Male Nisquallia exhibit mate-guarding behavior, in which a male clings to the female, even when mating is not going on. While mate guarding, males actively rock from side to side, and hold their hind legs up. In general, mate guarding in many species is thought to represent a competition between males and females. Males have better reproductive success if they can prevent a female they’ve mated with from mating with other males. Females, on the other hand, have better reproductive success if they mate with many males.

While photographing the mate-guarding pair in slides 5, 6 and 7 (cropped closeup), we accidentally documented a Chalcid wasp, Brachymeria tegularis, landing on the female. This species is a hyperparasitoid. It lays eggs on grasshoppers. The egg hatches and the larva burrows into the grasshopper, eventually attacking parasitic (or parasitoid) fly larvae already inside the grasshopper body. (Thanks to bugguide.net for the wasp ID.)

In slide 8, two males are grasping a female. Neither of the males appears to be actually mating. This behavior may be more common among flightless grasshoppers, where males have a more limited chance to find an unguarded female.

Several times, we observed males, while mate guarding, leaning over as if to reach their antennae toward the female’s face. In 2011, I captured the behavor on video. The video also shows the rocking behavior (slide 9).