Outbreak of Phenacoccus manihoti MAT-FERR. In Kamphaeng Phet Province

Abstract

Phenacoccus manihoti has introduced severe pest of cassava and immigration of pest-borne cutting stem, caused outbreak in several areas and widely spread. Addition, a severe of damages depends on environments, weather and existent of natural enemy. To reach sustainable management should be understanding the nature of pest and factors affected. The study tracked population changes of P. manihoti on various factors especially agro-meteological element. Cassava farmer fields at khlong Khlung and Mueang districts, Kamphaeng Phet province were studied every 4 weeks during October 2009 and October 2012 based on growing and existent of A. lopezi. The result showed that outbreaks of P. manihoti was not depended only on climate variability but also some element contribute to the outbreak. In case of non-parasitoids warp, consecutive days without rain small amounts increased more than 10 times in 28 days, a heavy rain did not eradicate but just reduced. But consecutive rain for example: in seven days it’s rain 4 days consecutive 2 weeks or 2 in 3 consecutive 4 weeks reduced amount almost completely. Rainfall reduced amount of P. manihote more than other mealybut. In case of released A. lopezi, the amount per plant was very small and significant shown effectively control P. manihoti, but also change amount of other mealybugs.