The effects of different temperature treatments on hatching rates and periods of the Casuarina moth''s (Lymantria xylina) diapausing eggs

• Main Authors: Chao-Chih Jeng, 鄭朝誌
• Other Authors: Shaw-Yhi Hwang
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/49206997583750376521

碩士 === 國立中興大學 === 昆蟲學系 === 91 === The casuarina moth (Lymantria xylina Swinhoe) is a serious defoliated pest of hardwood plant and fruit trees in Taiwan. The larvae feed on hardwood plants of more than 65 spices belonging to 23 plant Families. There host plants include nine economically important fruit trees that are cultivated widely in Taiwan, such as the longan and the litchi. The life history of casuarina moth is lasts for one year. This moth overwinters in diapausing egg stage for 8 or 9 months. We collected the egg masses of casuarina moth from field, removing outside hair-scaled shelter from the egg masses, then sterilized the eggs. We then put the eggs of the casuarina moth in the growth chamber(25℃、RH60%) for 10 days. After that 10-day period, the eggs were stored under four different temperatures. The eggs of the control treatment were stored in another growth chamber (27℃) directly. The hatching rate of the eggs under 6℃ is the lowest while the hatching rate of 15℃ treatment is the highest among the four treatments. No strong relationship was found from the first treatment to the last one between the treatment at 6℃ and the hatching days after the eggs were remove to normal growth chamber. Whereas, a negative relationship was found between treated temperatures and hatching days of all the treatments under 9℃, 12℃, and 15℃. The hatching days of the casuarina moth eggs under these temperatures (9, 12, and 15℃) decreased along with the increase of treated days.