三种杀虫剂对梨小食心虫和桃小食心虫的残效研究

Research of three insecticides' residual effect on oriental fruit moth and peach fruit moth

【目的】了解氯虫苯甲酰胺、氟虫双酰胺和灭幼脲对梨小食心虫和桃小食心虫的直接致死效果及对后续各虫态发育的影响。【方法】采用浸渍法,用3种杀虫剂分别处理2种食心虫的卵和老熟幼虫。【结果】氟虫双酰胺200 mg·kg-1和氯虫苯甲酰胺50 mg·kg-1、25 mg·kg-1虽能显著降低梨小食心虫卵孵化率,但幅度较小。各药剂浓度处理均可显著提高初孵幼虫死亡率。3种药剂基本不影响桃小食心虫卵孵化,但灭幼脲和氟虫双酰胺各浓度处理可显著提高初孵幼虫死亡率。氯虫苯甲酰胺降低了梨小食心虫的化蛹率、成虫羽化率,对F1代卵的孵化也有抑制作用。灭幼脲只影响处理当代虫的发育变态,对F1代卵孵化没有影响。除氯虫苯甲酰胺25 mg·kg-1处理外,其他药剂处理均可抑制桃小食心虫幼虫化蛹。所有试验药剂处理均显著抑制桃小食心虫的成虫羽化和产卵,其中氟虫双酰胺200 mg·kg-1、灭幼脲200mg·kg-1和100 mg·kg-1处理的桃小食心虫均不能产卵。【结论】综合以上试验结果,认为氟虫双酰胺、氯虫苯甲酰胺和灭幼脲对2种食心虫的初孵幼虫具有高杀虫活性;虽然对老熟幼虫直接致死效果低,但可以抑制其发育变态及繁殖,缓慢降低种群数量,起到控制害虫的效果。因此,在生产上使用上述3种杀虫剂防治梨小食心虫和桃小食心虫时,建议在卵期和幼虫脱果期喷药,便于及时控制食心虫危害。

[ Objective ] The oriental fruit moth （Grapholitha molesta Busck） and peach fruit moth （Carposina niponensis Wals. ） are two major pests that damage deciduous fruit trees in China. Their larva mainly bore apple, pear, peach, apricot, plum, hawthorn and Chinese jujube, resulting in fruit rotting and dropping, and severely affect production and quality. Moreover, the oriental fruit moth damages new shoots of various fruit trees, and inhibits shoot growth and flower bud formation. In recent years, severe outbreaks of some fruit tree pests happened because of the improvement of fruit production efficiency, the increase of cultivated species and area, mixing planting of different fruit trees and the prohibition of high toxic and long residue insecticides. Currently, the main methods to control these two pests are trapping at the adult stage and spraying at the egg and mature larvae stage. Technology of sex pheromone trapping and mating disruption succeeded. But chemical control is still involved in finding new high efficient, low toxic and low-residue insecticides. Flubendiamide and chlorantraniliprole are two diamide insecticides produced in the early of this century, which have special insecticidal mechanism and long residual activity, and be able to control many Lepidoptera pests with a low toxicity to bees and fish. They have been used to control various vegetable and fruit tree pests. Chlorbenzuron is a traditional and biorational insecticide controlling Lepidoptera pests, and has some biological activities on the egg, larva, pupa and adult. In order to gain better understanding of the direct lethality of ehlorantraniliprole, flubendiamide and ehlorbenzuron on the oriental fruit moth and peach fruit moth, and their influence on all stages＇ development, we used different doses of three insecticides respectively to treat the egg and larvae of oriental fruit moth and peach fruit moth. [ Methods ] Oriental fruit moth and peach fruit moth were used as experimental insects, and ＇Fuji＇ apples were immersed in different doses of flubendiamide, chlorantraniliprole and chlorben-zuron respectively for 5 s, naturally dried and then the eggs of oriental fruit moth and peach fruit moth were laid on the fruits. Five eggs were on each apple with 9 times of repeat, and distillated water was used as control. Fuirts were placed in a digital light illumination incubator with T=（24±1） ℃, L： D =16 ： 8 h, RH=（60℃ 10）%. The number of egg hatching was checked 5 days after incubation, the larvae survival number was checked 10 days after incubation, and the egg hatchability, larval mortality and ratio of survival larvae and egg were calculated. Further more, the immersion method was also used to treat the mature 20 larvae of each insect with 3 times of repeat. The number of larvae mortality, pupation, eclosion and oviposition were checked everyday to evaluate three insecticides＇ direct lethal effects on these two pests and their influence on all stages＇ development. [ Results] After treating apples with three insecticides, observe the influence of residual chemicals on egg hatching. Compared with control, flubendiamide（200 mg. kg^-1） and chlorantraniliprole （50 mg· kg 25 mg. kg^-1） significantly reduced egg hatchability of oriental fruit moth by 13.33%, 11.11% and 11.11%, respectively. Various concentrations of three insecticides significantly caused high mortality of the newly-hatched larvae. All three insecticides had no obvious effect on egg hatching of peach fruit moth, but various concentrations of flubendiamide and chlorbenzuron significantly increased the mortality of the newly-hatched larvae. Chlorantraniliprole reduced pupation rate, adult eclosion rate of the oriental fruit moth, and also inhibited egg hatching of F1 generation. Chlorbenzuron only affected the primary generation＇ s development and had no influence on F1 genera-tion＇ s egg hatching. All the doses except chlorantraniliprole 25 mg. kg^-1 inhibited the pupating of peach fruit moth. All the doses significantly inhibited adult eclosion and oviposition of peach fruit moth, and peach fruit moth treated with flubendiamide 200 mg. kg^-1, chlorbenzuron 200 mg. kg^-1 and 100 mg. kg^-1 lost fecundity. The results suggested that it would be better to use flubendiamide 200 mg. kg^-1 and chlorantraniliprole 50 mg. kg^-1, 25 mg. kg^-1 at the egg hatching stage and the chlorantraniliprole 50 mg. kg^-1 at the mature larvae emerging from fruit to control the oriental fruit moth, and use the flubendiamide 200 mg. kg^-1, 100mg. kg^-1, 67mg. kg^-1and chlorbenzuron 200 mg. kg^-1 at the egg hatching stage and fluben- diamide 200 mg. kg^-1 and chlorbenzuron 200mg. kg^-1, 100 mg. kg^-1 at the mature larvae emerging from fruit stage to control peach fruit moth. [ Conclusion ] When using these three insecticides to control orien-tal fruit moth and peach fruit moth emerging from fruit stage to control succeeding stage of mature larvae. in production, it＇ s better to spray at egg stage and mature larvae the pests which had high activity to newly-hatched larvae and thesucceeding stage of mature larvae.