Interspecific competition among larvae of Hemipyrellia ligurriens (Calliphoridae) and Boettcherisca formosensis (Sarcophagidae) (Diptera)

1. The effects of larval rearing density and species relative proportions on life-history parameters of two necrophagous Diptera, Hemipyrellia ligurriens (Wiedemann) (Calliphoridae) and Boettcherisca formosensis Kirner and Lopes (Sarcophagidae), were investigated in mixed cultures. Larval rearing density had a significant effect on larval to adult survivorship, duration of immature development, adult size and relative performance (measured by the composite index of performance, r′) of both species. However, species relative proportions affected adult size of both flies and the duration of immature development of B. formosensis only. 2. B. formosensis had a higher survivorship than H. ligurriens in all mixed cultures and showed a similar survivorship pattern to that in pure cultures. By contrast, survivorship of H. ligurriens was lower in mixed than in pure cultures. 3. H. ligurriens adults reared from mixed cultures were smaller than those from pure cultures of comparable density, but B. formosensis adults from pure and mixed cultures were of similar size. 4. The results suggest that competition between B. formosensis and H. ligurriens larvae was asymmetric and the former was the superior competior. 5. At low larval densities in mixed cultures, the presence of H. ligurriens enhanced the performance (as measured by r′) of B. formosensis, a consequence of suspected interspecific facilitation of larval growth. © 1990 Society of Population Ecology.link_to_subscribed_fulltex