A preliminary study on the phylogenetic relationships of Copelatus Erichson (Coleoptera: Dytiscidae: Copelatinae) based on larval chaetotaxy and morphology

The phylogenetic relationships of the diving-beetle (Dytiscidae) subfamily Copelatinae are not well known. Some authors postulated a sister-group relationship between Copelatus Erichson and the remaining Dytiscidae, relying mainly on the absence of a mandibular channel in Copelatus. Other authors suggested a more derived position of the genus. Larval characters have been underutilized in phylogenetic studies, mainly because the larvae of many taxa within the family and, in particular, within Copelatinae are unknown. A comprehensive approach aimed to study the phylogenetic placement of a member of this subfamily based on larval characters has not been produced so far. In this study, the phylogenetic relationships of Copelatus are explored based on a cladistic analysis of 24 taxa and 120 chaetotaxic and morphological characters from larvae. For this purpose, larvae of Copelatus longicornis Sharp are described and illustrated in detail for the first time, with particular emphasis on morphometry and chaetotaxy, with the latter being unexplored until now. The results support a derived position of Copelatus within Dytiscidae, with a sister-group relationship between this genus and a clade formed by the subfamilies Lancetinae, Coptotominae, Laccophilinae, Colymbetinae, Matinae, and Dytiscinae, and part of Agabinae. No evidence was found for a sister-group relationship between Copelatus and the remaining Dytiscidae so that the absence of a mandibular channel in this genus is likely a reduction. Copelatus is supported by three apomorphies within Dytiscidae: mandibular channel absent, internal margin of the stipes with three robust spinulae, and seta MX8 inserted subapically on the galea. Handling editor: K. Martens     

Taxonomic review and phylogenetic analysis of fifteen North American Entomobrya (Collembola,Entomobryidae), including four new species

The chaetotaxy of 15 species of eastern North American Entomobrya is redescribed in order to determine potential characters for the diagnosis of cryptic lineages and evaluate the diagnostic and phylogenetic utility of chaetotaxy. As a result, four new species (Entomobrya citrensis Katz & Soto-Adames, sp. n., Entomobrya jubata Katz & Soto-Adames, sp. n., Entomobrya neotenica Katz & Soto-Adames, sp. n. and Entomobrya unifasciata Katz & Soto-Adames, sp. n.) are described, and new diagnoses are provided for Entomobrya assuta Folsom, Entomobrya atrocincta Schött, Entomobrya decemfasciata (Packard), Entomobrya ligata Folsom, Entomobrya multifasciata (Tullberg), and Entomobrya quadrilineata (Bueker). Furthermore, previously undocumented levels of intraspecific variation in macrosetal pattern are reported, tempering the exclusive use of chaetotaxy for species delimitation. Phylogenetic relationships, estimated using both morphological and molecular data, indicate that Entomobrya is likely paraphyletic. The phylogenies also suggest that unreliable character homology, likely fostered by Entomobrya’s profusion of macrosetae, may limit the phylogenetic utility of chaetotaxy in groups characterized by an abundance of dorsal macrosetae.     

New Neotropical Species of the Genus Frankliniella Karny (Insecta: Thysanoptera: Thripidae)

Four new species of the genus Frankliniella Karny are described, two from Chile, F. rahakana sp. n. and F. otites sp. n.; one from Costa Rica, F. senckenbergiana sp. n. and one from Argentina, F. amigoi sp. n. F. rahakana sp. n. belongs to the ‘intonsa group’ and the other three to the ‘minuta group’ of Frankliniella.     

Perianal structures in myrmecophilous subterranean aphids (Insecta: Hemiptera: Aphididae) – Comparative morphology of trophobiotic organ with its first description in Lachninae

Scanning electron microscopy (SEM) and light stereoscopic microscopy (LSM) were used for the first time to elucidate the external morphology of the so called “trophobiotic organ” on the end of abdomen of apterous viviparous females of six aphid species (Insecta: Hemiptera: Aphididae), representatives of the myrmecophilous, subterranean aphids from the subfamilies Anoeciinae (Anoecia furcata), Eriosomatinae (Forda formicaria, Geoica utricularia, Tetraneura ulmi), and Lachninae (Protrama flavescens, Trama troglodytes). We examined and compared the external morphology in the parthenogenetic generation living on roots of deciduous plants. FE-SEM images based on HMDS preparation techniques revealed great similarity of perianal structures even between not closely related groups. Rectangular, vertically positioned anal plate, extremely shortened cauda and setae around the anus seem to be common features of these aphids. However, some differences in the number and length of setae, their arrangement and inclination of anal plate may be observed. The discussion focuses on the adaptive importance of such modifications, with respect to underground life mode and myrmecophily, but with reservations concerning living in galls by representatives of Eriosomatinae, which is hypothesized to be a factor driving the development of such modifications of perianal structures in this group of aphids.     

New species of springtails in the Proisotoma genus complex from Vermont and New York, USA with descriptive notes on Ballistura alpa Christiansen & Bellinger 1980 (Hexapoda, Collembola, Isotomidae)

Three new species of Isotomidae springtails are described from the Lake Champlain Basin (Vermont and New York, USA), Lake Willoughby and Greater Averril Pond in Vermont. Subisotoma joyceisp. n. and Scutisotoma champisp. n. were collected in sandy beaches whereas Ballistura rossisp. n. was found only in a constructed wetland built and managed by the University of Vermont. Scutisotoma champisp. n. was found in Lakes Champlain and Willoughby, and Greater Averril Pond and is probably present in most lakes and large ponds in the area. Subisotoma joyceisp. n. was found only along the southern and eastern coast of South Hero, and the mainland coast facing eastern South Hero. Ballistura alpa is redescribed and transferred to the genus Pachyotoma based on the absence of tibiotarsal seta B4/B5, the presence of secondary cuticular granules, 4 prelabral setae, a full complement of guard setae on labial papilla E and in having a bifurcate outer maxillary lobe with 4 sublobal setae.     

Larval morphology of Panorpodes kuandianensis (Insecta,Mecoptera, Panorpodidae) and its evolutionary implications

Larval characters play a significant role in evolutionary and systematic studies of holometabolous insects. However, Panorpodidae, a derived family of Mecoptera, are largely unknown in their immature stages to date. Here, the first instar larva of the short-faced scorpionfly Panorpodes kuandianensis Zhong, Zhang & Hua, 2011 is described and illustrated using light and scanning electron microscopy. The larva of Panorpodes is remarkable for the absence of compound eyes on the head and the presence of seven small unpaired proleg-like processes along the midventral line on abdominal segments II–VIII. The homology of these unpaired appendage-like processes, their ecological adaptation, and the evolutionary implications of some larval characters of Panorpodidae are discussed.     

Larval morphology of the scorpionfly Dicerapanorpa magna (Chou) (Mecoptera: Panorpidae) and its adaptive significance

Larval morphology can provide valuable characters for taxonomic and phylogenetic analyses of insects and reflect the adaptations to various living habits. Compared with the adult stages, larval study has lagged far behind in Mecoptera. Although several genera of Panorpidae have been studied for their larval stages, the larva of Dicerapanorpa Zhong and Hua, 2013 basically remains unclear. Here the larva of Dicerapanorpa magna (Chou) is described and illustrated in detail for the first time using light microscopy and scanning electron microscopy. The larva is eruciform, with eight pairs of abdominal prolegs in addition to three pairs of thoracic legs, as in other Panorpidae. The most remarkable characteristics of the larvae include a pair of erect subdorsal annulated processes each on abdominal segments I–IX (A1–A9) and a single middorsal annulated process on A10, as well as a pair of prominent compound eyes composed of over 40 ommatidia, which distinguish this genus from other genera of Panorpidae. The annulated processes may have adaptive significance for fossorial and soil-living habits.