BIO-ECOLOGY, DAMAGE ASSESSMENT AND MANAGEMENT OF ANGOUMOIS GRAIN MOTH, SITOTROGA CEREALELLA OLIVIER

Abstract

Seven sets of experiment including survey in farmers’ household storage in 16 districts of the northern region of Bangladesh and six laboratory experiments at central laboratory of Sher-e-Bangla Agricultural University were conducted to evaluate bio-ecology, damage assessment and protection status of stored rice grains and management practices of Angoumois grain moth Sitotroga cerealella Olivier from June 2013 to May 2016. The bio-ecology study in laboratory revealed that mean duration of incubation period of Angoumois grain moth was 5.67 to 8 days, larval period 15.6 to 17.6 days, pupal period 4.50 to 6.50 days, adult longevity 7.17 to 8.58 days and total life cycle 32.92 to 40.67 days. The highest reproduction rate per female was found in June (139.20) and the lowest reproduction rate recorded in December (39.08). The field survey revealed that about 96.3% farmers stored unhusked rice grains in their household and among them 99% faced the problem of Angoumois grain moth infestation. In storage, 100% farmers took preventive measures to protect grains from infestation, among them, 91% reported sun-drying of grains and 72% dried neem leaf powder for prevention of this pest. It was also observed that in case of curative measures 96% farmers adopted sun drying of grains again and 67% used Aluminium phosphide tablet with sun drying. About 73% farmers learnt with precautionary measures of fumigation and 44% emphasized on air tight containers during fumigation. Most (83%) of the farmers reported that sun drying of rice grains was important as ecofriendly management practice and this perception was followed by the use of neem leaf powder (73%). The results from varietal screening of free choice test revealed that BRRI dhan 52 had the lowest incidence of infested grain, lower weight loss and lower seed germination reduction which was identical with BRRI dhan 60 and BRRI dhan 29. Varietal screening of no choice test was consistent with the results. The susceptibility of hybrid rice grains to grain moth was very high. Plastic pot was the most suitable container for storage grains showing lowest infestation (26%) and highest seed germination (31.75%) at 180 DAIR. The results on the control of Angoumois grain moth using botanicals revealed that the neem leaf powder @ 2g/kg rice grains was the most effective botanical reported lowest infestation (16.25%) and highest seed germination (81%) at 180 DAIR. Among the fumigants used, Aluminium phosphide @ 200mg/kg rice grains was the most effective for grain moth control. The integrated management approach of Angoumois grain moth with Aluminium phosphide @ 100 mg/kg grains along with neem leaf powder @ 2 g/kg grains was the most effective management package. This package resulted lower grain infestation (1.50%), lower grain weight loss (0.15%) and higher seed germination (83.75%) at 180 DAIR.