Encoptolophus costalis

Distinguished from similar species by combination of: blue hind tibia; long wings extending 1-4 mm beyond abdomen; three dark bands on outer hind femur with dark knee; tegmina banded with weak apical dark bands on hind wings. Nymphs separable from Chortophaga viridifasciata by clavate (not ensiform) antennae, four distinct longitudinal ridges (not two) on fore- and midleg femur and tibia with black lines between them, and pink distal half of hind femur medial area in instar I (not entirely green). Instars IV-V separable by moderately sloping pronotal disk with obtuse posterior angle (vs. tectate disk with acute posterior angle in C. viridifasciata).

Inhabits mixedgrass, shortgrass, bunchgrass, and desert prairies. Most abundant in northern mixedgrass prairie. Favors moist areas of rich grass and sedge growth interspersed with bare ground. In southern distribution, occupies mesic swales and roadsides dominated by western wheatgrass, and prairies with Houston black clay soil dominated by Texas needlegrass. Also found in areas of fine sandy loam soil.

Western North America from Canada to Mexico. Recorded from Colorado, Montana, Nebraska, Texas, and Mexico (Northeast). Ranges widely across prairie provinces of Canada including Saskatchewan, Manitoba, and Alberta.

Intermediate-developing species. Hatching begins early to mid June in northern mixedgrass prairie, about three weeks after initial hatch of Ageneotettix deorum. Hatching period prolonged, continuing six to eight weeks. Adults appear August 8-14 in Wyoming and Saskatchewan. In southern distribution (northeastern Texas), adults appear by mid April with second generation by August; juvenile stages present throughout year with at least two generations annually.

Primarily grass-feeding species. Principal host plants are western wheatgrass (Agropyron smithii) and needleleaf sedge (Carex eleocharis). Other substantial food plants include northern wheatgrass, needleandthread, green needlegrass, and blue grama. Additional recorded foods: quackgrass, prairie junegrass, sand dropseed, little bluestem, sideoats grama, Kentucky bluegrass, foxtail barley, timothy, and Penn sedge. Forbs constitute only 1% of natural diet but 11 of 22 species tested were accepted in laboratory feeding trials including scarlet globemallow, prairie coneflower, dandelion, and Vicia sparsifolia. Has been observed feeding on dry plant litter and dry cow dung.

Egg stage overwinters. Hatching begins early to mid June in north, with prolonged hatching period of six to eight weeks potentially due to heterogeneous soil temperatures. Nymphal development requires five instars for both sexes, lasting 56-66 days based on field observations in northern mixedgrass prairie. Adults appear mid-August in north, mid-April in south with second generation in August. Fledgling adults require 2-3 weeks of growth and maturation before mating. Oviposition may begin by 16th day of adulthood. Females deposit eggs in bare ground interspersed among native grasses; test soil by boring several times before depositing clutch. Preferred oviposition substrate is Houston black clay soil. Pods 3/4 inch long, slightly curved, containing 14-20 tan eggs 4.0-4.4 mm long. Female brushes soil and litter over aperture after oviposition. In southern range, at least two generations annually with year-round juvenile stages.

Geophilus species spending almost all time on the ground. Nocturnal resting position: sitting horizontally on bare soil and litter, often under thin canopy of leaves surrounded by grasses. Basking begins 1-2 hours after sunrise: turns side perpendicular to sun rays and lowers associated hindleg to expose abdomen for 2-3 hours. Feeding occurs during midday hours (9:12 a.m. to 1:27 p.m.) at ground temperatures 76-126°F. At extreme high temperatures (125°F+), takes evasive action by resting in partial shade, sitting on grass 1/2 inch above ground, crawling into full shade, or climbing onto litter facing sun to expose minimum body surface. Second basking period occurs late in day until sunset. Males make frequent crepitation flights to arouse females; pursue potential mates on ground producing burst of vibratory stridulation followed by pulse of ordinary stridulation. Non-receptive females escape by flight. Males often attend ovipositing females but are kicked away. Flushed flight softly crepitates, travels 3-9 feet at heights of 3-12 inches, usually straight with occasional turn near end. Capable of longer dispersal and migratory flights; documented in mixed species swarm landing in urban area and in movement from depleted rangeland into adjacent crops.

Rangeland herbivore, usually subdominant member of grasshopper assemblages that contributes to cumulative grazing pressure but rarely causes significant damage alone. In favorable habitats can become dominant species, reaching up to 74% of grasshopper population with densities of 2.5 young adults per square yard, though impact on vegetation may remain limited. Functions as primary consumer in grassland food webs. Serves as prey for various vertebrate and invertebrate predators.

Minor agricultural pest. Reported as minor pest in alfalfa in Arizona and North Dakota, and as pest in fall wheat in Nebraska where adults migrated from depleted rangeland. Generally causes little economic damage due to typically low densities and preference for native grasses over crops. Adds to cumulative damage of more serious pest grasshoppers in rangeland assemblages. Subject of detailed ecological research at Matador site of International Biological Program in Saskatchewan.

• Chortophaga viridifasciataEarly instars (I-III) appear similar in green coloration and general structure. Separable by ensiform (not clavate) antennae, two distinct longitudinal ridges (not four) on fore- and midleg femur and tibia without black lines between them, entirely green hind femur medial area in instar I (not pink in distal half). Instars IV-V separable by tectate pronotal disk with acute posterior angle (vs. moderately sloping with obtuse angle).
• Hadrotettix trifasciatusLarger band-winged grasshopper in same subfamily with different color pattern: three dark bands on tegmina, orange or red hind tibia (not blue), and distinctive light annulus around hind femur. Nymphs have different leg color patterns and pronotal structure.

• grasshopper
• rangeland
• prairie
• herbivore
• pest
• North America
• band-winged
• Acrididae
• Oedipodinae

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Comparison
• Dusky Grasshopper
• Species Records and Accounts
• List of Species Fact Sheets| Grasshoppers of Wyoming and the West
• Greenstriped Grasshopper
• Threebanded Grasshopper
• Food preferences of the dusky grasshopper, Encoptolophus sordidus costalis (Scudder) (Orthoptera: Acrididae)