Scale insect female

Title Info
Common name Scale Insect, Giant
Scientific name Margarodidae
Taxonomic group Homoptera
Level Family
Source Dan L. Perlman
Selection and adaptations Selection
Selection Sexual selection
Behavior Communication; Mating
Organisms Animals
Animals Insects
Location Monteverde,Puntarenas,Costa Rica,North America
Giant scale insect female releasing sex pheromones, Costa Rica
Related materials: Giant Scale Insects
Compare the male and female giant scales for a great example of sexual dimorphism. The image of them mating shows that they are of the same species. Click the Related materials link to see all three images.

Giant scale insect female using pheromones to call a male, Costa Rica. This is an adult female giant scale insect, about 1/4 of an inch long (approximately 6 mm). She is wingless and sedentary, spending most of her adulthood drinking sap from an herbaceous plant using her straw-like sucking mouthparts. Late every afternoon, however, she changes behavior markedly. She raises her abdomen, as seen here, and apparently begins releasing one or more pheromones. Soon after, males begin to appear and mate with the females. Compare her appearance with that of the male; this is an outstanding example of sexual dimorphism and sexual selection. The male is brightly colored, winged, and mobile, and functions as a moving sack of sperm; the female need only stay put, feed, attract mates, and produce large numbers of eggs. Each sex is clearly optimized for its function.