Ageneotettix

Ageneotettix is distinguished from other slant-faced grasshopper genera (Gomphocerinae) by structural characters of the pronotum, antennae, and male genitalia. The genus lacks the lateral pronotal carinae present in some related genera. A. brevipennis is immediately recognizable by its short-winged condition. A. deorum can be separated from sympatric slant-faced species by its characteristic coloration and pattern, including the pale whisker-like markings on the face that give rise to its common name. Accurate identification to species typically requires examination of adult males, particularly the structures of the terminalia.

Members of Ageneotettix are slant-faced grasshoppers (subfamily Gomphocerinae) with the characteristic oblique facial profile typical of this group. The pronotum lacks lateral carinae, and the antennae are relatively short. Species within the genus show variation in wing development: A. brevipennis has abbreviated wings as indicated by its specific epithet. The genus is distinguished from related slant-faced genera by combinations of structural characters including details of the pronotal shape, antennae form, and male genitalia. Nymphs can be recognized by the degree of facial slope, general color pattern, shape of antennae and foveolae, and the extent of curving of the lateral carinae of the pronotum.

Species of Ageneotettix inhabit grassland ecosystems of western North America. A. deorum is particularly associated with mixedgrass prairie, where it is a characteristic and often dominant species. The genus occurs in northern mixedgrass prairie, shortgrass prairie, and desert grassland habitats. Specific microhabitat preferences vary by species, but members generally occupy the ground layer and lower vegetation strata of open grasslands with relatively sparse canopy cover.

The genus is distributed across western and central North America. Records indicate presence in Arizona, Colorado, Illinois, Indiana, and Michigan. A. deorum has the widest distribution, ranging across the Great Plains and intermountain West. A. brevipennis and A. salutator have more restricted ranges. The genus is absent from the Pacific coastal states and from the southeastern United States.

A. deorum belongs to the early hatching group of grasshoppers, with nymphs emerging in mid-spring. Adults are present from summer through fall, with the timing varying by latitude and elevation. In northern mixedgrass prairie, hatching typically occurs several weeks after the very early hatching species. The seasonal cycle is completed in one year, with eggs overwintering in the soil.

A. deorum is a grass-feeding specialist. In mixedgrass prairie, it feeds predominantly on grasses including blue grama and other graminoid species. The species has been documented as a pure grass feeder, with crop analyses showing nearly exclusive consumption of grass material. Food preference tests indicate selectivity among available grass species.

The life cycle is univoltine, with eggs overwintering in the soil and hatching in spring. Nymphs develop through five instars before becoming adults. The nymphal period typically spans 40-50 days under favorable conditions. Adults reproduce in summer and early fall, with females depositing egg pods in the soil. Egg pods are laid among grass roots or in bare ground, with depth and placement varying by soil conditions.

A. deorum is a ground-dwelling (geophilous) species that forages primarily at the base of grasses. Individuals bask in morning sun to elevate body temperature before becoming active. The species is capable of flight for dispersal, though it is not among the strongly migratory grasshopper species. Males produce species-specific acoustic signals by stridulation for mate attraction and recognition. When disturbed, individuals may jump or fly short distances to escape.

A. deorum is frequently the dominant species in grasshopper assemblages of northern mixedgrass prairie, sometimes comprising over 50% of total grasshopper abundance. As a primary consumer, it transfers significant energy from grasses to higher trophic levels. The species serves as prey for birds, small mammals, and insect predators and parasites. Its population dynamics influence competitive interactions within grasshopper communities and contribute to nutrient cycling through herbivory and excretion.

A. deorum is an important rangeland pest species due to its abundance and grass-feeding habits. At high densities, it contributes to forage loss in livestock grazing lands. The species was a major component of damaging grasshopper outbreaks in western Oklahoma in 1955 and has been implicated in other historical irruptions. Its economic impact is often in combination with other abundant grass-feeding species such as Aulocara elliotti. Management of A. deorum populations is a component of integrated pest management programs for western rangelands.

• AulocaraBoth are slant-faced grasshoppers in tribe Aulocarini, but Aulocara species typically have more pronounced facial markings and different pronotal proportions. A. elliotti is often codominant with A. deorum in mixedgrass prairie.
• AmphitornusAnother slant-faced genus in Gomphocerinae with overlapping distribution, but distinguished by differences in pronotal structure and color pattern, particularly the striped appearance of A. coloradus.
• PsoloessaSlant-faced genus of similar size and habitat preference, but with different seasonal timing and structural details of the head and pronotum.

• grasshopper
• slant-faced
• rangeland pest
• mixedgrass prairie
• grass feeder

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