Preventative Insecticidal Control of Green Peach Aphids, 2014 * Open Access

The study was conducted in a greenhouse at the AgriLife Research and Extension Center in Overton, TX. The objective of the trial was to assess the efficacy of different rates of Mainspring™ Cyantraniliprole (MoA 28), as a preventative treatment for green peach aphid ( Myzus persicae Sulzer) control on pansies ( Viola tricolor ), compared to that of Endeavor, a known effective product. Treatments were assigned to individual plans in 4-inch pots (experimental units) in a CRD with six replicates. Plants were kept in individual mesh cages (item 1462W, BioQuip Products Inc.) on a greenhouse bench.

Plants were artificially infested with aphids five days after treatment (DAT) by releasing 10 insects (fourth instar-to-adult) on the foliage of each pansy. Samples were taken using time counts performed weekly at 7, 14, 21, and 28 days after aphid infestation by counting all the aphids observed on a plant during 30 s. Plant salability (commercial viability) in a 0-5 scale and phytotoxicity on a 0 – 100 scale were assessed at 2 and 7 DAT. Number of aphids per plant at 7, 14, 21, and 28 days after inoculation were compared among treatments using ANOVA and all treatment mean-pairs separated using Tukey’s HSD. Commercial viability values for plants from each treatment were compared using a Likelihood ratio chi-square test.

All insecticide treated plants had significantly lower numbers of aphids than check plants at 7, 14, and 21 days after aphid introduction ( Table 1 ). Only the Endeavor and Mainspring ^™ drench (12 fl oz) treatments were significantly different from the check at 28 days after aphid introduction ( Table 1 ). One of the replicates from the Endeavor treatment was removed due to experimental error (not treated). Some plants were lost after 14 wks due to root rot (Pythium and Thielaviopsis) ( Table 1 ). There was no significant differences in the commercial viability of the pansies after two (X2 (10, N  = 36) = 9.977, P  = 0.443) and seven (X2 (5, N  = 36) = 6.351, P  = 0.2736) DAT.

In conclusion, both Endeavor and Mainspring ^™ drench (12 fl oz) were the most effective at suppressing aphids when used preventively. Conclusions regarding residual activity of the insecticides cannot be made from this data set because aphids were introduced only once, five days after pesticide application.

Author notes