Flight capability and flight motor pattern in a sedentary South African grasshopper, Phymateus morbillosus – a comparison with migratory species

Among the Acridoidea, not all species are strong fliers. We have examined the possible causes for loss of flight in a species with a reduced flight system, the South African grasshopper, Phymateus morbillosus (L.). This is a sedentary species that, in the field, displays only marginal flight (in males) or no flight (in females). In a wind tunnel, however, this species can be stimulated to perform flight movements for a short time. In the present study, several morphometric parameters and aspects of the flight motor output have been examined. The data are compared with those of the migratory locust species ( Locusta migratoria L. and Schistocerca gregaria Forsk.). Phymateus morbillosus can exhibit the typical flight motor pattern for short periods of up to 1 min. Morphometric data and wing‐beat frequency in P. morbillosus are similar to that of other members of this insect group. However, female specimens of P. morbillosus are too heavy to lift themselves for active flight. We assume that females of this species invest in the augmentation of reproduction rather than investing in the flight system.