Portal de Periódicos da CAPES

Some Interactions Between Flight, Protective Display, and Oviposition Behaviour in Callosamia and Rothschildia Spp. (Lepidoptera, Saturniidae)

1958; Brill; Volume: 13; Issue: 3-4 Linguagem: Inglês

10.1163/156853957x00065

1568-539X

A. D. Blest,

Lepidoptera: Biology and Taxonomy

1. An account is given of the course of extinction of the protective displays of two species of Saturniid moth, Rothschildia jacobaeae, and Callosamia promethea, when elicited repeatedly by a tactile stilulus. A relationship between flight responses and oviposition behaviour in the females is also discussed. 2. Both species possess rhythmic displays whose quantification is temperatre-independent, and hence unaffected by metabolic changes resulting from the moths own activity. 3. Experiments were conducted in a standardised flight-chamber. Tactile stimuli were administered with a thin wooden rod, each five seconds after the cessation of the activity elicited by its predecessor. 60 trials were conducted in each experiment, and the experiments were placed at individually different times after the completion of the post-eclosion sequence. 4. The activities released in the experiments were (a) Flight, and its preparatory movement, Shivering; (b) Display. Trials occurred in which neither activity was elicited. Display activity was scored as the number of cycles of the display rhythm performed. Two grades of flight intensity were distinguished, and used to give a flight score for each experiment. The tactile stimuli were ambivalent for the release of display and flight, and the same sets of effectors were used in performing the two responses. 5. Inverse relationships were found to exist between the Flight Score 60 trials, and various measures of display strength. The most important are :- (a) An inverse relationship between Flight Score and the highest level of display strength achieved, as measured by the mean of the three highest display strengths in each experiment. (b) An inverse relationship between Flight Score and the total number of Display Cycles performed in the course of 60 trials. The course of individual experiments over the whole 60 trials is consistent with the behaviour shown during the first 20 trials of the series. There is a sharp fall-off of all measures of display strength with increase in Flight Score above zero. In R. jacobacae there is a tendency for the display responses to show rebound after flight bursts. 6. The picture given by an analysis of this type differs from that yielded by the extinetion curves derived from massed data, which fail to reveal the relationship between flight and display behaviour. 7. Explanations of these relationships in metabolic terms, or in terms of muscular fatigue, depletion of reserve substances, etc., are shown to be inadequate. They are, however, consistent with the hypothesis put forward in a previous paper (BASTOCK and BLEST 1958) which proposed the existence of (a) short-term reciprocal inhibitory relationships between the acts of flight and of display, which prevent them from being performed simultaneously, in spite of their mechanical compatibility; (b) long-term relationships whereby a formal 'higher' unit mediating the excitation of flight responses inhibits a 'lower' unit mediating the display response. 8. In unmated females, oviposition follows flight alone, and virgin females will neither fly nor oviposit for several days after emergence unless listurbed.