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False codling moth larvae identification
Author: Dr. Corey Bazelet
Published: 10/01/2018

​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 or Dr. Pia Addison