Insect oviposition plasticity in response to host availability: the case of the tephritid fruit fly Bactrocera dorsalis

Abstract

1. Insect oviposition behaviour is ecologically and physiologically plastic. For tephritid fruit flies, Bactrocera dorsalis Hendel, host availability varies spatially and temporally. Females are expected to adopt adaptive oviposition strategies to maximise lifetime reproductive fitness, including survival. Bactrocera dorsalis oviposition tactics in response to different host availabilities were investigated.2. This study includes three treatments: (i) variable host densities (host density varied according to a fixed cycle from day to day over values of 1, 5, 10 and 20 hosts per cage), (ii) a fixed high host density (20 hosts per cage), and (iii) a fixed low host density (1 host per cage).3. Daily egg-laying number per female over the course of 27 days was entirely independent of host density and highly dependent on female age. As host availability increased, females accepted significantly more hosts, generally laid small egg clutches, and more broadly distributed the eggs.4. Tephritid fruit flies adaptively adjusted egg clutches in ways that reflected the variability of host availability. Egg-and time-limitation constraints appeared to drive these adjustments. Female egg maturation was triggered by oviposition activity and reflected marked lifetime trade-offs. Such strategies involved specific time schedules for egg laying.5.This study defined the oviposition plasticity of the tephritid fruit fly. These results have general implications for the behavioural ecology of insect herbivores and parasitoids.

Genetic changes during laboratory domestication of an olive fly SIT strain

“…; Xu et al. ). Nonetheless, despite the initial considerable reduction in the colonizing olive fly population, genetic variability was not affected proportionately: n e decreased by only 11.3%, whereas He increased by 23.6% (from F0 to F3).…”

“…In contrast, the Medfly, Ceratitis capitata, and the oriental fruit fly, Bactrocera dorsalis, present a much higher degree of plasticity, at least with regard to host-choice for oviposition. This plasticity may, in fact, allow for an easier adaptation in laboratory conditions with modest reduction of reproduction parameters (de Souza et al 1988;Diamantidis et al 2011;Xu et al 2012). Nonetheless, despite the initial considerable reduction in the colonizing olive fly population, genetic variability was not affected proportionately: n e decreased by only 11.3%, whereas He increased by 23.6% (from F0 to F3).…”

Fruit infestation patterns byAnastrepha fraterculusandCeratitis capitatareveal that cross-recognition does not lead to complete avoidance of interspecific competition in nature

“…Insects integrate a number of external cues and signals with their own internal state to decide whether to lay eggs in a given host or skip it and keep searching (Carriere, ; Díaz‐Fleischer & Aluja, ; Xu et al ., ). Oviposition in tephritids is a dynamic and plastic process (Mangel & Roitberg, ; Aluja et al ., ) and the response to HMPs is a good example of this plasticity.…”

Egg and time limitation mediate an egg protection strategy

“…Sensitivity to host availability, life expectancy and egg load influences the reproductive decisions in insects (Fletcher et al, 1994;Babendreier & Hoffmeister, 2002;Diaz-Fleischer & Aluja, 2003;Xu et al, 2012). Time and egg constraints on females have been argued to be major mediators in the reproductive behaviour of insects (Rosenheim, 2011), and host availability may be the most important factor influencing whether a female is egg limited or time limited (Ellers et al, 2000;Diaz-Fleischer & Aluja, 2003;Xu et al, 2012). Egg and time limitation have been shown to mediate oviposition behaviour among species of herbivorous insects and parasitoids that use discrete units of food for oviposition.…”

“…When assessing host quality or availability, females are generally more selective when egg limited, and less selective when time limited (Iwasa et al, 1984;Parker & Courtney, 1984;Odendaal & Rausher, 1990;Javois & Tammaru, 2004). For example, when tephritid fruit fly species Anastrepha and Bactrocera are egg limited, they more often reject lower-quality hosts and lay fewer eggs per fruit; but when time limited, they accept lower-quality hosts and lay more eggs per fruit (Diaz-Fleischer & Aluja, 2003;Xu et al, 2012). Egg-limited solitary parasitoids often avoid ovipositing in hosts that have been parasitized, but superparasitize hosts more often when time limited (van Alphen & Visser, 1990).…”