Abstract. 1. The work reported here investigated the incidence of dispersal by bagworm larvae Metisa plana (Walker) (Lepidoptera: Psychidae), a species with apterous females and winged males.2. A mark±recapture study conducted in a plantation of oil palm revealed that a significant proportion of larvae undertakes multiple episodes of ballooning, and suggested that ballooning represents a strategy for foraging both within and between hosts.3. Experiments conducted in a controlled cage environment indicated that increasing population density and defoliation of oil palm both promote dispersal by larvae.4. Neonatal larvae typically remained on the host where they emerged, indicating that pupation site of late-instar females influences the distribution of their progeny, and suggesting a high level of genetic relatedness in localised bagworm populations.5. Density-dependent dispersal may generate relatively uniform distributions of M. plana in plantations of oil palm, by simultaneously stabilising populations on heavily infested palms and redistributing larvae on lightly infested palms.6. The rate of ballooning was greater for female than for male larvae, possibly resulting from the sex-specific impact of population density on reproductive success or from late-instar females seeking suitable oviposition sites for their future progeny.

The common green bottle fly Lucilia sericata (Meigen) and other filth flies frequently visit pollen-rich composite flowers such as the Oxeye daisy, Leucanthemum vulgare Lam. In laboratory experiments with L. sericata, we investigated the effect of generic floral scent and color cues, and of Oxeye daisy-specific cues, on foraging decisions by recently eclosed flies. We also tested the effect of a floral pollen diet with 0–35% moisture content on the ability of females to mature their oocytes. Our data indicate that (1) young flies in the presence of generic floral scent respond more strongly to a uniformly yellow cue than to any other uniform color cue (green, white, black, blue, red) except for ultraviolet (UV); (2) the floral scent of Oxeye daisies enhances the attractiveness of a yellow cue; and (3) moisture-rich pollen provides nutrients that facilitate ovary maturation of flies. With evidence that L. sericata exploits floral cues during foraging, and that pollen can be an alternate protein source to animal feces and carrion, Pollen apparently plays a major role in the foraging ecology of L. sericata and possibly other filth flies. These flies, in turn, may play a significant role as pollinators, as supported by a recently published study.

Foraging behaviour by Ips typographus L. (Coleoptera; Scolytidae) was simulated to assess host finding and reproductive success of beetles following four different strategies: 1. random search, 2. upwind search, in which beetles follow a prevailing flight direction, 3. random search with short range olfactory attraction to susceptible trees (primary attraction), and 4. upwind search with primary attraction. For each strategy we varied three parameters in equidistant steps including number of susceptible trees per hectare (0.06-0.33), population size (200-1000 beetles), and flight capacity (500-3000 m). All possible combinations of these parameters were tested in 12 replicates with more than 400 000 imaginary beetles flown through the simulated forest. Reproductive success of strategy 4, which combined upwind flight with primary attraction, exceeded that of the other strategies (1-3) circa 27, 7, and 4 times, respectively. In random search, maintenance of the population required a flight capacity, population size and host tree abundance which are unlikely to occur at suboutbreak levels in nature.

Coleoptera, Oryctes monoceros, African Rhinoceros Beetle, Aggregation Pheromone, Ethyl 4-M ethyloctanoate Ethyl 4-m ethyloctanoate is a male-produced aggregation pheromone of the African rhinoc­eros beetle, Oryctes monoceros (Olivier). It was identified by coupled gas chromatographic-electroantennographic detection (GC -EAD) and coupled GC-mass spectrometry (MS) of Porapak Q-trapped male-produced volatiles. Natural and synthetic ethyl 4-m ethyloctanoate elicited comparable antennal responses. In a field experiment (La Me Research Station, Côte d’Ivoire), synthetic ethyl 4-methyloctanoate released at 30 mg/day attracted both male and fem ale Oryctes, whereas the known, non-beetle-produced attractant, ethyl chrysanthemate, did not attract any Oryctes. Upon improvement of trap design and placement, and the identi­fication of synergistic (plant) volatiles, pheromone-based mass trapping may become an alternative and/or additional strategy to manage O. monoceros, one of the most destructive pests of commercial coconut, oil, and date palms in Africa.

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