2.1 Insect rearing
The larvae and adults of G. molesta were obtained from infested fruits of pear orchard in Changli, Hebei, China in July 2018. The adults were fed with a 10% honey solution. The larvae were fed with fuji apples. The next generations were reared in an artificial climate cabinet (PXZ-430B, Ningbo Jiangnan Instrument Factory, China) at the College of Plant Protection, China Agricultural University (Beijing, China). Rearing conditions were 25 ± 0.5°C with a photoperiod of 14 L: 10 D (Light, Dark) and 70% relative humidity.