Pg. 20-21 Proefresultate met triflumuron vir die beheer van die lietsjiemot

Die lietsjiemot, Cryptophlebia peltastica, is ‘n belangrike plaag van lietsjievrugte. Tot dusver is geen plaagdoders teen die plaag aangewend nie en is papiersakke gebruik om die vrugte te beskerm. In hierdie artikel word die resultate van ‘n bespuitingsproef met triflumuron (‘n kitiensintese-inhibeerder) op lietsjies uiteengesit. Verskillende dosisse, nl 15 ml, 20 ml, 30 ml, 40 ml en 2×15 ml/100l water is beproef. Onge veer 28l spuitmengsel is met ‘n hoevolume spuitmasjien en kart spuitgewere op die buitenste lower toegedien. Met oestyd is die vrugte vir sewe dae geberg en daarna vir lietsjiemotbesmetting ondersoek. Die resultate het getoon dat al die triflumuron-behandelings goeie beheer gegee het van O tot 0,6 persent besmetting, terwyl 8 persent besmetting by die kontrole voorgekom het. Residu-resultate word nog afgewag.

Summary:

• The litchi moth (Cryptophlebia peltastica) is a significant pest attacking litchi fruit, laying eggs on the skin, with larvae feeding through the skin and flesh into the seed.
• The presence of larvae causes fruit spoilage due to fungal growth at larval entry points and can cause skin damage leading to fruit splitting.
• Until now, no insecticides have been used in South Africa for this pest; paper bags have been the main method of protection.
• The study tested triflumuron, a chitin synthesis inhibitor, on litchis at different dosages (15 ml, 20 ml, 30 ml, 40 ml, and two treatments of 15 ml/1000 L water).
• Triflumuron works by preventing larvae from moulting, is selective, non-systemic, and safe for beneficial insects like honeybees.
• Spraying was done on the outer foliage and fruit, with about 28 liters of spray mixture per tree.
• Fruit were harvested, stored for seven days, and then examined for moth infestation.
• Results showed excellent control with triflumuron treatments, reducing infestation rates to between 0% and 0.6%, compared to 8% infestation in untreated controls.
• The 15 ml dose about 40 days before harvest was found effective, with little difference compared to higher doses or multiple applications.
• Residue analysis results were pending at the time of the report.
• Natural egg parasitism of litchi moths was noted as an important factor in pest control.
• The study concludes that triflumuron is effective for controlling the litchi moth and offers a chemical control alternative to bagging fruit.