Determination of Super Cooling Points and Freezing Points of Asecodes hispinarum and Tetrastichus brontispae
Both Asecodes hispinarum and Tetrastichus brontispae are important parasitoid invasive pests of Brontispa longissima.Super cooling points and freezing points were assayed to understand the cold hardiness of these two parasitoids.The results indicated that Asecodes hispinarum and Tetrastichus brontispae had considerable high cold-resistance.They could survive in the areas where B.longissima are distributing.Both super cooling points and freezing points were different between A.hispinarum and T.brontispae.Either super cooling points or freezing points were the highest in pupae stage of these two parasitoids.However,there were no differences in super cooling points and freezing points between female and male insects.Asecodes hispinarum and Tetrastichus brontispae could be applied in the distribution areas of coconut leaf beetles in China.