In teaching the parts of insects to new students, I describe the insect antenna as the “Primary Oflactory Organ”, responsible for the “sense of smell.” However, this view is an oversimplification. Antennae are modified for many purposes including sound detection in mosquito and mating in pond skaters.
Locke Rowe and Colleagues have published in the journal, Science, a study of a pond skater, Rheumatobates rileyi. The antennae of the males are modified for grasping the head of the female during mating. In the photos below, the modifications of the male antennae are quite drastic compared to the antenna shape of the female, which is more similar to antennae of most pond skaters. The male antennae feature a number of spines and hooks to firmly grasp its mate. The picture (below, right) shows the heads of a mating pair of pond skaters. Note that the male antennae are adapted to grasping the head of the female and fit into a groove just above the eyes of the female pond skaters.
The pond skater antenna is another marvelous adaptation that goes beyond the standard odor detection. Male insects of many species commonly use their antennae to detect odors of the female (pheromones) to find their tiny mate in the midst of a complex environment. The use of the antennae to grasp the female during mating itself gives a new meaning to the term “hooking up”.
Left: The Antennae of the Male (left) Are Hooked for Grasping the Female (right) During Mating. The Female Antennae Are Not Modified For Grasping. (False Color Image)
Right: Antennae of the male shown grasping the head of the female.
Images: Locke Rowe