Eur. J. Entomol. 94 (4): 445-452, 1997

Migratory syndrome in the water strider Aquarius paludum (Heteroptera: Gerridae) reared in high versus low nymphal densities


The effect of crowding in nymphal stage on the induction of development of macropterous adults with high flight ability was studied in the laboratory in the water strider Aquarius paludum. High density induced a higher proportion of macropterous morphs than low density. No brachypterous adults developed flight muscles in either experimental density. When kept under high density, about 80% of adults kept indirect flight muscles for 25-30 days after adult emergence, whereas only about 50% or 60% of females and males, respectively, retained theirs when grown under low density. The remaining adults histolysed indirect flight muscles in both groups. Development during the fourth and fifth instars only under high density may induce a higher proportion of macropterous adults than those under low density.

Keywords: Gerridae, Aquarius paludum, water striders, rearing density, migratory syndrome, flight propensity, indirect flight muscles, reproduction

Accepted: February 22, 1997; Published: October 1, 1997