Social Wasps

—Sex attraction studies were carried out to investigate the mate-finding behaviour of invasive Vespula vulgaris (Linnaeus) (Hymenoptera: Vespidae) wasps. Delta traps were baited with live, caged males, and gynes (virgin queens) of V. vulgaris to determine whether either sex produced a long-range sex attractant. Traps baited with gynes caught 71 males, while the controls and live-male wasp baited traps did not catch gynes. Wind tunnel trials were performed to verify if the signal produced by the gynes was chemical in nature. First, V. vulgaris males were flown to live caged gynes, where more than half of the males tested flew upwind in a zigzagging pattern and made contact with caged gynes. Males were also flown to hexane rinses of gynes and flew upwind in a zigzagging pattern towards the gyne extract, although none made contact with the cotton roll stimulus. The results presented here demonstrate conclusively that V. vulgaris gynes produce a sex pheromone. Résumé—Des e ´tudes d'attraction sexuelle ont e ´té réalisées afin d'e ´tudier le comportement de recherche de partenaire chez la guêpe envahissante Vespula vulgaris (Linnaeus) (Hymenoptera: Vespidae). Nous avons appâtés des pièges Delta avec des mâles et des gynes (reines vierges) de V. vulgaris vivants et encagés pour déterminer si l'un ou l'autre des sexes produit une substance d'attraction sexuelle a ` longue portée. Les pièges appâtés de gynes ont capturé 71 mâles, alors que les pièges témoins et les pièges contenant des guêpes mâles vivantes n'ont attrapé aucune gyne. Des essais en soufflerie aérodynamique ont permis de vérifier si le signal produit par les gynes est de nature chimique. D'abord, nous avons introduit des mâles de V. vulgaris en vol en direction de gynes vivantes encagées: plus de la moitié des mâles se sont dirigés dans le vent en zigzagant et ont fait contact avec les gynes encagées. Nous avons aussi introduit des mâles en vol en direction de rinçages de gynes a ` l'hexane: les mâles ont volé en zigzagant dans le vent vers l'extrait de gynes, bien qu'aucun n'ait fait contact avec le rouleau de coton servant de stimulus. Nos résultats démontrent de manière décisive que les gynes de V. vulgaris produisent une hormone sexuelle.

Social wasps are common elements in Neotropics, although even elementary data about this taxon in the Amazon region is partially
unknown. Therefore the purpose of this work was to increase the knowledge of social wasp fauna at the Jaú National Park. A total of 494 specimens
of Polistinae was collected with active search, malaise trap and light trap. Forty-nine species belonging to fourteen genera were recorded. The richest
genera were Polybia (14 species), Agelaia (07), Mischocyttarus (05), Apoica (04), Brachygastra (04) and Protopolybia (04); the remaining genera
were represented by less than two species. The Jaccard similarity coefficient showed a higher similarity of the Jaú National Park with Ducke Reserve
(Manaus, Amazonas). Four species were collected for the first time in Amazonas state Agelaia flavipennis (Ducke), Polybia affinis Du Buysson,
Protopolybia nitida (Ducke) and Protopolybia sedula (de Saussure), only in the Jaú National Park, showing the importance of this park for the social
wasps preservation in the Amazon region.

A taxonomic revision of the Protopolybia picteti-emortualis species-group now demonstrates that this group is possibly the largest in Protopolybia, comprising 15 species: P. eldinaris sp. nov.; P. djaneteae sp. nov.; P. cameranii (Zavattari 1906) = P. bella (Von Ihering 1903) syn. nov.; P. fulvotincta stat. rev.; P. biguttata, P. nitida, P. alvarengai, P. iheringi, P. perfulvula, P. steinbachi, P. wheeleri, P. rotundata, P. picteti, P. emortualis and P. duckei. Male and female genitalia are illustrated for P. biguttata Bequaert, P. bella, P. nitida, P. fulvotincta and P. picteti. New collection records and a new identification key are presented for this species-group.

Social wasps are broadly distributed in Brazil, and their distribution is closely related to local plant composition. However, only a few studies on the diversity of these insects have been carried out in northeastern Brazil, and in Caatinga Biome the diversity is probably underestimated due to the lack of inventories for the region. Aiming at advancing the knowledge about the wasp fauna, we carried out this study from October 2005 to September 2006 in Ibipeba, northeastern Brazil. We collected 172 wasps of five genera and eight species, and recorded Polybia ruficeps Schrottky, 1902 for the first time in the state of Bahia. The most abundant species was Polybia ignobilis (Haliday, 1836) (n = 69), and the least abundant were Brachygastra lecheguana (Latreille, 1824) (n = 2) and Polistes canadensis (Linnaeus, 1758) (n = 2). The present study inventory focused exclusively on the diversity of social wasps in an area of Caatinga, which contributes to advance the local fauna knowledge.

"Nestmate discrimination plays an important role in preserving the integrity of social insect colonies. It is
known to occur in the primitively eusocial wasp Ropalidia marginata in which non-nestmate conspecifics
are not allowed to come near a nest. However, newly eclosed females are accepted in foreign colonies,
suggesting that such individuals may not express the cues that permit differentiation between nestmates
and non-nestmates. As cuticular hydrocarbons (CHCs) have been implicated as chemosensory cues used
in nestmate recognition in other species, we investigated, using bioassays and chemical analyses,
whether CHCs can play a role in nestmate recognition in R. marginata. We found that individuals can be
differentiated according to colony membership using their CHC profiles, suggesting a role of CHCs in
nestmate discrimination. Non-nestmate CHCs of adult females received more aggression than nestmate
CHCs, thereby showing that CHCs are used as cues for nestmate recognition. Contrarily, and as expected,
CHCs of newly eclosed females were not discriminated against when presented to a foreign colony.
Behavioural sequence analysis revealed the behavioural mechanism involved in sensing nestmate
recognition cues.We also found that newly eclosed females had a different CHC profile from that of adult
females, thereby providing an explanation for why young females are accepted in foreign colonies."