Color is necessary for specialized face learning in the Northern paper wasp, Polistes fuscatus

Visual individual recognition requires animals to distinguish among conspecifics based on appearance. Though visual individual recognition has been reported in a range of taxa, the features that animals rely on to discriminate between individuals are often not well understood. Northern paper wasp females, Polistes fuscatus, possess individually distinctive color patterns on their faces, which mediate individual recognition. It is currently unclear what facial features P. fuscatus use to distinguish individuals. The anterior optic tubercle, a chromatic processing brain region, is especially sensitive to social experience during development, suggesting that color may be important for recognition in this species. We sought to test the roles of color in wasp facial recognition. Color may be important simply because it creates a pattern. If this is the case, then wasps should perform similarly when discriminating color or grayscale images of the same faces. Alternatively, color itself may be important for recognition, which would predict poorer performance on grayscale image discrimination relative to color images. We found wasps trained on grayscale faces, unlike those trained on color images, did not perform better than chance. Suggesting that color is necessary for the recognition of an image as a face by the wasp visual system.

Age and social experience induced plasticity across brain regions of the paper wasp Polistes fuscatus

Developmental studies of brain volumes can reveal which portions of neural circuits are sensitive to environmental inputs. In social insects, differences in relative investment across brain regions emerge as behavioural repertoires change during ontogeny or as a result of experience. Here, we test the effects of maturation and social experience on morphological brain development in Polistes fuscatus paper wasps , focusing on brain regions involved in visual and olfactory processing. We find that mature wasps regardless of social experience have relatively larger brains than newly emerged wasps and this difference is driven by changes to mushroom body calyx and visual regions but not olfactory processing neuropils. Notably, social wasps invest more in the anterior optic tubercle (AOT), a visual glomerulus involved in colour and object processing in other taxa, relative to other visual integration centres the mushroom body calyces compared with aged socially naive wasps. Differences in developmental plasticity between visual and olfactory neuropil volumes are discussed in light of behavioural maturation in paper wasps, especially as it relates to social recognition. Previous research has shown that P. fuscatus need social experience to develop specialized visual processing of faces, which is used to individually recognize conspecifics. The present study suggests that the AOT is a candidate brain region that could mediate facial processing in this species.

ASPECTOS DA AGRESSIVIDADE EM Polistes canadensis (LINNEAUS) (HYMENOPTERA: VESPIDAE)

Na etologia, são reconhecidos dois tipos de explicações causais para os comportamentos dos animais: as explicações proximais apelam para variáveis motivacionais, experiências e genótipos, como causas, enquanto que as explicações finais referem-se a pressões de seleção e outros fatores que causam a evolução do comportamento (MAYR, 1961). As variáveis motivacionais, representam estímulos externos (de entrada no sistema) como as condições climáticas, que podem ser usados para explicar o comportamento dos animais (ENQUIST et al., 2005). Assim como os padrões rítmicos de atividades diárias em alguns insetos para o forrageio de abelhas, detalhados em alguns estudos, com Melipona scutellaris e Frieseomelitta doederleini (GOUW & GIMENES, 2013), logo, é necessário realizar mais pesquisas com outros comportamentos associando com os fatores climáticos para que possa entender suas causas proximais.O sistema de dominância tem uma grande importância na vida dos animais sociais, governando não apenas o padrão de sua interação social, mas onde e quando eles se movem ou descansam, onde e o que eles comem, e com que sucesso eles se reproduzem (ROWEL, 1974). Assim a agressão é um comportamento muito presente em algumas vespas, como em Polistíneos, onde a rainha e as operárias, as utilizam para estabelecer um sistema de dominância. Em trabalhos com Poliste galicus, Polistes canadensis e Polistes fuscatus foi possível observar um sistema de dominância linear, entre os membros da colônia, a partir de atividades agressivas (PARDI, 1948; WEST-EBERHARD, 1969).Sendo assim, este projeto teve como objetivo, analisar vários aspectos associados com o comportamento agressivo de Polistes canadensis na colônia, levando-se em conta a influência dos fatores externos (intensidade luminosa, umidade relativa e temperatura) e internos (número de indivíduos e células no ninho, número de ninhos satélites) ao longo do dia e de diferentes meses do ano.