Ovipositor Structure Research Articles

Ovipositor of bitterling fishes (Cyprinidae, Acheilognathinae): fine structure from a functional perspective

The study presents fine structure data on the ovipositor of four bitterling species (Rhodeus ocellatus, Rhodeus amarus, Paratanakia himantegus and Acheilognathus barbatulus). In A. barbatulus and P. himantegus, ovipositor structure has never been studied. Novel data on the structure of the ovipositor were collected using two complementary methods, light- and transmission electron microscopy. The new findings relate to the covering and lining epithelia, basal laminae, cell junctions and supporting/connective tissue layer. All examined fish shared the same basic ovipositor structure and the newly reported details, regardless of their species affiliation. Evaluation of structure modifications related to the passage of eggs through the ovipositor revealed a range of transitional tissue changes, corroborating their presumable role inferred from the study of fine structure.

Ultrastructural characterization of the scale cover of crypticAspidiotusspp. (Hemiptera: Diaspididae) and the ovipositor of their parasitoids

AbstractCorrectly identifying target insect pests and their natural enemies is important in biological control management programs. In the scale insect outbreak that devastated the coconut industry of the Philippines in 2009, the misidentification of the destructive pest population resulted in an unsuccessful biological control application. The scale cover has been proposed as a diagnostic feature to identify the cryptic Aspidiotus species from one another. Here, we examined the scale cover of three Aspidiotus species at higher magnification using scanning electron microscopy (SEM) to validate the observed difference in scale cover characteristics reported in previous literature. SEM observations revealed that the cryptic species A. destructor and A. rigidus scale covers are ultrastructurally similar, having irregularly arranged and highly agglutinated wax ribbons, whereas A. nerii has highly agglutinated wax ribbons arranged in an overlapping concentric pattern. Additionally, a comparative observation of the ovipositor of the hymenopteran parasitoids directly associated with the two cryptic Aspidiotus species, A. rigidus and A. destructor, was done to provide structural evidence that links ovipositor structure to host specificity. The structure of the ovipositor tip of the hymenopteran parasitoids directly associated with the two Aspidiotus species examined under SEM is congruent with their mode of parasitization.

New genera, new species and new records of leafhoppers (Hemiptera: Cicadellidae) from Vietnam.

Recent collecting in northern Vietnam yielded specimens of several new leafhopper species, two of which represent new monotypic genera, and several additional species not previously recorded from Vietnam. The two new genera (Hochiminus n. gen. and Pseudocestius n. gen.) and 15 new species (Abrus digitatus n. sp., Aeternus ninhbinhensis n. sp., Drabescoides bispinosa n. sp., Tenompoella vietnamensis n. sp., Uzelina (Uzelina) vietnamensis sp. n., Hochiminhus tamdaoensis n. sp., Pseudocestius cucphuongensis n. sp., Phlogothamnus pseudorugosus n. sp., Scaphoidella albopunctata n. sp., Bundera onukiiformis n. sp., Carinata arcuata n. sp., Traiguma hamocauda n. sp., Signoretia tamdaoensis n. sp., Amrasca (Quartasca) curvata n. sp., Amrasca (Quartasca) excavata n. sp.) are described and illustrated and comparative notes are provided. An additional 28 species representing 20 genera are newly recorded from Vietnam. Most of the latter were previously recorded only from southern China. The enigmatic species, Tardrabassus pakneunensis Dai Dietrich, previously known from two males collected in Laos in 1918, is newly recorded from Vietnam based on recently collected female specimens. The ovipositor structure of the female confirms placement of Tardrabassus in Iassinae. The female pregenital sternite and ovipositor of Hamulotettix ungulatus Dai Zhang are also illustrated for the first time. A new synonymy is also proposed: Ujna consors Distant, 1908 equals Mileewa puerana Yang Meng, 2010, n. syn.

Structural and transcriptional evidence of mechanotransduction in the Drosophila suzukii ovipositor

Drosophila suzukii is an invasive pest that prefers to lay eggs in ripening fruits, whereas most closely related Drosophila species exclusively use rotten fruit as oviposition site. This behaviour is allowed by an enlarged and serrated ovipositor that can pierce intact fruit skin, and by multiple contact sensory systems (mechanosensation and taste) that detect the optimal egg-laying substrates. Here, we tested the hypothesis that bristles present in the D. suzukii ovipositor tip contribute to these sensory modalities. Analysis of the bristle ultrastructure revealed that four different types of cuticular elements (conical pegs type 1 and 2, chaetic and trichoid sensilla) are present on the tip of each ovipositor plate. All of them have a poreless shaft and are innervated at their base by a single neuron that ends in a distal tubular body, thus resembling mechanosensitive structures. Fluorescent labelling in D. suzukii and D. melanogaster revealed that pegs located on the ventral side of the ovipositor tip are innervated by a single neuron in both species. RNA-sequencing profiled gene expression, notably sensory receptor genes of the terminalia of D. suzukii and of three other Drosophila species with changes in their ovipositor structure (from serrated to blunt ovipositor: Drosophila subpulchrella, Drosophila biarmipes and D. melanogaster). Our results revealed few species-specific transcripts and an overlapping expression of candidate mechanosensitive genes as well as the presence of some chemoreceptor transcripts. These experimental evidences suggest a mechanosensitive function for the D. suzukii ovipositor, which might be crucial across Drosophila species independently from ovipositor shape.

On the taxonomic position of Notosimus angustipennis (Melichar, 1906) (Hemiptera: Auchenorrhyncha: Fulgoroidea: Acanaloniidae)

The taxonomic position of the genus Notosimus Fennah, the family Acanaloniidae Amyot et Serville, 1843 is discussed and confirmed by the characters of ovipositor structure described and illustrated for the first time. Notosimus angustipennis (Melichar, 1906) is newly recorded from Cordoba Province in Central Argentina. The photos of holotype of N. angustipennis and the drawings of hind wing of this species as well as Acanalonia conica (Say, 1830) and A. pumila (Van Duzee, 1908) are given.

No more machismo in Callyntra (Coleoptera: Tenebrionidae): Callyntra femina, a new species discovered based on female genitalia and genetic evidence.

Callyntra is a genus of tenebrionid beetles endemic to the Southern Cone region of South America, with 23 species occurring in Chile and one shared with Argentina. The recent descriptions of new species were commonly based on the male genitalia structure, underestimating the utility of the female genitalia for this purpose. Analysis of the ovipositor structure of a series of females assigned to Callyntra carbonaria from the Bío-Bío and Araucanía in Southern Chile, have resulted in the discovery of a new species, Callyntra femina sp. nov., which was corroborated through molecular analysis using COI and 16S gene fragments. The phylogenetic analysis recovered C. femina as sister to a clade composed of C. rossi, C. carbonaria and C. riverai, being genetically more similar to C. rossi.

Revision of the Hawaiian psyllid genus Swezeyana, with descriptions of seven new species (Hemiptera, Psylloidea, Triozidae).

The endemic Hawaiian genus Swezeyana Caldwell, 1940 is highly distinctive due to the extremely long genal processes. In addition, some of the immatures are ornamented with extraordinary tubercles and tentacles. Two Swezeyana species are redescribed, and seven new species are described, bringing the total number of species in the genus to nine. All species are hosted by a single, endemic host plant, Planchonella sandwicensis (Sapotaceae), which is distributed across all major islands in the archipelago. The majority of Swezeyana species are single island endemics. A sister taxon pair is found sympatrically on the same individual plants on Kauai, and putative sister or at least closely related species are also found sympatrically on Oahu and Hawaii, suggesting these taxa may have diversified in sympatry. However, there is no observed ecological niche partitioning, despite some striking morphological diversity, as all Swezeyana species have free-living immatures that are found on the leaf surface, and therefore no apparent biological shifts are coincident with occupying the same host plant. Two species groups are represented by strikingly different female terminalia structure and endoskeletal development, although ovipositor structure is very similar between the two groups. Mitochondrial DNA barcodes (COI and cytB) are provided for eight of the nine species. A phylogenetic analysis of the mitochondrial barcode regions indicates species relationships within Swezeyana and provides a comparison of genetic divergence with other Hawaiian endemic genera.

Ovipositor morphology correlates with life history evolution in agaonid fig wasps

The high adaptive success of parasitic Hymenoptera might be related to the use of different oviposition sites, allowing niche partitioning among co-occurring species resulting in life history specialization and diversification. In this scenario, evolutionary changes in life history and resources for oviposition can be associated with changes in ovipositor structure, allowing exploitation of different substrates for oviposition. We used a formal phylogenetic framework to investigate the evolution of ovipositor morphology and life history in agaonid wasps. We sampled 24 species with different life histories belonging to all main clades of Agaonidae including representatives of all described genera of non-pollinating fig wasps (NPFW). Our results show an overall correlation between ovipositor morphology and life history in agaonid fig wasps. Ovipositor morphologies seem to be related to constraints imposed by features of the oviposition sites since ovipositor morphology has experienced convergent evolution at least four times in Sycophaginae (Agaonidae) according to the resource used. Non-galling species have more distantly spaced teeth with uneven spacing, as opposed to the observed morphology of galling species. Our results suggest that the ancestral condition for ovipositor morphology was most likely the presence of one or two apical teeth. Regarding life history, ovary galling species that oviposit in receptive figs possibly represent the ancestral condition. Different ovipositor characteristics allow exploitation of new niches and may be related to resource partitioning and species co-existence in the fig-fig wasp system.

Response and recovery of fathead minnows (Pimephales promelas) following early life exposure to water and sediment found within agricultural runoff from the Elkhorn River, Nebraska, USA

Agricultural runoff is a non-point source of chemical contaminants that are seasonally detected in surface water and sediments. Agrichemicals found within seasonal runoff can elicit endocrine disrupting effects in organisms as adults, juveniles and larvae. The objectives of this study were (1) to determine if exposure to water, sediment or the water-sediment combination collected from an agricultural runoff event was responsible for changes in endocrine-responsive gene expression and development in fathead minnow larvae, and (2) whether such early life exposure leads to adverse effects as adults. Larvae were exposed during the first month post-hatch to water and sediment collected from the Elkhorn River and then allowed to depurate in filtered water until reaching sexual maturity, exemplifying a best-case recovery scenario. Gas chromatography mass spectrometry (GC/MS) analysis of the water and sediment samples detected 12 pesticides including atrazine, acetochlor, metolachlor and dimethenamid. In minnow larvae, exposure to river water upregulated androgen receptor gene expression whereas exposure to the sediment downregulated estrogen receptor α expression. Adult males previously exposed to both water and sediment were feminized through the induction of an ovipositor structure whereas no impacts were observed in other reproductive or sex characteristic endpoints for either sex based on exposure history. Results from this study indicate that both water and sediments found in agricultural runoff elicit responses from minnow larvae, and larvae can recover following early life exposure under a best-case scenario.

Musculature of the ovipositor of Oxyna parietina (Linnaeus, 1758) (Diptera, Tephritidae) and its relation to the larval habits

The structure of the ovipositor sclerites and muscles was studied in the tephritid fly Oxyna parietina (Linnaeus, 1758) inducing galls on the stems of Artemisia vulgaris. Adaptations of the ovipositor structure associated with changes of the oviposition substrate due to new larval habits are analyzed. The ovipositor muscles of Oxyna parietina are compared to those of Campiglossa. The genera Oxyna Robineau-Desvoidy, 1830 and Campiglossa Rondani, 1870 belong to the same genus-group of Tephritini, but differ in their host associations and oviposition habits: the larvae of Campiglossa plantaginis (Haliday, 1833) develop in the capitula of Aster tripolium and other asters (Asteraceae). The ovipositor sclerites and muscles are similar in the two genera. Progression of hemolymph into the membranous sheath of the ovipositor and protraction of the aculeus are necessary conditions for laying eggs into the capitula of Asteraceae (Campiglossa plantaginis), as well as for insertion of eggs into the axils of Artemisia leaves (Oxyna parietina). The most significant characters of Oxyna and Campiglossa include the presence of the hyaline apodeme and associated muscles MVM 6 and MVM 7 (instead of the median apodeme in Urophora). Thus, in other tephritid flies similarity in the structure of the ovipositor muscles may reflect similar morphofunctional adaptations to laying eggs into similar substrates, but similarity of Campiglossa and Oxyna in the structure of the ovipositor muscles is due to their close relations.

Revision of the frog fly genus Caiusa Surcouf, 1920 (Diptera, Calliphoridae), with a note on the identity of Plinthomyia emimelania Rondani, 1875.

The Oriental, Australasian and Oceanian genus Caiusa Surcouf, 1920 is revised, species concepts being based on male and female genitalia. A key to males for all known species, and a key to females for all except one are given. All relevant types still in existence have been studied, complete synonymies given and the geographical distribution reconsidered. The eight species included in the genus are: Caiusa borneoensis sp. nov. (Malaysia, Thailand, Vietnam); Caiusa coomani Séguy, 1948 (China, Malaysia, Singapore, Thailand, Vietnam); Caiusa indica Surcouf, 1920 (Australia, Cambodia, India, Indonesia, Malaysia, Papua New Guinea, Philippines, Singapore, Solomon Islands, Sri Lanka, Thailand, Vietnam); Caiusa karrakerae sp. nov. (Malaysia, Thailand); Caiusa kurahashii sp. nov. (Indonesia, Japan, Philippines); Caiusa pooae sp. nov. (Thailand); Caiusa testacea Senior-White, 1923 (India, Nepal, Sri Lanka) and Caiusa violacea Séguy, 1925, stat. rev. (Cambodia, China, Laos, Malaysia, Taiwan, Thailand, Vietnam). A lectotype is designated for Caiusa indica to fix the interpretation of the name. Caiusa nigronitens Senior-White, 1923, syn. nov. and Caiusa surcoufi Bezzi, 1927, syn. nov. are established as junior synonyms of Caiusa indica. Caiusa violacea is correctly diagnosed and errors in the original description of the female holotype are pointed out. Caiusa dubiosa Villeneuve, 1927 is established as a junior synonym of C. violacea, syn. nov. Seven Caiusa species have been reared from the egg mass of various species of frogs. The reproductive mode of the eighth species, i.e., C. indica, is unknown. Five species, i.e., C. borneoensis, C. coomani, C. karrakerae, C. kurahashii and C. violacea have been reared from one or more of the foam nesting frog species Chiromantis nongkhorensis (Cochran, 1927), Polypedates leucomystax (Gravenhorst, 1927), Polypedates megacephalus Hallowell, 1861, Rhacophorus annamensis Smith, 1924, Rhacophorus dulitensis Boulenger, 1892, Rhacophorus kio Ohler & Delorme, 2005 and Rhacophorus owstoni (Stejneger, 1907) all belonging in the family Rhacophoridae in Anura. These five Caiusa species all have a specialised ovipositor tip, with small spine-like setae on the ST8 and the hypoproct, probably enabling the flies to oviposit on a foam nest with a hardened outer surface. They form a monophyletic group on account of these features of the ovipositor, unique in the Oestroidea. The sixth species, C. testacea, has been reared from a frog egg mass, the frog species being unknown. Its ovipositor structure is also unknown. The seventh species, C. pooae, has been reared once from the jelly-like egg mass of Feihyla hansenae (Cochran, 1927), also in Rhacophoridae. Caiusa pooae females do not have spine-like setae on the ovipositor, a fact correlated with the soft outer surface of the jelly-like egg mass on which a C. pooae female had oviposited. The extreme rarity of C. pooae oviposition on Feihyla hansenae egg masses may indicate that this fly perhaps has another, unknown, regular oviposition substrate. Caiusa pooae and C. indica make up a second monophyletic group within Caiusa. Caiusa indica, the most common and most widespread species of the genus, has an ovipositor structure similar to C. pooae. Its breeding substrate is unknown and it occurs both within and outside the distributional area of Rhacophoridae. Possibly both C. indica and C. pooae share a regular oviposition substrate that has still to be discovered. The holotype female of Plinthomyia emimelania Rondani, 1875 from Sarawak is established as a member of the genus Bengalia Robineau-Desvoidy, 1830, thus Plinthomyia Rondani, 1875 becomes a junior synonym of Bengalia Robineau-Desvoidy, 1830, syn. nov. It is removed from the synonymy of Phumosia Robineau-Desvoidy, 1830.

Phylogenetic affinities of Monarea Szépligeti, 1904 (Hymenoptera: Braconidae, Doryctinae, with description of a new species from Mexico.

The genus Monarea Szépligeti is recorded from Mexico for the first time. A new species, Monarea fridae sp. nov., is described and illustrated from the states of Morelos, Puebla and Jalisco, Mexico. The phylogenetic placement of the genus is investigated based on nuclear (28S) and mitochondrial (COI) DNA sequence data. Based on the relationships recovered, Monarea is transferred to the tribe Holcobraconini, which is also supported by features of the internal ovipositor structure and the venom glands and reservoir. A key to the four currently recognised species of Monarea is provided.

The making of a pest: the evolution of a fruit-penetrating ovipositor inDrosophila suzukiiand related species

Evolutionary innovation can allow a species access to a new ecological niche, potentially reducing competition with closely related species. While the vast majority of Drosophila flies feed on rotting fruit and other decaying matter, and are harmless to human activity, Drosophila suzukii, which has a morphologically modified ovipositor, is capable of colonizing live fruit that is still in the process of ripening, causing massive agricultural damage. Here, we conducted the first comparative analysis of this species and its close relatives, analysing both ovipositor structure and fruit susceptibility. We found that the ovipositor of the species most closely related to D. suzukii, Drosophila subpulchrella, has a similar number of enlarged, evolutionarily derived bristles, but a notably different overall shape. Like D. suzukii, D. subpulchrella flies are capable of puncturing the skin of raspberries and cherries, but we found no evidence that they could penetrate the thicker skin of two varieties of grapes. More distantly related species, one of which has previously been mistaken for D. suzukii, have blunt ovipositors with small bristles. While they did not penetrate fruit skin in any of the assays, they readily colonized fruit interiors where the skin was broken. Our results suggest that considering evolutionary context may be beneficial to the management of invasive species.

The ovipositor musculature of Carpomya schineri (Loew) (Diptera, Tephritidae)

The structure of the ovipositor sclerites and musculature was studied in the tephritid fly Carpomya schineri (Loew) whose larvae develop in the fruits of Rosa. The structural characters of the ovipositor of this species facilitating laying eggs into such fruits are discussed. The ovipositor musculature and functioning in Carpomya are very similar to those in Ceratitis and Bactrocera; species of all these genera lay eggs in fruits. In the details of the ovipositor musculature, Carpomya is more similar to Ceratitis than to Bactrocera. The genera Carpomya, Ceratitis and Bactrocera are phylogenetically close but Ceratitis and Bactrocera belong to sister tribes within one subfamily, Dacinae. Thus, morpho-functional similarity of the ovipositor structure may not only reflect close relationship but also result from common adaptive transformations.

Nature's Swiss Army Knives: Ovipositor Structure Mirrors Ecology in a Multitrophic Fig Wasp Community

BackgroundResource partitioning is facilitated by adaptations along niche dimensions that range from morphology to behaviour. The exploitation of hidden resources may require specially adapted morphological or sensory tools for resource location and utilisation. Differences in tool diversity and complexity can determine not only how many species can utilize these hidden resources but also how they do so.Methodology and Principal FindingsThe sclerotisation, gross morphology and ultrastructure of the ovipositors of a seven-member community of parasitic wasps comprising of gallers and parasitoids developing within the globular syconia (closed inflorescences) of Ficus racemosa (Moraceae) was investigated. These wasps also differ in their parasitism mode (external versus internal oviposition) and their timing of oviposition into the expanding syconium during its development. The number and diversity of sensilla, as well as ovipositor teeth, increased from internally ovipositing to externally ovipositing species and from gallers to parasitoids. The extent of sclerotisation of the ovipositor tip matched the force required to penetrate the syconium at the time of oviposition of each species. The internally ovipositing pollinator had only one type of sensillum and a single notch on the ovipositor tip. Externally ovipositing species had multiple sensilla types and teeth on their ovipositors. Chemosensilla were most concentrated at ovipositor tips while mechanoreceptors were more widely distributed, facilitating the precise location of hidden hosts in these wasps which lack larval host-seeking behaviour. Ovipositor traits of one parasitoid differed from those of its syntopic galler congeners and clustered with those of parasitoids within a different wasp subfamily. Thus ovipositor tools can show lability based on adaptive necessity, and are not constrained by phylogeny.Conclusions/SignificanceOvipositor structure mirrored the increasingly complex trophic ecology and requirements for host accessibility in this parasite community. Ovipositor structure could be a useful surrogate for predicting the biology of parasites in other communities.

A reclassification of the weevil subfamily Cyclominae (Coleoptera: Curculionidae)

The structure of mainly the ovipositor is used to better define and constitute the tribes of the weevil subfamily Cyclominae, whose composition and classification are highly confused in existing catalogues. Eight tribes are recognised in the subfamily, Cyclomini, Amycterini, Hipporhinini, Rhythirrinini, Listroderini, Notiomimetini, Dichotrachelini and Aterpini, while Diabathrariini, Gonipterini and Viticiini are excluded from it. Based on unique modifications of the ovipositor for laying eggs into the soil, the reconstituted Cyclomini, Amycterini and Hipporhinini can be regarded as monophyletic groups, while Rhythirrinini may still comprise two separate lineages. Largely due to their unmodified ovipositor and a lack of detailed taxonomic studies, Listroderini and Notiomimetini remain undefined although better constituted, while the position of the monotypic Dichotrachelini in Cyclominae is uncertain and the tribe Aterpini remains in need of comprehensive study to determine whether any of its current genera can be retained in the subfamily. As a result, the concept of the subfamily Cyclominae as a monophyletic taxon remains in doubt. Ovipositor structure further indicates a sister-group relationship between Amycterini and Hipporhinini and is also significant in delineating higher taxa in other terricolous weevils, i.e. Brachycerinae and Microcerinae. A checklist of the genera and species of the tribe Cyclomini is provided. Several taxonomic changes are proposed, as detailed in an appendix: 7 new synonymies, 2 synonymies reinstated, 4 tribes resurrected, 4 tribes transferred and 56 genera transferred.

The ovipositor morphology in the members of the family Scathophagidae (Diptera) with reference to their biology

Relation of the ovipositor structure and the egg-laying habit with the larval biology in the family Scathophagidae was investigated. The ovipositor was examined and illustrated for 29 species including Phrosia albilabris (F.), Cordilura umbrosa (Lw.), Spathephilus breviventris (Lw.), Scathophaga stercoraria (L.), Chaetosa punctipes (Mg.), Pogonota barbata (Ztt.), Cochliarium cuneiventris (Ztt.), and Delina nigrita (Fll.). Species with different bionomics and different larval feeding tissues, i.e., different substrates for oviposition, were distinguished. Comparative morphological analysis of the author’s and literature data on 29 species belonging to 15 genera has shown the constancy of the ovipositor structure within the genera examined. Two principal types of the ovipositor structure were distinguished: (a) the elongate ovipositor with the distal position of the terminal part of the abdomen (the proctiger), this type is characteristic of phytophagous species (the delinine type); and (b) the shortened ovipositor with the proctiger shifted dorsally (the scathophagine type), this type is typical of predatory and saprophagous species. The delinine type of the ovipositor is adapted to inserting eggs into hard plant tissues. Changes in the feeding habits of the larvae were found to be associated with changes in the ovipositor structure. The dependence of the ovipositor structure on the egg-laying habit and on the larval biology enables hypothesizing biological features of those species for which the relevant data are not available yet. The morphogenesis of the ovipositor is speculated based on the data on its structure.

Evolution of the planthoppers (Insecta: Hemiptera: Fulgoroidea)

The planthopper superfamily Fulgoroidea (Insecta: Hemiptera) comprises approximately 20 described insect families, depending on which classification is followed. Multiple competing hypotheses of fulgoroid phylogeny have been published, based on either morphological character coding or DNA sequence data; however, those hypotheses disagree in several key aspects regarding the evolution of planthoppers. The current paper seeks to test these hypotheses, including the Asche (Asche, M. 1987. Preliminary thoughts on the phylogeny of Fulgoromorpha (Homoptera Auchenorrhyncha). In: Proceedings of the 6th Auchenorrhyncha Meeting, Turin, Italy, 7–11 September, 1987, pp. 47–53.) hypothesis of a trend in ovipositor structure, which may be correlated with planthopper feeding ecology. Presented here are phylogenetic reconstructions of Fulgoroidea based on analysis of DNA nucleotide sequence data from four loci (18S rDNA, 28S rDNA, Histone 3, and Wingless) sequenced from 83 exemplar taxa representing 18 planthopper families and outgroups. Data sets were analyzed separately and in various combinations under the maximum parsimony criterion, and the total combined dataset was analyzed via both maximum parsimony and partitioned Bayesian criteria; results of the combined analyses were concordant across reconstruction paradigms. Relationships recovered suggest several major planthopper lineages, including: (1) Delphacidae + Cixiidae; (2) Kinnaridae + Meenoplidae; (3) Fulgoridae + Dictyopharidae; (4) Lophopidae + Eurybrachidae (possibly + Flatidae); (5) Ricaniidae + Caliscelidae (possibly + Tropiduchidae). Results also suggest the placement of Achilixiidae outside of Cixiidae and of Tettigometridae as one of the more recently diversified lineages within Fulgoroidea. The resulting phylogeny supports Asche’s (1987) hypothesis of a functional trend in ovipositor structure across families.

Phylogeny of the genera of the parasitic wasps subfamily Doryctinae (Hymenoptera: Braconidae) based on morphological evidence

The evolutionary relationships among most (143 genera) of the currently recognized genera of the braconid wasp subfamily Doryctinae were investigated using maximum parsimony analysis, employing 100 characters from external morphology and four additional, less well-studied character systems (male genitalia, ovipositor structure, venom apparatus and larval cephalic structure). We investigated the ‘performance’ of characters from external morphology and the other character systems and the effects of abundant missing entries by comparing the data decisiveness, retention and consistency indices of four different character partitions. The results indicate that the performances of the different partitions are not related to the proportions of missing entries, but instead are negatively correlated to their proportion of informative characters, suggesting that the morphological information in this group is subject to high levels of homoplasy. The external morphological partition is significantly incongruent with respect to a data set comprising the other character systems based on the ILD test. Analyses supported neither the monophyly of the large tribes Doryctini and Hecabolini, nor the monophyly of the Spathiini and Heterospilini. Relationships obtained from successive approximation weighting analysis for the complete data differ considerably from the currently accepted tribal and subtribal classifications. The only exceptions were the Ypsistocerini and the Ecphylini, whose recognized members were recovered in single clades. A close relationship between the Binaerini and Holcobraconini, and also Monarea, is consistently supported by venom apparatus and ovipositor structure characters but is not indicated by external morphological data. Low bootstrap values obtained for most of the recovered clades in all analyses do not allow us to propose a meaningful reclassification for the group at this time. A complete list of the recognized genera and their synonymies is given. © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society, 2004, 142, 369–404.

Inferring life history from ovipositor morphology in parasitoid wasps using phylogenetic regression and discriminant analysis

Our understanding of the critical shift in life history among insect parasitoids from ectoparasitism to endoparasitism is hindered by the fact that this particular life history trait is not known for many phylogenetically important taxa. One method of coping with this problem is to seek correlations between the ovipositor structure and this life history trait among taxa whose life history is known, and then to use this to infer the trait in species whose life history in unknown. In one group of parasitoid wasps, the Ichneumonoidea (Hymenoptera), we scored a total of 20 morphometric and morphological characters of the ovipositor for 41 species whose life histories are known – representing all the main clades in which there have been independent transitions to endoparasitism plus a broad range of the ectoparasitoid groups; we then used phylogenetic regression and discriminant analyses to infer the life history of four species whose life histories are unknown. To allow for the effect of phylogenetic non-independence in the discriminant analysis, we carried out analyses using different randomly chosen representatives of the endoparasitoid clades (phylogenetic regression controls for phylogeny). These two methods gave congruent results from which we conclude that Megalohelcon and Gnamptodon are endoparasitoids, and Aspilodemon and Allobracon are ectoparasitoids. We discuss the consequences of these inferences for our understanding of the evolution of endoparasitism in the Ichneumonoidea. © 2003 The Linnean Society of London. Zoological Journal of the Linnean Society, 2003, 139, 213–228.