Dargida diffusa (Walker) Wheat

Pogue, Michael G., 2010, The Hadeninae (Lepidoptera: Noctuidae) of Great Smoky Mountains National Park, USA 2380, Zootaxa 2380 (1), pp. 1-75 : 24

15. Dargida diffusa (Walker) Wheat Head Armyworm Moth (adult), Wheat Head Armyworm (larva)

( Figs. 30–31 , Map 16)

The former name of this species was Faronta diffusa . A recent revision has synonymized the genus Faronta with Dargida ( Rodríguez and Angulo 2005) .

Identification: Forewing length 13–16 mm. This is an easily recognized species with the cream-colored forewing and horizontal stripes. The space between the costa and R vein from base to apex is a mixture of white and pale gray scales. A grayish-brown triangular patch at end of discal cell extends from vein M3 to M1 to outer margin. Vein Cu is highlighted white with two black dashes, one at base and one at the fork of Cu and Cu1 just below vein Cu. Reniform spot is a small black dot. Hindwing is white with veins highlighted with gray and becomes more heavily suffused with gray toward outer margin. Some specimens can have almost a completely gray hindwing.

Flight period: Mid-June.

Collected localities: North Carolina : Haywood Co., Purchase Knob. (1 specimen)

Elevation range: 4924 ft. (1501m)

General distribution: This is a widespread species occurring from Nova Scotia to Saskatchewan in Canada and from Maine to North Carolina and across the Midwest and Southwest to California and Oregon .

MAP 16. Collecting localities of Dargida diffusa .

Larval hosts: This is the Wheat Head Armyworm and is a pest of wheat and other grains, including sorghum and corn. This is a polyphagous species preferring species in the grass family ( Poaceae ). Other hosts include: slender wheatgrass ( Elymus trachycaulus (Link) Gould ex Shinners ssp. subsecundus (Link) A. Löve & D. Löve , Poaceae ), big bluestem ( Andropogon gerardi Vitman , Poaceae ), common oat ( Avena sativa L., Poaceae ), bluejoint ( Calamagrostis canadensis (Michx.) P. Beauv. , Poaceae ), orchardgrass ( Dactylis glomerata L., Poaceae ), barnyardgrass ( Echinochloa crus-galli (L.), Poaceae ), Canada wildrye ( Elymus canadensis L., Poaceae ), foxtail barley ( Hordeum jubatum L., Poaceae ), common barley ( Hordeum vulgare L., Poaceae ), rice ( Oryza sativa L., Poaceae ), timothy ( Phleum pratense L., Poaceae ), cereal rye ( Secale cereale L., Poaceae ), yellow foxtail ( Setaria pumila (Poir.) Roem. & Schlult. ssp. pumila , Poaceae ), green bristlegrass ( Setaria viridis (L.) P. Beauv., Poaceae ), indiangrass ( Sorghastrum nutans (L.) Nash, Poaceae ), sorghum (Sorghum bicolor (L.) Moench, Poaceae ), common wheat ( Triticum aestivum L., Poaceae ), splet ( Triticum spelta L., Poaceae ), corn ( Zea mays L., Poaceae ), bindweed ( Convolvulus sp. , Convolvulaceae ), clover ( Trifolium sp. , Fabaceae ), and black bindweed ( Polygonum convolvulus L., Polygonaceae ) ( Tietz 1972).

Figures

FIGURES 25–32. Adults. 25, Orthosia revicta, m, New York, Tompkins Co., Ringwood Reserve near Dryden, 2 May 1965, D.C. Ferguson. 26, Orthosia rubescens, m, Connecticut, New Haven Co., Bethany, 13 Apr. 1968, D.C. Ferguson; 27, Orthosia rubescens, m, New York, Long Island, 11 Apr. 1901; 28, Orthosia rubescens, m, Connecticut, New Haven Co., Bethany, 13 Apr. 1968, D.C. Ferguson; 29, Nephelodes minians, m, Tennessee, Cocke Co., Foothills Parkway, second overlook East, 1800 ft., 21 Sep. 2001, D.R. Davis, USNMENT 00153373; 30, Dargida diffusa, m, New Mexico, Union Co., Clayton, 5.3 mi NW of Hwy. 87 on 370, 5214 ft., 23 Aug. 2004, M.G. Pogue; 31, Dargida diffusa, m, Colorado, Fremont Co., Coaldale, Hayden Creek, 6800 ft., 9 July 1982, D.C. Ferguson; 32, Hadena ectypa, f, Illinois, Cook Co., Chicago, 10 July 1927.