Distribution and host ranges of Ceratitis rosa and Ceratitis quilicii (Diptera: Tephritidae) in South Africa.

Abstract

Two fruit fly (Diptera: Tephritidae) species of economic importance: Ceratitis rosa Karsch and Ceratitis quilicii De Meyer, Mwatawala & Virgilio are present in South Africa. The two species were considered as one species prior to 2016, but were subsequently separated. In this study, the distribution and abundance of the two species were quantified in seven provinces in South Africa through trapping with Enriched Ginger Oil as an attractant. Trapping was conducted over three seasons across two years (2020 and 2021): late summer, autumn-winter, and spring-early summer. Host ranges of the two species were investigated by fruit sampling in and outside of trapping sites. Ceratitis quilicii was more widely distributed than C. rosa with the latter being recorded in only three north-eastern provinces. There were geographical limits for both species with no records of them in Northern Cape Province. Catches of C. quilicii were higher in summer with average temperatures varying from 15 to 27°C while for C. rosa, catches remained low and consistent between seasons. Ceratitis quilicii catches decreased at lower rates than those of C. rosa at temperatures below 15°C. The two species were reared from 13 plant species from nine families. Four of these hosts were infested by both C. quilicii and C. rosa in the same province where they occurred. Preferred hosts of the two species belonged to the Myrtaceae family. The characterisation of the distribution, abundance and host ranges of these pests will provide a baseline for pest status determination and implementation of management actions.