Taxonomic notes on the paper wasps of the genus Ropalidia in the Indian subcontinent (Hymenoptera: Vespidae)

The taxonomy of Ropalidia wasps in the Indian subcontinent is revised, recognizing 26 species in the subcontinent. Their diagnostic characteristics are summarized in a key to species. New synonymies proposed in the present study are: R. bicolorata shiva Das and Gupta, 1989 under R. bicolorata van der Vecht, 1962; R. colorata sordida van der Vecht, 1941 under R. colorata van der Vecht, 1941; R. rodialipa Lambert and Narendran, 2005 and R. anupama Lambert and Narendran, 2005, both under R. cyathiformis Fabricius, 1804; R. jacobsoni flavoscutellata Das and Gupta, 1989, and R. bangalorica Lambert and Narendran, 2005, both under R. jacobsoni du Buysson, 1908; R. travancorica Lambert and Narendran, 2005, under R. marginata Lepeletier, 1836; R. sridharani Lambert and Narendran, 2005, under R. rufocollaris Cameron, 1900; Ropalidia rufoplagiata nursei van der Vecht, 1941 under R. rufoplagiata Cameron, 1905; Icaria lugubris Smith, 1858, under R. sumatrae Weber, 1801; and a revised synonymy is Icaria pendula Smith, 1857, under R. variegata Smith, 1852. The new replacement name Ropalidia kasaragodensis Lambert and Narendran is proposed for R. indica Lambert and Narendran, 2005, non van der Vecht, 1941.     

Genetic relatedness and population structure in the social wasp,Mischocyttarus mexicanus (Hymenoptera: Vespidae)

Summary In primitively eusocial wasps workers often retain the ability to become queens, so their continued performance in the worker role is partly dependent on elevated genetic relatedness between workers and the brood they rear. In colonies of the social wasp,Mischocyttarus mexicanus, workers were related to female pupae by 0.29±0.12, a value that is significantly below the full sister value of 0.75, but not significantly below 0.50, worker relatedness to daughters. Though individuals often build new nests within meters of their natal nest, there was no genetic population structure discernable among four nest clusters, or inbreeding of any kind.     

Morphology of the fifth sternal glands of Neotropical social wasps (Hymenoptera,Vespidae, Polistinae)

Glands play a central role in the social behavior of insects, and comparative analysis of their structure may provide insights about their evolution and their role in insect social biology. Here, we describe the glands of the fifth metasomal sternite of ten polistine wasps with different social behaviors. The glands of foragers of these species were studied using semithin sections of Araldite‐embedded tissue, and scanning electron microscopy. The structure of the glands observed was mostly similar to what has previously been reported for independent‐founder and swarm‐founder species, respectively. Scale‐shaped modifications in the fifth sternite are reported for the first time for members of the genera Synoeca and Epipona. Two previously unreported glands in the fifth sternite are also described. A more restrictive definition of the name Richards' gland is proposed, applying to the class 3 cells associated with scale modifications of the fifth sternite, based on structural differences between the glands observed, homology requirements, and functional evidence. Previous phylogenetic reconstructions of this character suggest that it appeared early in the Vespidae and disappeared four times, with a single reappearance in the genus Vespula. The restricted definition of Richards' gland suggests that this structure is an exclusive trait of the Epiponini, with two reversals.     

Observations onApoica pallens,a nocturnal neotropical social wasp (Hymenoptera: Vespidae,Polistinae, Epiponini)

Summary Colonies and nests ofApoica pallens in the llanos region of Venezuela range from small foundress nests to large mature colonies. Nests are sited on small diameter, near-horizontal branches in a variety of shrub and tree species. During the day, adult wasps cluster on the face of the nest in an array that seems to be determined by orientation to gravity; defense of the colony against parasitoids and ants by the resting wasps may be more a passive than an active behavior. Wasps fan their wings to cool the colony during the day, but no foraging for water accompanies the fanning behavior. Nightly foraging activity begins with the explosive departure from the nest of hundreds of wasps, most of which rapidly return. Moderate foraging levels early at night give way to very low foraging levels in pre-dawn hours. The period of moderate foraging may be extended for longer hours during increased moonlight. Foraging wasps collect arthropod provisions for larvae. Larvae produce a trophallactic saliva; adults engage in inter-adult trophallaxis; brood are cannibalized. During cluster formation prior to swarm emigration, adult wasps do not appear to scent-mark substrates such as leaves. Instead,A. pallens exhibits a calling behavior, unique among polistine wasps studied to date, in which the gaster is held rigidly away from the thorax and metasomal sternal glands are exposed. Swarms can emigrate during the day.A. pallens may incorporate absconding and colony relocation as features of its colony cycle in the highly seasonal llanos.     

Relationship between body size and flying-related structures in Neotropical social wasps (Polistinae,Vespidae, Hymenoptera)

Body size influences wing shape and associated muscles in flying animals which is a conspicuous phenomenon in insects, given their wide range in body size. Despite the significance of this, to date, no detailed study has been conducted across a group of species with similar biology allowing a look at specific relationship between body size and flying structures. Neotropical social vespids are a model group to study this problem as they are strong predators that rely heavily on flight while exhibiting a wide range in body size. In this paper we describe the variation in both wing shape, as wing planform, and mesosoma muscle size along the body size gradient of the Neotropical social wasps and discuss the potential factors affecting these changes. Analyses of 56 species were conducted using geometric morphometrics for the wings and lineal morphometrics for the body; independent contrast method regressions were used to correct for the phylogenetic effect. Smaller vespid species exhibit rounded wings, veins that are more concentrated in the proximal region, larger stigmata and the mesosoma is proportionally larger than in larger species. Meanwhile, larger species have more elongated wings, more distally extended venation, smaller stigmata and a proportionally smaller mesosoma. The differences in wing shape and other traits could be related to differences in flight demands caused by smaller and larger body sizes. Species around the extremes of body size distribution may invest more in flight muscle mass than species of intermediate sizes.     

Taxonomic Review on the Far Eastern Species of the Genus Discoelius Latreille (Hymenoptera: Eumeninae, Vespidae)

Far eastern species of the genus Discoelius Latreille are taxonomically reviewed. Two species are confirmed: Discoelius zonalis (Panzer) and D. dufourii Lepeletier. Discoelius japonicus originally described from Japan is synonymized under D. zonalis. Discoelius dufourii is newly recorded in Manchuria and Korea. The taxonomic status of D. manchurianus is briefly discussed.     

Distribution of social wasps (Hymenoptera: Vespidae) in New Zealand in 1987

Abstract

More than 50 000 social wasps (Hymenoptera: Vespidae) were collected between March and August 1987 from throughout New Zealand. The most widespread species is the German wasp (Vespula germanica). The common wasp (V. vulgaris) has colonised about half the country and appears to be still spreading. It tends to appear in urban areas first, presumably because it is transported there with people and/or their belongings. The Asian paper wasp (Polistes chinensis) and Australian paper wasp (P. humilis), are confined to the northern half of the North Island, but the former species is spreading south.     

Richards' gland and associated cuticular modifications in social wasps of the genusPolybia Lepeletier (Hymenoptera,Vespidae, Polistinae,Polybiini)

Insectes Sociaux - O.W. Richards recently discovered an exocrine gland that opens on the fifth (penultimate) sternite of females of many species of polybiine wasps. Recent experimental evidence...     

Distributed cognition and social brains: reductions in mushroom body investment accompanied the origins of sociality in wasps (Hymenoptera: Vespidae)

The social brain hypothesis assumes the evolution of social behaviour changes animals'' ecological environments, and predicts evolutionary shifts in social structure will be associated with changes in brain investment. Most social brain models to date assume social behaviour imposes additional cognitive challenges to animals, favouring the evolution of increased brain investment. Here, we present a modification of social brain models, which we term the distributed cognition hypothesis. Distributed cognition models assume group members can rely on social communication instead of individual cognition; these models predict reduced brain investment in social species. To test this hypothesis, we compared brain investment among 29 species of wasps (Vespidae family), including solitary species and social species with a wide range of social attributes (i.e. differences in colony size, mode of colony founding and degree of queen/worker caste differentiation). We compared species means of relative size of mushroom body (MB) calyces and the antennal to optic lobe ratio, as measures of brain investment in central processing and peripheral sensory processing, respectively. In support of distributed cognition predictions, and in contrast to patterns seen among vertebrates, MB investment decreased from solitary to social species. Among social species, differences in colony founding, colony size and caste differentiation were not associated with brain investment differences. Peripheral lobe investment did not covary with social structure. These patterns suggest the strongest changes in brain investment—a reduction in central processing brain regions—accompanied the evolutionary origins of eusociality in Vespidae.     

Abundance of wasps and prey consumption of paper wasps (Hymenoptera, Vespidae : Polistinae) in Northland, New Zealand

Polistine and vespine wasps were captured in Malaise traps in two fire-modified shrubland habitats of varying canopy height and composition at Lake Ohia, Northland, New Zealand. Prey consumption rates were calculated for the Asian paper wasp (Polistes chinensis antennalis) occupying these two areas of shrubland and a home garden in Whangarei, Northland. The sites were systematically searched for nests and wasp prey determined by intercepting foragers returning to nests. The Asian paper wasp predominated in the Malaise trap samples from the low- growing habitat while the German wasp (Vespula germanica) was more common in the taller vegetation type. The Asian paper wasp was more abundant than the German wasp in the samples in February and early March. Only four Australian paper wasps (Polistes humilis) and no common wasps (Vespula vulgaris) were caught. Asian paper wasps collected an estimated 15 000 prey loads per ha per season from one of the shrubland areas, and 478 000 prey loads per ha per season from the second area. These convert to estimates of 31 and 957 g per ha per season of invertebrate biomass removed by paper wasps from each habitat, respectively. The estimate for the garden site was 79 g per ha per season. Wasp nest densities varied between 20 and 210 nests per hectare. The biomass estimates are similar to average figures calculated for vespine wasps in scrubland and pasture. Both Asian paper wasps and Australian paper wasps preyed mainly on lepidopteran larvae. The cabbage white butterfly (Pieris rapae) was the most commonly collected species. Noctuid species were also well represented. Both male and female Asian paper wasps collected nectar in late March and early April.     

Colony structure and nest characteristics of European wasps, Vespula germanica (F.) (Hymenoptera: Vespidae), in Victoria, Australia

Abstract European wasps, Vespula germanica , are common across southern and south-eastern Australia and have a negative impact upon urban areas, primary industries, and natural ecosystems. Aspects of colony structure and nest characteristics are examined for nests located in the ground and collected from urban and rural sites in Victoria during two summer−autumn field seasons (1996 and 2001). On average, nests were located 28 cm beneath the surface (range 5−58 cm). The average number of combs in the nest and the total area of the nests increased from early February to late May. In addition, the proportion of cells used to produce workers and different life stages (larvae, pupae) also varied throughout the season; being consistent with studies from New Zealand. No differences in colony structure or nest character­istics were detected between urban and rural nests.     

Bionomic notes on Pachysomoides sp. (Hymenoptera: Ichneumonidae), a parasitoid of the Neotropical social wasp Polistes satan Bequaert (Hymenoptera: Vespidae)

Although most polistine wasp species are found in the Neotropical region, mainly in Brazil, only a very limited number of South American parasitoids or parasites are known to exist. We assessed the frequency of a hymenopterous parasitoid, Pachysomoides sp. (Ichneumonidae, Cryptinae), in the nests of the Brazilian independent‐founding wasp Polistes satan and compared the rates of the parasitization of P. satan by Pachysomoides sp. between the dry (winter) and wet (summer) seasons. Pachysomoides sp. larvae were seen to feed on P. satan pupa and were found in both the upper and lower parts of the host pupal cell (ca. 10 individuals in each host pupal cell). Approximately one‐third of the pupal cells in the P. satan colonies were parasitized in the dry season, whereas there were no parasitized pupal cells in the wet season. Consequently, the rates of parasitization by Pachysomoides sp. were significantly greater during the dry season than during the wet season due to unknown reasons.     

中国楼梯草属(荨麻科)几种植物的订正

根据对中国楼梯草属Elatostema植物标本的研究,将碧江楼梯草E．bijiangense归并入楼梯草E． involucratum,长叶墨脱楼梯草E．medogense var．oblongum和树志楼梯草E．shuzhii归并入墨脱楼梯草E． medogense,光茎钝叶楼梯草E．obtusum var．glabrescens归并入三齿钝叶楼梯草E．obtusum var．trilobula- tum,三裂楼梯草E．sinense var．trilobatum归并入对叶楼梯草E．sinense,赤水楼梯草E．strigulosum var．semitripilinerve归并入伏毛楼梯草E．strigulosum。     

Comb cutting inRopalidia plebeiana: a new process of colony fission in social wasps (Hymenoptera: Vespidae)

Summary Females of an Australian polistine wasp,Ropalidia plebeiana, often use their mandibles to cut their nest-comb in spring, dividing it into two or more completely independent nests. Prior to the division, each of the major egg layers, often with some subordinates, tended to occupy a different part of a single comb. These females gnawed cells in the intermediate zone between such territories, and ultimately divided the comb. Many other females also built new nests near the nest aggregations, but addition of new nests by comb cutting represented 34.8 % of the increase in nest number. This method of colony fission is so far unknown in any eusocial Hymenoptera.     

Taxonomic notes on some species of Elatostema (Urticaceae) from China

Elatostema bijiangense W. T. Wang, E. medogense W. T. Wang var. oblongum W. T. Wang, E. shuzhii W. T. Wang, E. obtusum Wedd. var. glabrescens W. T. Wang, E. sinense H. Schorter var. trilobatum W. T. Wang and E. strigulosum W. T. Wang var. semitripi-linerve W. T. Wang are reduced to synonymies.     

Taxonomic Review of the Genus Anterhynchium Saussure (Eumeninae, Vespidae, Hymenoptera) from East Asia

ABSTRACT Taxonomic study of the genus Anterhynchium from the Eastern Asia is carried out. A total of 15 forms included in four species were reviewed: A. melanopterum, A. flavopunctatum flavopunctatum, A. flavopuntatum opulentum, A. yunnanensis, A. flavomarginatum flavomarginatum, A. f. koreanum, A. f. tsushimarum, A. f. umenoi, A. f. micado, A. f. procella, A. f. insulicola, A. f. sulphreum, A. f. amamense, A. f. hanedai and A. f. formosicola. However, the A. flavopunctatum opulentum and A. yunnanensis are only cited for future work, due to the lack of available materials. Key to the other species and subspecies are revised, and photos showing diagnostic characters and coloration are presented. The male genitalic characters for accurate identification were separately discussed.     

Vespidae of Viet Nam (Insecta: Hymenoptera) 2. Taxonomic notes on Vespinae

The taxonomy of the Vietnamese species of the social wasp subfamily Vespinae is revised. Vespa auraria Smith, 1852, is synonymized under V. velutina Lepeletier, 1836. Vespula koreensis (Radoszkowski, 1887) is recorded as new for Viet Nam, and its color characters are described. A key to vespine species of Viet Nam based on morphological characters is provided.     

First records of Synoeca septentrionalis Richards, 1978 (Hymenoptera, Vespidae, Epiponini) in the Brazilian Atlantic Rain Forest

Nests of Synoeca septentrionalis were collected in two Brazilian Atlantic Rain Forest localities (Itabuna and Santa Terezinha, in the state of Bahia and Alfredo Chaves in the state of Espírito Santo). Synoeca septentrionalis was previously recorded only from Central America and northwestern South America. This findingextends its geographical distribution to Northeast and Southeast regions of Brazil, and represents the first record for Synoeca septentrionalis in the Brazilian Atlantic Rain forest, raising to three the number of Synoeca species known from Bahia State.