QUANTITATIVE LOSSES AND PHYSICAL DAMAGE CAUSED TO WHEAT KERNEL (TRITICUM AESTIVUM L.) BY KHAPRA BEETLE INFESTATION

Wheat and other cereals sustain huge quantitative and qualitative losses each year all over the world due to the attack of storage pests. The damage caused by Khapra beetle is comparatively greater than other pests because of its ability to increase rapidly even under unfavourable environmental conditions. A study was therefore initiated to probe into quantitative and physical losses of stored wheat caused by Khapra beetle infestation. We observed more than 20 % loss in weight of seeds after a storage period of 6 months under natural conditions, initially infested with only 10 pairs of Khapra beetle larvae. There was found a strong positive relationship among the progeny development and number of damaged grains as well as with weight loss as depicted by values of the correlation coefficient i.e., 0.95 and 0.87, respectively. Moisture contents also exhibited a strong positive correlation with the loss in weight of wheat grains (R=0.83). The beetle larvae also showed varying levels of preference to different wheat varieties. Wafaq-2001 was found to be the most resistant among the commonly grown varieties of Pakistan. It was therefore concluded that the wheat grains of promising varieties stored for edible and seed purposes must be protected from the attack of Khapra beetle infestation to maintain nutrition, viability of wheat grains and indirectly to ensure the food security.