Phytalmia mouldsi  Phytalmia mouldsi is in the subfamily Phytalmiinae which includes all of the antlered fruit flies. They were discovered by M. S. Moulds in 1977 and are found only in an isolated rainforest of Australia. Antlered flies, collectively, are notable for their unique mating behavior and the unusual antler-like extensions on the heads of the males. This species exhibits sexual dimorphism where the females and males look different from one another. The males have red, paddle-shaped, antler-like protrusions on their cheek region that will bend under pressure. The females have no antlers. The males are generally larger than the females and have longer back legs than females. The male characteristics (size, long back legs, antlers) are most likely a result of sexual selection. The longer back legs and larger size give males an advantage when engaging in vertical pushing contests with other males. Females have a smaller rear to foreleg ratio because they do not engage in pushing contests. Antler size is strongly correlated with body size in males. It is hypothesized that antlers developed as size indicators and not as weapons so that the males can avoid wasting time and energy in fights against larger males. Also, males have pronounced spines on their fore femurs that are used to grip females. "Phytalmia mouldsi" lives only in one rainforest area on the northeast coast of the Cape York Peninsula of Australia. They lay their eggs and the larvae only eat one specific species of decaying tree: Dysoxylum gaudichaudianum. "Phytalmia mouldsi" uses a resource defense mating system. In this system the males search for a desirable spot for the females to deposit their eggs, and then they guard that spot and await interested females. They will fight off other males who want that spot even while mating with or guarding a female. When a female approaches the male will extend its wings out and keep the female from reaching the oviposit site. The male will then mount the female and latch on behind the wings of the female. This is called a “wing-lock.” The male will hold onto the female in this way during copulation and while the female is ovipositing. This way the male can protect his egg site and the female from other males. If one male challenges another male for his site or his female the males will judge each other and if one is substantially smaller than the other the smaller one will forfeit without a fight.