[5][6] Adults can range from 11 to 12 mm in length and have a red/orange and black X-shaped pattern on their wings underneath the triangle that is typical to hemipterans.

Geographic location has a large effect on egg production rate and clutch size, although the intrinsic increase in reproduction depends on to what the individual is acclimated.

[15] A migratory syndrome has been described in the northern population, meaning that traits such as wing length, fecundity, developmental time and flight duration are all genetically correlated.

Groeters and Dingle[16] suggested that selection is specific to the populations environment due to the small correlations between life-history strategies across geographic ranges.

The fact that these insects return to northern environments after migration could be the influence of a genetic predisposition or selected for due to crowding and increased intraspecific competition for resources in the southern areas.

[19] In addition to its plant-based diet, O. fasciatus has been observed feeding on aphids, monarch caterpillar eggs, and larvae, displaying opportunistic behavior.

[citation needed] When given sunflower seeds in a laboratory, this bug obtained 90% of their lipids, 50% of their protein and 20% of their carbohydrates, making it an efficient feeder.

Adults wander during the daytime in search of food since milkweeds live in patches that can vary in size and distance apart from one another.

When a follicle is found, they inject saliva into it through their long rostrums, this pre-digests the seed and allows O. fasciatus to suck it up through their anterior pump and pharynx.

Adults can survive on other types of seeds, such as sunflower, watermelon, almond, and cashew, as shown in lab populations.

[19] During the final instar of development, oil accumulates, perhaps to allow for more efficient absorption of nutrients, aid in osmoregulation or to preserve cleanliness of the habitat.

[22] The phylogenetic placement of O. fasciatus is ideal to use as an outgroup to make comparisons to more derived holometabolous insects, acting as a valuable organism for the study of evolutionary patterns.