Abstract
Ecology, biology, breeding and control measures of
Bandicota bengalensis (Gray) were studied at Mymensingh from
July 1984 through June 1986.
In the study area, maximum number of rat was Bandicota
bengalensis followed by Rattus rattus L., Mus musculus L.,
M. booduga (Gray) and B. indica (Bechstein). The percentage
of trap and tile success were found to be 7.52 and 17.86
respectively. Evidence suggested that these estimates were
low.
Percentage of pregnant female (B. bengalensis) was more
in the months of December and May in comparison to other
months. Virtually all adult males examined were in a state
of active sperm production. The mean number of embryos per
pregnant female was 6.24. The incidence of pregnancy was
estimated and the mean annual production of young per adult
female was calculated to be almost 76 in number. Growth rate
for cage - reared youngs of B. bengalensis showed that, from
birth to 28 days, females tended to grow faster than males.
Order of preference and rate of consumption for seven
food grains to caged B. bengalensis were studied. The daily
mean food comsumption rate varied from 4.31 to 6.71 percent
of the body weight of the rats. The rate of consumption of
food from multiple cup was higher than single cup but less
than the double cup tests.Rat damages to T. Aman, Wheat and Boro rice were
assessed in the fields at different growth stages. Damage
was highly correlated with stem density and the burrow
openings. Damage before the booting stage was less but
increased rapidly during the dough and mature stages. The
yield reductions of T. Aman, wheat and Boro rice were found
to be 2.25, 4.86 and 3.74 per cent respectively.
Burrowing pattern of B. bengalensis showed that the
male and female occupied separate burrows. In the female
burrow, a brood chamber contained 1 to 14 number of youngs.
When harvesting was almost over, 7.51 live burrow systems
were found in a hectare of land. In each burrow system 1 to
9.24 kg of paddy were found to be hoarded.
The reductions of rat population in the crop fields
after treatment with the rodenticides like warfarin,
aluminium phosphide and zine phosphide were found to be
67.88%, 77.33% and 70.33%, respectively.