Sexually-dimorphic
Guides
Androloma disparata
Disparate Forester
Androloma disparata, commonly known as the Disparate Forester, is a sexually dimorphic moth species in the family Noctuidae. It occurs in Mexico and Texas. The larvae feed on plants in the Vitaceae family, including pepper vine (Ampelopsis arborea). The species is assigned Hodges number 9322.
Apantesis nais
Nais tiger moth
Apantesis nais, commonly known as the Nais tiger moth, is a species of tiger moth in the family Erebidae. First described by Dru Drury in 1773, this medium-sized moth is distinguished by its striking black-and-cream forewing pattern and variable reddish or yellow hindwings with bold black spotting. The species exhibits sexual dimorphism in wing pattern, with males displaying more extensive pale markings than females. It is widely distributed across eastern and central North America.
Cimbex americanus
elm sawfly, North American Elm Sawfly
Cimbex americanus, commonly known as the elm sawfly, is a large, non-stinging sawfly in the family Cimbicidae. Adults measure approximately 20–30 mm in body length and are among the largest sawflies in North America. The species exhibits sexual dimorphism in coloration: males have yellow-orange abdomens, while females display black abdomens with yellow transverse bands. Larvae feed on foliage of various broadleaf trees, particularly elm and willow, and can reach 50 mm in length. The species has a single generation per year, with larvae overwintering in soil cocoons before pupating in spring.
Cnephasia longana
Long-winged Shade, Omnivorous Leaftier Moth, Strawberry Fruitworm
Cnephasia longana is a small tortricid moth native to western Europe and introduced to western North America. Adults show strong sexual dimorphism in wing coloration. The species is notable for its broad larval diet spanning multiple plant families and its status as a pest of cereal crops. First-instar larvae overwinter in bark crevices before resuming feeding in spring.
Dasychira basiflava
Yellow-based Tussock Moth, yellow-based tussock
Dasychira basiflava, commonly known as the Yellow-based Tussock Moth, is a species of tussock moth in the family Erebidae. First described by Alpheus Spring Packard in 1864, this species exhibits pronounced sexual dimorphism in size, with females substantially larger than males. It is widely distributed across eastern and central North America, with populations extending from southeastern Alaska to the southern United States. The species shows geographic variation in voltinism, with one generation per year in northern regions and partial second generations in the south.
Dasylophia anguina
black-spotted prominent
Dasylophia anguina, the black-spotted prominent, is a sexually dimorphic moth in the family Notodontidae. Males display black streaks on the forewing with white hindwings, while females show a yellow-brown basal patch with gray hindwings. The species exhibits geographic variation in voltinism, with one brood in northern regions and two or more in the south.
Dasymutilla leda
Dasymutilla leda is a species of velvet ant in the family Mutillidae, native to the central United States. Only females have been collected by scientists, making this a species known exclusively from wingless, solitary individuals. The male remains undescribed, though D. myrice has been proposed as a possible match based on distribution and coloration patterns. Like other velvet ants, females are capable of delivering a painful sting and are parasitoids of ground-nesting bees and wasps.
Dynastes grantii
Grant's Hercules Beetle, Western Hercules Beetle
Dynastes grantii is a large rhinoceros beetle native to the southwestern United States and northern Mexico. Adult males possess prominent thoracic horns used in combat, while females lack horns entirely. The species exhibits distinctive grayish-white elytra often marked with irregular black spots. With a body length ranging from 3.5 to 6.0 cm, it is among the largest beetles in its range. The species has a prolonged life cycle, with larvae requiring approximately two years to develop before pupation.
Euclemensia barksdalensis
Euclemensia barksdalensis is a micro-moth in the family Cosmopterigidae, described from Louisiana in 2011. The species is named for Barksdale Air Force Base, its type locality. Sexual dimorphism in forewing length has been documented, with males slightly larger than females. This species belongs to a genus whose members are associated with scale insects.
Heliopetes ericetorum
Northern White-Skipper
Heliopetes ericetorum is a skipper butterfly in the family Hesperiidae, commonly known as the Northern White-Skipper. It occurs in arid regions of western North America, from eastern Washington south through the southwestern United States to Baja California, Mexico. The species produces two broods annually and adults are active from spring through fall. Larvae feed on mallow plants (Malvaceae), while adults are characterized by white wings with dark marginal markings that differ between sexes.
Ufeus faunus
Ufeus faunus is a noctuid moth species described by Strecker in 1898. It is restricted to the southwestern United States, with documented records from southwestern California to southern New Mexico. The species exhibits sexual dimorphism in forewing pattern and size, with females being slightly larger and possessing additional dark streaking. Larval development occurs under bark of riparian trees, with a univoltine life cycle producing adults in spring.
Uroctonus mordax
California forest scorpion, western forest scorpion
Uroctonus mordax is a small scorpion species in the family Vaejovidae, endemic to the coastal forests of California and extending into western Oregon and southern Washington. It is strongly associated with Redwood Forests and Oak Woodlands, where it occupies a foundational ecological role. The species exhibits distinctive physical traits including a squat body, slender tail, and sexually dimorphic coloration. It is notable for its mild venom and reclusive, nocturnal behavior.
Xysticus cristatus
common crab spider
Xysticus cristatus, commonly known as the common crab spider, is a small ambush predator in the family Thomisidae. Females reach 6–8 mm body length, while males are smaller at 3–5 mm. The species exhibits cryptic coloration ranging from light cream to dark brown or greyish, with distinct patterning that blends with dried leaf litter. It hunts by waiting motionless with forelegs spread wide, capturing insects that blunder within reach. The species has a broad Palearctic distribution and has been introduced to North America.