Abstract:
Markets importing citrus fruit including lemons, Citrus limon (L.) Burman f., from South
Africa require that the fruit be free of fruit fly pests (Diptera: Tephritidae). Historically there
has been no fruit fly infestation recorded on lemons destined for export from SouthAfrica. In
this study, we assessed the host status of commercial export grade Eureka lemons, Citrus
limon (L.) Burmanf. cv. Eureka, for four fruit fly pest species of economic importance in South
Africa: Ceratitis capitata (Wiedemann), Ceratitis rosa Karsch, Ceratitis quilicii De Meyer,
Mwatawala & Virgilio, and Bactrocera dorsalis (Hendel). Trapping was conducted in 10
Eureka lemon orchards in two major citrus production regions over two citrus seasons
between 2016 and 2017 to determine the level of fruit fly abundance in the sampled orchards.
Lemons were collected at harvest over the two seasons in the same orchards where trapping
was conducted. Fruit fly infestation of the sampled lemons was determined by dissection.
Additionally, infestation of lemons was determined under forced exposure to mature mated
females of C. capitata and B. dorsalis. Trapping data showed the presence of adults of all four
fruit fly species in the sampled lemon orchards.Nofruit fly infestation was detected in 43 222
Eureka lemons sampled at harvest. There was also no infestation of lemons under forced
exposure conditions. The results of this study provide evidence with 99.99 % efficacy and a
99%confidence level that SouthAfrican commercial export grade Eureka lemon fruit is not a
host for C. capitata, C. rosa, C. quilicii or B. dorsalis.
