False codling moth (FCM) is one of South
Africa’s most detrimental agricultural pests, causing substantial damage
annually to citrus, peach, nectarine, apple and many other crops. FCM naturally
occurs in South Africa but has spread throughout Africa and to some parts of
the Middle East. FCM has not successfully established in Europe, and governing
bodies in European countries are concerned that should FCM arrive, it could
become a serious pest to their commercial crops. Therefore, the European Union
(EU) closely monitors shipments of fruit from South Africa, and if a single FCM
is found, the shipment may even be rejected and returned to South Africa,
causing devastating financial losses to the South African fruit industry.
However, in South Africa, FCM is one of
approximately six different moths which all occur relatively commonly in fruit
orchards, and which all look very similar to the casual observer. While adult
moths often have patterns on their wings which can be used to distinguish them,
the caterpillars (larvae) of the moths actually cause more damage to the crops
by boring into fruit or chewing through leaves, and these caterpillars are very
difficult to differentiate. Identification of the caterpillars often requires
examination with a microscope, and some level of expertise and training to
correctly identify the species. Given the expanding regulations by the EU
targeting FCM but excluding the other moths, which do not pose a serious threat
to European crops, it is crucial to identify FCM accurately.
In November 2017, two training sessions
were hosted by Stellenbosch University’s Department of Conservation Ecology and
Entomology’s Integrated Pest Management (IPM) Initiative. In these sessions,
Mr. Matthew Addison of Hortgro first presented a detailed explanation of new
monitoring protocols developed for the detection of FCM. Then, Dr. Pia Addison,
presented details of FCM larval biology, collection and identification
techniques. Dr. Addison and Dr. Corey Bazelet demonstrated the various tools
available for moth larva identification, some of which were developed
especially for these training sessions. Finally, participants were given the
opportunity to practice caterpillar handling, preservation, and identification
using stereomicroscopes, specimens and the available tools.
Participants of the two training sessions
included 29 representatives of companies which supply agricultural products,
private consultants, and fruit growers. All participants were given a starter
kit for specimen collection, a poster explaining FCM diagnostic features, a
pamphlet for identification of the most common caterpillars which could be
easily confused with FCM, and a flash drive containing a digital identification
tool which was developed as part of the MSc thesis of Ms. Monique Rentel in
2012.
In cases where a caterpillar is severely
damaged or has only recently hatched from its egg, FCM identification may not
be possible using microscopic diagnosis. In these cases, DNA barcoding is the
most reliable technique to use. If you require assistance with identification
of suspected FCM, would like to attend a training session, or would like to
receive identification tools and materials provided during this workshop,
please contact Dr. Corey Bazelet cbazelet@sun.ac.za or Dr. Pia Addison
pia@sun.ac.za.