Behavioral Responses of Doryctobracon areolatus and Diachasmimorpha longicaudata (Hymenoptera: Braconidae) to Host Fruits Exploited by Heterospecific Compet

ABSTRACT

The ability to discriminate host resources previously exploited by competitors may reduce the fitness costs associated with interspecific competition and improve host‐use efficiency in parasitoids. Although recognition of cues deposited by conspecific females has been documented in several fruit fly parasitoids, information regarding the detection of heterospecific exploitation cues remains limited. We investigated extrinsic competition between the native parasitoid Doryctobracon areolatus (Szépligeti) and the exotic parasitoid Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae) by evaluating their olfactory choices and foraging behavior on guava, Psidium guajava L. cv. ‘Paluma’, fruits infested with Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae). Olfactory responses were assessed using a Y‐tube olfactometer, and detailed behavioral observations were conducted in glass arenas on fruits previously exposed to heterospecific parasitoids. Both parasitoid species displayed a consistent directional preference toward unexploited host fruits over heterospecific‐exploited resources ( preference for D. areolatus and for Di. longicaudata ), with choice proportions not differing significantly between species (χ ²  = 1.33, d.f = 1, p  = 0.248). Behavioral observations revealed that of tested females accepted the host fruit and performed ovipositor insertion ( probing ). Previous exploitation by a heterospecific competitor significantly altered post‐landing patch assessment in both species, inducing extended resting and probing durations (). These results demonstrate that both parasitoid species recognize host habitats altered by prior heterospecific activity and adjust their patch allocation strategies accordingly. The observed behavioral modifications provide key insights into host‐habitat assessment and functional complementarity in integrated pest management programs.