The mullein bug, Campylomma verbasci, is a mirid (hemipteran) pest of apple and pear orchards. The early nymph stages of the mullein bug cause damage by feeding on flower calyx (petal sepals) and on young fruit (those generally less than 15mm), causing “stings”, raised pimple-like warts, which in large numbers can deform the apple. Apples, especially golden delicious, are more susceptible than pears to damage from C. vervasci. While the mullein bug has 3-4 generations per year, it is only the first generation of nymphs each season that causes damage. Most individuals in the subsequent generations migrate from orchards to herbaceous weeds, most commonly mullein (Verbascum thapsus L.). The mullein bug still does occur in orchards (albeit in smaller numbers) for the rest of the summer, but after petal fall is no longer much threat to apple production. In fact, at this stage the mullein bug becomes a beneficial predator of mites, aphids, psyllids, thrips, and other small arthropod pests in orchards. Adults and nymphs remaining in the orchards may sometimes attack and cause damage to vegetative portions of fruit trees, but it is thought that this damage occurs only when an inadequate supply of prey arthropods is present. In the fall, C. vervasci adults migrate back to the orchards from their mullein hosts to mate and lay eggs to overwinter on tree bark.
The mullein bug is tolerant to many pesticides. When necessary, pesticide treatments are used on the first generation, in the narrow window after overwintered eggs hatch and before fruit predation occurs.
(Reding et al. 2001; Higbee; Alston and Reding 2011)