Study On The Damage Characteristics Of Weevils On Wheat And Maize In Different Conditions

Sitophilus oryaze?L.?and Sitophilus zeamais?M.?are important stored grain pests.Weevils have significant differences in grain damage in different environments.It is of great significance to study the effects of pests on the quality of grain and other hazards in different conditions.And it is of great significance to formulate control strategies,prevention measures scientifically and scientific governance timely.In this paper,are studied at 20,25and 30?,in the conditions of grain security moisture,and the population density of 2,4 and 6 adults.The detection indicators are thousand kernel weight?TKW?,bored kernel percentage?BKP?and gluten water absorption of wheat flour,during the infection of wheat and maize,to explore the relationship between the damage characteristics and the quality indicators of wheat and maize at different times.The main findings are as follows:At 20,25 and 30°C,moisture of 13.5%of the wheat was infected with 6 individuals/kg of Sitophilus oryaze?L.?,and after 42days the TKW decreased from the initial 43.74 g,43.75g and 43.76 g to 43.36 g,43.06 g and 42.69 g respectively.In the condition of 30°C,the moisture of 13.5%of wheat infected with 2,4 and 6 individuals/kg of Sitophilus oryaze?L.?,the loss of TKW was not significant at 7 days,the weight of TKW significantly after 14 days,and the infection of ricegrass at 6 individuals/kg was 13.5%.The loss of TKW was greatest after wheat,and the loss exceeded 1 g at 42 days.At 20,25,and 30°C,when the Sitophilus oryaze?L.?infected wheat for 7 days,the BKP did not change significantly.The 6individuals/kg of Sitophilus oryaze?L.?infected 13.5%of water was highest after 42 days of wheat,which was 1,1.67 and 2.33%respectively.At 20,25,and 30°C,6 individuals/kg of Sitophilus oryaze?L.?infected 11.5,12.5,and 13.5%moisture wheat,the gluten water absorption was significantly different from the 7th day onwards.After 13.5%of the wheat was infected with 6 individuals/kg of Sitophilus oryaze?L.?,the gluten water absorption dropped to a minimum of 178.4,171.1 and 164.1%,respectively.In the condition of 30°C and 15%moisture,Sitophilus zeamais?M.?are harmful to maize.of.In this condition,the highest BKP reached 2.67%,and the TKW dropped to 303.72g.With the increase of time,when the population density was more than 2 individuals/kg,the TKW and the BKP were the most significant.When the population density was 2individuals/kg,the damage of Sitophilus zeamais?M.?to maize was not serious in 42 days.At the temperature of 30?,the TKW decreased most when Sitophilus zeamais?M.?were infected with 2,4,and 6 individuals/kg at 42 days,which were 5.35,9.12 and 11.84 g and the BKP were 1.67,2.33 and 3.00%respectively.Weevils have less ability to harm wheat in low oxygen conditions.The lower the O₂concentration,the higher the TKW of wheat and the lower the BKP.On the 14th day,the Weevils began to harm the wheat and the BKP appeared.The 6%-10%O₂ concentration has a significant effect on the feeding of Weevils.The 6%O₂ concentration can better control the growth of the population of the Weevils.After 42 days of Sitophilus oryaze?L.?and Sitophilus zeamais?M.?harm wheat,the BKP rate is 1.00%,and the TKW are 43.58 g and 43.62 g.The researches indicated that temperature,grain moisture,insect population density and O₂ concentration can significantly affect the degree of damage to the grain caused by the insects.Grain with higher grain moisture than safe grain storage is more vulnerable to weevils.Changes in TKW,BKP and gluten absorption are closely related to temperature and population density.At 30°C,after the grain was infected with 6 individuals/kg of weevils,the TKW and gluten water absorption decreased significantly,and the BKP increased significantly.At 6%O₂ concentration,weevils'reproduction and feeding ability were significantly inhibited,TKW decreased slowly,and BKP did not increase significantly.Comparing the damage of Sitophilus zeamais?M.?and Sitophilus oryaze?L.?,the feeding capacity of the two species was relatively close within 42 days.