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 – that 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)
- Alston, D. and M. E. Reding, 2011. Campylomma Bug (Campylomma verbasci). Utah State University, cooperative extension. Retrieved October 14, 2011 from http://utahpests.usu.edu/ipm/htm/fruits/fruit-insect-disease/campylomma-bug97
- Higbee, B.S. Campylomma verbasci (Hemiptera: Miridae) Mullein plant bug. In “Biological Control: a guide to natural enemies in North America” ed. A Shelton. College of Agriculture and Life Sciences, Cornell University. Retrieved October 14, 2011 from http://www.biocontrol.entomology.cornell.edu/predators/Campylomma.html
- McMullen, R. D., and C. Jong. 1970. The biology and influence of pesticides on Campylomma verbasci (Hemiptera: Miridae). The Canadian Entomologist 102: 1390-94.
- Reding, M. E., E H. Beers, J. F. Brunner, and J. E. Dunley 2001. Influence of Timing and Prey Availability on Fruit Damage to Apple by Campylomma verbasci (Hemiptera: Miridae). Journal of Economic Entomology 94(1):33-38. 2001 doi: 10.1603/0022-0493-94.1.33
- Thistlewood, H.M.A. et al. 1990. Seasonal abundance of the mullein plant bug, Campylomma verbasci (Hemiptera: Miridae), on apple and mullein in the Okanagan Valley. The Canadian Entomologist 122: 1045-58.