Influence Of Temperature And Photoperiod On The Growth Development And Diapause Of The Oriental Fruit Moth, Grapholitha Molesta

Oriental fruit moth belong to Lepidoptera, Olethreutidae. Oriental fruit moth is not only one of the important pests of fruit production in north of China,but also a worldwide fruit pest. Through the test, at 20℃, 23℃and 26℃, combined with six treatments of photoperiod(11L︰13D,12L︰12D,13L︰11D,13.5L︰10.5D,14L︰10D,15L︰9D), this paper comparative investidied the influence of temperature and photoperiod on the growth development of larvae, fecundity, percentage of diapause, critical photoperiod and sensitive stage of the oriental fruit moth, the results were as follows: Temperature and photoperiod have significant influence on the larvae growthdevelopment of oriental fruit moth. It growing with the temperature rise gradually shortened, the growth development of larvae is 20℃>23℃>26℃.At 20℃and 23℃, the growth development of larvae growing with the light of prolonged gradually shortened. At 26℃, the growth development of larvae is longest in the photoperiod of 13L︰11D,and was significantly longer than others. The growth development of larvae is shortest in the photoperiod of 12L︰12D.At 26℃, The photoperiod was significant influence on the fecundity of oriental fruit moth.The specific performance:in the photoperiod of 12L︰12D,the longevity of adult was longest,the oviposition was most too. In the photoperiod of 11L︰13D, the longevity of adult was shortest and the oviposition was lowest. In this test, the pre-oviposition of adults were no significant differences in the five treatments of photoperiod.Temperature and photoperiod were significant influence on the diapause of larvae of oriental fruit moth. In the general trend,the percentage of diapause of oriental fruit moth represents that percentage of diapause reduced with the temperature increasing rately. It showed that 20℃>23℃>26℃. In the photoperiod of 15L︰9D,the percentage of diapause of oriental fruit moth were all zero in the three test temperature, all the oriental fruit moth individuals did not occur diapause. At 20℃and 23℃, with the extension of the photoperiod, the percentage of diapause of oriental fruit moth were gradually declined, and in the photoperiod of 11L︰13D, 12L︰12D and 13L︰11D, the percentage of diapause were all 100%. But at 26℃, the percentage of diapause of oriental fruit moth all did not appear to 100% in all treatment of photoperiod, but the percentage of diapause in long photoperiod (13.5L︰10.5D, 14L︰10D,15L︰9D)were significantly below the percentage of diapause in short photoperiod (11L︰13D,12L︰12D,13L︰11D).Different instar of oriental fruit moth has significant differences in the different photoperiod. The sensitive stage of oriental fruit moth was first instar. Under constant temperature 20℃,the critical photoperiod of oriental fruit moth was LD13h48min︰10h12min; under constant temperature 23℃, the critical photoperiod was LD13h36min︰10h24min; under constant temperature 26℃, the critical photoperiod was LD11h48min︰12h12min.