The Area-Wide Spatio-Temporal Distribution of Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) in a Heterogenous Fruit Production Region of the Western Cape, South Africa

The area-wide spatio-temporal distribution of Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) trap catches was investigated in the regions of Elgin/Grabouw, Villiersdorp and Vyeboom, collectively known as EGVV, Western Cape, South Africa. The primary fruit crops planted in EGVV include various varieties and cultivars of pome fruit, stone fruit, citrus, wine grapes and berries. Fruit fly trapping data from four consecutive seasons were sourced from a centralised database managed by a non-profit company, which operates an area-wide integrated pest management (AW-IPM) programme, incorporating the sterile insect technique (SIT) for C. capitata fruits flies, within EGVV. Mean trap catch between regions and seasons was compared. The spatio-temporal variation of mean trap catch was also investigated. A geographic information system (GIS) was used to symbolise and map mean trap catch per trap location. There was no significant difference in the mean trap catch between regions. Significant differences did occur between some seasons in Villiersdorp and Vyeboom but not in Elgin/Grabouw. The spatial distribution of trap catches between seasons varied greatly, indicating no definitive pattern. However, traps with the highest seasonal trap catch occurred mostly in the southeastern parts of each region and traps with lower levels were distributed mostly in the northwestern parts of each region. The results suggest a relationship between the geographic characteristics of EGVV and the abundance and distribution of C. capitata. It is recommended that an in-depth spatio-temporal analysis be carried out to better understand the geographical distribution of trap catches in the study area.