Hypochlora alba

Distinguished from the similar green Hesperotettix viridis by: (1) pale green vs. medium green body color; (2) green antennae with brown spots or suffusions in older instars vs. black antennae with pale anterior annuli; (3) hind femur pale green with brown spots or medium green vs. medium green with black spots (instars I–II) or black chevrons (instars III–V). The combination of short wings, pale green coloration with brown spotting, and exclusive association with Artemisia ludoviciana confirms identification. Male genitalia distinctive: cercus bulbous at base with finger-like apex.

Medium-sized, short-winged grasshopper with pale green coloration that matches its host plant. Body covered with many small brown spots visible under magnification. Broad green band runs behind the eye on the side of the head, continuing onto the lateral lobe of the pronotum and sides of the meso- and metanotum. Dry, pinned specimens turn dull yellowish-tan. Male cercus broad at base, slender apically; furcula short and slender; subgenital plate bears apical tubercle. Females rarely possess long wings extending 2–3 mm beyond abdomen. Nymphs pale green with brown spots; antennae green with pale anterior annuli on segments (blue in first instar); hind femur pale green and spotted brown or medium green; hind tibia pale green.

Grasslands east of the Rocky Mountains, particularly mixedgrass prairie, tallgrass prairie, and sand prairies. Occupancy depends on presence of host plant Artemisia ludoviciana, which grows in patches of 10–50 square yards, often in well-watered situations such as sandy loam slopes and ravine bottoms. In Colorado, not found above 6,000 feet elevation despite host plant occurring at higher altitudes.

North America east of the Rocky Mountains. Documented in 11 U.S. states and 3 Canadian provinces. GBIF records include Colorado, Nebraska, and South Dakota. Distribution is irregular and patchy, closely tracking but not fully coextensive with host plant range; host plant extends farther in all directions and to higher elevations.

Late-developing species. Hatching begins approximately one month after Ageneotettix deorum, typically starting May 15 in eastern Kansas, June 1 in southeastern North Dakota and northern Colorado. Hatching continues for approximately one month. Nymphal period lasts 44–46 days. Adults appear from late July through early October, with peak activity in August and September.

Feeds primarily and almost exclusively on Artemisia ludoviciana (cudweed sagewort, white sagebrush). Trace amounts of other Artemisia species documented: A. frigida and A. cana observed in Montana, A. glauca in Kansas. Trace amounts of six grasses and nine forbs found in crop contents from Kansas, Nebraska, and North Dakota, likely incidental ingestion. The only grasshopper species known to survive on A. ludoviciana; polyphagous species cannot digest its pubescent leaves efficiently.

• Artemisia ludoviciana - primary hostExclusive host plant; monophagous specialization
• Artemisia frigida - secondary hostObserved feeding in Montana
• Artemisia cana - secondary hostObserved feeding in Montana
• Artemisia glauca - secondary hostTrace amounts in crop contents, Kansas

Hemimetabolous development with five nymphal instars for both sexes. Eggs laid in soil in interspersed bare areas of grassland; female holds upright plant while ovipositing with hindlegs raised. Egg pod slightly curved, 5/8 to 3/4 inch long, containing 8–12 tan eggs 3.8–4.9 mm long, oriented nearly vertically in soil. Embryonic diapause occurs; eggs overwinter at depth of approximately 1 inch. One generation annually.

Strictly phytophilous: nymphs and adults spend nearly entire lives on host plant. Rests vertically head-up on main stems at heights of 8–12 inches before sunrise; occasionally rests horizontally on top leaves. Basks by turning side perpendicular to sun rays and lowering associated hindleg, typically for approximately two hours after sunrise. Feeds on young leaves from edge to midvein, with younger nymphs (instars I–III) gouging tissue from upper, less hairy leaf surfaces, leaving thin areas and holes; older instars and adults feed on leaf edges. When disturbed, jumps 2–8 inches between host plant stems, retaining vertical orientation; occasionally jumps to ground but immediately returns to host. Does not drop to ground to evade predators (unlike Chorthippus curtipennis). At temperatures above 100°F, moves to shady side of stem while maintaining vertical head-up posture. Limited dispersal: daily displacement 0–10 feet, with some individuals remaining on same plant for entire day; one fifth instar observed on same plant for five consecutive days.

Specialist herbivore tightly linked to Artemisia ludoviciana. Serves as model organism for studying monophagy and plant-insect coevolution; uniquely adapted to process pubescent leaves that deter other grasshoppers. Population dynamics indicate stable persistence in host plant patches; contributes to forb-feeding guild in tallgrass and mixedgrass prairies. Fourth most abundant species in Konza Prairie tallgrass prairie studies (1982–1986), comprising 7% of 8,100 collected grasshoppers and ranking second among forb-feeders.

Minor economic importance. Host plant Artemisia ludoviciana has fair to good forage value for sheep and fair for cattle in New Mexico, less value farther north; serves to bind soil and prevent erosion. Grasshopper causes minor visible damage to host plant leaves at typical densities (six adults per square yard in patches), but does not threaten rangeland productivity. No significant pest status; specialized diet prevents crop damage. Studied for insights into digestive adaptations of specialist herbivores.

• Hesperotettix viridisBoth are green, spur-throated, phytophilous grasshoppers. Distinguished by body shade (medium vs. pale green), antennae coloration (black with pale annuli vs. green with brown spots), and hind femur patterning (black spots/chevrons vs. brown spots).
• Melanoplus lakinusBoth are short-winged Melanoplinae with limited dispersal. H. alba distinguished by pale green coloration, exclusive Artemisia association, and geographic restriction east of Rockies; M. lakinus is brown with fuscous and yellow markings, feeds on Chenopodiaceae, and ranges in western North America.

• monophagous
• phytophilous
• short-winged
• specialist herbivore
• Artemisia

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Cudweed Grasshopper
• Snakeweed Grasshopper
• Grasshoppers of Colorado
• Grasshoppers of Colorado
• Grasshoppers of Colorado
• Lakin Grasshopper
• Morphology and Distribution of Sensilla on the Antennae and Mouthparts of Hypochlora alba (Orthoptera: Acrididae)