Behavioural plasticity in relation to egg and time limitation: the case of two fly species in the genus Anastrepha (Diptera: Tephritidae)

Abstract

Díaz -Fleischer, F. and Aluja, M. 2003. Behavioural plasticity in relation to egg and time limitation: the case of two fly species in the genus Anastrepha (Diptera: Tephritidae). -Oikos 100: 125-133.Reproductive opportunities in insects that deposit their eggs in discrete resource patches are frequently limited because the availability of oviposition substrates is often spatially and temporally restricted. Such environmental variability leads individuals to confront time-or egg-limitation constraints. Additionally, species with different oviposition strategies (i.e. single egg layers vs clutch layers) commonly deal with different structural and ecological characteristics of larval host plants. To test the hypothesis that oviposition strategies such as laying eggs singly or in batches (clutches) are related to these constraints (i.e. egg vs time limitation), we compared the lifetime oviposition patterns of two closely related sympatric species of Anastrepha (Diptera: Tephritidae) with different oviposition strategies. We exposed five cohorts of A. obliqua and A. ludens females, over the course of their adult lifetimes, to three conditions of ''habitat quality'' (measured as host density per cage): unpredictable habitat quality (host density varied randomly from day to day between 1, 5, 15, 30 and 60 hosts/cage), low habitat quality (fixed density of one host/cage) and high habitat quality (fixed density of 60 hosts/cage). Responses to host density conditions were strikingly different in the two species. (1) Frequency of host visits and oviposition events increased in A. obliqua but not in A. ludens when host densities increased. (2) Anastrepha ludens females accepted low quality hosts (i.e. fruits on which eggs had already been laid and were therefore partially covered with host marking pheromone) significantly more often than A. obliqua females did. (3) Females of A. obliqua adjusted their oviposition activity to variations in host density, whereas A. ludens females exhibited a constant oviposition pattern (i.e. did not respond to variations in host density). Based on the above, it is likely that in A. obliqua oviposition is governed by egg-limitation and in A. ludens by time-limitation constraints. We discuss the relationship between the oviposition strategies of each fly species and the fruiting phenology and density of their native host plants. We also address the possible influence of oogenesis modality and parasitism by braconid wasps in shaping oviposition behaviour in these insects.F. Díaz-Fleischer, Campaña Nacional Contra Moscas de la Fruta, Desarrollo de Métodos, 2a. A6. Sur No.

Offspring genetic structure reveals mating and nest infestation behaviour of an invasive parasitic fly (Philornis downsi) of Galápagos birds

“…Multiple ectoparasite infestations have implications for total parasite intensity and thus, the level of impact sustained by the host. The propensity of parasitic insects to oviposit on a previously infested host is influenced by a number of factors, including the detection of host-marking pheromone from previous ovipositing females (Arredondo and Diaz-Fleischer 2006), host density and distribution (Cronin and Strong 1999;Diaz-Fleischer and Aluja 2003), female egg load (Minkenberg et al 1992), costs of larval competition (Dukas et al 2001), and competition between unrelated conspecifics (Frank 1994;Atkinson et al 2002;Puustinen et al 2004). Our findings support previous studies of Philornis that have documented or suggest multiple infestations (reviewed in O'Connor et al unpublished), though multiple infestations by P. downsi have not previously been confirmed in nests of Darwin's finches (Fessl et al 2006a).…”

Selection of artificial hosts for oviposition by wild Anastrepha obliqua (Macquart) (Diptera, Tephritidae): influence of adult food and effect of experience

“…Thus, a polyphagous insect with high behavioral adaptability, as A. obliqua, may keep a large number of hosts. Several authors (Carey et al 1986;Prokopy & Reynolds 1998;Díaz-Fleischer & Aluja 2003a, 2003b) and the present study have reported the plasticity of fruit flies concerning their oviposition behavior strategies. In this sense, further investigations on the factors related to this behavior are needed.…”

Grapefruit as a Host for the West Indian Fruit Fly (Diptera: Tephritidae)

“…Birke et al (2006) discuss the role of the longer aculeus in A. ludens that allows oviposition deeper into the peel and may be an adaptation for survival of eggs and early instars in citrus. Aluja et al (2001) and Dṍaz-Fleischer and Aluja (2003aAluja ( , 2003b review several differences in egg production and oviposition in A. ludens and A. obliqua. Fruit odors and odors from other reproducing females were noted to affect A. obliqua reproduction but not A. ludens.…”