Coexistence between two fruit fly species is supported by the different strength of intra‐ and interspecific competition

Abstract

1. Unravelling the strength and modes of interspecific interactions between resident and introduced species is necessary in order to understand the basis of their coexistence or the displacement of the former by the latter. In Argentina, the indigenous Tephritidae fly Anastrepha fraterculus overlaps its distribution and host fruit with the introduced species Ceratitis capitata.2. This study focused on the relative strength of intra-and interspecific competition during the larval stage as a potential factor supporting coexistence. Classical competition experiments (addition and substitution) were conducted between larvae of the two species reared in artificial larval diet. The study evaluated whether a temporal separation between oviposition events affects the outcome of the competition.3. When both species started to consume the resource at the same time, A. fraterculus experienced a negative effect in larval survival, pupal weight and duration of larval stage, while for C. capitata, pupal weight decreased. When A. fraterculus started feeding 1 day earlier than C. capitata, the negative effects became milder, and when the temporal separation increased, these effects were reversed. Substitution experiments showed an increase in pupal weight when larvae had to share the resource with heterospecific larvae, and showed negative effects suffered for both species when they shared the resource with conspecific individuals.4. These results suggest that intraspecific competition is stronger than interspecific competition, and a differential oviposition preference could generate an asynchrony of these species in nature. Such mechanisms could favour coexistence between A. fraterculus and C. capitata in an environment previously occupied only by the former.

Co-Existence of <i>Bactrocera dorsalis</i> Hendel (Diptera: Tephritidae) and <i>Ceratitis cosyra</i> Walker (Diptera: Tephritidae) in the Mango Orchards in Western Burkina Faso

“…Interspecific competition is among the most common interactions induced after a biological invasion, at least for insect species [6]. Several studies have shown that B. dorsalis has a high potential to displace some native species from their spawning site as well as their natural geographic range [7] [8]. [7] indicated the rapid displacement of C. cosyra by B. dorsalis at Nguruman, Kenya, 4 years after its detection in the African continent.…”

Olive fruit volatiles route intraspecific interactions and chemotaxis in Bactrocera oleae (Rossi) (Diptera: Tephritidae) females

“…Either biotic and abiotic factors can modify the VOC emissions from olives 21,22 and can change their attractiveness toward the olive fruit fly and its natural enemies 23,24 . As reported for other phytophagous species 25,26 , the presence of a pre-existing infestation can alter the volatile emission and can decrease fruit appeal for conspecific oviposition, reducing progeny competition during the larval development.…”

“…involving contending species), but it can be also exploited by conspecifics 30,31 . Intraspecific competition is probably the most triggering kind of competition for monophagous species, since the conspecific individuals share the same resource requirements 25,26 . Here, the results obtained by both behavioural assays and GC-MS analyses support our hypothesis that olfactory cues from olives play a role on the preferences of B. oleae females.…”

Competitive interactions and partial displacement of Anastrepha obliqua by Ceratitis capitata in the occupation of host mangoes (Mangifera indica)

“…Classical niches theory postulates that one of the principal determining factors influencing the outcome of competitive interactions is resource overlap (Duyck et al ., 2004). Under such a scenario, when an invasive species has a competitive advantage over a native species, the latter may suffer decreased abundance while still managing to co‐occur with the invader as a result of resource constraints (David et al ., 2017, Masselière et al ., 2017, Liendo et al ., 2018). In their review, Reitz & Trumble (2002) suggested that while other mechanisms, including anthropogenic action and environmental changes in temperature may be responsible for the niche displacement of a species, the principal cause for such processes involves the introduction of an invasive non‐native species.…”

“…Although patterns of development of immature stages, along with oviposition behaviour of the females are similar between Anastrepha species and C. capitata , these species differ in terms of their preference for fruit ripeness for oviposition. Some Anastrepha species are reported to prefer unripe fruits for oviposition (Diaz‐Fleischer & Aluja, 2003; Liendo et al ., 2018), while C. capitata prefers to lay eggs in ripe ones (Joachim‐Bravo et al ., 2001a). The clutch size also is different.…”