Spatial and temporal distribution of false codling moth across landscapes in the Citrusdal area (Western Cape Province, South Africa).
Author(s)Stotter, Robert L.
Contributor(s)Samways, M. J.
University of Stellenbosch. Faculty of AgriSciences. Dept. of Conservation Ecology and Entomology.
KeywordsFalse codling moth (FCM) -- Citrusdal
False codling moth, Distribution of
Dissertations -- Conservation ecology and entomology
Theses -- Conservation ecology and entomology
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AbstractThesis (MScAgric (Conservation Ecology and Entomology)--University of Stellenbosch, 2009.
The false codling moth (FCM), Thaumatotibia leucotreta (Meyrick)
(Lepidoptera: Tortricidae), is an indigenous pest of citrus fruit in southern Africa, and is a
pest of high phytosanitary concern, impacting negatively on the export of fresh citrus
fruit from South Africa to some international markets. FCM is a particularly serious pest
in the Citrusdal area in the Western Cape Province of South Africa. FCM is known to
infest most types of citrus, with navel oranges being particularly prone to attack, whereas
lemons are not considered to be a favoured host. Conventional control strategies that rely
on the use of insecticides are of limited use due to high levels of insecticide resistance in
FCM populations. Mating disruption, the Sterile Insect Technique (SIT) and the
integration of different control techniques are options that are currently being adopted.
Little is known about FCM host preferences in this geographical area, or about its
dispersal capacity. The ability of FCM to migrate between various host patches,
including citrus orchards and indigenous fynbos vegetation, and its ability to maintain a
viable population in alternative host plants when there is no fruit available for infestation
in citrus orchards has not been well studied. Knowledge of these largely behavioural
facets is important in planning an effective control strategy for FCM.
Towards addressing this dearth of knowledge, FCM pheromone traps were set out in
transects in the Citrusdal area. These transects included citrus orchards, and extended
beyond citrus orchards, to include a range of habitat types and elevational gradients. This
provided a grid to assess the spatial and temporal distribution of male FCM in the area.
In addition, intensive sampling and inspection of potential host plant material was
undertaken in the area in an attempt to identify any alternative host plants.