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This unique species has provided the first convincing evidence of senescence in an insect population in the wild (Bonduriansky & Brassil 2002).

 

Because male antler flies are astonishingly aggressive, I named this species litigata, which translates loosely as 'those who love to pick fights' (Bonduriansky 1995). They readily attack muscid flies vastly larger than themselves, or even the tip of a biologist's pen! On antlers, these males form complex, highly structured aggregations. Some individuals defend stable territories, while others simply wander in search of females, which arrive on antlers to feed, mate and oviposit (Bonduriansky & Brooks 1998, 1999). Antler flies appear to engage in mutual mate choice, with both males and females rejecting some potential mates (Bonduriansky & Brooks 1998). Following copulation, the female expels and ingests much of the male's ejaculate, then inserts her ovipositor into minute cracks or pores in the antler surface and deposits her eggs. During oviposition, the male remains on the female's back and 'guards' her by warding off rival males with his wings (Bonduriansky & Brooks 1998b). Larvae develop in the porous bone matrix inside antlers, and come to the antler surface when ready to pupate. Here, the larvae perform an astonishing leap off the antler surface (see below). They land on the surrounding leaf-mould, burrow into the soil, and undergo their pupal development.

 

The known distribution of antler flies extends across the eastern part of Canada, from Newfoundland and Cape Breton, Nova Scotia, to southern Ontario. In Algonquin Park, Ontario, the first adults emerge from pupae in the soil and appear on antlers in late May or early June. The mating season continues until late August.

 

 

The final instar larvae of many species of piophilid flies (as well as flies of several other families) have the ability to leap. This amazing behaviour was first described in the 17th century by the Dutch naturalist Jan Swammerdam, who observed maggots of the 'cheese skipper' fly Piophila casei (which he called 'the Mite') leaping off cheeses and cured meats. Swammerdam wrote:

 

 

The ability to leap may facilitate larval movement from the feeding substrate to pupation sites. Because larval creeping locomotion is excruciatingly slow and rather inefficient, maggots may face considerable energetic costs and, more importantly, great risk of being captured by predatory insects on the surfaces of carcasses or antlers. The ability to leap may represent a solution to both of these problems (Bonduriansky 2002).

 

As if the ability to leap were not enough, these maggots are also able to hear and respond to sound. I found that final instar maggots respond to the sound of a rattle by coming to the surface of their feeding substrate and leaping off. Moisture elicits a similar response. The timing of pupation appears to be facultative in this species, and final instar maggots may wait inside their food substrates (antlers or carcasses) until they perceive stimuli associated with rain (i.e., rattling sound or moisture) before initiating the hazardous migration to their pupation sites. Observations suggest that rain facilitates larval locomotion, and may reduce risk of predation (Bonduriansky 2002). 

 

After burrowing into the leaf-litter or soil, the piophilid larva moults into a pupa, and undergoes metamorphosis into the adult stage. Pupal metamorphosis takes about two weeks at room temperature.

 

 

After reaching the soil surface, newly emerged adults hide in vegetation until their wings have unfolded and their exoskeleton has hardened. After this, they either return to their natal antler, or fly away to seek fresher antlers.

 

 

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