| Yellow peach moth Conogethes punctiferalis (Guenée) (Lepidoptera: Pyralidae) is a multivoltine insect, which distributes in the south eastern Asia and Australia. The larvae are polyphagous pests on fruits, oil crops, vegetables, and grain crops. In China, this species has caused serious damage to peach, chestnut, sunflower, sorghum across the Yangtze River valley and central regions. In the last decade, there have been reports presenting evidence of its change in voltinism and expanding range to northerly, which causes serious damage to maize. To survive in the cool temperate zone, this species has to survive low temperatures. It overwinters as the fifth instar larvae in diapause, but the available diapause data are very limited. The issue of change in the moth voltinism cannot be adequately solved in the absence of information pertaining to the identity of the key factors involved in the induction of diapause in the insect. In this paper, a mothedology of mass rearing and 3 artificial diets were reported. In addition, the role of photoperiod and temperature in the induction of diapause for yellow peach moth were investigated. The cold tolerance of overwintering larvae from different host plants and its relationship with larval weight, water content, lipis as well as sugurs content in the haemolymph were investigated. The major results as follows:1. A mass rearing method and three types of artificial diets of yellow peach moth larvae were reported. The effect of the pest rearing by the the three types of artificial diets and chestnut have been compared. The pupation rates, pupal weights, emergence rates, sex ratios, the singal oviposition quantity and hatchability rates of the yellow peach moth were 42.8%-47.3%, 63.4-70.3 mg, 87.9%-90.3%, 1.02-1.21, 38.2-54.9and 70.4%-74.2%when reared by attifical diets, which were no significant differents.2. Effect of photoperiod and temperature on the regulation of the larval diapause of a summer maize region population was investigated. Photoperiod experienced by the larvae was used to program the onset of larval diapause. Short photoperiod throughout larval development yields a high diapause incidence in the larvae. Measurement of the effect of photoperiod on diapause induction revealed critical photoperiod of about 12 h 51 min light/day at 25℃. Its photoperiodic response also was highly temperature dependent. Irrespective of photoperiods, all larvae entered diapauses at 20℃, and few or none did so above 30℃. When long photoperiod (LD 14:10 h) were alternated with short photoperiod (LD 11:13 h) at different larval ages at 25℃, no critical instar for diapause determination was detected. However, three instars and 10.3 d short photoperiod exposure were the required instar and day numbers for diapause induction in 50% of the larvae, suggesting that the counter of the photoperiodism for diapause induction in C. punctiferalis measures the number of instars induced, in addition to measuring the inductive cycles of short photoperiod. 3. In contrast with feeding on sorghum and sunflower, larvae feeding on maize had significant lower suppercooling point (-17.74℃), significant more laval weight and high percent of lipid content, but significant lower percent of water content. These suggested that the larvae developed more favorable on maize than on sorghum and sunflower. The major sugurs contained in overwintering larvae were trehalose, glycerol, myo-inositol and glucose. The glycerol contents increased with decreasing contents of trehalose or glucose from earlier of December to 20th of January, suggesting that glycerol play an important role in increasing larval cold tolerance.
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