible to virus than fourths. The LT₅₀ values for 3 × 10⁵, 3 × 10⁴, and 3 × 10³ PIB's/larva were 5.9, 6.58, and 8.15 days, respectively, in third-instar assay; the corresponding figures for the two highest concentrations were 9.3 and 10.7 days in the older larvae. Lethally infected individuals died after one or, exceptionally, two molts. No correlation was found between pupal weight or adult emergence of survivors and the virus dose administered to the larvae.     

栎黄枯叶蛾幼虫龄数的确定

【目的】为明确栎黄枯叶蛾Trabala vishnou gigantina Yang幼虫的发育状况,以便进行预测预报及采取防治措施。【方法】通过野外采样获取不同发育状态的栎黄枯叶蛾幼虫,对其头壳宽度,体长,体宽,额宽,上颚基部宽和单眼间距6项形态指标进行测量,利用Crosby生长法则和线性回归方法,推断栎黄枯叶蛾幼虫的龄数。【结果】栎黄枯叶蛾幼虫有7龄,头壳宽度为最佳分龄结构。单眼间距、额宽和上颚宽3项指标均可作为分龄的辅助手段,体长和体宽变异较大,不宜用作幼虫龄数划分。【结论】研究结果为生产上合理防治该害虫提供了参考依据。     

Simultaneous dislocation of all five carpometacarpal joints

A case of unique combination of simultaneous dislocation of all five carpometacarpal joints is presented. The mechanism of injury in this case seems to be some manner of punching with a closed fist rather than direct violence. Satisfactory results were achieved using simple principles of manipulation under anesthesia, open reduction, and skeletal fixation, followed by intensive physiotherapy.     

Reproduction in captive Taiwan macaques (Macaca cyclopis) in comparison to other common macaque species

Twenty-five years of reproductive and birth data from a Macaca cyclopis colony at the New England Regional Primate Research Center (NERPRC) indicate that these animals are seasonal breeders with a birth peak between February and May. Interbirth intervals have a mean of 587.5 ± 45.6 days. The age at first reproduction for females is 5.08 ±.357 years and for males 5.01 ± .94. The normal menstrual cycle length ranges from 24–31 (mean 27.9 ± .506) days, with “offseason” long cycles ranging from 43–69 days. For 10 females studied prospectively, the sex skin color cycle ranged from 23–34 days and exhibited no long cycles. The peak estradiol value was 1.35 nmol/L on day 11 (range 10–12) of the menstrual cycle. Estradiol values ranged from 0.7–2.0 nmol/L. The peak progesterone value was 23 nmol/L on day 21 (17–23). Progesterone levels ranged from 10–42 nmol/L. The observed lower fecundability of M. cylopis in a timed mating program is consistent with later ages at first reproduction and longer interbirth compared to the other species in breeding colonies at NERPRC. © 1995 Wiley-Liss, Inc.     

Indoor airbornePenicillium species in Taiwan

Penicillium species, well-known indoor airborne fungi, are considered to be important causative agents of extrinsic bronchial asthma. For selecting the proper species for clinical investigations, it is important to know which are found indoors. In the present study, 176 plates of modified Mehrlich's Medium were exposed for 20 min in living rooms and bedrooms of 88 homes in Taipei, Taiwan. A total of 5897 colonies of fungi were isolated, varying from one to 329 per house. Of the total, 910 colonies (15.4%) were identified asPenicillium spp. The three most frequently encountered species wereP. citrinum, P. crustosum andP. implicatum. Penicillium citrinum accounted for 40.5% (369 from 28 houses);P. implicatum, for 5.2% (47 from three houses); andP. crustosum, for 2.1% (19 from seven houses).Penicillium citrinum was judged to be the most prevalent airborne fungus in Taiwan. The allergenic significance of this mold is under further investigation.     

星天牛幼虫龄期的划分

本文测量了人工饲养的星天牛Anoplophora chinensis(Forster)幼虫的9个形态结构数据,运用频次分布、均差分析和回归分析对测量数据进行统计分析,结果表明,星天牛幼虫可分5龄,其额宽是最佳的分龄结构,其次是上颚长和上颚宽。     

Cold tolerance of the overwintering larval instars of light brown apple moth Epiphyas postvittana

The light brown apple moth, Epiphyas postvittana, a leafroller native to southeastern Australia was discovered in California in 2006. The highly polyphagous nature of this pest adds to the importance of being able to predict the potential distribution of this invader across the North American continent. The spread of ectothermic species that lack winter diapause, such as E. postvittana, can be limited by their ability to tolerate cold temperature extremes. In this study we examined the cold hardiness of 4th to 6th instar E. postvittana, the only life stages known to overwinter in California, through a combination of supercooling point (SCP) and mortality at low temperatures. Our results showed that the mean SCP for E. postvittana ranged from −14.1 °C for 6th instars to −16.0 °C for 4th instars. Lethal time leading to 50% mortality (LT₅₀) for the three instars combined were 2.5 h at −10.5 °C, 41 h at −6.5 °C and 198 h at −0.9 °C. At 3 °C, the LT₅₀ of 4th instars was significantly lower at 775 h than that for 5th and 6th instars combined at 1029 h. The cold hardiness characteristics of later-instar E. postvittana larvae were comparable to those of pink bollworm, Pectinophora gossypiella, a diapausing invasive with a geographic distribution restricted to southern California. Slightly greater cold hardiness is shown by the indigenous non-diapausing leafroller Argyrotaenia franciscana, which is restricted to the Pacific Coast of North America. We therefore conclude that the moderate cold hardiness of E. postvittana will substantially limit its spread into northern temperate regions of North America.     

The millipede family Polydesmidae in Taiwan, with descriptions of five new species (Polydesmida, Diplopoda)

Polydesmidae are represented in Taiwan by seven species in two genera. Neither of the genera is endemic to Taiwan, but six of the species are, including five new: Nipponesmus minorsp. n., Epanerchodus bispinosussp. n., Epanerchodus curtigonopussp. n., Epanerchodus flagellifersp. n. and Epanerchodus pinguissp. n. In addition, the diagnosis of the hitherto enigmatic genus Nipponesmus Chamberlin & Wang, 1953 is refined vis-à-vis the especially similar, Central Asian, Siberian and Eastern European genus Schizoturanius Verhoeff, 1931, chiefly based on new material of the type-species Nipponesmus shirinensis Chamberlin & Wang, 1953; this species is adequately redescribed and represents still another Taiwanese endemic. A key to all three currently known species of Nipponesmus Chamberlin & Wang, 1953 is given. The highly speciose Central to East Asian genus Epanerchodus Attems, 1901 is represented in Taiwan by five species, all keyed, including Epanerchodus orientalis Attems, 1901, which is long known to be highly variable in Japan and found particularly polymorphous and apparently allochthonous in Taiwan. The following synonymy is formalized: Epanerchodus orientalis orientalis Attems, 1901 = Epanerchodus orientalis takakuwai Verhoeff, 1913, syn. n. The genus Usbekodesmus Lohmander, 1932 is formally synonymized with Epanerchodus Attems, 1901, syn. n., resulting in the following new formal transfers: Epanerchodus redikorzevi (Lohmander, 1932), Epanerchodus swatensis (Golovatch, 1991), Epanerchodus varius (Geoffroy & Golovatch, 2004), Epanerchodus anachoretus (Golovatch, 1986), Epanerchodus buddhis (Golovatch, 1986), Epanerchodus occultus (Golovatch, 1986), Epanerchodus sacer (Golovatch, 1987), Epanerchodus theocraticus (Golovatch, 1990) and Epanerchodus theosophicus (Golovatch, 1986), all comb. n. ex Usbekodesmus. The distributions of all seven species of Polydesmidae occurring in Taiwan are mapped and discussed.     

Cochylini (Lepidoptera: Tortricidae) in Taiwan: One newly recorded genus and five newly recorded species

Ten species of the tribe Cochylini of Taiwan are reviewed. One genus Gynnidomorpha Turner, 1916, and five species: Cochylidia contumescens (Meyrick, 1931), C. oblonga Liu & Ge, 2012, Eupoecilia ingens Sun & Li, 2013, Gynnidomorpha permixtana (Denis & Schiffermüller, 1775) and G. pista (Diakonoff, 1984) are newly recorded for Taiwan. Images of the all the adults and partial genitalia are provided, along with a table showing the distribution of the tribe Cochylini in Taiwan, China.