Characterization of microsatellite loci isolated from the wasp, Microstigmus nigrophthalmus (Hymenoptera)

Fifty‐two microsatellite loci were characterized in 22–31 unrelated females of the wasp (Microstigmus nigrophthalmus) collected from the Mata do Paraiso, Viçosa, M.G., Brazil. Fifty‐one of these loci were developed from a microsatellite‐enriched genomic library derived from M. nigrophthalmus and one was derived from the wasp, Ormyrus nitidulus. The genus Microstigmus represents an independent origin of social behaviour in the Hymenoptera and is thus of great potential in the study of social evolution.     

Nesting Biology of Microstigmus thripoctenus Richards, with a Study on Nest Recognition (Hymenoptera: Crabronidae)

In a study carried out on Microstigmus thripoctenus on Barro Colorado Island (Republic of Panama) between March and May 1998, 29 active nests were located. The nests contained between one and seven cells, with one (female) to six (three females and three males) adults. Using simple manipulations in which wasps were offered a choice between experimentally emptied foreign nests and their own nest when the adults were away, it was observed that returning adults were able to recognize their own nest. Foreign nests were always rejected by females coming from nests with a single adult, whereas individuals from nests with several adults in five of seven cases did accept the foreign nests, continuing their normal activities in them, without destroying their contents. Adopted foreign nests were inspected at a higher rate following adoption. Nests containing several adults tended to remain longer on leaves supporting them, and their external surfaces were inspected more frequently and longer than those of nests containing only one occupant. Nests are not associated with any particular plant and were found attached to leaves of 19 species of understory plants.     

Ultrastructural characteristics of the spermatozoa of Scelionidae (Hymenoptera, Platygastroidea) with phylogenetic considerations

The Scelionidae sperm are distinguished from those of all hymenopterans already studied at least by the presence of a single mitochondrial derivative and the absence of a centriolar adjunct. The absence of an acrosome, in Telenomus podisi , is also unique. The helical nucleus and mitochondrial derivative spiralling around a twisted axoneme can be considered as synapomorphies shared with the Chalcidoidea, and the mitochondrial derivative running together with the nucleus for a long distance can be considered as a synapomorphy shared with the Diapriidae. Therefore, from a consideration of these features, it is possible to suppose that the Scelionidae, Chalcidoidea and Diapriidae are more closely related between themselves than are any of them to the Cynipoidea, since the latter does not share any of the above-mentioned features. This supposition agrees with phylogenetic analyses that supported the inclusion of Platygastroidea (Scelionidae and Platygastridae) and Chalcidoidea within the Proctotrupomorpha lineage, as well as the close relationship of these to the Diapriidae, and the exclusion of the Cynipoidea from this lineage.     

短柄泥蜂亚科中国新记录亚族、属及种类记述(膜翅目:方头泥蜂科)

记述短柄泥蜂亚科1中国新记录亚族(圆痣短柄泥蜂亚族Ammoplanina Evans)、2中国新记录属(锐痣短柄泥蜂属Ammoplanops Gussakovskij和圆痣短柄泥蜂属Ammoplanus Giraud)及5中国新记录种(脊锐痣短柄泥蜂Ammoplanops carinatus Gussakovskij,...     

Morphology of male reproductive system in three species of Trypoxylon (Trypargilum) Richards (Hymenoptera: Crabronidae)

Variations in the adult male reproductive system among different groups of Hymenoptera offer characteristics that help studies on behavior and phylogenetics. The objective of this study was to describe the adult male reproductive system of three Trypoxylon (Trypargilum) species. For that, tissues were disseced, fixed in 2.5% glutaraldehyde in 0.1 M sodium cacodylate buffer, pH 7.2 and postfixed in 1% osmium tetroxide. The material was dehydratated and embedded for light and electron transmission microscopes. The species have similar reproductive systems, which are formed by a pair of testes, each one with three fusiforme follicles, from which emerges an efferent duct that later joins forming a deferent duct. The deferent duct opens into an ejaculatory duct. The first half of the deferent duct is enlarged and differentiated in a region specialized in sperm storage, the seminal vesicle. The accessory gland flows in the post-vesicular region of the deferent duct. The testes and vesicles are both covered with a conjunctive capsule. Sexually mature individuals have all spermatogenesis stages in their follicles. Sperms are released from testes in bundles which are disorganized inside seminal vesicles.     

Quantitative Aspects of Antenna Grooming in Bees (Apoidea: Hymenoptera)

Antenna grooming in more than 100 species of bees (Apoidea), representing 34 genera of the 7 major bee families is recorded and quantitatively analysed. Most species of bees fall into one of two groups with respect to repetitive antenna cleaning: “Uniscrapers” predominantly clean their antennae with one stroke, “biscrapers” mostly with two subsequent strokes. Uniscrapers are more consequent in their behaviour than biscrapers. Most biscrapers occasionally clean their antenna with one or three strokes. Individual variation in the ratio of stroke repetition is considerably larger in bi- than in uniscrapers. In several species males and females differ with respect to their antenna cleaning behaviour, females tend to be more uniscraping. Most species of the families Colletidae, Halictidae, and Andrenidae, as well as the species of the genera Ceratina and Nomada (Anthophoridae) are biscrapers. Almost all species of Melittidae, Megachilidae, Apidae, and Anthophoridae (except Ceratina and Nomada) are uniscrapers. Bees with an antenna cleaner with ancestral (plesiomorphic) morphology are mostly, but not always, biscrapers, those with a derived antenna cleaner are always uniscrapers. Bees with a derived antenna cleaner perform on average less cleaning actions and strokes than those with an ancestral antenna cleaner. Uniscrapers with an ancestral strigilis do on average more cleaning actions per minute than biscrapers, thus they compensate partly for the fewer number of strokes. But nevertheless the uniscrapers do fewer strokes than the biscrapers (both with an ancestral strigilis). Females clean their antennae on average more often than males. It is interpreted that the behaviour of uniscraping and a derived morphology of the antenna cleaner result in greater efficiency than the status which is ancestral for Apoidea (biscraping and a plesiomorphic antenna cleaner).     

Nest preference and ecology of cavity-nesting bees (Hymenoptera: Apoidea) in Punjab,Pakistan

Among bees, 85 % are solitary species, most of them are ground-nester and some are cavity-nesting and construct their nests in pre-existing cavities. This work was conducted to evaluate the substrate preference and nest architecture (acceptance, occupation percentage, seasonality and parasitism) of cavity-nesting bees in different substrates. Trap nests offered comprised five different materials (drilled cavities in wood, bamboo, cardboard tubes, plastic soda straws, and mud blocks). These were installed in four districts for two years. The nesting cavities of five different diameters (6, 8, 10, 12 and 14 mm) were provided in each nesting material with an average length of 180 ± 9.92 mm. In all the materials, 5400 nesting cavities were offered, out of which 628 were colonized by bees from two families (Megachilidae and Apidae) and six species (Megachile cephalotes, M. lanata, M. bicolor, Xylocopa basalis, X. fenestrata and Ceratina smaragdula), including one parasitic bee (Euaspis carbonaria). The bee species differed significantly in occupying five nesting materials. The most preferred diameters were 8 mm and 10 mm, with 52.20% and 29.45% of colonization, respectively. Nesting was done throughout the year except in winter. This study will serve as a baseline for future studies and conservation programs of cavity-nesting bees in Pakistan.     

Guidelines on sampling intensity of bees (Hymenoptera: Apoidea: Apiformes)

Changes in bee fauna, such as the disappearance of certain species or increasing abundance of others, are very important. The common belief that pollinating insects are facing problems also prompts detailed studies of the bee fauna in order to track on-going changes. Assessment of the state of bee communities in particular ecosystems or ecosystem complexes within a landscape, tracing the course of trends in fauna and also predicting their future structures resulting from current changes, are only possible if sampling is carried out at an appropriate frequency, so that representative materials are obtained. The aim of the present study was to determine what sampling intensity during the growing season would enable the collection of representative materials to evaluate species diversity of bees in a study area. Repeated bee sampling at monthly intervals throughout the period of activity of bees resulted in the identification of 73 bee species, corresponding to 51.4 % of the estimated number of bee species in the study area. When samples were obtained twice a month, 93 bee species were captured, accounting for 65.5 % of the estimated number of bee species. When sampling took place nearly four times a month, 108 bee species were captured, making up 76 % of the estimated number of bee species; the materials obtained at this sampling rate may be regarded as representative. The importance of accounting for the phenology of a given animal group during a sampling effort is also emphasised.     

Diversity in bee (Hymenoptera: Apoidea) and social wasp (Hymenoptera: Vespidae, Polistinae) community in "campos rupestres", Bahia, Brazil

Hymenoptera such as bees and social wasps are regular floral visitors in "campos rupestres" vegetation. A community of bees and social wasps was studied during floral visitation in an area of "campos rupestres", at Chapada Diamantina, BA, Brazil, from September 2001 to April 2002. The community was described in relation to diversity, evenness, and dominance rank, considering the individuals abundance (H' = 2.14/ J' = 0.55) and biomass (H' = 2.34/ J' = 0.60). Thirty nine bee (588 individuals/ 15.742 g) and 11 social wasp species (52 individuals/ 2.156 g) were collected, being the first report of social wasps for the Brazilian "campos rupestres". The main species regarding number of individuals were Trigona spinipes (Fabricius), Apis mellifera L., Frieseomelitta francoi (Moure), and Bombus brevivillus Franklin. About 48% of the species were represented by a single individual. There was an inversion in the dominance rank when the species biomass was considered. B. brevivillus, A. mellifera, T spinipes, and other species represented by 15 individuals or less, such as the social wasps Synoeca cyanea (Olivier), Polistes canadensis (L.) and Myschocyttarus drewseni (Saussure), and the bees Eufriesea nigrohirta (Friese), Xylocopa grisescens Lepeletier and Megachile (Pseudocentron) sp.l were the predominant species. The use of biomass in diversity analysis permitted to detect differences in the relative contribution of species in hierarchy dominance. The comparison between bee faunas from different areas indicates a large similarity of the sampled fauna in Palmeiras (Bahia State) with neighboring ecosystems, although with low values of similarity.     

The phylogenetic position of the enigmatic wasp family Heterogynaidae based on molecular data, with description of a new, nocturnal species (Hymenoptera: Apoidea)

Abstract.  The wasp family Heterogynaidae is described and previous phylogenetic hypotheses on its position within the Apoidea are discussed. The higher level phylogeny of the Apoidea based on sequence data of a nuclear gene, long-wavelength (LW) opsin, is analysed for the first time. Although preliminary because of limited taxon sampling and use of a single gene, the analysis reveals some significant results. Monophyly of the Apoidea, including the Heterogynaidae, is supported strongly, as is monophyly of Heterogynaidae. The monophyly of the bees is also confirmed, but support is rather weak. Monophyly of the Ampulicidae + Sphecidae, which is the sister group to the remaining Apoidea (Crabronidae + Anthophila + Heterogynaidae), is confirmed. Our results imply that Sphecidae may be paraphyletic with respect to Ampulicidae, and Crabronidae with respect to bees and Heterogynaidae. Remarkably, Heterogynaidae is well nested within the Crabronidae + Anthophila clade, which is in conflict with the morphological data. This result implies that Heterogynaidae may not have originated from a basal node within Apoidea, as previously considered, and that the character states presumed to be plesiomorphies may instead be homoplasies. Our analysis confirms the value of LW opsin in resolving deeper nodes within Apoidea. A new species, Heterogyna nocticola Ohl, from the Sultanate of Oman is described based on both sexes, with a diagnosis, information on distribution and collecting period. A key to the Palaearctic species of Heterogynaidae is presented.     

An interesting case of gynandromorphism in Andrena helvola (Linnaeus, 1758) (Hymenoptera: Apoidea: Andrenidae)

A gynandromorphic specimen of Andrena helvola (Linnaeus, 1758) having secondary sexual characters on the head is described.     

The evolution of food-producing glands in eusocial bees (Apoidea,Hymenoptera)1

A food-producing role for cephalic exocrine glands has arisen independently in both taxa of highly eusocial bees, Apis and Meliponini. With several exceptions, there is little evidence that food is produced by glands of solitary bees or by most bees at lower levels of sociality. We suggest that this association with sociality is due to four adaptive features of these glands: (1) food from the glands allows feces from queens and larvae to have a small volume, (2) the queen's fecundity can be increased, (3) nutrient recovery via cannibalism can be facilitated, and (4) rearing of emergency replacement queens is accelerated. Acceleration of the rearing of other castes and of queens in the normal process of colony fission is not clearly an advantage ascribed to these glands. Trophic eggs produced by meliponine colony workers are analogous to the secretions from food-producing glands in Meliponini and Apis workers.     

Wild bees (Hymenoptera: Apoidea) in an urban botanical garden in Buenos Aires,Argentina

We assessed bee diversity and abundance in a botanical garden in the city of Buenos Aires during two consecutive spring–summer periods. Every 15 days, we collected by hand-netting bee specimens seen foraging on flowers during five-minute censuses at every entomophilous herbaceous plant. A total of 66 bee species (Hymenoptera: Apoidea) were recorded. Richness and abundance of native, generalist, and above-ground nesting (cavities) species were higher than that of exotic, specialist, and below-ground (soil) nesting ones, respectively. Social bees were more abundant, while the richness of solitary species was higher than that of social bees. Cleptoparasitic species were represented by a high number of species, even though only a few individuals were captured. Our results suggest that the studied area is an important bee reservoir within the city.     

Sensilla numbers and antennal morphology of parasitic and non-parasitic bees (Hymenoptera : Apoidea)

The antennal forms and sensilla of 114 species of bees (Hymenoptera : Apoidea), representing all major lineages, were compared to ascertain the relationship between sensory structures and behavior. For all taxa, males and females of parasitic bee species do not differ significantly in the relative sizes of their antennal structures. For non-parasitic species, females have relatively longer scapes, but relatively shorter flagella. There are significant taxonomic effects in these relationships; the family Megachilidae is aberrant. These findings may relate to similarities in search behavior of males (both parasitic and non-parasitic) and parasitic females, which in general may be more dependent on longer-range olfactory cues, while non-parasitic females also use visual cues and contact or short-range olfactory cues. In the family Halictidae, there is a significant association between body-size and density of sensilla placodea. Among non-parasitic female bees, pollen specialists and generalists do not differ in the relative density of sensilla. Parasitic forms in Halictidae, however, have fewer sensilla placodea per unit aarea than do their hosts.     

Comparative analyses of lemon-smelling secretions from heads of Andrena F. (Hymenoptera,Apoidea) bees

• 1.1. Volatile cephalic secretions from male and female Andrena F. bees were analysed by capillary gas chromatography and mass spectrometry.
• 2.2. Eight species. A. clarkella (K.), A. fucata Smith, A. helvola (L.), A. praecox (Scop.), A. labiata F., A. fuscipes (K.), A. denticulata (K.) and A. nigriceps (K.), were studied, in A. nigriceps (K.) only females were available.
• 3.3. These species were found to contain some acyclic monoterpenes, especially geranial and neral, and/or straight-chain ketones with 8–14 carbon atoms.
• 4.4. The volatile compounds emanate from the mandibular glands.
• 5.5. Six of the species studied show large similarities in the composition of male and female cephalic secretions, whereas in one species. A. helvola (L.), characteristic differences were found between the sexes.
• 6.6. The possible role of the cephalic secretions in relation to territorial flight, population congregation, and sexual attraction is discussed.

     

Floral resource partitioning by social wasps (Hymenoptera: Vespidae) and bees (Hymenoptera: Apoidea) in an area of caatinga in Brazil

Wasps and bees are important components of flower visitor guilds in the Neotropical region. The abundance of social wasps and bees, collected during flower visits, was used to calculate niche breadth and niche overlap indices, in order to characterize the utilization of the floral resources by those insects. Samples were taken monthly, for 13 months (156h), by two collectors which captured the specimens on flowers using entomological nets, while walking along a way in an area of caatinga at Itatim, State of Bahia, Brazil. Wasps and bees heavily visited a few sources of floral resources, but the most visited plants by each group were different, and few plant species were important for both groups, resulting in low niche overlap between bees and wasps. The niche overlap among wasp species was generally higher than among bee species. The general overlap, which takes into consideration all species together was low (< 30%).     

Phylogeny and classification of the Xeromelissinae (Hymenoptera: Apoidea, Colletidae) with special emphasis on the genus Chilicola

Abstract A phylogenetic analysis and classification are provided for the bee subfamily Xeromelissinae based on 248 morphological characters, many of which are novel and illustrated. A total of 47 ingroup species was included in the analysis, representing at least two divergent members from each described genus or subgenus and seven taxa which did not readily fall within previously described subgenera. Three most parsimonious trees were found (length, 1508; consistency index, 40; retention index, 70). The result shows that Xeromelissa renders Chilimelissa paraphyletic, and the 20 known Chilimelissa species are reassigned to Xeromelissa, giving the following new combinations: X. luisa (Toro & Moldenke) (this is the type species of Chilimelissa), X. mucar (Toro & Moldenke), X. xanthorhina (Toro), X. brevimalaris (Toro), X. rosie (Toro and Packer), X. laureli (Toro and Packer), X. chusmiza (Toro), X. longipalpa (Toro), X. pedroi (Toro & Moldenke), X. australis (Toro & Moldenke), X. chillan (Toro & Moldenke), X. farellones (Toro & Moldenke), X. machi (Toro), X. minuta (Toro & Moldenke), X. nortina (Toro & Moldenke), X. sielfeldi (Toro & Moldenke), X. obscura (Toro & Moldenke), X. irwini (Toro & Moldenke), X. nolanai (Toro & Moldenke) and X. rozeni (Toro & Moldenke). Group support was estimated using symmetric resampling and group supported/contradicted (GC) ratios, which compare the frequency of each most parsimoniously resolved clade with the alternative arrangement that was most commonly found in resampling. Relationships among subgenera for Chilicola are weakly supported. By contrast, when three previously synonymized subgenera (Stenoediscelis, Heteroediscelis and Oediscelisca) are resurrected, there is good support for all subgenera (GC ≥ 99), except two: a paraphyletic Oediscelis and a polyphyletic Anoediscelis. Both of these subgenera became monophyletic following successive approximations character weighting. Four distinctive new subgenera are described: Unicarinicola Packer subgen.n. , Obesicola Packer subgen.n. , Capitatiscopa Packer subgen.n. and Toroediscelis Packer subgen.n. , and a revised key to the subgenera of Chilicola is provided.