In the warmest part of the year, the Mexican Yellow ventures north to brighten the summer days of the U.S. Southwest and western plains.
Yellows are a group of pale yellow butterflies, some of which have pointed hindwings. The Mexican Yellow is one of those, and it is a helpful feature for identification. On the underside, a light brown diagonal streak crosses the hindwing which may also have rippled brown freckles on it. The forewing has a dark edge and the underside has a single black dot near the center of the edge. The top side of the forewings are a pale yellow with a thick, irregular-shaped black border that makes the yellow parts look somewhat like a dog's profile. Hindwings may have a two-toned yellow interior, but also have a thick, black edge.
While common in Mexican states, this species is less so in the United States. Its caterpillar is green with a thin, white line that runs down the side of the body. It feeds on fern acacia, a native plant known for its drought tolerance. Locust leaves and other legumes are also food plants. Look for the sunny adults flying in prairies and hillsides. In Mexico, this species also takes advantage of more humid, tropical areas.
Scientific Name: Eurema mexicana
Butterfly or Moth
Size (Adult; Length): 44mm to 63mm (1.72in to 2.46in)
Colors: yellow, brown, black
Descriptors: sulphur, flying, tropical, pointed tip on wing
Note: An insect's reach is not limited by lines drawn on a map and therefore species may appear in areas, regions and/or states beyond those listed above as they are driven by environmental factors (such as climate change), available food supplies and mating patterns. Grayed-out selections indicate that the subject in question has not been reported in that particular territory. U.S. states and Canadian provinces / territories are clickable to their respective bug listings.
Butterfly and Moth Anatomy
Antennae: Butterflies and Moths have a pair of antennae on the head used as sensors.
Head: The head is home to the insect's eyes, antennae, and proboscis.
Thorax: Home to the three pairs of legs as well as vital internal organs.
Abdomen: Contains vital internal organs such as the heart(s) and reproduction facilities.
Forewing: The upper, forward wing pair used for flying.
Hindwing: The lower, rearward wing pair used for flying.
NOTE: Butterflies and Moths are part of the Lepidopteran order as they share many similarities.