Predation of Biomphalaria glabrata during the development of Belostoma anurum (Hemiptera, Belostomatidae)

Abstract

Belostoma anurum was reared under laboratory conditions. Specimens were exposed to semi-natural conditions of photo period. The mortality rate was 26.3% during the post embryonic period (38.6 ± 0.7 days). During this time the average predation of Biomphalaria glabrata was of 99.0 ± 9.4 snails. The mean increment ratio of length and dry weight per instar was of 1.4 ± 0.1 and 2.8 ± 0.5, respectively. The predation by B. anurum adults can be divided into two different periods: phase I (4.8 ± 1.4 snails/day) and phase II (1.8 ± 0.5 snails/day). The higher predation in phase I suggested the sexual maturation of the belostomatid.

The influence of temporally variable predation risk on indirect interactions in an aquatic food chain

“…Belostoma are voracious, able to consume up to six snails in 12 h in laboratory feeding trials (Wojdak 2004) and average one snail killed every 2 days in natural settings (Kesler and Munns 1989). A longer-term laboratory study following individuals of Belostoma anurum from first to fifth instars found an average consumption of 2.6 snails per day over 38 days (Pereira et al 1993). The abundance of Belostoma in natural ponds is highly variable-in a onetime survey of a local pond in our area we found a range of 0-22 bugs/m 2 (average 1.20 bugs/m 2 , L. K. Belden and J. M. Wojdak, unpublished data) while Kesler and Munns (1989) found 0-41 bugs/m 2 in a pond in Rhode Island, USA (biweekly samples over 1 year).…”

Distribution patterns of aquatic and semi aquatic Heteroptera in Retiro das Pedras, Brumadinho, Minas Gerais, Brazil

“…Owing to their peculiar morphological and behavioural features these predaceous insects, irrespective of developmental stage, are able to subjugate and consume several prey items. It confers to the group marked relevance to the trophic structure and nutrient transfer in freshwater sources as well as an eminent potential for controlling disease vector populations (Pontier & Delplanque, 1976;Cooper, 1983;Santamarina-Mijares & Gonzáles-Broche, 1985;Victor & Ugwoke, 1987;Consoli et al, 1989;Kesler & Munns, 1989;Pereira et al, 1991Pereira et al, , 1993Pereira & Melo, 1998).…”