Egg size increases with maternal age in the cotton stainer bugs Dysdercus fasciatus and D.cardinalis (Hemiptera: Pyrrhocoridae)

Egg‐size variation over the reproductive span of laboratory‐reared females is described in two species of cotton stainers: Dysdercus fasciatus Sign. from woody Malvales and D.cardinalis Gerst. from herbaceous Malvales. Egg size increases with maternal age due to a decrease in clutch size as maternal age advances in both species. The two species are similar in size, but egg size is about 28% larger and clutch size about 19% smaller in D.fasciatus than in D.cardinalis . These contrasts may be related to the host‐plant biology which differs between the two species.