JOURNAL OF NANJING FORESTRY UNIVERSITY ›› 2020, Vol. 44 ›› Issue (4): 131-136.doi: 10.3969/j.issn.1000-2006.201904025

Previous Articles     Next Articles

Effects of temperature on growth and development of Pagiophloeus tsushimanus Morimoto

JIA Zhiyi1(), CHEN Cong1, MA Yuxuan1, LI Shouyin1, FAN Binqi2, WANG Yan2, HAO Dejun1()   

  1. 1.Co -Innovation Center for the Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China
    2.Forest Station of Shanghai, Shanghai 200072, China
  • Received:2019-04-12 Revised:2020-04-20 Online:2020-07-22 Published:2020-08-13
  • Contact: HAO Dejun E-mail:18751953180@163.com;djhao@ njfu.edu.cn

Abstract: Objective

Pagiophloeus tsushimanus is a new wood-boring beetle,which has outbreaks in Cinnamomum camphora plantations in recent years. This pest mainly excavates the phloem and xylem tissue of the stems of host plants during the larval stage, which causes structural weakness and disrupts the flow of water and nutrients within host trees. The purpose of this study was to clarify the developmental threshold temperature and effective accumulated temperature of P. tsushimanus, to confirm the influence of temperature on the growth and development of this beetle and to facilitate the prediction of its occurrence.

Method

The developmental duration of P. tsushimanus was determined in an illuminated incubator with a 0/24 h (light/dark) cycle and relative humidity of (65 ± 5)%, under one of five constant temperatures (19, 22, 25, 28 and 31 ℃). There were three duplicates for each temperature treatment, with 84 eggs for each duplicate. Once hatched, the neonate larvae were transferred to a half artificial diet and reared until pupation. The developmental duration of the egg, larva and pupa was investigated using five temperature treatments and the development rates were calculated. The developmental threshold temperature (C) and effective accumulated temperature (K) of P. tsushimanus were determined using the linear regression and least square methods.

Result

The developmental threshold temperatures of the egg, larva and pupa were estimated to be 9.03, 13.04 and 10.32 ℃, and the effective accumulated temperatures were 221.21, 955.69 and 206.00 (℃·days), respectively.The linear regression and exponential models of the relationship between the temperature and developmental rates of P. tsushimanus were confirmed. The exponential model fitted well and could accurately reflect the relationship between the temperature and developmental rates of each stage of P. tsushimanus. The results concerning the prediction formula were basically consistent with that of a field survey from 2014 to 2018 in Shanghai. The life table of the experimental population under different temperature conditions was observed and recorded. In the range of 19-28 ℃, the hatching rate of P. tsushimanus eggs increased with the increasing temperature, while the hatching rate was only 76.19% at 31 ℃. In the range of 22-28 ℃, the pupation rate of P. tsushimanus larvae was over 70%.In the range of 19-31 ℃, the pupation and eclosion rates were relatively low, and the eclosion rate was no more than 60%.

Conclusion

The development and growth of P. tsushimanus were significantly affected by the temperature.As the temperature increased, the developmental duration was significantly shortened and the development rate was accelerated. At a temperature of 28 ℃, the hatching, pupation and eclosion rates of P. tsushimanus all reached maximum values, indicating that 28 ℃ was the optimal temperature for the development and growth of this beetle. Therefore,28 ℃ could be a suitable temperature for indoor artificial rearing.

Key words: Pagiophloeus tsushimanus Morimoto, growth and development, developmental threshold temperature, effective accumulated temperature

CLC Number: