The suborder Symphyta has about 8,200 species, and includes sawflies, horntails and wood wasps. These wasps are plant feeders as larvae, except the parasitic wood wasp (family Orussidae), which lays its eggs in tree trunks and feeds on beetle larvae. Wood wasps are abundant in Southern California. Sawflies, horntails and wood wasps feature a broadly attached abdomen and complex wing veins.
True parasitic wasps are a large group, with 76,000 species. Their main feature is a specialized long ovipositor, which is used to insert eggs into or onto a host without moving it to the nest. Wasps from the family Braconidae lay eggs into caterpillars, are considered important agriculture pest controllers, and thus helpful to humans.
Stinging parasitic wasps or stinging parasitoids number 13,600 species. They use the ovipositor, which is linked to poison glands, to sting their host, which is later moved to the nest. Then, the eggs are laid on the host from another organ, located in the abdomen. The young larvae feed on the carcass as soon as they emerge.
This group includes more than 17,000 species of wasps that hunt other insects for food, but also eat nectar and pollen. These are often solitary wasps, such as the family Pompilidae or spider wasp, and also includes the genuses Anoplius, Bembix and Oxybelius. Most predatory wasps lay a single egg into plant stems or directly into the soil. Male predatory wasps are often smaller than females.