title: Costs and benefits of larval jumping behaviour of Bathyplectes anurus.
abstract: 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.
authors.affiliation: Institute of Biological Control, Faculty of Agriculture, Kyushu University, Fukuoka, 812-8581, Japan. yoriyoripp@gmail.com.
authors.forename: Yoriko
authors.identifier: http://orcid.org/0000-0001-7928-1420
authors.initials: Y
authors.lastname: Saeki
authors.affiliation: Institute of Biological Control, Faculty of Agriculture, Kyushu University, Fukuoka, 812-8581, Japan.
authors.forename: Soichiro
authors.initials: S
authors.lastname: Tani
authors.affiliation: Laboratory of Insect Natural Enemies, Division of Agricultural Bioresource Sciences, Department of Bioresource Sciences, Faculty of Agriculture, Kyushu University, Fukuoka, 812-8581, Japan.
authors.forename: Katsuto
authors.initials: K
authors.lastname: Fukuda
authors.affiliation: Institute of Biological Control, Faculty of Agriculture, Kyushu University, Fukuoka, 812-8581, Japan.
authors.forename: Shun-ichiro
authors.initials: S
authors.lastname: Iwase
authors.affiliation: Laboratory of Insect Natural Enemies, Division of Agricultural Bioresource Sciences, Department of Bioresource Sciences, Faculty of Agriculture, Kyushu University, Fukuoka, 812-8581, Japan.
authors.forename: Yuma
authors.initials: Y
authors.lastname: Sugawara
authors.affiliation: Institute of Biological Control, Faculty of Agriculture, Kyushu University, Fukuoka, 812-8581, Japan. tuda@grt.kyushu-u.ac.jp.|Laboratory of Insect Natural Enemies, Division of Agricultural Bioresource Sciences, Department of Bioresource Sciences, Faculty of Agriculture, Kyushu University, Fukuoka, 812-8581, Japan. tuda@grt.kyushu-u.ac.jp.
authors.forename: Midori
authors.initials: M
authors.lastname: Tuda
authors.affiliation: Institute of Biological Control, Faculty of Agriculture, Kyushu University, Fukuoka, 812-8581, Japan.|Laboratory of Insect Natural Enemies, Division of Agricultural Bioresource Sciences, Department of Bioresource Sciences, Faculty of Agriculture, Kyushu University, Fukuoka, 812-8581, Japan.
authors.forename: Masami
authors.initials: M
authors.lastname: Takagi
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D049628:Body Size; D003362:Cost-Benefit Analysis; D017753:Ecosystem; D004924:Escape Reaction; D006813:Humidity; D007814:Larva; D008027:Light; D013696:Temperature; D014863:Wasps / Q000502:physiology*
keywords: Biological control; Cocoon; Habitat selection; Leaping behaviour; Locomotory mode; Parasitoid