Influence of timing and prey availability on fruit damage to apple by Campylomma verbasci (Hemiptera : Miridar)

Campylomma verbasci Meyer is a zoophytophagous mirid that feeds on small ar thropods as well as apple (Malus domestica Borkhausen) fruits, causing econ omic damage to some cultivars. The influence of timing and prey availabilit y on the amount of fruit damage was studied to determine whether either fac tor could be used to refine a management program. C. verbasci nymphs were c aged on branches of fruiting 'Golden Delicious' apple trees during the peri od from bloom through early fruit set. The greatest amount of fruit damage occurred during the bloom period; little or no damage occurred after fruit reached approximate to 13 mm in diameter. The availability of prey did not reduce the incidence of fruit damage by C. verbasci, nor did it influence t he survival of nymphs. Nymphal survival was higher, however, in cages where a blossom or fruitlet was present versus a vegetative spur. These data sup port the hypothesis that post petal fall insecticide applications (those ma de after the fruit is greater than approximate to 10-13 mm in diameter) are not useful in preventing economic levels of fruit damage in Washington Sta te, and that petal fall applications would only prevent a fraction of the t otal amount of damage by this pest. The data from this study do not support the hypothesis that manipulating arthropod prey species of C. verbasci wil l prevent fruit damage. There was evidence to support the hypothesis that n ymphs can survive a relatively short period (7 d) without arthropod prey.