First record of new exotic Mealybug species, Phenacoccus solenopsis Tinsley, 1898 (Hemiptera: Pseudococcidae), its Host range and abundance in the Eastern Sri Lanka.

Abstract

Mealybugs (Hemiptera: Pseudococcidae) are a small group of sap sucking insect pests which cause severe economic damage to wide range of homegarden, horticultural and field crops. Therefore, a survey of mealybugs in Batticaloa District of Eastern Sri Lanka was conducted to gather information on their species composition, distribution and pest status. Among the different species identified, the cotton mealybug, Phenacoccus solenopsis Tinsley was found to be the predominant species comprising about 70% of the collected specimens. This species has not been previously reported to occur in Sri Lanka. It now appears to be widespread in the Eastern parts of the country. This is an exotic species originated from USA. The new mealybug was identified by the authors and confirmed as Phenacoccus solenopsis Tinsley by Dr.C.J.Hodgsn, Department of Biodiversity and Systemic Biology, National museum of Wales, Cardiff, Wales, UK. This first record of P.solenopsis in Sri Lanka, where it was found infesting mainly on shoe flower plants Hibiscus rosa-sinensis. The description of the adult female cotton mealybug is presented in this paper. Samples were collected from twenty five different locations within the study area and twenty six plant species from ten different families were recorded as hosts with various levels of infestations. In addition the abundance of P.solenopsis on the shoe flower plant, which is the major hosts in the homegardens, shows a clear seasonal variation and during the period of study two generations were found. Among the climatic factors, rain fall affects significantly on the abundance of this species. The implications of the introduction of this exotic polyphagous pest species and its potential threat to agriculture in Sri Lanka are discussed in this paper.