braconid & Ichneumonid wasps
Braconidae and Ichneumonidae
Braconid wasps: commonly Pholetesor ornigis, Macrocentrus linearis (Nees) and Macrocentrus ancylivorus
Ichneumonid wasps: Gambrus and Itoplectis spp.
- Often dark, though some are brightly coloured
- Range in size from 2-15 mm and have long antennae
- Appearance of braconid wasp immature life stages can be variable, though most or all development occurs within a host
- Many braconid wasps leave the host as mature larvae and spin silken cocoons in which to pupate
- A caterpillar surrounded by multiple small cocoons is an obvious sign of parasitism by braconid wasps
- Parasitized aphid “mummies” are light brown and appear somewhat swollen, with a papery consistency
- An exit hole where the new wasp emerged may be present
- P. ornigis (braconid wasp)
- Laid directly into host leafminer larva
- Not observed
- Development occurs within the host, and larva leaves shrunken dead host to pupate
- Larva spins cocoon
- Not usually observed out of host
- The most identifiable lifestage of the parasitoid is the cocoon, which can be found within the mine and appears as a pale tightly woven tube-like structure with a dark band around the middle
- A single new parasitoid is produced per mine
- Small black wasp not normally observed in the vineyard
- Variable in size and colour (5-40 mm)
- Females will lay their eggs on or in the host, which may include both larval and pupal stages of caterpillars
- As with braconid wasps, antennae are long
- The abdomen is often longer than the thorax
- Some species have very long ovipositors
Often Confused With
Parasitic wasps are often difficult to distinguishing between each other. Learn to recognize the signs of parasitism in vineyard pests.
Interaction with Host
Braconid and ichneumonid wasps require a host for development. Adult females will also feed on immature caterpillars.
Braconid wasps attack a wide range of insect groups, including caterpillars, flies, and beetles, though many are specialized. A common species in vineyards is the native P. ornigis, a parasite that develops within its host. Larvae of leafminers are among its hosts.
Period of Activity
Spring through fall.
Monitoring and Management
These parasitoids are sensitive to many broad-spectrum insecticides. Select reduced-risk products when spraying for other pests where options exist.