Central branchings of three sensory axons from a moth ear (Agrotis segetum, Noctuidae)

The central branchings of the sensory neurons in the noctuid moth ear have been investigated by introducing cobalt chloride through the cut ends of their axons. Three sensory axons stained, corresponding to the two auditory neurons (A cells) and the B neuron. The three axons were identified using physiological criteria. All three cells share the same basic morphology. Their axons divide into anterior and posterior branches, which contain numerous side branches. Their profiles lie ipsilateral, but A₁ gives off some fine side branches that cross the midline. The profiles of A₁ and B extend throughout all three thoracic ganglia, occupying a ventral, medial position. The branchings of A₂ remain within the meso- and metathoracic ganglia occupying a more dorsal and lateral position. We compare our results with those of an earlier anatomical study, and discuss them in relation to described interneurones and to behaviour     

Do body size and diet breadth affect partitioning of species diversity? A test with forest Lepidoptera

Two of the major themes resulting from recent macroecological research are the central roles that body size and niche breadth may play as determinants of species geographical distribution. Unanswered questions, however, linger regarding how similarities in body size or niche breadth affect the allocation of α‐ and β‐diversity across spatial scales. Using data on moth diversity in the eastern deciduous forest of North America, we tested the predictions that smaller‐bodied and diet‐restricted species would have lower levels of α‐diversity within forest stands and greater β‐diversity at higher sampling scales compared to larger or more generalist species. Moths were sampled using a nested sampling design consisting of three hierarchical levels: 20 forest stands, 5 sites and 3 ecoregions. Body size for 492 species was estimated as mean forewing length, and diet breadth was assessed from the published literature. Moth species were then classified according to body size (small or large) or diet breadth (generalist or restricted), and partitioning was conducted on each group. Diversity partitions for large‐ and small‐bodied species yielded similar patterns. When observed diversity components differed from those derived from our null model, a consistent pattern was observed: α‐diversity was greater than expected, β‐diversity among forest stands was less than expected, and β‐diversity among sites and ecoregions was higher than expected. In contrast, diet‐restricted moths contributed significantly less to stand‐level α‐diversity than generalist feeders. Furthermore, specialists contributed to a greater proportion of β‐diversity across scales compared to generalist moths. Because absolute measures of β‐diversity among stands were greater for generalists than for restricted feeders, we suggest that regional β‐diversity of forest moths may be influenced by several possible factors: intraspecific aggregation of diet‐restricted species, local fluctuations in population size of eruptive generalists and small geographical distributions of generalist moths than predicted by the geographical extent of putative host plants     

The role of ecological availability and host plant characteristics in determining host use by the bogus yucca moth Prodoxus decipiens

1. Specialisation in host plant use is strongly correlated with speciation in many plant‐feeding insects. Specialised taxa, however, could be restricted in host range due to limits in ecological availability of host plant species rather than trade‐offs in using alternate host species. 2. Moths in the genus Prodoxus are extreme specialists on Yucca and speciation is closely tied to host plant shifts. However, many Yucca ranges are allopatric. This study examined whether the bogus yucca moth Prodoxus decipiens is limited in host range because of biogeographic factors or due to differences in the characteristics of host plant species. 3. In a common garden, local P. decipiens moths that use Yucca filamentosa were exposed to individuals of five Yucca species, two that are known hosts of P. decipiens in other parts of its range and three that are used by its sister species, Prodoxus quinquepunctellus. 4. Local moths were attracted to flowers of all Yucca species and females attempted oviposition in the flowering stalks of all species. However, larvae successfully completed development to diapause in only one of the five host plant species. Larval development on non‐natal Yucca species was significantly reduced compared with the local host. 5. The results suggest that differences in host plant characteristics among Yucca species would result in strong natural selection during a host shift. Thus, specialisation in host plant use is probably due to trade‐offs involved with using novel host plant species as well as ecological availability.     

A synthesis of laboratory and field studies on the effects of transgenic Bacillus thuringiensis (Bt) maize on non‐target Lepidoptera

One of the major applications of transgenic crops in agriculture are the so‐called Bacillus thuringiensis Berliner (Bt) plants, in particular Bt maizes, which produce insecticidal Cry proteins that target specific orders, such as the Lepidoptera or Coleoptera. We reviewed publications that reported on the direct toxic effects of Bt‐maize and/or Cry proteins of current Bt‐maize events on larvae of non‐target butterflies and moths (Lepidoptera). In total, 20 peer‐reviewed publications were identified, of which 16 papers contributed laboratory‐based data and seven field‐based data. An adverse effect on caterpillars was recorded in 52% of all laboratory‐based and in 21% of all field‐based observations. The variables most often studied and having the highest occurrence of effects were larval survival, body mass, and developmental time. Parameters of the adult stage were under‐represented in the studies. Overall, 11 lepidopteran species were tested. The majority of the studies originated from the USA, with the Monarch butterfly being the most studied, whereas other species and other parts of the world were widely neglected. Laboratory experiments were often run under unrealistic conditions from an ecological point of view. Although the papers we reviewed indicated a potential hazard for Lepidoptera that are exposed to and feed on lepidopteran‐specific Bt‐maize pollen, a general conclusion on the level of risk for butterflies and moths cannot as yet be drawn. A comprehensive risk characterization would require thorough hazard identification, exposure assessment, and impact assessment. However, our review showed that even the basic level of hazard characterization is as yet incomplete. Reasons for this are the still‐limited numbers of publications and concurrent lack of knowledge, the restriction of data to only a few species, the over‐representation of North American species, and the identified limitations of both laboratory and field experiments. The findings of this review suggest that more realistic, ecologically meaningful, and detailed experiments and analyses are crucial to improve the present assessment of Bt‐maize cultivation effects on Lepidoptera.     

蓖麻蚕对鼠生殖系统雌激素样效应的研究

目的研究蓖麻蚕雌蛾乙醇提取物(EEFM)的雌激素效应,以寻找理想的ERT药源并提高蓖麻蚕的综合利用价值.方法根据每日药物及剂量处理,将雌性小鼠随机分为模型对照组,正常对照组,乙烯雌酚组,EEFM低剂量(EEFM-L,0.2 g/kg·d-1)组,EEFM高剂量(EEFM-H,0.4 g/kg·d-1)组.测定实验鼠的子宫、免疫器官脏器指数、阴道角化细胞发生率及POD活性.结果EEFM两个剂量对未成年雌性小鼠、成年去势雌性小鼠子宫作用效应均达到显著或极显著.EEFM对去势成年雌性小鼠角化细胞发生率的影响约为乙烯雌酚(DES)组的2/3(EEFM-H77.20%,DES95.7%),效果极显著.结论EEFM对实验鼠具有显著的雌激素效应,对免疫器官元不良影响(DES组显著降低实验鼠胸腺重量),有可能成为雌激素替代疗法(ERT)的理想药源物质.     

Nocturnal anti-predator adaptations in eared and earless Nearctic Lepidoptera

Nocturnal flight exposes insects to selection pressures thatinclude reduced light and the hunting behavior of insectivorousbats. Using a phylogenetically based selection of wild mothscollected from a Nearctic site, we report that earless speciesfly less throughout the night than eared species. This supportsthe hypothesis that this behavior has evolved as a passive defenseagainst the transient attacks of aerially foraging bats in insectsthat do not possess long-range auditory detection abilities.We measured the eyesize of a selection of moths whose 24-h flightactivities are known and confirm that nocturnal lifestyle resultsin larger eyes. With the exception of hawkmoths, there is noeyesize difference between eared and earless moths, suggestingthat earless moths do not preferentially use vision to detectthe approach of bats.     

Large‐scale mating disruption of Ephestia spp. and Plodia interpunctella in Czech Republic,Greece and Italy

Field trials were carried out to evaluate the use of the pheromone (9Z,12E)‐tetradecadienyl acetate (TDA/ZETA) for mating disruption (MD) of Pyralidae moths associated with stored products, in most cases the Raisin moth, Ephestia cautella (Walker), Mediterranean flour moth, Ephestia kuehniella Zeller and Indianmeal moth, Plodia interpunctella (Hübner). The experiments were conducted in the Czech Republic, Greece and Italy during 2007 and 2008 in storage facilities that varied in their size and type, and included flour mills, retail stores, storage rooms with currants and raw grain stores. After a summer pre‐treatment monitoring period to assess moth population in, dispensers containing TDA were placed in the fall. Adjacent facilities without dispensers were used as control units. Pheromone‐baited traps were used to monitor the population fluctuation of the pyralid moths during the entire experimental periods. The presence of MD dispensers notably reduced the number of adults found in the traps in comparison with control rooms. Monitoring of female oviposition, measured as number of hatched larvae in cups containing food, indicated that there was a reduction in the number of larvae in the areas with MD dispensers. The results of the present work indicate that the use of mating disruption is feasible against pyralid moths in storage facilities, and should be further evaluated as a component of an integrated pest management based control strategy.     

The Hawaiian amphibious caterpillar guild: new species of Hyposmocoma (Lepidoptera: Cosmopterigidae) confirm distinct aquatic invasions and complex speciation patterns

Although aquatic caterpillars are a globally rare lifestyle, we have found them in multiple, independent lineages of the endemic moth genus Hyposmocoma across all of the Hawaiian Islands with flowing water. We formally describe 11 new species of Hyposmocoma that belong to four different larval case types: cone, bugle, medium burrito, and large burrito: Hyposmocoma kahamanoa sp. nov. from Oahu Island, Hyposmocoma kamakou sp. nov. from Molokai Island, Hyposmocoma kahaiao sp. nov. , Hyposmocoma waihohonu sp. nov. , and Hyposmocoma moopalikea sp. nov. from Maui Island, and Hyposmocoma aumakuawai sp. nov. , Hyposmocoma eepawai sp. nov. , Hyposmocoma ipowainui sp. nov. , Hyposmocoma kawaikoi sp. nov. , Hyposmocoma uhauiole sp. nov. , and Hyposmocoma wailua sp. nov. from Kauai Island. We also illustrate and describe in detail the aquatic case‐bearing larva of Hyposmocoma kahamanoa. Despite having similar ecologies as algae and lichen grazers at and below the water line of streams, prior research indicates that species with each case type constitute an independent lineage, with terrestrial sister taxa, and therefore the different groups of species bearing unique case types each represent an independent aquatic invasion. The case‐bearing larvae often occur sympatrically, and on Kauai even species with similar case‐types occur together, suggesting complex patterns of speciation and either past periods of isolation or sympatric speciation. Phylogenetic analysis of 2243 base pairs from two nuclear and one mitochondrial gene for 18 species confirm that each species is endemic to a single volcano, and that morphological divergence within case‐types has not been dramatic. Diversification has been complex, and superficially similar case type lineages are not all monophyletic. Kauai, the oldest but smallest of the major high islands, supports more species in the aquatic guild than any other island, thus island age, rather than size, may be important in generating diversity in this group. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 162 , 15–42.     

Allopatric distribution and diversification without niche shift in a bryophyte-feeding basal moth lineage (Lepidoptera: Micropterigidae)

The Lepidoptera represent one of the most successful radiations of plant-feeding insects, which predominantly took place within angiosperms beginning in the Cretaceous period. Angiosperm colonization is thought to underlie the evolutionary success of the Lepidoptera because angiosperms provide an enormous range of niches for ecological speciation to take place. By contrast, the basal lepidopteran lineage, Micropterigidae, remained unassociated with angiosperms since Jurassic times but nevertheless achieved a modest diversity in the Japanese Archipelago. We explored the causes and processes of diversification of the Japanese micropterigid moths by performing molecular phylogenetic analysis and extensive ecological surveying. Phylogenetic analysis recovered a monophyletic group of approximately 25 East Asian endemic species that feed exclusively on the liverwort Conocephalum conicum, suggesting that niche shifts hardly played a role in their diversification. Consistent with the low flying ability of micropterigid moths, the distributions of the Conocephalum specialists are each localized and allopatric, indicating that speciation by geographical isolation has been the major process shaping the diversity of Japanese Micropterigidae. To our knowledge, this is the largest radiation of herbivorous insects that does not accompany any apparent niche differentiation. We suggest that the significance of non-ecological speciation during the diversification of the Lepidoptera is commonly underestimated.