Population dynamics of Monolepta hieroglyphica Motschulsky)in cornfields
Author of the article:ZHANG Cong** YUAN Zhi-Hua WANG Zhen-Ying*** HE Kang-Lai BAI Shu-Xiong
Author's Workplace：State Key Laboratory for the Biology of the Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
Key Words： Monolepta hieroglyphica, population dynamics, population density, occurrence regularity
Abstract： [Objectives] To determine the frequency of occurrence of Monolepta hieroglyphica （Motschulsky） in corn fields, and to provide a scientific basis for forecasting and developing integrated management measures to control this pest. [Methods] The population dynamics of M. hieroglyphica were systematically studied in corn fields in Xinzhou and Jinzhong in ShanxiProvince. [Results] Overwintering eggs in corn fields ofXinzhou City,ShanxiProvince hatched in late-May and the neonate larvae bored into and made tunnels in corn roots for feeding. The peak period of M. hieroglyphica larvae was in mid-June after which some mature larvae began to pupate in soil. M. hieroglyphica adults began to emerge in late June with peak emergence in early August. The adult population in corn fields declined sharply after mid-August when most corn silks had withered and corn leaves had become yellow. M. hieroglyphica adults were not observed in corn fields in mid-October but were seen sporadically in weeds. The growth of corn in Jinzhong, where corn crops depend on rain for water, was 10 days slower than at Xinzhou where crops can be irrigated. Adults began to emerge later at Jinzhong than at Xinzhou, but trends in adult population dynamics were similar at both sites. The density of M. hieroglyphica adults was greater on the edges than in the center of corn fields but this difference was not statistically significant during the peak of adult abundance. [Conclusion] M. hieroglyphica has one generation per year inShanxiProvinceand emerge 10 days earlier at Xinzhou than Jinzhong. Soil surface characteristics, irrigation methods and corn growth rates are important factors that affect the emergence of M. hieroglyphica.