关键词: 亚洲玉米螟, 铜, 阿维菌素, 生长发育, 求偶行为, 定向行为, 生殖力, 卵孵化率

Abstract: 【Aim】 To explore the effects of the heavy metal Cu²⁺ and the pesticide avermectin and their combined stress on the growth and development and reproductive behavior of the Asian corn borer, Ostrinia furnacalis in farmland.【Methods】 We added 50 mg/kg of Cu²⁺ and 0.039 mg/L of avermectin (LC₁₀ concentration against the 3rd instar larvae of O. furnacalis) to the artificial diet, respectively, and simultaneously, and then got three kinds of treated diets containing Cu²⁺ (Cu), avermectin (Av) and both (Av+Cu), 
taking the normal artificial diet as the blank control group. We fed the neonate larvae of O. furnacalis with the four diets under laboratory conditions, and systematically investigated and recorded the parameters of growth and development (larval duration, pupal 
duration, pupal weight, adult weight, growth rate, adult emergence rate and adult longevity)， calling behavior (calling rate and average calling duration), orientation behavior (take-off rate, orientation rate, average response time, flying halfway rate and landing to pheromone source rate), and reproduction (number of eggs laid per female and egg hatching rate).【Results】 Cu, Av and their combined stress (Av+Cu) had certain effects on the growth and development and reproduction of O. furnacalis. On the one hand, the postembryonic developmental duration (larval plus pupal duration) of female and male O. furnacalis in Cu treatment alone was significantly shortened as compared to  that in the blank control group. After Av treatment alone, the postembryonic developmental duration of female and male O. furnacalis was significantly prolonged to 38.31 and 38.95 d, respectively, being 67.07% and 67.38% longer than that of the blank control group, respectively. After Cu treatment alone, the body weight of female pupae, male pupae, female adults and male adults of O. furnacalis decreased significantly, being 13.16%, 6.45%, 7.13% and 4.60% lower than that of the blank control group, respectively. Then after Av treatment alone, the body weight of female pupae, male pupae and female adults of O. furnacalis decreased significantly, being 26.50%, 8.96% and 12.46% lower than that of the blank control group, respectively, while the body weight of male adults was significantly higher than that of the blank control group by 6.05%. At the same time, Cu treatment had a certain impact on the calling behavior of female adults. After Cu treatment, the highest calling rate and average calling duration in each scotophase decreased with the scotophase, while those in the blank control group showed a trend of increasing first and then decreasing with the scotophase. After Av treatment, the calling behavior of female adults was promoted: the highest calling rates in all scotophases except the scotophase 5 (the 5th scotophase after emergence of females) reached 100%; the average calling duration in Av treatment groups was significantly longer than that in the blank control groups in all scotophases except the scotophase 3 (the 3rd scotophase after emergence of females), and the average calling duration in Av treatment group was the highest (5.71 h) in scotophase 5. Compared to the blank control group, Cu and Av treatment alone significantly inhibited the orientation behavior of male adults and the number of eggs laid per female of O. furnacalis. On the other hand, the effects of the combined stress of Av and Cu and their single stresses were different. Compared to the blank control group, Av+Cu treatment inhibited the growth and development of O. furnacalis, causing significant extension of the developmental duration and body weight loss. The female and female postembryonic developmental duration in Av+Cu treatment was 37.60 and 37.04 d, respectively, only shorter than that in Av treatment. The body weight of female and male pupae and female adults in the Av+Cu treatment group was the lowest, significantly lower than that in the blank control group. In the mating combinations of female and male adults stressed by Av+Cu and female and male adults in the blank control group, the landing to pheromone source rate of male adults and the number of eggs laid per female were significantly lower than those of the mating combination of female and male adults in the blank control group, and both were the lowest. The calling behavior of female adults of O. furnacalis after Av+Cu stress was relatively consistent with that after Av treatment, and the highest calling rates in all scotophases reached 100%. The average calling duration in each scotophase in Av+Cu treatment group was significantly longer than that in the blank control group and Cu treatment group, and showed no significant difference from that in Av treatment group, and the average calling duration in Av+Cu treatment was the longest (6.16 h) in scotophase 3.【Conclusion】Single and combined stresses of Cu and Av inhibit the growth and development, disturb the reproductive behavior of adults and reduce the fecundity of O. furnacalis. Among the effects of the combined stress of Cu and Av on O.furnacalis, Av plays a leading role.

Key words: Ostrinia furnacalis, copper, avermectin, growth and development, calling behavior, orientation behavior, fecundity, egg hatching rate