A molecular phylogeny for the oldest (nonditrysian) lineages of extant Lepidoptera,with implications for classification,comparative morphology and life‐history evolution

Within the insect order Lepidoptera (moths and butterflies), the so‐called nonditrysian superfamilies are mostly species‐poor but highly divergent, offering numerous synapomorphies and strong morphological evidence for deep divergences. Uncertainties remain, however, and tests of the widely accepted morphological framework using other evidence are desirable. The goal of this paper is to test previous hypotheses of nonditrysian phylogeny against a data set consisting of 61 nonditrysian species plus 20 representative Ditrysia and eight outgroups (Trichoptera), nearly all sequenced for 19 nuclear genes (up to 14 700 bp total). We compare our results in detail with those from previous studies of nonditrysians, and review the morphological evidence for and against each grouping The major conclusions are as follows. (i) There is very strong support for Lepidoptera minus Micropterigidae and Agathiphagidae, here termed Angiospermivora, but no definitive resolution of the position of Agathiphagidae, although support is strongest for alliance with Micropterigidae, consistent with another recent molecular study. (ii) There is very strong support for Glossata, which excludes Heterobathmiidae, but weak support for relationships among major homoneurous clades. Eriocraniidae diverge first, corroborating the morphological clade Coelolepida, but the morphological clades Myoglossata and Neolepidoptera are never monophyletic in the molecular trees; both are contradicted by strong support for Lophocoronoidea + Hepialoidea, the latter here including Mnesarchaeoidea syn.n. (iii) The surprising grouping of Acanthopteroctetidae + Neopseustidae, although weakly supported here, is consistent with another recent molecular study. (iv) Heteroneura is very strongly supported, as is a basal split of this clade into Nepticuloidea + Eulepidoptera. Relationships within Nepticuloidea accord closely with recent studies based on fewer genes but many more taxa. (v) Eulepidoptera are split into a very strongly supported clade consisting of Tischeriidae + Palaephatidae + Ditrysia, here termed Euheteroneura, and a moderately supported clade uniting Andesianidae with Adeloidea. (vi) Relationships within Adeloidea are strongly resolved and Tridentaformidae fam.n. is described for the heretofore problematic genus Tridentaforma Davis, which is strongly supported in an isolated position within the clade. (vii) Within Euheteroneura, the molecular evidence is conflicting with respect to the sister group to Ditrysia, but strongly supports paraphyly of Palaephatidae. We decline to change the classification, however, because of strong morphological evidence supporting palaephatid monophyly. (viii) We review the life histories and larval feeding habits of all nonditrysian families and assess the implications of our results for hypotheses about early lepidopteran phytophagy. The first host record for Neopseustidae, which needs confirmation, suggests that larvae of this family may be parasitoids. This published work has been registered in ZooBank: http://zoobank.org/urn:lsid:zoobank.org:pub:C17BB79B‐EF8F‐4925‐AFA0‐2FEF8AC32876 .     

Functional morphology,ontogeny and evolution of mantis shrimp‐like predators in the Cambrian

Abstract: We redescribe the morphology of Yohoia tenuis (Chelicerata sensu lato) from the Cambrian Burgess Shale Lagerstätte. The morphology of the most anterior, prominent, so‐called great appendage changes throughout ontogeny. While its principal morphology remains unaltered, the length ratios of certain parts of the great appendage change significantly. Furthermore, it possesses a special jack‐knifing mechanism, i.e. an elbow joint: the articulation between the distal one of the two peduncle elements and the most proximal of the four spine‐bearing claw elements. This morphology might have enabled the animal to hunt like a modern spearer‐type mantis shrimp, an analogy enhanced by the similarly large and protruding eyes. For comparison, details of specimens of selected other great‐appendage arthropods from the Lower Cambrian Chengjiang Lagerstätte have been investigated using fluorescence microscopy. This revealed that the morphology of the great appendage of Y. tenuis is much like that of the Chengjiang species Fortiforceps foliosa and Jianfengia multisegmentalis. The morphology of the great appendage of the latter is even more similar to the morphology developed in early developmental stages of Y. tenuis, while the morphology of the great appendage of F. foliosa is more similar to that of later developmental stages of Y. tenuis. The arrangement of the elbow joint supports the view that the great appendage evolved into the chelicera of Chelicerata sensu stricto, as similar joints are found in various ingroup taxa such as Xiphosura, Opiliones or Palpigradi. With this, it also supports the interpretation of the great appendage to be homologous with the first appendage of other arthropods.     

Embryogenesis of Dinocras cephalotes, Perla grandis and P. marginata (Plecoptera: Perlidae) in different temperature regimes

1. Temperature dependence of embryogenesis of the three perlid stoneflies Dinocras cephalots , Perla grandis and P. marginata was investigated by means of incubation experiments. Special emphasis was laid on the effect of fluctuating temperatures and on intraspecific differences between populations from two different field sites in the Swiss prealps (i.e. River Necker and River Thur).
2. Dinocras cephalotes embryos develop between 6.3 and 26.6 °C. The lower threshold temperature is lower than has been reported for more northern populations (i.e. from England and Norway), indicating the existence of a latitudinal gradient. Perla grandis eggs only developed between 9.9 and 18.4 °C. In P. marginata , successful embryogenesis was observed between 9.9 and 18.4 °C, but not enough eggs were available to explore the threshold temperatures.
3. Embryogenesis of D. cephalotes and P. grandis was significantly faster at a 12/16 °C daily fluctuating temperature regime than at a constant 14 °C. However, no significant difference was found between the development under simulated field temperature regimes (with less distinct daily amplitudes) and constant temperatures.
4. D. cephalotes , hatching of eggs from the Necker population was much less synchronous than that in the Thur population. Since the Necker discharge regime is harsher than the Thur regime, it is possible that this asynchrony spreads the risk of destruction during bed-moving floods.     

Increased gene sampling yields robust support for higher‐level clades within Bombycoidea (Lepidoptera)

This study has as its primary aim the robust resolution of higher‐level relationships within the lepidopteran superfamily Bombycoidea. Our study builds on an earlier analysis of five genes (～6.6 kbp) sequenced for 50 taxa from Bombycoidea and its sister group Lasiocampidae, plus representatives of other macrolepidoteran superfamilies. The earlier study failed to yield strong support for the monophyly of and basal splits within Bombycoidea, among others. Therefore, in an effort to increase support specifically for higher‐level nodes, we generated 11.7 kbp of additional data from 20 genes for 24 of 50 bombycoid and lasiocampid taxa. The data from the genes are all derived from protein‐coding nuclear genes previously used to resolve other lepidopteran relationships. With these additional data, all but a few higher‐level nodes are strongly supported. Given our decision to minimize project costs by augmenting genes for only 24 of the 50 taxa, we explored whether the resulting pattern of missing data in the combined‐gene matrix introduced a nonphylogenetic bias, a possibility reported by others. This was achieved by comparing node support values (i.e. nonparametric bootstrap values) based on likelihood and parsimony analyses of three datasets that differ in their number of taxa and level of missing data: 50 taxa/5 genes (dataset A), 50 taxa/25 genes (dataset B) and 24 taxa/25 genes (dataset C). Whereas datasets B and C provided similar results for common nodes, both frequently yielded higher node support relative to dataset A, arguing that: (i) more data yield increased node support and (ii) partial gene augmentation does not introduce an obvious nonphylogenetic bias. A comparison of single‐gene bootstrap analyses identified four nodes for which one or two of the 25 genes provided modest to strong support for a grouping not recovered by the combined‐gene result. As a summary proposal, two of these four groupings (one each within Bombycoidea and Lasiocampidae) were deemed sufficiently problematic to regard them as unresolved trichotomies. Since the alternative groupings were always highly localized on the tree, we did not judge a combined‐gene analysis to present a problem outside those regions. Based on our robustly resolved results, we have revised the classification of Bombycoidea: the family Bombycidae is restricted to its nominate subfamily, and its tribe Epiini is elevated to subfamily rank (Epiinae stat.rev. ), whereas the bombycid subfamily Phiditiinae is reinstated as a separate family (Phiditiidae stat.rev. ). The bombycid subfamilies Oberthueriinae Kuznetzov & Stekolnikov, 1985, syn.nov. and Prismostictinae Forbes, 1955, syn.nov. , and the family Mirinidae Kozlov, 1985, syn.nov. are established as subjective junior synonyms of Endromidae Boisduval, 1828. The family Anthelidae (Lasiocampoidea) is reincluded in the superfamily Bombycoidea.     

Survivorship of seedlings of false sandalwood (Myoporum platycarpum) in the chenopod rangelands grazed by sheep,kangaroos and rabbits at Whyalla,South Australia

ABSTRACT Myoporum platycarpum R. Br. (Myoporaceae) is widely distributed through semi‐arid New South Wales, South Australia, Western Australia and Victoria, where it occurs as an upper‐storey dominant or co‐dominant tree over chenopod shrublands. Previous studies have concluded that the seedlings and juveniles of many shrubs and trees, including M. platycarpum, are selectively grazed by sheep and rabbits, which threatens their long‐term survival in rangelands. The aim of this study was to assess the survivorship of M. platycarpum seedlings grazed by sheep and rabbits in a rangeland setting. Seedlings of M. platycarpum were raised in the greenhouse and planted in the field and individually fenced to allow or prevent access by various herbivores. Over 1 year, the frequency of grazing and size of canopy was recorded. A flexible mixed model incorporating cubic smoothing splines was used to describe the relationship between change in canopy volume over time, fixed effects (exclosure type, time, rainfall and egesta weights) and random variability among plants, replicates and sites. The mixed models showed that there were no significant differences in canopy volume over time between sheep and rabbit‐proof exclosures, indicating that rabbits were not significantly affecting the seedlings, browsing only five of those available to them, of which three survived. Large herbivores (sheep and/or kangaroos) grazed un‐caged seedlings, resulting in significantly smaller canopy volumes, and higher death rates (80%). Although supplementary irrigation was applied, background losses due to desiccation in caged seedlings were up to 50%.