Clemson University Arthropod Collection (CUAC)
Poecilocapsus lineatus (Fabricius, 1798)
Fourlined Plant Bug
HEMIPTERA: Heteroptera: Miridae
Description: Adult specimens in the CUAC pinned collection range from 6.39 to 7.51 mm in length and 2.52 to 3.57 mm in width. The head is yellow with brown and yellow antennae. The pronotum and wings are yellow with four dark brown to black longitudinal stripes. Indicative of the Miridae is the presence on the hemelytra of a cuneus and one or two closed cells at the base of the membrane. In the middle of the cuneus there is a dark brown to black spot. Compound eyes are present but ocelli are lacking. Antennae and beak are 4-segmented. (Triplehorn and Johnson 2005).
Life Cycle: There is one generation per year. The overwintering stage is the egg. Eggs are typically inserted in the stems of woody plants but have also been found in the stems of herbaceous plants (Wheeler and Miller 1981). Nymphs molt five times. Mating and ovipositing occurs around six weeks after nymphs emerge from the egg. Dates for egg hatch and subsequent development varies depending on latitude. In south central Pennsylvania eggs hatched in mid to late April and adults were seen by late May. In northern Pennsylvania development was 1-3 weeks later. Development in Lafayette, IN was 2-3 weeks earlier than in Ithaca, NY (Wheeler and Miller 1981). Nymphs and adults were observed during June, July and August in southern Manitoba (Diehl et al 1997).
Locations: The fourlined plant bug is widely distributed throughout Canada (Diehl et al. 1997). It has been recorded in the following states: CT, DC, FL, IA, IL, IN, KS, MA, MD, ME, MI, MO, TX and WI (Henry and Froeschner 1988). Although SC, OH, NC and TN were not listed in the Catalog of the Heteroptera (1988), the CUAC holds specimens from SC dating back to 1935, and from OH (1924), NC (1938), and TN (1937). Specimens in the CUAC are from Barnwell, Charleston and Pickens Counties in SC; Tompkins County in NY; Haywood County in NC; Erie County in OH and Sevier County in TN.
Dates of Collections: In SC collections were made in May and June. The specimen from NY was collected on June 13. The specimen from NC was collected on May 25. The specimen from OH was collected on June 30. The specimens from TN were collected on June 12.
Plant Hosts: The fourlined plant bug has been found in association with 250 species of plants in 57 families (Wheeler and Miller 1981). Vegetable and fruit crop hosts are beans, cucumber, Jerusalem artichoke, lettuce, parsnips, peas, potato, radish, squash, currants and gooseberry. Woody ornamental plant hosts are azalea, buddleia, deutzia, dogwood, forsythia, viburnum and weigela. Preferred herbs in the Labiatae are catnip, hyssop, lavender, marjoram, mints and sage. Preferred herbaceous ornamentals in the Compositae are ageratum, chrysanthemum, coreopsis, dahlias, gaillardia and globe thistle. Other preferred plants are bittersweet (Solanum dulcamara L.); Canada thistle (Cirsium arvense (L.) Scop.); common burdock (Arctium minus Bernh.); purple loosestrife (Lythrum salicaria L.); common dandelion (Taraxacum officinalis L.); common mugwort (Artemisia vulgaris L.); common mullein (Verbascum thapsus L.); evening primrose (Oenethera biennis L.); ground ivy (Glechoma hederacea L.), musk thistle (Cardus nutans L. ssp. leiophyllus (Petrovic) Stojanov & Stef.) and teasel (Dipsacus sylvestris Huds.) (Wheeler and Miller 1981, Powell et al 1996, Diehl et al 1997).
Feeding Injury: The visible effects of feeding by the fourlined bug differ depending upon a plant’s leaf shape, pubescence, texture and venation. Lesions appear to occur as soon as the stylet punctures the plant tissue. Lesions may appear as round or irregular shaped holes, or water-soaked areas. Thick pubescence may mask lesions. With a heavy infestation plants may look burned. Injury may not be as significant on woody plants as feeding is usually restricted to sucker shoots or water sprouts (Wheeler and Miller 1981). Unlike other phytophagous mirids whose saliva contains pectinase, amylase and protease, the saliva of the fourlined plant bug contains only one hydrolytic digestive enzyme, exopectinase (Wheeler 2001). This enzyme, along with possibly other unknown salivary constituents, is responsible for the breakdown of cell walls and removal of the palisade parenchyma (Cohen and Wheeler 1998).
Cohen A C and A G Wheeler, Jr. 1998. Role of saliva in the highly destructive fourlined plant bug (Hemiptera: Miridae: Mirinae). Annals of the Entomological Society of America 91:94-100.
Diehl J K, N J Holiday, C J Lindgren and R E Roughley. 1997. Insects associated with purple loosestrife, Lythrum salicaria L., in southern Manitoba. The Canadian Entomologist 129:939-948.
Powell, S D, J F Grant, and P L Lambdin. 1996. Incidence of above-ground arthropod species on musk thistle in Tennessee. Journal of Agricultural Entomology 13:17-28.
Triplehorn, C A and N F Johnson. 2005. Borror and Delong’s introduction to the study of insects. Thomson Brooks/Cole. USA. 864pp.
Wheeler, A G and G L Miller. 1981. Fourlined plant bug (Hemiptera: Miridae), a reappraisal: life history, host plants, and plant response to feeding. The Great Lake Entomologist 14:23-35.
Wheeler, A G. 2001. Biology of the plant bugs (Hemiptera: Miridae) Pests, predators, opportunists. Cornell University Press. Ithaca and London. 507 pp