Uv-vision
Guides
Colias eurytheme
Orange Sulphur, Alfalfa Butterfly, Alfalfa Caterpillar
Colias eurytheme, the orange sulphur or alfalfa butterfly, is a widespread North American pierid butterfly found from southern Canada to Mexico. The species is highly variable in coloration, with both orange and white morphs present, and exhibits complex thermal biology and sexual selection dynamics. Larvae are significant agricultural pests of alfalfa and other legumes, while adults are known for mass emigration events when host crops are harvested. The species has been extensively studied for its metabolic responses to temperature, costs of mating in females, and disruptive sexual selection patterns.
Xenos peckii
Xenos peckii is a highly specialized endoparasitic insect in the order Strepsiptera, commonly known as twisted-wing parasites. It is an obligate parasite of paper wasps, specifically Polistes fuscatus, with development occurring entirely within the host's abdominal cavity. The species exhibits extreme sexual dimorphism: males are free-flying adults with reduced wings and unusual eyes containing green- and UV-sensitive photoreceptors, while females are neotenic, lacking wings, legs, and eyes, and remain permanently embedded within the host. Males locate females through a species-specific sex pheromone, (3R,5S,9R,7E,11E)-3,5,9,11-tetramethyl-7,11-tridecadienal, which females actively release by inflating and extruding their cephalothorax through the host's cuticle. The species has been documented across temperate North America and possesses unique cellular mechanisms for meiotic spindle formation that have been studied ultrastructurally.