Abstract: The calling and mating behavior of Holcocerus arenicola, a primary root-boring pest of sand Salix （Salix psammophila） were observed during the 6 h of the scotophase to investigate their activity rhythm. The pheromone titer was analyzed by the electroantennogram （EAG） and gas chromatograph （GC） to determine the diel periodicity of pheromone production during one scotophase and the effect of female age on pheromone production. The results showed that most females initiated calling during the 0.5-1 h after lights off, and the maximum calling occurred during the 2nd night after emergence. The mating was observed during the 1-2 h of the dark phase, and the mating percentage of 1-d-old females was the highest. Mating lasted for an average of 24.16±2.64 min and occurred earlier as females got older. The sexual activity of 5- to 6-d-old females was rarely observed in the test. The synthesis of pheromone started 1-2 h prior to the onset of calling and reached a peak during the first 2 h of the scotophase. The pheromone titer during the calling period decreased significantly with age, being highest in extracts from newly emerged females. Field trial showed that traps baited either with virgin females or female sex gland extracts could effectively capture males. These results suggest that there was a synchronous relationship between the pheromone titer and the sexual activity, and also a potential use of long-range sex pheromone for the control of H. arenicola.

Key words: Holcocerus arenicola, Salix psammophila, sexual activity, sex pheromone, diel periodicity