Selectiveness of Cnaphalocrocis medinalis to Host Plants

A field experiment was conducted to study the selectiveness of Cnaphalocrocis medinalis Güenée (commonly known as the rice leaffolder or rice leafroller) towards five rice varieties (Yangfujing 8, Yangdao 6, Shanyou 136, Huaidao 9 and Ningjing 1) and three weed species (Echinochloa crusgalli, Leptochloa chinensis and Leersia hexandra). The results showed that the rice varieties carried significantly higher numbers of C. medinalis moths and eggs than the weed species. Among the rice varieties, Yangfujing 8 was associated with a higher moth number. However, there was little difference in the number of C. medinalis eggs among the rice varieties. Additionally, a laboratory experiment was performed to investigate the olfactory response of female C. medinalis towards volatile compounds from different rice varieties, as well as its oviposition preference towards these rice varieties. The volatiles of Yangfujing 8, Yangdao 6 and Shanyou 136 attracted C. medinalis similarly to those of TN1. In contrast, the volatiles of Huaidao 9 and Ningjing 1 clearly deterred C. medinalis. Nevertheless, C. medinalis did not exhibit clear oviposition preference towards any of the five tested rice varieties.