Influence of host use adaptation on the dispersal propensity of Callosobruchus maculatus

Abstract

Local adaptation can lead to significant differences in host use that may influence population growth and spread. Here, we test the potential for adaptation of one behavioural component (host acceptance) to lead to cross‐adaptation for a separate behavioural component (dispersal propensity) using the cowpea seed beetle, Callosobruchus maculatus. C. maculatus originating from the same source population were subjected to selection for host use by rearing them for over 40 generations on either the preferred host of the ancestral population, Vigna radiata, or a marginal host for the ancestral population, Cicer arietinum. Host acceptance was then assayed using four choice and no‐choice oviposition assays including a low‐quality host, Lens culinaris, a marginal host, C. arietinum, and two high‐quality hosts, V. radiata and V. unguiculata. Dispersal was assayed in interconnected arenas containing one of three different hosts: V. radiata, V. unguiculata or C. arietinum. As expected, differences in host acceptance were present, in this case consisting of greater acceptance of the lower quality hosts in the C. arietinum population, but no significant differences in host preference hierarchy. Dispersal propensity in the C. arietinum population was significantly lower than in the V. radiata population, despite the absence of any difference in selection pressures for dispersal. Furthermore, significant differences in dispersal propensity in arenas containing different hosts were present in the V. radiata population, but not in the C. arietinum population. Results highlight the need to consider local adaptation when developing management recommendations, even for behaviours for which selection pressures are not directly apparent.

Differing effects of parental and natal hosts on the preference and performance of the stored product pests Callosobruchus maculatus and C. analis

“…Bean beetles are responsive to these cues, affecting host preference (Messina, 2004;Messina et al, 2018). Most studies show that females preferred their natal host when given a choice (Messina and Slade, 1997;Boeke et al, 2004;Paukku and Kotiaho, 2008;Rova and Björklund, 2011;Bergeron et al, 2019), suggesting a learned response, but some studies did not find a preference (Mainali et al, 2015;Bergeron et al, 2019). Therefore while many studies have demonstrated the capability of herbivorous insects to learn during oviposition (Jones and Agrawal, 2017), the existence of such a learned response in Callosobruchus is uncertain.…”