| In order to clarify the changes of cold-resistant substances in larvae, pupae and adults of the Tuta absoluta under low-temperature stress, the changes in the contents of water, fat content and cold-resistant substances (proteins, alginate and sorbitol) in each insect state were measured and analysed under low-temperature stress at 4℃, with a view to clarifying the cold-resistant substances and their characteristics in different insect states of the Tuta absoluta.The results showed that low temperature significantly reduced the water content of larvae and pupae from 74.46±1.64% to 68.66±0.90% and 70.23±0.65% to 66.92±0.93%, respectively; the fat content of larvae was significantly reduced from 227.64±6.28 μmol/ml to 186.29±6.28 μmol/ml under low temperature; while the fat content of each insect state was significantly reduced from 227.64±6.28 μ mol/ml to 186.29±6.28 μmol/ml under low temperature. The protein content of all insect forms increased significantly at low temperature, with the greatest increase in the pupal stage, from 405.03±13.678 μg/mg to 554.82±29.41 μg/mg, an increase of 149.79±29.41 μ mol/mg. Alginate and sorbitol accumulated significantly in the pupal stage, from 31.44±0.48 mg/ml to 39.82±1.8 mg/ml, respectively. The significant accumulation of alginate and sorbitol from 31.44±0.48 mg/ml to 39.82±1.07 mg/ml and from 49.41±0.72 mg/ml to 52.15±0.68 mg/ml ,respectively during the pupal stage indicated that they were the key chilling resistance substances during the pupal stage. Therefore, different insect forms of T.absoluta responded to low temperatures, among which the pupae of T.absoluta may rely on proteins, alginate and sorbitol to overwinter in the open ground in Ningxia. |
