Study on Citrus Tristeza Virus (Ctv) Vectors in a Mandarin Farm of Kavrepalanchowk District, Nepal

Abstract

Globally the pathogen of tristeza disease is transmitted by different species of aphids. Among them T. citricida and T. aurantii are two potential CTV vectors in Nepal. The present study was conducted to study the CTV vectors in mandarin farm of Kavrepalanchowk district, Nepal. The study was carried from August 2016 to April 2017. Data collection was carried out using yellow trap method. The local temperature and humidity of the farm was recorded with the help of alcohol thermometer and hygrometer respectively. Toxoptera citricida and Toxoptera aurantii were found potential aphid vectors for virus transmission. Among identified species, T. citricida abundance was higher (90%) than T. aurantii (10%). In the present investigation, abundance of aphids was found to be affected by local temperature, humidity, aspects and seasons. The abundance of aphid species was correlated with temperature (p<0.05) similarly negative relation was obtained between humidity (P<0.05) and abundance of CTV vectors. Minimum abundance of aphids were recorded during winter season (P<0.05). These results highlight effects of bioclimatic parameters on distribution and diversity of CTV vectors in Citrus farm of Kavrepalanchok district, Nepal