Factors affecting the reproductive biology of Melittobia digitata and failure to meet the sex ratio predictions of Hamilton's local mate competition theory

2003 ◽  
Vol 109 (1) ◽  
pp. 1-12 ◽  
Author(s):  
M.F. Cooperband ◽  
R.W. Matthews ◽  
S.B. Vinson
2009 ◽  
Vol 100 (2) ◽  
pp. 241-245
Author(s):  
F.P. Zhang ◽  
D.R. Yang

AbstractStudies on mating ecology and sex allocation in fig-parasitizing wasps ovipositing from outside the fig have given valuable insights into known factors that are responsible for the theory of sex ratio. Similarly, internally ovipositing fig-parasitizing wasps and fig-pollinating wasps provide interesting models for comparative analysis. In addition to the fig-pollinating wasp Eupristina sp., we found that Ficus curtipes hosts two species of internally ovipositing fig-parasitizing wasps: D. yangi and Lipothymus sp. Eupristina sp. males showed less aggression. Eupristina sp. has wingless males that mate only within the natal patch, providing excellent examples of full local-mate competition. D. yangi males showed high levels of aggression and lethal combat. D. yangi has winged males but mate mostly within the natal patch. Only a few matings occur after male dispersal. Its sex ratio was lower than the prediction of partial local mate competition theory. Wingless male Lipothymus sp., which mate partly after dispersal, did not present fatal fight. Therefore, the mating behaviour of D. yangi and Lipothymus sp. did not follow predicted patterns, based on wing morph. The mating pattern of D. yangi and Lipothymus sp. should follow the partial local mate competition theory. Furthermore, there was not a significant correlation between the proportion of males and the proportion of fruit parasitized in both winged D. yangi males and wingless Lipothymus sp. males.


Author(s):  
Ryosuke Iritani ◽  
Stuart A West ◽  
Jun Abe

AbstractHamilton’s local mate competition theory provided an explanation for extraordinary female biased sex ratios in a range of organisms. When mating takes place locally, in structured populations, a female biased sex ratio is favoured to reduce competition between related males, and to provide more mates for males. However, there are a number of wasp species where the sex ratios appear to more female biased than predicted by Hamilton’s theory. We investigated theoretically the extent to which cooperative interactions between related females can interact with local mate competition to favour even more female biased sex ratios. We found that: (i) cooperative interactions between females can lead to sex ratios that are more female biased than predicted by local competition theory alone; (ii) sex ratios can be more female biased when the cooperative interactions are offspring helping parents before dispersal, rather than cooperation between siblings after dispersal. Our results can be applied to a range of organisms, and provide an explanation for the extreme sex ratio biases that have been observed in Sclerodermus and Melittobia wasps.


2004 ◽  
Vol 82 (12) ◽  
pp. 1969-1974 ◽  
Author(s):  
B H King ◽  
J A D'Souza

Empirical studies of how constrained females affect sex ratio are few. Constrained females are those that can produce only sons (e.g., in haplodiploid species, females that have not mated or older females that have used up their sperm). In the parasitoid wasp Nasonia vitripennis (Walker, 1836), failure to mate soon after emergence increased the probability of a female being constrained and thus affected sex ratio directly. Local mate competition theory shows that whether a female is constrained can also affect sex ratio indirectly by affecting what sex ratio other females produce. However, this was not the case in N. vitripennis. A female's sex ratio was not significantly different when she was with another young mated female versus a virgin female or an old mated female depleted of sperm. These results suggest that N. vitripennis females may be unable to recognize whether another female is constrained. The increased proportion of sons in response to other females relative to when alone did not persist the day after exposure.


Science ◽  
2011 ◽  
Vol 334 (6059) ◽  
pp. 1127-1129 ◽  
Author(s):  
E. Macke ◽  
S. Magalhaes ◽  
F. Bach ◽  
I. Olivieri

1980 ◽  
Vol 86 (3) ◽  
pp. 409-419 ◽  
Author(s):  
P.D. Taylor ◽  
M.G. Bulmer

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