Pulp partitioning and worker specialization in polistine wasps (Hymenoptera,Vespidae, Polistinae)

The character of pulp partitioning was studied in three Palaearctic polistine wasps (Polistes dominula and P. gallicus in the Black Sea Biosphere Reserve, and Polistes nimpha in the Lugansk Nature Reserve, Ukraine) and in five Neotropical species (P. lanio, P. versicolor, Mischocyttarus injucundus, M. alfkeni, Metapolybia cingulata, and Protopolybia exigua in Trinidad). In independent-founding Polistes and Mischocyttarus species, all cases of pulp partitioning were connected with aggression on the part of the foundresses. An experimental increase of nesting density of P. dominula led to changes in the relative abundance of workers in the polyethic task groups. Some workers practically stopped hunting and switched over to pulp delivery; some of these workers possessed well-developed ovaries and were able to lay eggs. The experimentally removed part of the nest envelope in the swarm-founding wasp Metapolybia cingulata was restored only in colonies that included young workers. The specific features of nest building activity in independent-founding and swarm-founding polistine wasps are discussed.     

Some aspects of interrelations between ants (Hymenoptera,Formicidae) and polistine wasps (Hymenoptera,Vespidae)

Embodied, situated and enactive aspects of relationships of polistine wasps with ants are considered within the framework of the theory of autopoiesis. The idea of the embodied interaction implies specific nestbuilding and protective behavior in polistine wasps. The paper examines the adaptive role of applying ant repellent on the petiole and nest and the latitude gradient of such behavior in re-social wasp species. The situated interaction is considered in the environmental context: the mortality of Polistes gallicus (L.) colonies as a result of predatory attacks of ants Myrmica bergi Ruzsky is analyzed in the Lower Dnieper basin (Ukraine). The enactive interaction includes both spontaneous autonomous activity of its participants as a result of self-organization and specific features of the spatial structure of the prey’s population forming under the impact of the predator. The applicability of some “predator-prey” models is discussed.     

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.     

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...     

Uncovering head gland diversity in neotropical Polistinae wasps (Hymenoptera,Vespidae): Comparative analysis and description of new glands

Exocrine glands are involved in several wasp colony activities; however, the number of known glands in the Vespidae is rather low when compared to other social insect groups. The aim of this study is to survey the head of Neotropical social wasps and to provide a detailed comparative study of the glands found in the Polistinae. A total of 33 species distributed over 13 genera were studied with serial histological sections of the head, excluding the labiomaxillary complex. Additionally, the exoskeleton was explored using scanning electron microscopy looking for associated modifications. A total of eleven exocrine glands were observed, five are structures recorded for the first time for the Hymenoptera, three are new records for the Polistinae and three are previously known organs. The glands studied are: ocellar gland I, ocellar gland II, periocular gland, subantennal gland, hypopharyngeal gland, clypeal gland, posterobasal genal gland, ectal mandibular gland, mesal mandibular gland, intramandibular gland I, and intramandibular gland II. The widespread distribution of most of these glands suggests an origin prior to the evolution of the Polistinae. Our results highlight the importance of detailed morphological studies to unveil the significance of chemical communication in one of the most characteristic groups of social animals.     

The queen colony phase of vespine wasps (Hymenoptera, Vespidae)

Characteristics of queen nests of the Vespinae are reviewed including the number of cells and each brood stage in the mature nest, cell-building and egg-laying rates, length of each brood stage and the occurrence of brood cannibalism. Success rates of queen nests of the Vespinae are reviewed with their causes of failure including the effect of queen usurpation, and with particular reference to variation of queen behaviour or queen quality. Evidence for the differences between potentially successful and unsuccessful queen nests is given. Simulation models of queen nests are developed for potential successful and unsuccessful colonies to determine the extent of larval cannibalism, larval life extension and for unsuccessful queen nests, oophagy. The variation of cell building rate, the importance of ambient temperature and the fast development of the first batch of eggs are considered in relation to polistine studies. The causes of the variation of queen quality are unknown but could be related to the amount of food received as larvae or as adults before leaving the natal colony.     

Distribution and nests of paper wasps of Polistes (Polistella) in northeastern Vietnam,with description of a new species (Hymenoptera,Vespidae, Polistinae)

Seven species of the subgenus Polistella Ashmead of the genus Polistes Latreille including a new species, P. brunetus Nguyen & Kojima, sp. n. described here, are recognized to occur in northeastern Vietnam, the easternmost part of the eastern slope of the Himalayas. A key to these species is provided. Their distributional records are remarked. Nests of P. delhiensis Das & Gupta, P. mandarinus de Saussure and P. brunetus are also described.     

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.     

The role of parasitoids in regulation of Polistes wasp population (Hymenoptera, Vespidae: Polistinae)

The study conducted in 2005–2010 analyzes the behavioral response of the parasitoids Latibulus argiolus (Rossi) (Hymenoptera, Ichneumonidae) and Elasmus schmitti Ruschka (Hymenoptera, Eulophidae) to the distribution of their host, Polistes wasps (Hymenoptera, Vespidae). Various conditions of the parasitoid-host system and conditions of regulation of the host abundance are discussed. The parasitoid females are more active in wasp colony clusters and tend to infest larger nests. If the parasitoids are abundant, infestation of host colonies starts earlier, sometimes before the worker emergence; therefore, density-dependent behavioral response of parasitoids is caused primarily by the impact of the aggregation component. Thus, the host population density factor appears to be mediated not only by the non-uniform development rates of colonies and their spatial distribution, but also by the seasonal (temporal) aspect of their development. Low density of the host population, at which the parasitoids regulate the wasp abundance, corresponds to a certain phase of the seasonal colony development, namely to the period before the emergence of workers. On the whole, we are dealing with a host-parasitoid system in which the spatial and temporal factors are closely interrelated.     

Social wasps of the subfamily Vespinae (Hymenoptera, Vespidae) of the Kyrghyz Republic

Based on newly collected and museum material, the distribution of species of the Vespinae in the Kyrghyz Republic is discussed. Vespula austriaca is recorded for the first time from Kyrghyzstan. Dolichovespula norwegica is first reported in the Pamir‐Alai Mountains, providing the southernmost record for the species.     

Reproductive strategies of male paper wasps (Hymenoptera,Vespidae) in the southern Dnieper area

The reproductive strategies of Polistes nimphus (Chris) and P. gallicus (L.) males in the Low Dnieper area are described. In the P. nimphus population, territorial and migrating males were observed. The territorial males of P. gallicus formed swarms or patrolled their areas singly. The male color variants and size were shown to correlate with their reproductive strategies. The territorial males of P. nimphus had a paler coloration and smaller head and wings than migrating males. The swarming territorial males of P. gallicus were paler and had a larger head and wings than single territorial males. The geographic variability of precopulatory behavior of males of the studied species is discussed.     

A biometric study of seasonal variation in worker wasps (Hymenoptera: Vespidae)

The seasonal changes in some morphometric characters of worker wasps of Vespula vulgaris and Vespula germanica are described and discussed in relation to colony populations and economics.     

Comparison of three liquid lures for trapping social wasps (Hymenoptera: Vespidae)

Two citrus-based sodas and a known wasp attractant were compared in a field trial to assess their attractiveness to local nuisance wasp species. The wasps captured included Vespula germanica (F.), Vespula maculifrons (Buysson), Vespula vulgaris (L.), Vespula flavopilosa Jacobson, Vespula squamosa (Drury), Dolichovespula maculata (L.), Polistes fuscatus (L.), Polistes metricus Say, and Polistes dominulus (Christ). Wasps in the genus Vespula were present in significantly higher numbers in traps than Dolichovespula and Polistes. Both citrus soda products were superior to the isobutanol-acetic acid mixture as attractants for almost all of the wasp species.