Meeting Abstract

17.11  Friday, Jan. 4  Overlap between the fore and hind wings in the moth Manduca sexta is different associated with sex and weight in free flight. MALEC, A.M.; WILLIS, M.A.*; Case Western Reserve University; Case Western Reserve University

Moths and butterflies have four-wings, but most flight studies focus on their forewings and treat them as functionally two-winged fliers. In fact, previous studies showed that a variety of moths and butterflies can fly with their hind wings removed, but are less maneuverable. How the fore and hindwings work together to affect this increased maneuverability is unknown. It is known that the fore and hindwings in male and female moths are linked in anatomically different ways. By studying this natural anatomical difference in fore-hindwing interaction we might reveal how the wings interact in flight. In the moth Manduca sexta, females are larger and heavier, on average, than males so comparing the two sexes may provide important clues about how the wings, and the whole moth, operate together to generate the maneuvers we observe. To test the effects of weight, sex, and wind speed on fore-hindwing overlap, we marked male and female moths on the thorax, fore, and hindwings. By measuring the change in angle between the fore and hindwings as moths flew through either 75 cm/s or 150 cm/s winds, we were able to quantify the changes in wing overlap and thus wing area. Regression analyses revealed a significant relationship between wing area and body weight and analyses of covariance showed that this relationship was different in males and females. Further analyses and experiments are ongoing to determine if the observed changes in overlap are actively controlled by the moths or a passive property of the mechanics of the flight system. We thank Jennifer Avondet for her assistance in managing the insect colony and help with all aspects of this project. A.M.M. was supported by the Howard Hughes Medical Institute funded Summer Program in Undergraduate Research. M.A.W. was supported by an Air Force Office of Scientific Research grant FA9550-07-0149.