Foraging patterns in a nocturnal swarm-founding wasp, Apoica flavissima van der Vecht (Hymenoptera: Vespidae)

Foraging behaviour has a remarkable significance to colonies of social insects since it is directly related to the supply of food, water, and pulp. Social wasps of the genus Apoica Lepeletier are primarily nocturnal, but studies concerning the general aspects related to this habit are still scarce. This study showed that the rates of foraging flights were higher during the full moon and last quarter moon phases. Frequencies of arrival and departure were correlated with time and temperature at night. The results suggest that the moonlight is an important component to general activities in this genus.

O comportamento de forragear é fundamental para o desenvolvimento das colônias de insetos sociais, pois permite que as colônias sejam supridas de alimento, água e materiais utilizados para a construção dos ninhos. Vespas sociais do gênero Apoica Lepeletier (Hymenoptera: Vespidae) têm comportamento de forrageamento noturno como uma de suas principais características, porém estudos sobre aspectos abióticos que influenciam esse comportamento são ainda escassos. Este estudo mostra que a freqüência de forrageamento foi maior em noites de luas cheia e crescente. Além disso, as saídas e retornos ao ninho correlacionaram-se positivamente com o período da noite e a temperatura. Os resultados sugerem que a luminosidade é um componente importante nas atividades gerais das colônias do gênero.

Efficacy of insect parasitoid Dirhinus himalayanus (Hymenoptera: Chalcididae) & insect growth regulator, triflumuron against house fly, Musca domestica (Diptera: Muscidae).

BACKGROUND & OBJECTIVES: In fly management programme chemicals are extensively used. Combined use of insect growth regulator (IGR) and parasitoids would yield a better reduction in fly density, as exposure of fly larvae to sub lethal dose of IGR enhances pupal duration and thereby increases the exposure time for parasitism. The objective of the present study was to explore the additive effect of both Dirhinus himalayanus, an insect parasitoid and triflumuron, an IGR in controlling house fly, Musca domestica. METHODS: In the field trial the study sites were allocated based on two-way ANOVA performed on one year pre-treatment survey. Parasitoid release and IGR treatment were initiated when the growth rate (lambda) of M. domestica was in an increasing trend. Parasitoids were released at a rate of 6 number/m2 for three months (February-April 2000), whereas IGR was applied at a dose of 10 mg/m2 at fortnightly interval from February to December 2000. Control efficacy was assessed using Mulla's formula. RESULTS: Reduction in puparia density was 59.29, 48.67 and 69.08 per cent respectively in areas, where parasitoids, ICR and combination of both IGR and parasitoids were used. Corresponding figures for adult population were 55.69, 49.71 and 77.14 per cent respectively. The per cent reduction in puparia and adult density was significantly (P<0.05) higher in the experimental areas than in the check. When the per cent reduction in adult and puparia density among different experimental areas was compared, it was observed that the reduction in fly density was significantly higher in the areas, where the combination of both parasitoid-IGR (P=0.00102) and IGR (P=0.03175) were used, while in areas where parasitoid (P=0.06191) were released the reduction in fly density was not significant. Similarly, there was a significant reduction in puparia density in areas where both parasitoid-IGR combination (P=0.0001) or IGR (P=0.002) were used, whereas in parasitoid (P=0.0612) released areas it was not significant. INTERPRETATION & CONCLUSION: The results show that the combined use of parasitoid and IGR is effective in reducing puparia and fly density. Therefore, for sustenance of an effective fly control programme, both parasitoid and IGR may be used.

Two new species of Crawfordia Pierce from South America, (Strepsiptera: Stylopidae)

Several stylopized specimens were found among the Hymenoptera collection of the Instituto Oswaldo Cruz (Rio de Janeiro, Brazil). A paper by Kogan & Oliveira (1966) described the parasites of Polybia represented among those specimens. I describe herein the first neotropical species of the genus Crawfordia parasitizing species of Psaenithia (Andrenidae, Panurgini). The presence of vestigial thoracic segmentation of the female cephalothorax is a peculiar trait of this genus of Strepsiptera. Triungulinids are described in detail for the first time in this genus.