Parasitic wasps Aphidius colemani and Aphidius ervi for aphid control

Control of a wide range of aphids with simultaneous release of Aphidius colemani and Aphidius ervi wasps- Bugsforgrowers

Aphid endoparasitic wasps including Aphidius colemani and Aphidius ervi are 2-3 mm and 4-5 mm long and slender bodied beneficial insects, respectively. Adults/mummies of these two endoparasitic aphid wasps are commercially sold together and have been used to target their different species specific host aphids that occur as a mixed population and cause a serious damage to many economically important crops grown in the greenhouses, fields, organic vegetable gardens and orchards.

Parasitic wasp Aphidius colemani specifically control following aphid species

• Cotton aphid, Aphis gossypii
• Green peach aphid, Myzus persicae
• Melon aphid, Aphis gossypii

Aphid wasp Aphidius ervi specifically control following aphid species

• Glasshouse potato aphid, Aulacorthum solani (Host crops: Potatoes, sweet pepper etc)
• Green peach aphid, Myzus persicae (Host crops: Potatoes, sweet pepper etc)
• Pea aphid, Acyrthosiphon pisum (Host crops: Alfalfa, Clover, peas)
• Potato aphid, Macrosiphum euphorbiae (Host crops: 200 different plants including potatoes)

Key factors for effectiveness of Aphidius colemani and Aphidius ervi wasps

• For effective control of aphids, release 2-5 adults of both endoparasitc aphid wasps (Aphidius colemani and Aphidius ervi) per 10 square feet of aphid infested area.
• Both endoparasitic aphid wasps including Aphidius colemani and Aphidius ervi adults are very active searchers of their aphid hosts even at very low population densities.
• Both Aphidius colemani and Aphidius ervi use volatile chemical cues released from host-aphid-damaged plants to located colonies of host aphids.
• Once Aphidius colemani and Aphidius ervi wasps find their specific host aphid colony (Fig. 1), they use both visual and olfactory cues to find an appropriate size aphid to lay eggs.
• When females of both Aphidius colemani and Aphidius ervi wasps find an appropriate size aphid, they use their ovipositors to lay a single egg inside the aphid host.
• Then eggs hatch inside the aphid and the hatched larvae start feeding and developing into pupae and then into adult.
• This parasitized aphid then bloat, dies and its body becomes crispy that referred to as mummy (Fig. 1.), which is typically golden to brown or black in color.
• After 14- 15 days, adult wasps will start emerging from mummies and life cycle continues.
• If ants are present on aphid infested plants in your garden or greenhouse, control them first before releasing both Aphidius colemani and Aphidius ervi wasps as ants will defend aphids from predators and parasites to protect their honeydew food. If ants are not controlled, effectiveness of wasps as a parasite will be reduced.
• Both Aphidius colemani and Aphidius ervi wasps performs better against aphids when aphid population is at very low level in the garden.
• As adult both Aphidius colemani and Aphidius ervi wasps are generally attracted to yellow sticky traps and get killed before they can parasitize aphids by laying eggs in aphid body, remove all the yellow sticky traps used for whitefly control before releasing wasps in your gardens, greenhouse, fields and orchards.
• The preventive applications of both Aphidius colemani and Aphidius ervi together will prevent out-break of certain species of aphids.

How Aphidius colemani and Aphidius ervi are applied in the greenhouses or fields

• Both Aphidius colemani and Aphidius ervi are generally shipped as mixture of ready-to-use adults in small vials.
• When package is arrived and you are not ready to release wasps in your garden, store packages in a cool place and avoid direct exposure to sunlight.
• It is always better to release these wasps in the field within 15-20 hours of their arrival or storage.
• As a preventive measure, release adult wasps by opening vials and walking slowly in the garden. Adult wasps should escape themselves from the vials.
• As a curative measure, wasp adults should be released directly in the colonies of aphids or in the heavily infested areas with aphids in the vegetable gardens, greenhouses or fields.
• Under favorable environmental conditions and if there is enough food around, these parasites may recycle continuously and help to keep the aphid population under economic threshold level.

How Aphidius colemani and Aphidius ervi wasps work in the greenhouses or fields

• Both Aphidius colemani and Aphidius ervi are generally shipped as a mixture of ready-to-use adults in vials.
• When a mixture of Aphidius colemani and Aphidius ervi wasp adults are applied in the vegetable gardens, greenhouses or fields, they will be attracted to their specific aphid host colonies by responding to the smell of honeydews secreted by aphids on the infested plants or to the volatile chemicals from aphid damaged plants.
• When adult wasps come across to colonies of aphids, they will select a suitable size aphid using their antennae and vision to lays in aphid body.
• Once an appropriate size aphid is found, adult wasp using its ovipositor lay eggs inside aphid body.
• Wasp eggs hatch within the aphid body and hatched young larvae start feeding on the body content of aphid, complete its development and pupate within the aphid body.
• The parasitized dead aphids will then turn into crispy, gold to brown or black colored mummies (Fig.1).
• After 14- 15 days, adult wasps will start emerging from mummies, life cycle will continue and they will continue to suppress the population of host aphids that are responsible for causing economic damage to many crops grown in your gardens or fields.

Why you need a mixture of two endoparasitic wasps including Aphidius colemani and Aphidius ervi

• they can reduce the crop damage by parasitizing and killing a mixed population of a variety of host species of aphids that are responsible for the crop damage
• they can parasitize and kill all different stages of their specific aphid hosts
• they are able to actively search for their aphid hosts, parasitize and kill them
• they can reproduce and continue their life cycle on aphids in your garden after first application
• they are commercially available and easy to apply in the greenhouses or fields

Why parasitic wasps are safer than traditional pesticides

• they do not cause damage to plants
• they can be used and applied around children and pets
• they do not cause any harm to the personnel involved in their production and application
• food products are safe to handle and eat when they are treated with wasps
• they do not harm humans, animals and pollute the environment

Research Papers

1. Battaglia, D., Poppy, G.M., Powell, W., Romano, A., Tranfaglia, A. and Pennacchio, F. 2000. Physical and chemical cues influencing the ovipositional behaviour of Aphidius ervi. Entomologia Experimentalis et Applicata, 94, 219–227.
2. Van Driesche, R. G., Lyon, S., Sanderson, J. P., Bennett, K. C., Stanek, E. J., III and Zhang, R.T. 2008. Greenhouse trials of Aphidius colemani (Hymenoptera: Braconidae) banker plants for control of aphids (Hemiptera: Aphididae) in greenhouse spring floral crops. Florida Entomologist 91: 583-591.