Abstract:

At present, Monochamus alternatus is a challenge in the prevention and control of forestry pests at home and abroad. Based on the fact that Monochamus alternatus is a wood-feeding insect and has its own nitrogen-fixing ability, the nitrogen fixation ability of Monochamus alternatus can be destroyed by screened chemicals, resulting in the death of Monochamus alternatus due to the lack of nitrogen nutrition. This is a new way of pest control. The authors used acetylene reduction method and enzyme-linked immunosorbent assay kit, to determine the difference of nitrogenase activity between intestinal nitrogenase bacteria of Monochamus alternatus and insects at different growth stages (adults, larvae and eggs) under different chemical treatments. The results showed that the treatment of abamectin and NH₄Cl had great influence on nitrogenase activity of Monochamus alternatus adults. The nitrogenase activity under both the two chemical treatments was only 0.1 IU/g and 0.08 IU/g, respectively. Compared with that of the control, the nitrogenase activity was decreased by 1.82 IU/g and 1.85 IU/g, respectively. Strain EH had the strongest nitrogen fixation activity, but its nitrogen fixation activity was only 1.2 nmol/(mL·h) under NH₄Cl treatment, 50.9 nmol/(mL·h) less than the normal nitrogen fixation activity. In theory, NH₄Cl can be used to control Monochamus alternatus in forests.

Key words: Monochamus alternatus, nitrogen fixation, activity, chemicals