Study on the life cycle of Tribolium castaneum (Coleoptera: Tenebroinidae) on different cereals.

Background: Tribolium castaneum is one of the most destructive pest of stored grains products around the world. The present study was conducted to observe the life cycle of Tribolium castaneum on different cereal flour varieties i.e. Triticum aestivum (wheat flour), Oryzae sativa (Rice flour), Zea mays (Corn flour), Vigna unguiculata (Cow peas Flour), Sorghum bicolor (Sorghum flour) and Hordeum vulgar (Barley flour). From two sources the samples were being collected, i.e. grocery Stores/super mart (Source-I) and flour mills/warehouses (Source-II) at the ideal temperature and relative humidity under laboratorial conditions at the Zoology department, Shah Abdul Latif University Khairpur. Results During the present study it was recorded that Tribolium castaneum consistently undergoes six larval stages on each cereal flour from source-I and source-II. Among the cereal flours It was noticed that total duration from eggs to adult remains fastest on wheat flour i.e. 41.8 ± 0.80 followed by sorghum flour 52.9 ± 0.90 and lowest on Cow-peas flour 65.5 ± 1.00 followed by corn flour 61.8 ± 0.96 and average total duration from eggs to adult on rice flour 54.9 ± 0.83 followed by Barley flour 53.9 ± 0.82. The length of eggs was 2.9mm and width was 0.7mm were recorded and the length of larva from 1st instar to 6th instar was 5mm to 12mm and width was 2.1mm to 3.7 were recorded and length of pupa was 15.2mm and width was 3.8mm and length of adult was 17.2 mm and width was 4mm were recorded respectively. Conclusions The results of this study indicated that cow-peas flour was the least suitable for development of Tribolium castaneum as compared to wheat flour. Additionally, postharvest products from source-II (flour mills) were found to be extremely susceptible to Tribolium castaneum . Study of life cycle of Tribolium castaneum in different cereals flours would be helpful in post-harvesting of the insect pest in various stored grain food materials.