Insidious flower bug, Orius insidiosus (Say) (Hemiptera: Anthocoridae), predation on western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), on Transvaal daisy, Gerbera jamesonii, cut flowers and chrysanthemum, Tanacetum × grandiflorum, plants under laboratory and greenhouse conditions

The insidious flower bug, Orius insidiosus (Say) (Hemiptera: Anthocoridae), is a generalist predator that feeds on western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), larvae and adults. Our study involved a series of experiments conducted under laboratory and greenhouse conditions from 2017 to 2020 to: 1) determine the number of insidious flower bug adults that should be released to manage western flower thrips populations below damaging levels, 2) assess if integrating the insidious flower bug with the insecticide spinosad (Conserve®) is a viable alternative plant protection strategy, and 3) determine if short (<12 h) or long (>12 h) day lengths/photoperiods affect insidious flower bug predation on western flower thrips under greenhouse conditions. We found that releasing three or four insidious flower bug adults was most effective in managing western flower thrips populations on chrysanthemum, Tanacetum × grandiflorum, plants with the mean number of western flower thrips adults and larvae per chrysanthemum plant < 10. We determined that spinosad can be used with the insidious flower bug to manage western flower thrips populations. Finally, we ascertained that insidious flower bug predation was not affected by short [10.5:13.5 (light:dark hours)] or long [14.5:9.5 (light:dark hours)] day lengths/photoperiods. Consequently, greenhouse producers can release the insidious flower bug anytime during the growing season, even from fall through winter, to manage populations of western flower thrips on chrysanthemum. In addition, greenhouse producers can integrate spray applications of spinosad with the insidious flower bug as long as the applications do not negatively affect insidious flower bugs.