Seasonal abundance of red flour beetle, Tribolium castaneum (Herbst.) (Coleoptera : Tenebrionidae) in food grains stored in a large warehouse

摘要

Food grain storage plays a vital role in ensuring food security in India. Food grains under storage are affectedboth qualitatively and quantitatively by several insect pests. The red flour beetle, T. castaneum is an important secondarystorage pest that damages the food grains. The present experiment aimed to study the population fluctuations of T. castaneum(larva and adults) in different seasons of the year in bagged food grains stored in bulk quantities in a large food grain warehouseand was conducted consecutively for 2 years (February 2017 to January 2019). Three godowns of 5000 MT capacity wasselected and a total of 27 stacks were selected randomly to draw representative samples from each stacks to find out thepopulation of T. castaneum. Significantly higher mean populations were recorded during months of May (5.71 ± 0.23), June(5.37 ± 0.22) and July (4.61 ± 0.28). Significantly lesser population in food grains were recorded during December (0.74 ± 0.11)and January (0.86 ± 0.06) month. During the month of October, November, December, January and February the meanpopulation of T. castaneum recorded was lesser than 2 insects per 500g of representative sample, which is classified under‘FEW’ classification with reference to infestation level. The correlation and regression analysis revealed that temperaturesignificantly influenced the development of T. castaneum population in large food grain warehouse.The results also shown thatas the temperature increased from 25 o C, there was increase in the population of T. castaneum and higher population wererecorded during the months with temperature above 30 o C which showed that there is a vital role of temperature in populationbuild-up of T. castaneum in large food grain warehouses.