Evaluation of Products for Pineapple (Ananas comosus MD-2) Symphylids Control

The symphylids, Scutigerella spp. and Hanseniella spp. are common soil pests in Costa Rican pineapple plantations. These arthropods feed on plant roots causing extensive crop damage which reduces water and nutrient uptake ending in yield reduction. Often, this problem is misdiagnosed since this pest may not be familiar to farmers and technicians. An experiment in a randomized complete block design with four repetitions was conducted to evaluate products for symphylids control. The treatments were: 1: untreated control, 2: commercial chemical treatment with Mocap® 72EC at 10 L ha-1, 3: Thiamethoxam 1.5 kg ha-1, 4: Acetamiprid 1.25 kg ha-1, 5: Steinernema carpocapsae 1 kg ha-1, 6: Spirotetramat 1 L ha-1, 7: Inorganic fertilizer 4 L ha-1, and 8: Biostimulant fertilizer 5 L ha-1 + Quillay extract 4 L ha-1. All rates were applied with spray boom in 3800 L of water solution ha-1 48 days after planting. The pre-treatment incidence of symphylids by 10 plants by repetition was similar (P= 0.3140) among treatments varying between 50 and 80% and the number of symphylids by plant differed (P= 0.0406) which varied between 1.0 and 3.6 by plant. When comparing the treatment effect, the average of the evaluations at 15, 30 and 45 days after product application, the lowest incidence was recorded in the plants applied with Mocap® with 17.5% which differed (P< 0.0001) from all those applied with the other products where it varied between 69.2 and 84.2%. The number of symphylids by plant was lower (P< 0.0001) in those applied with Mocap® with 0.4 differing from the other treatments where the population ranged between 1.9 and 3.0 per plant. When the product effect was compared, pre-application evaluation 0 days versus the average of 15, 30 and 45 days, only in the plants applied with Mocap® the incidence was reduced (P= 0.0084) from 57.5 to 17.5% and the number of symphylids by plant decreased (P= 0.0019) by 83%. Of the products evaluated only Mocap® gave satisfactory control.