Bio-ecology and Control of Pezothrips kellyanus (Thysanoptera: Thripidae) on Citrus in Cyprus

Kelly’s citrus thrips is one of the most common thrips species found in Cyprus citrus orchards. Kelly’s citrus thrips larvae were the sole insect stage causing feeding damage mainly on immature lemon and grapefruit fruits. Under Cyprus conditions Kelly’s citrus thrips adults prefer to concentrate mostly in the northern and eastern sides of both lemon and grapefruit canopies. The recorded mean number of adults in the northern side of lemon canopies was 60.7, followed by eastern – 48.4 adults (F0.05 (3, 32) = 2.431; P< 0.083; Mean sq. = 2952.60), while on grapefruit canopies was 45.3 and 30.8 adults (F0.05 (3, 32) = 4.237; P< 0.012; Mean sq. = 2578.30) in the northern and eastern sides, respectively. In 2006, damage of lemon and grapefruit fruits reached 64.0% and 45.8%, respectively, while in 2007 damage was recorded at 50.4% and 91.2%, respectively. Depending on weather conditions and pest’s abundance, the first chemical spraying should be applied 10-20 days after massive petal fall and calyx closure at the fruitlet stage, and the second one-two weeks after the first application. Various insecticides were evaluated in field trials in lemon and grapefruit plantations against Kelly’s citrus thrips. Statistically significant differences were observed in 2006 and 2007. In 2006, the best protection of lemons provided by the neonicotinoid acetamiprid (93.0%) and the carbamate methiocarb (79.7%), while on grapefruits the most effective insecticides were acetamiprid (95.1%) and the macrocyclic lactone spinosad (75.7%). In 2007, acetamiprid and the Insect Growth Regulator lufenuron provided 85.1% and 82.2% protection of lemons, respectively, while on grapefruits best results were obtained with acetamiprid and the organophosphate chlorpyrifos providing 86.5% and 84.1% protection, respectively. _____________________________________________________________________________________________________________