Pg. 41-50 Pre-harvest moth control and moth breeding

The South African Litchi Growers’ Association is striving to gain access to more foreign markets. Fruit flies and moth species attacking the fruit are quarantine pests which can deny producers access to these markets. Quarantine treatments are therefore required. The focus is to develop quarantine cold treatments for both fruit fly and moth species and to combine it with preharvest management practices, resulting in an effective systems approach. 

One of the objectives of the study was to develop a rearing technique for litchi moth. Infested litchi fruit were collected in different production areas. Alternative host plants were also collected. Fruit were examined and all 5th instar larvae found were placed in containers with a layer of sand for the larvae to pupate in. Male and female pupae were placed in a small container to enhance mating of moths. Litchi fruit were collected, peeled and put in a jar filled with alcohol. As soon as the moths emerged, pips and filter paper were drenched in the jar with fruit and alcohol for egg laying. Eggs were placed on a maize meal medium used for rearing false codling moth with either grounded litchi pips or litchi juice as an additive. Larvae developed successfully in the different mediums and pupated in the cotton wool plugs.  An attempt was made to breed the second generation in a similar way, but this was not successful. 

Fruit in different production areas were collected and infestation levels determined. The highest infestation level of 8.2% was found on the ARC-ITSC Nelspruit experimental farm. The litchi moth was the dominant species found. No macadamia nut borers were reared from litchi fruit during the past season. Moths were monitored in the Hazyview, Malelane, Nelspruit and Tzaneen areas. 

Fenpropathrin (Meothrin, Philagro South Africa), triflumuron {Alsystin, Bayer CropScience), fenpropathrin in combination with a granulovirus (Cryptogran, River Bioscience) and triflumuron in combination with a granulovirus (Cryptogran, River Bioscience) were tested for controlling the moths. The best results were obtained with triflumuron, triflumuron in combination with a granulovirus and fenpropathrin in combination with a granulovirus.

Powered by BetterDocs