Objective  Correlations between the growth, reproduction, and distribution of Leptocybe invasa, an insect that causes galls in plants, and the surrounding temperature were studied to facilitate the monitoring and controlling the spread of the pest wasp.

  Method  Duration and speed of each development state of the wasp were measured by inoculating and feeding the larvae indoor at 19, 22, 25, 28 and 31℃. Graphic, linear, and logistic regression analyses were applied to establish the correlations. Threshold and effective temperatures for the emergences of various stages of the insect were obtained using a linear regression model.

  Result  Temperature was found to significantly affect not only at the stage from egg to pupa, but also the entire development and adult life of the insect. The increasing temperature hastened the insect development process. The graphic linear regression model seemed to more accurately describe their correlation than the other models. In Gannan, Jiangxi, the threshold emergence temperature of the eggs was found to be 10.78℃; that of the larva, 10.29℃; that of the pupa, 14.64℃; the adult survival threshold temperature, 14.73℃; and, the temperature for the development of an entire generation, 12.68℃. The accumulated effective temperature for the eggs was found to be 86.96℃; that for the larva, 588.24℃; that for the pupa, 92.59℃; that for the adult survival, 104.17℃; and, that for the development of an entire generation, 712.34 d·℃. And, the optimum temperature for the egg development, 25.68℃; for the larvae, 25.65℃; for the pupa, 24.58℃; for the adult survival, 26.42℃; and, for the development of an entire generation, 23.84℃ with a range between 12.21℃ and 35.48℃. The model estimated 4.27 generations of L. invasa had taken place between 2017 and 2019 which was in agreement with what was observed in the field.

  Conclusion  Temperature was critical for the development of L. invasa. Understanding the correlation would aid in predicting the development, infestation time and area, and emerging generations of L. invasa for effective control of the pest.