Final answer:
The subject of this question is Biology. The American snout butterfly is distinctively identified by its 'snout' and squarish tip of the forewings, along with its dusty orange and brown wing pattern with white spots on the top surface. It is commonly found from Texas to Canada and related species can be seen in the Caribbean.
Step-by-step explanation:
The subject of this question is Biology because it pertains to the identification of a butterfly species, specifically the American snout butterfly (Libytheana carinenta).
The American snout butterfly is distinctively identified by its 'snout' and squarish tip of the forewings, along with its dusty orange and brown wing pattern with white spots on the top surface. It is commonly found from Texas to Canada and related species can be seen in the Caribbean.
The information provided suggests that the butterfly spotted on the bluebonnets in Fort Worth, Texas is indeed an American snout butterfly.