Original paper
Bioecology of the water-bug Sphaerodema annulatum Fabricius (Heteroptera: Belostomatidae)
Saha, T. C.; Raut, S. K.
Archiv für Hydrobiologie Volume 124 Number 2 (1992), p. 239 - 253
13 references
published: Mar 31, 1992
DOI: 10.1127/archiv-hydrobiol/124/1992/239
ArtNo. ESP141012402007, Price: 29.00 €
Abstract
The water-bugs Sphaerodema annulatum Fab. are rapacious. Under laboratory conditions they fed on insects, snails and fish fingerlings. They became sexually mature at an average age of 31.1 ± 0.99 S.E. days. In laboratory a female bug in its life span, laid, on the average 2279.3 ± 73.09 S.E. eggs in 19.0 ± 0.26 S.E. clutches. The egg metamorphosed into adult through five larval stages. The larval stages are morphologically alike but they are distinguishable from each other through the morphometric parameters of the scutellum. Birth rate varied with the age of the bugs and the rate was maximum between 28 to 41 days of their age. The mortality rates were 20.8 %, 14.8 %, 4.8 %, 4.4 % and 4 % in eggs, 1st, 2nd, 3rd, 4th and 5th instar respectively. Of the total eggs only 4 % were seen to attain the adult stage. The maximum life span of a male and a female bug was recorded 363 days and 351 days, respectively. On an average, the male survived for 310.55 ± 4.30 S.E. days and the female survived for 293.6 ± 7.63 S.E. days.
Keywords
water-bugs • fish fingerlings • snails • scutellum • male • female