Aphid killer wasps, Aphelinus abdominalis are tiny parasitic wasps that have been used as an excellent biological control agent in controlling various species of aphids that cause a serious damage to many economically important crops grown in the greenhouses, fields, organic vegetable gardens and orchards. These small parasitic wasps are naturally found in North America and also commercially available.
- - Aphid killer wasps, Aphelinus abdominalis are effective against following species of aphids
- Alfalfa aphid, Acyrthosiphon pisum
- Bird cherry-oat aphid, Rhopalosiphum padi
- California Laurel aphid, Euthoracaphis umbellulariae
- Cereal aphid, Sitobion avenae
- Cotton aphid, Aphis gossypii
- Green peach aphid, Myzus persicae
- Melon aphid, Aphis gossypii
- Potato aphid, Macrosiphum euphorbiae
- + Key factors for aphid killer wasp, Aphelinus abdominalis effectiveness
Aphelinus abdominalis wasps are tiny natural parasites of aphids.
- Adults of aphid killer wasp, Aphelinus abdominalis are attracted to the colonies of aphids by responding to alarm signals produced by plants that infested with aphids and smell of honeydews secreted by aphids on the infested plants.
Aphelinus abdominalis larvae are parasitic in nature feed on the body content of aphids whereas their adults feed only on honeydews secreted by aphids.
Aphelinus abdominalis wasps perform better against aphids when aphid population is at very low level in the garden.
- The preventive applications of Aphelinus abdominalis will prevent out-break of certain species of aphids.
- The adult of aphid killer Aphelinus abdominalis wasps are generally attracted and stuck to yellow sticky traps and get killed before they can parasitize aphids by laying eggs in aphid body. Therefore, before releasing wasps, remove all the yellow sticky traps that are used for whitefly control in your gardens, greenhouse, fields and orchards.
- If ants are present on aphid infested plants in your garden or greenhouse, control them first before releasing Aphelinus abdominalis 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.
Aphelinus abdominalis wasps perform better against aphids when temperatures are between70 and 77°F and relative humidity between 60 and 80%.
- + How Aphelinus abdominalis are applied in the greenhouses or fields
Aphelinus abdominalis are generally shipped as ready-to-emerge mummies (containing wasp pupae) 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, try to release adult wasps that are already emerged from mummies by opening vials and walking slowly in the garden. Adult wasps should escape themselves from the vials. Then randomly place the un-hatched mammies in shaded areas in the garden.
- As a curative measure, aphid mummies or hatched 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 Aphelinus abdominalis wasps work in the greenhouses or fields
Aphelinus abdominalis are generally shipped as ready-to-emerge mummies (see below).
- When aphid mummies (containing wasp pupae) are applied in the vegetable gardens, greenhouses or fields, adult wasps immediately start emerging from aphid mummies (sometime in the package you may see some already emerged wasp adults).
- Emerged adults of Aphelinus abdominalis will be attracted to colonies of aphids by responding to alarm signals produced by plants infested with aphids and smell of honeydews secreted by aphids on the infested plants.
- When adult wasps come across to colonies of aphids, they will select a suitable size aphid using their antennae to lays in aphid body.
- Once an appropriate size aphid is found, adult wasp turn around and extend and insert its ovipositor tip into the abdomen (ventral side) of aphid and then lay eggs.
- Wasp eggs hatch within the aphid body and hatched young larvae start feeding on the body content of aphid and complete its development within the aphid body.
- The parasitized aphids will survive, reproduce and feed on plant tissue for a while but eventually they will die when the larvae of Aphelinus abdominalis wasp mature and pupate.
- The dead aphids then turn into “mummies” (which are commercially sold to use as biological control of aphids).
- After 14- 15 days, adult wasps will start emerging from mummies and life cycle continues.
Aphelinus abdominalis wasps perform better against aphids when temperatures are between 70°F and 77°F and relative humidity between 60 and 80%.
- + Why you need them
- they can reduce the crop damage by parasitizing and killing various species of aphids, which are responsible for the damage
- they can parasitize and kill all different stages of their aphid hosts
- they are able to actively search for their aphid hosts and parasitize 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 damage plants
- can be used and applied around children and pets
- 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
- Azzouz, H., Cherqui, A., Campan, E.D.M., Rahbe, Y., Duport, G., Jouanin, L., Kaiser, L. and Giordanengo, P. 2005. Effects of plant protease inhibitors, oryzacystatin I and soybean Bowman-Birk inhibitor, on the aphid Macrosiphum euphorbiae (Homoptera, Aphididae) and its parasitoid Aphelinus abdominalis (Hymenoptera, Aphelinidae). Journal of Insect Physiology 51: 75-86.
- Couty, A., Clark, S.J. and Poppy, G.M. 2001. Are fecundity and longevity of female Aphelinus abdominalis affected by development in GNA-dosed Macrosiphum euphorbiae? Physiological Entomology 26: 287-293.
- Gillespie, D.R., Nasreen, A. Moffat, C.E., Clarke, P. and Roitberg, B.D. 2012. Effects of simulated heat waves on an experimental community of pepper plants, green peach aphids and two parasitoid species. OIKOS 121: 149-159.
- Holst, N. and Ruggle, P. 1997. A physiologically based model of pest-natural enemy interactions. Experimental and Applied Acarology 21: 325-341.
- Honek, A., Jarosik, V., Lapchin, L. and Rabasse, J.M. 1998. Host choice and offspring sex allocation in the aphid parasitoid Aphelinus abdominalis(Hymenoptera : Aphelinidae). Journal of Agricultural Entomology 15: 209-221.
- Le Ralec, A., Curty, C. and Wajnberg, E. 2005. Inter-specific variation in the reactive distance of different aphid-parasitoid associations: analysis from automatic tracking of the walking path. Applied Entomology and Zoology 40: 413-420.
- Molck, G. and Wyss, U. 2001. The effect of experience on the parasitization efficiency of the aphid antagonist Aphelinus abdominalis in greenhouse crops. Zeitschrift Fur Pflanzenkrankheiten und Pflanzenschutz-Journal of Plant Diseases and Protection 108: 616-625.
- Molck, G., Pinn, H. and Wyss, U. 2000. Manipulation of plant odour preference by learning in the aphid parasitoid Aphelinus abdominalis (Hymenoptera : Aphelinidae). European Journal of Entomology 97: 533-538.
- Pons, X., Lumbierres, B., Antoni, R. and Stary, P. 2011. Parasitoid complex of alfalfa aphids in an IPM intensive crop system in northern Catalonia. Journal of Pest Science 84: 437-445.