Description: Adult specimens in the CUAC pinned collection range from 4.50 to 6.13 mm in length and 2.35 to 2.80 mm in width. Colors range from light to dark brown with various red and black markings. Most retain the yellow v- or y-shape on the scutellum. 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. Compound eyes are present but ocelli are lacking. Antennae and beak are 4-segmented. (Kelton 1975, Triplehorn and Johnson 2005).
Life Cycle: Adults overwinter in plant litter in fields, woods, timber margins, stream and ditch banks, and road rights-of-way (Khattat and Stewart 1980, Cleveland 1982). Elongate, slightly curved eggs, approximately 1mm long and 0.26 mm wide, are inserted into the stems, leaf petioles and leaf mid-ribs of host plants, which are mostly herbaceous. The truncate end that is flush with the plant surface is where the first instar nymph emerges. Eggs take 5 to 17 days to hatch depending on temperature. Nymphs molt 5 times taking an average of 15 to 30 days to reach adult stage, also depending on temperature (Sorenson 1939, Peairs and Davidson 1956, Metcalf et al. 1962). Two to five generations may occur depending on latitude (Peairs and Davidson 1956, Metcalf et al. 1962, Johnson and Lyon 1991).
Locations: Lygus lineolaris is distributed throughout North America (Kelton 1975). Specimens in the CUAC collection are from Anderson, Barnwell, Lee, Pickens, Oconee, and Spartanburg Counties in SC; Story County in Iowa; Haywood County in NC; and Tompkins County in NY.
Dates of Collections: In SC collections were made in the months March through November. The specimen from Iowa was collected on April 9. Specimens from NC were collected on October 25. Specimens from NY were collected on August 10.
Plant Hosts: The tarnished plant bug has been found in association with hundreds of plant species from over 50 families. Fruit and vegetable crops include apple, apricot, blackberry, cherry, currants, grape, peach, pear, plum, quince, raspberry, strawberry, beans, beets, cabbage, carrots, celery, cucumber, green pepper, lettuce, peas, potato, sugar beet, tomato and turnips. Plant hosts in commercial flower production are asters, carnations, chrysanthemums, daffodil, dahlias, marigolds, peonies, and roses. It also feeds on other crops such as alfalfa, amaranth, clover, cotton, soybean and tobacco. It is also known as a pest of white oak trees and conifers (Peairs 1956, Kelton 1975, South 1991, Young 1986, Wheeler 2001). Wild plant species serve as an important host for food and ovipositing especially when plant crops are unavailable. Herbaceous wild plants that are important alternate host in cotton production are bitterweed (Helenium amarum Raf.), buttercup (Ranunculus sp.), Carolina geranium (Geranium carolinianum L.), common yarrow (Achillea millefolium L.), fleabane (Erigeron annua (L.) Pers.), goldenrod (Solidago sp.), horseweed (Conyza canadensis (L.) Cronq.), mayweed (Anthemis cotula L.), smartweed (Polygonum sp.), sunflower (Helianthus sp.), vetch (Vicia sativa L. ssp. sativa), Virginia pepperweed (Lepidium virginicum L.), water hemlock (Cicuta sp.), white evening primrose (Oenothera speciosa Nutt.), whiteheath aster (Aster ericoides L.), wild carrot (Daucus carota L.), wild mustard (Sinapsis arvensis L.), and woolly croton (Croton capitatus Michx.) (Cleveland 1982, Fleischer and Gaylor 1987). Common mullein (Verbascum thapsus L.) and henbit (Lamium aplexicaule L.) are important hosts for overwintering adults (Khattat and Stewart 1980, Snodgrass 2003).
Other Food Sources: Tarnished Plant Bug is also known to feed on other insects including the alfalfa weevil (Hyperia postica Gyllenhal), alfalfa blotch leafminer (Agromyza frontella Rondani), braconid wasp (Apanteles glomeratus L.), leafhoppers (Empoasca fabae Harris), pea aphid (Acyrthosiphon pisium Harris, M.), pea aphid parasitoids (Aphidius and Praon spp.), spotted alfalfa aphid (Therioaphis maculata Buckton), and tobacco budworm (Heliothis virescens Fabricius). In laboratory settings it frequently becomes cannibalistic (Lindquist and Sorenson 1990, Wheeler 2001).
Feeding Injury: Generalized feeding damage of plants includes wilting; necrosis; fruit abscission; deformed fruit, seed and other tissues; and altered vegetative growth (Tingey and Pillemer 1977). Penetration of plant tissues is with a stylet that is pointed apically and with sharp lateral serrations along its length angled back towards the head. Feeding is by a combination of stylet penetration and the salivary enzymes, pectinase, amylase and proteases that digest plant tissues. The resulting “slurry” is pumped up the food canal (Hanly and Pollard 1983, Wheeler 2001). More specific wound responses to feeding are apical seediness in strawberries; catfacing of apples and peaches; shriveled seed in alfalfa and carrot; premature drop of buds, flowers and fruits in cotton and tomato; and split stems and swollen nodes in cotton. In conifers, cotton and alfalfa, feeding injury to the terminal tips causes increased vegetative branching (Tingey & Pillemer 1977, South 1991). Lygus lineolaris is also known to vector the bacterial disease, fireblight (Erwinia amylovora Burrill), to various fruits through feeding wounds (Wheeler 2001, Braun and Hildebrand 2006).
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