The western flower thrips, Frankliniella occidentalis, is invasive and polyphagous. Its visual signal plays a crucial role in host location, suggesting that thrips has diurnal behavior. However, any diel rhythmicity of the thrips behavior is not yet well understood. This study analyzed the diurnal rhythmicity of the feeding and mating behaviors of thrips, and the patterns were explained in terms of diel rhythmicity by assessing the expression of genes associated with the circadian clock. Most feeding behaviors were observed during photophase in both larvae and adults. In mating behavior, which is mainly exhibited in 2~3 days-old young adults after emergence, most adults copulated at photophase. This diurnal pattern of the mating behavior was further supported by the analysis of a temporal calling behavior for mating, which was biased toward photophase. Four genes associated with the circadian clock were predicted in the F. occidentalis genome: period (PER), Timeless (TIM), Doubletime (DBT), and clock (CLK). All these genes exhibited a characteristic diel pattern in their gene expressions in a 24 h-period. The high expression peaks of these genes except for DBT were observed at photophase. To confirm the functional association of these genes with the feeding and mating behaviors, individual RNA interference specific to each gene was executed by feeding the gene-specific double-stranded RNA. Aside from DBT, suppression of these gene expressions resulted in significant deviations of the diel rhythms of the behaviors. These results suggest that the genetic components of the diel rhythmicity mediate the diurnal feeding and mating behaviors of F. occidentalis.

The twospotted spider mite, Tetranychus urticae and the western tarnished plant bug, Lygus hesperus are major arthropod pests of strawberries in California. Other important insect pests include the greenhouse whitefly, Trialeurodes vaporariorum and the western flower thrips, Frankliella occidentalis. Chemical pesticides play a major role in managing these pests, but not without the associated risk of pesticide resistance and environmental safety. Two field studies were conducted in Santa Maria to evaluate the potential of botanical and microbial pesticides in the integrated pest management (IPM) of strawberry. Chemical, botanical, and microbial pesticides were evaluated against T. urticae in a small plot study in 2013 and against L. hesperus and other insect pests in a large plot study in 2015 in commercial strawberry fields. Bug vacuums were also used in the 2015 study. Results demonstrated that non-chemical alternatives can play an important role in strawberry IPM.

The effects of soluble silicon fertilization on monocots and dicots have been widely studied. However, little is known regarding its effects on protecting epiphytes against insect and fungal pests. The efficacy of silicon fertilizer to reduce damage by thrip pest complexes, namely: Thrips palmi Karny, Frankliniella occidentalis Pergande, Chaetanaphothrips orchidii Moulton, and Chaetanaphothrips signipennis Bagnall (Thysanoptera: Thripidae), and fungal pathogens: Botrytis cinerea Persoon (Helotiales: Sclerotiniaceae) and Fusarium spp. Link (Hypocreales: Nectriaceae) was examined during a nine-month greenhouse trial in Hawaii. The trial assessed yield, quality, and pest damage across three common varieties of dendrobiums. All replicates received additional soluble silicon fertilizer applications alternating weekly between soil drench and foliar (50 mg Si/plant) applications. Yield, quality, and spray length, pest damage, plant vigor, SPAD, and leaf temperature were measured. Data were analyzed using a generalized linear model (glm) with repeated measures followed by post-hoc pair-wise comparisons in R, version 4.3.1. Treatment effects were significant at P