ABSTRACT Collection of pollen was verified in 248 samples of the material on the hind tibial scopae of the solitary bee, Epicharis rustica (Olivier, 1879) captured on their return to the nest. Of the total, 54% (133) of the samples had material on the scopae, 48 of then had only oil and 85 (64%) had both oil and pollen. For seven weeks, almost all (91%) of the 85,000 the pollen grains were of the tree, Byrsonima sericea DC. In the latter weeks the proportion of this species decreased. Like several other members of the genus, E. rustica is univoltine, oligolectic and nests in aggregations.

An occupied nest of Epipona media Cooper was discovered and collected in a cabruca (cocoa plantation with native tree cover). This is the first record of E. media from Bahia State. We described the nest structure and compared the adults with the closely related species Epipona tatua Cuvier.

The holotype female, allotype male and nest are described of a new species of social wasp, Mischocyttarus (Kappa) santacruzi (Hymenoptera, Vespidae) from Atlantic coastal forest, Bahia, State, eastern Brazil. Morphologically the species is close to M. (Kappa) adolphi Zikán.

The females and nests are described of two new species of social wasps (Hymenoptera, Vespidae) from dry evergreen forest on the Ilha de Maraca, Roraima, Brazil. Mischocyttarus (Monocyttarus) maracaensis sp.n. closely resembles M. flavicornis Zikan, 1935 in morphology and coloration. Polybia (Myrapetra) roraimae sp.n. is a member of the P. occidenlalis (Olivier, 1791) group of species.

An important aspect of the hunting strategy of neotropical social wasps (Hymenoptera: Vespidae) is where they hunt. Three species used two behavioural components in their selection of a place to search for prey. The wasps uti lizcd the odour of freshly damaged leaves as cues (which could be synomones) to select which leaves to inspect and also they remembered a place to which they were strongly attracted to hunt recently and returned there. Polybia ignobilis (Haliday, 1836) and Polistes satan Bequaert, 1940 hunted on a lawn of Digitaria diversinervis Stapf immediately after it was mown in significantly larger numbers than at other times. P. ignobilis and Polistes versicolor (Olivier, 1791) hunted in significantly greater numbers on freshly cut leaves of passion vine (Passiflora edulis Sims) than on uncut leaves. Sometimes wasps inspected cards rubbed with freshly crushed leaves of P. edulis, but not control cards. Preliminary data suggest that several other species of social wasps around Brasilia hunt in a similar manner on native and exotic plants. Apparently the production of ephemeral odours by freshly cut leaves attract generalist insectivorous predators which perceive these scents and the social wasps investigated are members of the third trophic level of the plants' defence against attacks by herbivores. Available information suggests a difference between the behaviour of generalists and that of specialist arthropod predators which arc attracted to the odour emitted after their particular prey have damaged the leaves.

At a locality near Brasilia the sizes of hunting areas and of colonies of 13 species of social wasps varied greatly. Size of the hunting area varied 152 fold and was strongly related to the number of adult wasps per colony which varied 400 fold. The total number of adults of the 13 species was estimated at 182.9/ ha (range 7.1 fold among the species) and their total biomass was 1.6 kg/ ha (range 3.6 fold). Hunting range was not significantly related to body size. Variation in wing area (11.3 fold) was similar to that of the fresh weight of the adult female (10.7 fold). Eleven species showed habitat preferences where they hunted. Models relating prey size to the distance prey are carried are discussed.

A new species of termite, Orthognathotermes heberi, is described and the soldiers illustrated. It is similar in morphology and the structure of its nests to O. gibberorum from Mato Grosso. The soldiers are strongly dimorphic, 14% being minor soldiers whose heads are only 59% the length of those of the major ones. No such dimorphism has been recorded in any of the seven species already known in the genus.