Insect Connect
Insect Connect
Insect Connect
University of California
Insect Connect

What is a natural enemy?

Natural enemies are insects that eat other organisms that we consider pests. They can be divided into two categories:

Natural enemies are grouped into two types based on their life cycle:

1) predators

2) parasitoids

Predators consume their prey (just like other animal predators). This board group includes some well known members like lady beetles (lady bugs) as well as some lesser known insects such as lacewings. 

Lacewing larvae are predators.

Parasitoids are like parasites because the feed off a host, but, unlike parasites, parasitoids kill their hosts. Many, many insects have parasitoids that attack them. The attackers are either parasitoid wasps or tachinid flies. They deposit their eggs near, on, or actually inside their hosts. The larvae hatch and feed on the host, either inside or attached on the outside) until they are ready to pupate.

Parasitoid wasp

In a home or school garden, the parasitoids you are most likely to interact with are aphid parasitoids. These are tiny wasps (don’t worry, they can’t sting you!) that lay their eggs inside of aphids. The larvae eat the aphid from the inside out, then for a cocoon in the shell of the aphid. As this stage the aphid appears hard and is a different color from a healthy aphid; this is called a mummy.

A live aphid (left) and an aphid with a parasitoid living in it (right)

The adult wasp emerges from the aphid mummy to continue the cycle.

See our insect pages for more information about predators and specific parasitoids!

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