1. Monarch Danaus plexippus, male, Prince George's County, Maryland, USA, October 1, 2006. Pausing to sun itself. Note the dark patch of androconia (pheromone-dispensing scales) along the rearmost branch of the cubital vein on the hindwing. These collections of androconia are often called "scent patches". Female Monarchs do not possess scent patches. Nikon D80; Nikkor 70-300mm f4-5.6G AF lens (@300mm); 1/200, f10, ISO 200.

2. Monarch D. plexippus, male, Prince George's County, Maryland, USA, October 1, 2006. Nikon D80; Nikkor 70-300mm f4-5.6G AF lens (@300mm); 1/200, f11, ISO 200.