Flight Mimicry

Insect flight has been widely studied: Dudley [55] reviewed the biomechanics, Taylor [56] examined the control of insect flight, and Land [57] reviewed the visual control. Flight behavior of insects is commonly cited in early studies as being mimetic though these references are often anecdotal. For example, Opler [58] carried out an extensive study of the neotropical neuropteran Climaciella brunnea in Costa Rica. After studying their palatability, distribution, and markings, he concluded that five morphs of this harmless species were Batesian mimics of different species of polistine wasps. This was based on the wasps' palatability, distributions, and markings. However, he also suggested that their body posture and flight characteristics, which presumably were similar to those of the hymenopterans, were also evidence of the mimicry. Opler did not elaborate on the flight behavior, and so this is clearly an interesting research opportunity.

There are many other examples of anecdotal references to mimetic flight behavior. Dressler [59] described a Mullerian mimicry complex in bees of the genus Eulaema and in passing mentions two asilid flies that "in flight at least, mimic Eulaema quite accurately," thus suggesting that they are Batesian mimics. The implication is that they are not particularly similar in their morphology.

Carpenter [35] observed longicorn beetles that mimic wasps of the family Bra-conidae, describing them as indistinguishable in flight. Other coleopterans show remarkable flight adaptations. The fore wings of beetles are hardened into protective cases, the elytra. In flight the elytra are normally held out to the sides with the beetle relying on rapid beating of the hind wings for propulsion. Acmaeodera species, however, fly with the elytra lying in place over the abdomen, so that the warning coloration is still visible, giving the impression of a hymenopteran in flight. To achieve this, the elytra have evolved a special modification ("emargination") that allows free motion of the hind wings at the base. This uncharacteristic beetle behavior is clearly a mimetic adaptation, and because captive birds readily eat the beetle, it is undoubtedly a Batesian mimic [60].

However, in only two groups of insects has flight mimicry been studied in any detail and with any attempt at quantification: (1) the Mullerian mimicry of tropical butterflies and their Batesian mimics, and (2) the Batesian mimicry by hoverflies of the family Syrphidae of various members of the hymenoptera.

0 0

Post a comment