Costs and benefits of larval jumping behaviour of Bathyplectes anurus
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Bathyplectes anurus, a parasitoid of the alfalfa weevils, forms a cocoon in the late larval stage and exhibits jumping behaviour. Adaptive significance and costs of the cocoon jumping have not been thoroughly studied. We hypothesised that jumping has the fitness benefits of enabling habitat selection by avoiding unfavourable environments. We conducted laboratory experiments, which demonstrated that jumping frequencies increased in the presence of light, with greater magnitudes of temperature increase and at lower relative humidity. In addition, when B. anurus individuals were allowed to freely jump in an arena with a light gradient, more cocoons were found in the shady area, suggesting microhabitat selection. In a field experiment, mortality of cocoons placed in the sun was significantly higher than for cocoons placed in the shade. B. anurus cocoons respond to environmental stress by jumping, resulting in habitat selection. In the presence of potential predators (ants), jumping frequencies were higher than in the control (no ant) arenas, though jumping frequencies decreased after direct contact with the predators. Body mass of B. anurus cocoons induced to jump significantly decreased over time than cocoons that did not jump, suggesting a cost to jumping. We discuss the benefits and costs of jumping behaviour and potential evolutionary advantages of this peculiar trait, which is present in a limited number of species.
KeywordsBiological control Cocoon Habitat selection Leaping behaviour Locomotory mode Parasitoid
We are indebted to four anonymous reviewers and M. Hart for their valuable and constructive suggestions. This study was supported by a Grant-in-Aid from JSPS (KAKENHI 22570215, 23405008 and 25430194) and by Kyushu University Interdisciplinary Programs in Education and Projects in Research Development (25412) to M. Tuda.
- Alcock J (1998) Animal behaviour: an evolutionary approach, 6th edn. Sinauer Associates, Inc, MassachusettsGoogle Scholar
- Alexander RM (2000) Hovering and jumping: contrasting problems in scaling. In: Brown JH, West GB (eds) Scaling in Biology. Oxford University Press, Oxford, pp 37–50Google Scholar
- Cherry RH, Armbrust EJ, Ruesink WG (1976) Lethal temperatures of diapausing Bathyplectes curculionis (Hymenoptera: Ichneumonidae) a parasite of the alfalfa weevil (Coleoptera: Curculionidae). Great Lakes Entomol 9:189–193Google Scholar
- Gauld ID, Bolton B (1988) The Hymenoptera. British Museum (Natural History) and Oxford University Press, OxfordGoogle Scholar
- Heinrich B (1981) Insect thermoregulation. John Wiley & Sons, New YorkGoogle Scholar
- Horn DJ (1976) Brief note behavior of Gelis species’ parasitizing Bathyplectes, parasitoids of the alfalfa weevil. Ohio J Sci 76:279–280Google Scholar
- Ito T (2012) Jumping cocoons of Orchestes jozanus (Kono). Monthly J Entomol 499:22–24 (In Japanese)Google Scholar
- Kats L, Dill LM (1998) The scent of death: chemosensory assessment of predation risk by prey animals. Ecoscience 5:361–394Google Scholar
- Kingsolver JG, Huey RB (2008) Size, temperature, and fitness: three rules. Evol Ecol Res 10:251–268Google Scholar
- Tagawa J (1996) Function of the cocoon of the parasitoid wasp, Cotesia glomerata L. (Hymenoptera: Braconidae): protection against desiccation. Appl Entomol Zool 31:99–103Google Scholar