Les recherches sur les lépidoptères foreurs des graminées et leurs antagonistes : bilan et perspectives

Ancistrocerus, Discoelius and Symmorphus are xylicolous predatory wasps, the former two genera hunting caterpillars, the last one using both caterpillars and larvae of Chrysomelidae beetles. One of the aims of this study was to compare the stinging pattern of species from these genera with the ancestral “complete four-sting pattern” (C4SP) and reduced “two-sting pattern” (C2SP). Another aim was to clarify whether stinging pattern of predatory wasps depends mostly on the prey type or on the systematic position of the wasp. Sting traces on 6123 paralysed prey specimens, taken from 409 fresh wasp nests made by 10 wasp species in reed (Phragmites australis) trap-nests in three localities of Lithuania, were studied. The total number of stings applied to a prey specimen, the number and the share of stings directed to its body segments and the probability of stinging the segments were considered. The main conclusions of the study are: (1) the total number of stings delivered to a prey is species-specific, in some cases it may be used to distinguish fresh nests of related wasp species, as those of Symmorphus crassicornis and S. murarius and those of Discoelius dufourii and D. zonalis. (2) The distribution of stings is significantly different from the basic patterns C4SP and C2SP in all ten studied wasps; however, four caterpillar-hunting species have the distribution close to the C2SP The stinging pattern of three Symmorphus species hunting Chrysomelidae larvae included regular stings to the throat, three thoracic and the first abdominal segment; it could be abbreviated as C5SP (a complete five-sting pattern). (3) The distribution of stings among the segments of prey was found to be more dependent on the taxonomic position of the wasp species than on the prey type, thus it might be used as a behavioural character in comparative and phylogenetic studies. (4) The stinging pattern depended on the prey type as well: in the caterpillar-hunting S. debilitatus, it was quite different from the stinging pattern of the Symmorphus that hunt Chrysomelidae larvae.     

Development of microsatellite markers for the critically endangered Limonium dufourii (Girard) Kuntze (Plumbaginaceae)

Limonium dufourii is an endemic plant from the eastern Mediterranean coast of Spain with a triploid chromosome number and apomictic reproduction. We have isolated and characterized 13 polymorphic microsatellite loci from an enriched library in order to investigate its population genetic structure. Simple sequence repeat (SSR) loci were screened in 120 individuals from the six extant populations of this species. They show an average of 5.76 alleles per locus, ranging from 2 to 18, with seven loci exhibiting heterozygosities larger than 0.60. Three loci present one single allele in each individual, whereas one locus presents three alleles in every individual analysed.     

Identification of the sibling species of the Drosophila willistoni subgroup through the electrophoretical mobility of acid phosphatase-1

The Drosophila willistoni group consists of 23 species of which six are sibling species and belong to the D. willistoni subgroup: D. willistoni, Drosophila equinoxialis, Drosophila tropicalis, Drosophila insularis, Drosophila pavlovskiana and Drosophila paulistorum. These sibling species are abundant in the Neotropical region and can hardly be differentiated by the usual taxonomic traits. Four of them (D. willistoni, D. equinoxialis, D. tropicalis and D. paulistorum) cover extensive geographic distribution areas overlapping in places while two of them are endemic (D. insularis and D. pavlovskiana). In this study, we presented a method for the identification of five sibling species of the D. willistoni subgroup based on the allozyme variation of acid phosphatase‐1 (Acph‐1) in acrylamide gel electrophoresis. Our work showed that Acph‐1 allozyme differences can be used for species‐diagnostic characterization. This method was shown to be a more efficient tool for species identification than others because it is both quicker and produces reliable results.     

Taxonomic revision of the genus Dolophilodes subgenus Dolophilodes (Trichoptera: Philopotamidae) of Japan

Japanese species of the genus Dolophilodes subgenus Dolophilodes are revised taxonomically. Seven described species are recognized: D. japonicus (Banks), D. shinboensis (Kobayashi), D. auriculatus Martynov, D. nomugiensis (Kobayashi), D. babai (Kobayashi), D. iroensis (Kobayashi) and D. commatus (Kobayashi). In addition, two new species, D. angustatus and D. dilatatus, are described. Males of all nine species and females of all but D. babai are described and illustrated. The subgenus Hisaura Kobayashi is synonymized under the subgenus Dolophilodes. Three synonymies of species proposed are Wormaldia triangulata Kobayashi under D. nomugiensis, D. kunashirensis Ivanov under D. iroensis and Sortosa kaishoensis Kobayashi under D. commatus.     

Relationships within the melanogaster species subgroup of the genus Drosophila (Sophophora)

The polytene chromosomes of two new species of Drosophila, D. sechellia and D. orena, both members of the melanogaster species subgroup, are described. The chromosomes of D. sechellia, a species endemic to certain islands in the Seychelles, are homosequential with those of D. simulans and D. mauritiana. The chromosomes of D. orena, a species from the mountains of west Africa, are very similar to those of D. erecta. We discuss the interrelationships of the eight known species of the melanogaster species subgroup, based upon an analysis of their chromosome banding patterns.     

Ongoing hybridization obscures phylogenetic relationships in the Drosophila subquinaria species complex

Inferring evolutionary relationships among recently diverged lineages is necessary to understand how isolating barriers produce independent lineages. Here, we investigate the phylogenetic relationships between three incompletely isolated and closely related mushroom‐feeding Drosophila species. These species form the Drosophila subquinaria species complex and consist of one Eurasian species (D. transversa) and two widespread North American species (D. subquinaria and D. recens) that are sympatric in central Canada. Although patterns of pre‐ and post‐mating isolation among these species are well characterized, previous work on their phylogenetic relationships is limited and conflicting. In this study, we generated a multi‐locus data set of 29 loci from across the genome sequenced in a population sample from each species, and then, we inferred species relationships and patterns of introgression. We find strong statistical support that D. subquinaria is paraphyletic, showing that samples from the geographic region sympatric with D. recens are most closely related to D. recens, whereas samples from the geographic region allopatric with D. recens are most closely related to D. transversa. We present several lines of evidence that both incomplete lineage sorting and gene flow are causing phylogenetic discordance. We suggest that ongoing gene flow primarily from D. recens into D. subquinaria in the sympatric part of their ranges causes phylogenetic uncertainty in the evolutionary history of these species. Our results highlight how population genetic data can be used to disentangle the sources of phylogenetic discordance among closely related species.     

Systematic analysis of Dendrobium Swartz section Dendrocoryne in the Australian region

Dendrobium sect. Dendrocoryne is a difficult taxonomic group of allied species and species complexes, occurring on the eastern Australian coastline, Lord Howe Island and New Caledonia. Significant morphological characters were assessed from all key areas of the distribution range. Patterns of variation between species, varieties and hybrids were investigated by principal coordinate analysis. The analyses affirm 12 species in the sect. Dendrocoryne described by Schlechter (1912, 1982) and Dockrill (1969, 1992), including a cluster of small statured D. gracilicaule, D. adae, D. fleckeri, and D. finniganense, and three variable species complexes – D. speciosum, D. kingianum and D. tetragonum. Recently described D. finniganense and D. callitrophilum are interpreted as members of the section. Phylogenetic relationships are presented based on parsimony analysis of 31 morphological characters. Analyses do not support proposals to recognize new genera for D. tetragonum, D. callitrophilum and D. aemulum, or to create new species within D. tetragonum, D. jonesii, D. speciosum and D. kingianum. The phylogeny indicates that rainforest taxa are earlier lineages and xerophytic taxa are more derived.     

Breeding site specificity in the domestic species of Drosophila

Summary The emergences of domestic Drosophila species from fruits and vegetables in a market are analysed by partitioning the species diversity. Confidence limits are determined for the components of diversity.Despite some coexistence of different species within the same breeding site, ecological differences between them are revealed. Partitioning of the breeding sites is more important than partitioning of the season. D. melanogaster, D. simulans, and D. subobscura are specialised on fruits and D. busckii on vegetables. D. immigrans and D. hydei are less specialised. The coexistence is explained by reference to ecological theory.     

Taxonomic study of the genus Dichrogaster Doumerc (Hymenoptera: Ichneumonidae: Cryptinae) in Japan

Japanese species of the genus Dichrogaster are revised. Four species are recognized. Two species, D. imperialis n. sp. and D. parva n. sp., are described. Dichrogaster liostylus (Thomson) and D. kichijoi (Uchida) are redescribed. A key to the Japanese species is provided.     

Identification and comparisons of the yolk polypeptides and the genes which code for them in D. melanogaster sibling species

Summary The yolk proteins stored in Drosophila, oocytes for utilisation during embryogenesis are an ideal system for studying the regulation of gene expression during development. The 3 major polypeptides found in yolk in D. melanogaster are synthesised in the fat body and ovarian follicle cells and selectively accumulated by the oocyte during vitellogenesis. In order to understand more about their regulation and the mechanism of uptake, studies on other species are necessary.Three yolk polypeptides have previously been identified in the D. melanogaster sibling species (D. melanogaster, D. simulans, D. mauritiana, D. erecta, D. teissieri, D. orena and D. yakuba). In D. melanogaster three genes located on the X chromosome are known to code for these yolk polypeptides. in this study genomic Southern transfers and in situ hybridisation experiments were carried out on the sibling species. Using the three cloned yolk protein genes from D. melanogaster, homologous sequences could be detected in the sibling species. It is suggested that three yolk protein genes occur in each of these species, all being located on the X chromosome, and that two of the genes are very closely linked in these same species. Yolk protein gene-homologous DNA sequences have also been identified in two more distantly related species D. funebris and D. virilis.     

A revision of the Afrotropical genus Dhatrichia (Trichoptera, Hydroptilidae)

Five previously described species of Dhatrichia Mosely, 1948 are recognized: D. inasa Mosely, 1948 from Yemen; D. bipunctata Statzner, 1977 from Zaire; D. lerabae (Gibon, Guenda & Coulibaly, 1994) comb. n. from Burkina Faso and Ghana; and D. cinyra Wells & Andersen, 1995 and D. divergenta Wells & Andersen, 1995 from Tanzania. A sixth species D. feredougoubae Gibon, 1987 from the Ivory Coast and Ghana is transferred to Microptila Ris, 1897 comb. n. In addition, nine new species are described and illustrated as males: D. ankasaensis sp. n., D. botiensis sp. n., D. hunukani sp. n., D. minuta sp. n., D. paraminuta sp. n. and D. wliensis sp. n. from Ghana, D. anderseni sp. n. from Tanzania, and D. madagascarensis sp. n. and D. giboni sp. n. from Madagascar. Females are associated, described and illustrated for all species, except D. inasa and D. giboni. The larvae and pupae of D. ankasaensis, D. hunukani, D. lerabae, D. minuta and D. wliensis are described and illustrated as the first known immatures of the genus. Keys to known larvae, pupae, males and females are provided. A phylogenetic analysis of the genus revealed four species groups. The most plesiomorphous taxa are West African, followed by East African and Malagasian taxa. A sister group relationship between the Eburneo–Ghanean and the Sudanian biogeographical regions is encountered twice. Among several possible sister taxa, the sister group turned out to be Kumanskiella Harris & Flint, 1992 and Microptila Ris, 1897 in part, combined. Implications for generic classification and biogeography are outlined. A morphometric principal component analysis revealed good separation of the sexes by the number and shape of antennal segments, and by eye size. Other measures are strongly dependent on overall size, and show best separation of females between species and species groups. A functional fit between male inferior appendages and secondary sexual characters in female sternite VIII is demonstrated for all species with associated females.     

Evolution of mimicry in the New World Dysdercus (Hemiptera: Pyrrhocoridae)

Evolution of mimicry rings is reconstructed for the New World species of cotton-stainer bugs (Dysdercus, Hemiptera: Pyrrhocoridae). Using a cladistic analysis of 43 species (including D. silaceus Doesburg, 1968 stat. nov . and D. modestus Doesburg, 1968 stat. nov .), evolution of colour patterns and biogeographical history of the clade are hypothesized. Three probable mimicry rings are obtained from the analysis, together with data about their possible model–mimic or comimic–comimic structures: (a) ‘Yellow’ species in north-western South America and in the Andes (several possible models, D. rusticus, D. mimus part., D. imitator part., and D. collaris part. as mimics); (b) ‘Median Yellow–Black’ species with a median-forewing black pattern in north-western South America and Central America (several possible models, D. basialbus as a mimic); (c) ‘Median Red–Black’ species with a median-forewing black pattern in the Caribbean islands (D. andreae, D. discolor, D. neglectus–D. sanguinarius clade, and D. jamaicensis–D. fervidus–D. ocreatus clade as comimics). A few additional, less supported rings are also identified. Two highly polymorphic species (D. obscuratus, D. mimus) seem to enter different mimicry rings in different regions.     

Divergence in wing morphology among sibling species of the Drosophila buzzatii cluster

The Drosophila buzzatii species cluster consists of the sibling species D. buzzatii, D. koepferae, D. serido, D. borborema, D. seriema, D. antonietae and D. gouveai, all of which breed exclusively in decaying cactus tissue and, except for D. buzzatii (a colonizing subcosmopolitan species), are endemic to South America. Using a morphometric approach and multivariate analysis of 17 wing parameters, we investigated the degree of divergence in wing morphology among the sibling species of this cluster. Significant differences were obtained among the species and discriminant analysis showed that wing morphology was sufficiently different to allow the correct classification of 98.6% of the 70 individuals analysed. The phenetic relationships among the species inferred from UPGMA cluster analysis based on squared Mahalanobis distances (D²) were generally compatible with previously published phylogenetic relationships. These results suggest that wing morphology within D. buzzatii cluster is of phylogenetic importance.     

Evolution of the transposable element mariner in the Drosophila melanogaster species group

The population biology and molecular evolution of the transposable element mariner has been studied in the eight species of the melanogaster subgroup of the Drosophila subgenus Sophophora. The element occurs in D. simulans, D. mauritiana, D. sechellia, D. teissieri, and D. yakuba, but is not found in D. melanogaster, D. erecta, or D. orena. Sequence comparisons suggest that the mariner element was present in the ancestor of the species subgroup and was lost in some of the lineages. Most species contain both active and inactive mariner elements. A deletion of most of the 3 end characterizes many elements in D. teissieri, but in other species the inactive elements differ from active ones only by simple nucleotide substitutions or small additions/deletions. Active mariner elements from all species are quite similar in nucleotide sequence, although there are some-species-specific differences. Many, but not all, of the inactive elements are also quite closely related. The genome of D. mauritiana contains 20–30 copies of mariner, that of D. simulans 0–10, and that of D. sechellia only two copies (at fixed positions in the genome). The mariner situation in D. sechellia may reflect a reduced effective population size owing to the restricted geographical range of this species and its ecological specialization to the fruit of Morinda citrifolia.     

Molecular systematics and evolution of the subgenus Mesocarabus Thomson, 1875 (Coleoptera: Carabidae: Carabus), based on mitochondrial and nuclear DNA

The subgenus Mesocarabus Thomson, 1875 is a western Palaearctic group that currently includes five species: four of them inhabiting western Europe (Carabus lusitanicus Fabricius, 1801, Carabus problematicus Herbst, 1786, Carabus dufourii Dejean & Boisduval, 1829, and Carabus macrocephalus Dejean, 1826) and one found in the Rif Mountains in northern Morocco (Carabus riffensis Fairmaire, 1872). Representatives of Mesocarabus have been included in previous molecular phylogenetic studies, but taxon‐ or gene‐sampling limitations yielded inconclusive results regarding its monophyly and sister relationship. Here we perform molecular phylogenetic analyses based on five mitochondrial (3625 nt) and eight nuclear (5970 nt) genes sequenced in many Mesocarabus populations, and in related western Palaearctic Carabus Linnaeus, 1758. We conducted parsimony, maximum‐likelihood, and Bayesian analyses and found a well‐supported sister relationship between a monophyletic Mesocarabus with Iberian species of the subgenus Oreocarabus Géhin, 1876. Within Mesocarabus, the European species form a monophyletic lineage sister to Moroccan C. riffensis. A time‐calibrated phylogeny suggests the split between Mesocarabus and Oreocarabus occurred at 11.8 Mya (95% highest posterior density, HPD, 8.7–15.3 Mya), and the divergence between C. riffensis and European Mesocarabus at 9.5 Mya (95% HPD 7.0–12.5 Mya). The early diversification of Mesocarabus and related subgenera during the Miocene, and alternative hypotheses concerning the origin of Mesocarabus in the Iberian Peninsula and the Betic‐Riffian plate are discussed using calibration data and dispersal–vicariance biogeographic analyses. Finally, we found instances of incongruence between mitochondrial DNA and nuclear‐based phylogenies of Mesocarabus, which are hypothesized to be the result of introgressive hybridization. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 166 , 787–804.     

Conservation of the 93D puff of Drosophila melanogaster in different species of Drosophila

Temperature shock (TS) results in activation of a specific set of puffs in polytene nuclei of D. melanogaster. Earlier studies in this species from several laboratories revealed certain unique features of the major TS puff at 93D locus, which is also specifically induced by benzamide (BM) and by incubation of glands in heat shocked glands' homogenate (HSGH). We have now extended studies on TS response to several other species of Drosophila to ascertain whether loci homologous to 93D puff of D. melanogaster are present in other species. In polytene nuclei of two closely related (D. ananassae, D. kikkawai) and in two distantly related species (D. hydei, D. nasuta), six to nine puffs are induced by TS. Interestingly, in each species one of the major TS puffs, viz., 2L-2C in D. ananassae, E-11BC in D. kikkawai, 2R-48A in D. nasuta and 2-48C in D. hydei, is also specifically induced by BM, autologous species' HSGH and vitamine-B₆ (vit-B₆) treatment. HSGH of a different species fails to induce these puffs. These puffs thus resemble the 93D locus of D. melanogaster, although the 93D puff does not respond to vit-B₆. These observations are discussed in relation to the conservation of 93D puff locus in different species of Drosophila.     

Evolution of the transposable element Uhu in five species of Hawaiian Drosophila

The complete DNA sequence of three independent isolates of Uhu, a member of the Tc1-like class of transposable elements from D. heteroneura (Uhu-1, Uhu-3, and Uhu-4), has been determined. These isolates have between 95 and 96.4% nucleotide sequence identity indicating that Uhu is well conserved within this species. A comparison of the DNA sequences of Uhu and the D. melanogaster Hb1 transposable element shows that the nucleotide substitution rate for Uhu is comparable to the synonymous rate for the Adh gene in these species. Uhu has been identified in four other species of endemic Hawaiian Drosophila, D. silvestris, D. differens, D. planitibia and D. picticornis, and nine Uhu elements were isolated from genomic libraries of these four species. A 444 base pair region from within the coding region of the Uhu element, with well conserved ends, was amplified by the polymerase chain reaction and used for sequence comparison of elements from different species. The analysis of the sequence similarities between the elements within and between the species shows a grouping of the two pairs of most closely related species (D. heteroneura and D. silvestris, and D. differens and D. planitibia), but shows a much larger variation within the most recently diverged species (D. heteroneura and D. silvestris) than expected. There are extensive nucleotide substitutions and deletions in the Uhu elements from D. picticornis showing that they are degenerating and being lost in this species. These observations indicate that the Uhu element has been transmitted vertically and that transposition may have been activated at the time of formation of each species as it colonized the newly formed islands of the Hawaiian archipelago.     

Three new species of Dactylogyrus Diesing, 1850 (Monogenea: Dactylogyridae) from the gills of the bala sharkminnow Balantiocheilos melanopterus (Cyprinidae) from Thailand

Three new species of Dactylogyrus are described from the gills of the cyprinid fish Balantiocheilos melanopterus (Bleeker) imported from Thailand via the aquarium trade. They are D. coartatus n. sp., D. macrocolpius n. sp. and D. melanopteri n. sp. The double-bar species, D. coartatus n. sp. and D. melanopteri n. sp., are characterised by hooks that are markedly large in relation to the size of the anchors. Clip-like anchors with a sharply recurved, long point are a unique feature of D. coartatus n. sp. The single-bar species, D. macrocolpius n. sp., is characterised by having a copulatory organ composed of a spiral copulum and a medial accessory piece with thorns.     

Systematic significance of tridentate pedicellariae in the echinoid genera Diadema and Echinothrix

Abstract. The tridentate pedicellariae in all species of Diadema and Echinothrix recognized by Mortensen, plus species described later (to include D. palmeri and two color morphs of E. calamaris) were examined to identify diagnostic species characters, and to determine whether such characters are useful in inferring phylogenetic relationships between species. Nineteen morphological characters were measured and analyzed, and species‐specific characters were identified. The morphometric data were then transformed using gap coding and a parsimony analysis was undertaken. The resulting cladogram for the tridentate pedicellariae present in species of Diadema was compared with the mitochondrial DNA phylogeny of Lessios et al., with a good level of congruence observed. Very narrow forceps‐like tridentate pedicellariae were found to be basal among Recent species, present only in D. setosum and D. palmeri. Members of D. palmeri were found to be unique within the genus, having both the forceps‐like form and a broad form of tridentate pedicellaria. The very narrow forceps‐like form is absent in all subsequent divergent species, while the broad form of tridentate pedicellaria in D. palmeri is basal to the broad forms in D. antillarum, D. mexicanum, D. paucispinum, and both the broad and narrow forms of tridentate pedicellaria of D. savignyi. The greatest similarity was found between the broad forms of tridentate pedicellaria in D. antillarum and D. mexicanum. These species were also found to have narrow forms of tridentate pedicellaria that showed a reasonable level of association to one another and to the rostrate form in D. ascensionis. Since the work of Mortensen, D. ascensionis has been shown, using mitochondrial DNA, to be nested within D. antillarum. The results of this study show that the tridentate pedicellaria in D. ascensionis are distinctly different from all other forms within the genus, to the extent that they belong to a rostrate subclass. This indicates that, among Diadema species, the tridentate pedicellariae are one of the first morphological characters to diverge in genetically isolated populations. Unlike the tridentate pedicellariae in Diadema, the different forms of tridentate pedicellariae in E. calamaris and E. diadema showed a stronger association intraspecifically than between forms interspecifically. The small forms of tridentate pedicellaria of the white and brown color morphs in E. calamaris showed a high level of association, while the large forms showed only a moderate association, far lower than would be expected between color morphs of the same species. This suggests that they are either subspecies or recently diverged separate species. This study demonstrates the taxonomic value contained within the characters of the tridentate pedicellariae for both differentiating species (even subspecies) and inferring phylogenetic relationships between species.