Brood size: a major factor influencing male dimorphism in the non‐pollinating fig wasp Sycobia sp.

Abstract

Abstract. Male polymorphisms have been described in some non‐pollinating fig wasps, as well as in other animals. The proximal basis and the maintenance of alternative male reproductive strategies are either genetic or environmental. Here we studied male dimorphism in the non‐pollinating fig wasp Sycobia sp. We conducted experimental manipulations to study the factors influencing offspring male morph allocations and explore a possible basis for the determination and maintenance of male dimorphism in Sycobia sp. The results showed that brood size was the major and underlying factor influencing the male morph ratio. When the brood size increases, the wingless male ratio also increases. Also, our results indicated that there was no direct maternal control on offspring male morph allocation. Male dimorphism in Sycobia sp. probably represents an environmentally determined conditional strategy, which responded to offspring population density at the level of the individual fig.