Preliminary observations of sperm storage in Adalia bipunctata (Coleoptera: Coccinellidae): sperm size and number

Abstract

Sperm storage in Adalia bipunctata (L.) (Coleoptera, Coccinellidae) was examined and compared between diapausing and non-diapausing females. We observed that non-diapausing females store on average 13,688 (±722, S.E.) sperm in their spermatheca and that every female examined had sperm in storage (n=16). In contrast, most diapausing females had empty spermatheca and only two had sperm in storage (n=15). Mean sperm number in diapausing females was 250 (±112, S.E.). The mean length of the spermatozoa stored by non-diapausing females was 2,068.5 μm (±9.8, S.E.), ranging from 1,530.8 to 3,171.7 μm. Sperm length in diapausing females was only measurable in one female and was of 2,102.9 μm (±22.4, S.E.).