Comparative fecundity and associated factors for two sibling species of the Anopheles gambiaecomplex occurring sympatrically in The Gambia

Abstract

For two sibling species of mosquitoes belonging to the Anopheles gambiae complex of malaria vectors, the effects of body size (wing length) and bloodmeal size (haematin excretion) on fecundity of wild females were investigated in The Gambia, West Africa. Freshly blood-fed individuals from sympatric populations of An.arabiensis and An.gambiae sensu stricto were sampled by collection at 07.00-09.00 hours from within bednets during July/August 1993, at the beginning of the rainy season. The possible confounding effect of infection with Plasmodium parasites was removed by eliminating infected mosquitoes from the study samples. An.arabiensis females comprised 75% of the An.gambiae sensu lato population and were significantly larger (greater mean wing length) than those of An.gambiae s.s. mosquitoes. Mean egg production per female (for the subsequent gonotrophic cycle, excluding pre-gravids) for the two species was not significantly different, though the relationship between wing length and egg production showed An.gambiae s.s. to be more fecund than the An.arabiensis of the same size. Pre-gravid An.gambiae s.s had consumed significantly smaller bloodmeals than gravid females but the mean wing length of these two gonotrophic categories was not significantly different. In contrast, An.arabiensis pre-gravids were smaller and had consumed smaller bloodmeals than the gravids.

Behavioural determinants of gene flow in malaria vector populations: Anopheles gambiae males select large females as mates

“…An initial experiment confirmed previous reports [22,23] that oviposition likelihood depended on the size of females and this observation was consistently repeated in the two subsequent experiments that examined this relationship in more detail (Table 3, Figure 2). This first experiment also showed that increased competition actually reduced the likelihood of oviposition, despite the increased insemination probability expected (Table 3).…”

“…freeborni [21], recent field studies of An.gambiae have shown that large males are no more likely to fall out of mating swarms in copula than are small males [24]. Here, however, we have shown that the size of female An.gambiae has major impact on not only their fecundity [22,23] but also their chance of being chosen as mates by the males who compete intensely for the privilege. Under these laboratory conditions, female size is the major factor influencing mate choice by males within and between strains as well as the size of subsequent egg batches.…”

“…Greater size has been shown to be associated with both prolonged swarming and successful insemination within swarms, by wild An. freeborni males [21] and increased fecundity in females of the An.gambiae complex [22,23] so we investigated this relationship in more detail with three successively more detailed experiments.…”

Nature beats nurture: a case study of the physiological fitness of free-living and laboratory-reared maleAnopheles gambiae s.l.

“…The relationship between wing length and body mass is variable, and its exact nature can differ between mosquitoes of different species, strain and rearing background (Nasci, 1990;Siegel et al, 1992;Siegel et al, 1994). Despite this limitation, Anopheline mosquito wing length has consistently been shown to be a significant predictor of traits such as fecundity and survival (Ameneshewa and Service, 1996;Hogg et al, 1996;Kittayapong et al, 1992;Lehmann et al, 2006;Lyimo and Takken, 1993), and thus was selected as a useful approximator of mosquito fitness for our purposes.…”

Studies on Aedes albopictus Larval Mass-Rearing Optimization

“…The relationship between wing length and fecundity was also signiÞcant and positive, but with lower correlation coefÞcients and higher variance, indicating that other factors also affect fecundity. Several other studies have shown a positive relationship between wing length (or other measures of body size) and fecundity (Livdahl and Sugihara 1984;Packer and Corbet 1989;Briegel 1990a,b;Reeves 1990;Bradshaw and Holzapfel 1992;Clements 1992, Siegel et al 1992Renshaw et al 1994;Hogg et al 1996). Koenraadt (2008) found that the cephalothorax length is the most reliable pupal parameter to predict adult male body size in Ae.…”