Comparing Three Solutions for Extracting Western Flower Thrips from Coleus Shoots
Western flower thrips [Frankliniella occidentalis (Pergande)] are small-bodied insects that prefer tight spaces such as flower buds and young leaves. Western flower thrips (WFT) pose sampling problems when compared with larger insects commonly found in plant canopies. Techniques to wash insects from plant canopies exist; however, plant type, plant age, and spatial distribution of insects within the canopy impact the efficacy of sampling. An experiment was designed to determine if 75% ethyl alcohol (EtOH), 0.1% detergent solution, or deionized water effectively wash WFT from the foliage of six coleus [Solenostemon scutellarioides (L.) Codd] genotypes inoculated with 32 adults and larvae. The number of WFT recovered after filtration through three mesh sizes varied between blocks and extraction solutions. The mean number of thrips recovered from coleus shoots with 75% EtOH solution, 0.1% detergent solution, or deionized water was 6.7, 8.4, or 0.8, respectively. The number of thrips recovered did not vary by coleus genotype, indicating the extraction solutions were equally effective on smooth leaf or curly leaf type plants. The 75% EtOH extraction solution is recommended for subsequent experiments.