Abstract:  In order to explore the induced resistance of wolfberry by exogenous jasmonic acid and the influence on insects, in the laboratory at 25℃ three concentrations of jasmonic acid (JA) and the control (acetone and distilled water at the ratio of 1∶599) were used to spray seedlings of wolfberry Lycium barbarum Linn., which were used to rear the wolfberry aphid Aphis sp., and then the developmental duration, body weight and fecundity of these aphids were tested. The results showed that the developmental duration, adult longevity, fecundity and body weight were significantly influenced on JA-induced wolfberry seedlings and the influence was related to the JA concentration. The longest nymphal period was observed on 0.01 mmol/L JA-induced seedlings, which was 4.93 d, 1.9 d longer than that of control. The adult fecundity was reduced significantly, and the higher the concentration of JA solution, the lower the fecundity of the adult. Nineteen less nymphs produced per adult on the 0.1 mmol/L JA-induced seedlings than on the control seedlings. The adult longevity on the induced seedlings was about 3 d shorter than that on control. The daily body weight began to be influenced significantly on the 3rd day post JA treatment. On the 5th day post JA treatment, the average body weight was 0.395 mg for aphids on the control, and only 0.211 mg for aphids on 0.01 mmol/L JA-induced seedlings, and the range of body weight difference between aphids on JA-induced and control seedlings was 0.128-0.184 mg.

Key words: Aphis sp., wolfberry, induced resistance, jasmonic acid, developmental duration, reproduction