Hosts or Prey
Eggs of leaf beetles, true bugs, weevils, and certain other insects
Identification
Mymaridae are commonly called fairyflies because of their tiny size. Their presence can sometimes be recognized by a color change (e.g., darkening) they may cause in a parasitized host egg. When the adult Anaphes wasp emerges it leaves a round hole in the host egg and tiny dark fecal pellets (meconium) can be visible inside the egg shell. When the insect species that laid the egg emerges because it was not parasitized, the hole is usually ragged and the egg shell is left empty.
Adult Anaphes are blackish wasps about 1/32 inch (0.8 mm) long. The clear wings are relatively long and fringed with fine hairs that allow adults to float long distances with the wind.
Eggs, larvae, and pupae occur hidden within eggs of hosts. Eggs and first instars are about 1/100 inch (0.25 mm) long. The pale eggs are ovoid with a distinct tail (pedicel).
The head of the first instar is broad and conical and ends with a sharp hook so overall the head is beaklike. The abdomen and thorax are elongate and have about six segments.
Late instars are plump with a short projection on both ends. The last instar and pupa are about 1/32 inch (0.8 mm) long. The red coloration of the eyes and ocelli (light receptors on top the head) can be apparent in pupae and visible through the surface of the host egg and plant in which the egg is embedded.
Life Cycle
Anaphes species develop through four life stages: egg, larva, pupa, and adult. After hatching from an egg, the larvae develop through increasingly larger instars while feeding on the host egg's contents. The last instar pupates inside the host then emerges as an adult wasp.
The adult female searches for suitable host eggs in which to deposit her eggs. Unmated females produce only male progeny. Mated females can produce both females and males. Each female parasitizes about 2 to 4 dozen host eggs during her life span of 1 to 2 weeks.
Egg to adult development requires about 10 days when temperatures are warm. Anaphes species have several generations per year.
Habitat
Anaphes can occur in field, tree, and vine crops and in gardens, landscapes, and wildlands wherever eggs of their host insects occur. The most common hosts are eggs of leaf beetles or weevils. Some Anaphes species parasitize eggs of true bugs (Heteroptera), sawflies, or other insects.
To improve biological control
- Control ants because they attack natural enemies of various pests.
- Grow flowering insectary plants to provide nectar to nourish adult natural enemies.
- Reduce dustiness that disrupts the activities of natural enemies (e.g., periodically hose off small plants or irrigate overhead).
- Avoid the application of broad-spectrum, persistent insecticides for all pests because they are toxic to natural enemies.
For more information see Protecting Natural Enemies and Pollinators and the table of relative toxicities of insecticides and miticides to natural enemies and honey bees for specific crops.
Species
Various Anaphes species have been introduced around the world to provide biological pest control. About 250 species are known and all are parasitoids of insect eggs. At least 10 Anaphes species occur in California: A. brevis (=A. brunnea =A. brunneus), A. confertus (=A. conferta), A. conotracheli, A. fuscipennis, A. gerrisophaga, A. iole, A. longiclava, A. luna, A. nitens, and A. sinipennis. Each parasitizes eggs of multiple species. For example, A. iole parasitizes eggs of at least 19 species, mostly true bugs.
More Information
- Catalog of Hymenoptera in America North of Mexico. Vol. 1: Symphyta and Apocrita (Parasitica), U.S. Department of Agriculture
- Introduced Parasitoids and Predators of Arthropod Pests and Weeds: A World Review, U.S. Department of Agriculture
- Preimaginal Development of Anaphes n. sp. (Hymenoptera: Mymaridae), an Egg Parasitoid of the Carrot Weevil (Coleoptera: Curculionidae), Biological Control
- Review of Anaphes Haliday (Hymenoptera: Mymaridae) with Key to Species in Europe and a World Catalogue, Zootaxa
- Universal Chalcidoidea Database, Natural History Museum of London
Scientific classification:
- Phylum: Arthropoda
- Class: Insecta
- Order: Hymenoptera
- Family: Mymaridae
