Wednesday, May 2, 2012

Rejection: Courtship Behaviour in the Orange Tip Butterfly

Male Orange Tip Butterfly, Anthocharis cardamines
With the flowering of the Cuckoo Flower (Cardamine pratensis), so one of its main grazers follows suit and take to flight. The larvae of the Orange Tip butterfly (Anthocharis cardamines) feed on a variety of brassicaceous plants, but have a distinct preference for C. pratensis and Garlic Mustard (Alliaria petiolata). Since these food plants have differing habitats –  hedgerows and tracks in arable woodland (C. pratensis) and wet pastures and woodlands (A. petiolata) – A. cardamines is a widespread butterfly, but occurs in low densities (1).
Female Orange Tip Butterfly, Anthocharis cardamines
Mating and courtship is pretty low-key for the Orange Tip, with females accepting a mate within seconds of courtship. However, one notable display is evident, that of the rejection dance of the female. Females who have already mated and want to shoo away the persistent males will flatten their wings against their perch and elevate their abdomen. This is followed by an opening of the genital valve, purportedly to release anti-aphrodisiac hormones to discourage the males (2). This behaviour was observed in the pair pictured, a female in flight that perched upon pursuit by a male and proceeded to display her abdomen on two separate occasions, after which the male left without mating.

Orange Tip Butterfly pair, Anthocharis cardamines. The female (left) is in the process of rejecting the male (right) by using the raised abdomen display.
Oddly, this very same rejection dance is also used by virgin females just prior to mating. It is thought that the differences between the two occasions is that virgin females release aphrodisiac hormones from the genital opening to attract the males (2).
Female Orange Tip Butterfly, Anthocharis cardamines, in raised abdomen display
Females will lay their eggs at the base of the flowers of the host plants, after which the larvae will feed on the flowers. Only one eggs is deposited per flower as cannibalism is frequent among larvae (1).

  1. Dempster, 1997. Oecologia 111 pp. 549-556
  2. Wiklund and Forsberg, 1986. Animal Behaviour pp. 328-332

No comments:

Post a Comment