1. Catch a Monarch in a butterfly net. It's easiest to target the stationary, nectaring ones. Record which type of plant the Monarch was caught on.
2. Determine the gender of the Monarch. The abdomen of the male terminates in a pair of claspers (cerci) that the female lacks. The hind wings of the male also contain two raises spots called the androconial patches that store and release hormones. In additional, the veins in the hind wings of the male are thinner and less pronounced than in the female's hind wings.
|Female on left; Male on right|