Abstract
It was studied the biology of Cyrtonata bistigma (Boheman, 1856), Chelymorpha cribraria
(Fabricius, 1775) and Charidotella zona (Fabricius, 1801) (Chrysomelidae:Cassidinae),
proceeding from aquatic macrophyte Ipomea aquatica Forsskal (Convolvulaceae) at the
Marchantaria island (Solimões river, floodplain) near from Manaus, Amazonas, Brazil.
These three studied species differed significantly at larval development time, female’s
longevity, fecundity, maturity age and length. Analyzing the development time of
immature stages, is possible to verify that the eggs incubation period, 1st and 5th stages, and
the pupal stage, were the most longer. At the end of immature stages, C. cribraria showed
the bigger survival ratio (90%), followed by C. bistigma (71%) and C. zona (66%). The
adult sexual ratio emerged in the laboratory was 1.3♂: 1.0 ♀ to C. bistigma, 1.0♂: 1.4♀ to
C. cribraria and 1.1♂: 1.0♀ to C. zona. There was not significant variance to larval
development time (C. bistigma: t=0,829; p=0,409; n=99; C. cribraria: t=1,611; p=0,110;
n=126; C. zona: t=0,133; p=0,894, n=166) and adult longevity (C. bistigma: t=0,646;
p=0,521; n=60; C. cribraria: t=0,493; p=0,624; n=60; C. zona: t=0,246; p=0,806; n=60)
between males and females to these species. The generation time was to C. bistigma 36.3
days, C. cribraria 31.9 days, and, to C. zona 37.2 days. C. bistigma reached the bigger
value in net reproductive ratio (Ro=109.8), followed by C. cribraria (Ro=89.6) and C.
zona (Ro=22.4). The intrinsic rate of increase were r=0.13, r=0.14 and r=0.08 to C.
bistigma, C. cribraria and C. zona, respectively. At feeding tests over 8 aquatics
macrophytes from floodplain and I. batatas from land, the adults of the three species
survived only in I. aquatica and I. batatas. C. bistigma and C. zona displayed a bigger
survival at I. aquatica than at I. batatas, suggesting its feed acceptability only at host plant
inside the natural habitat.
