What are Eriophyids?
Eriophyids (from Greek: ery-o- + phrygia = hair) are small parasitic wasps which feed on plants. They are not insects, but rather they belong to another group of arthropods called Hemiptera. There are several species of these parasites which include the common garden wasp, the European corn borer, and the cottony cushion scale. All these wereps have one thing in common – they parasitize plant cells where they lay their eggs. These eggs hatch into larvae, which feed on the host plant until it dies or the larva pupates out. When the adult wasp emerges from its cocoon, it feeds on other hosts.
The term “eriophile” comes from the Latin word eros meaning love and philere meaning flesh. Eriophyes is a ery- prefix that means “to wear away” or “to eat.” The eriophyid mites are known as the most damaging group of mites that attack a wide range of plants such as roses, grasses, fruit trees, beans, and many more.
Eriophyes was first reported by Carl Peter Thunberg in the year 1784. It causes damage on several crops and is found in practically every continent in the world. The most damaging eriophyid mite species are Eriophyes insularis, E.
pomi, and E. bilobeatae.
Eriophyid mites are a threat not only to plants but also to humans as they can cause allergies and affect human health directly. Some eriophyid mites can be used as a method of biological pest control in agriculture. Eriophyes tassei, for example, is a beneficial species in biological control.
The eriophyoid mites are more sensitive to cold than many other types of mites. They have a hard time not only surviving the cold but also tolerating it.
Eriophyid Mite Infestations
Eriophyid mites live and feed on plant tissue. They can cause considerable damage to the area infested with them. The life cycle of these mites is very similar to that of insects.
The females are larger than the males and much more noticeable as they are the ones that suck the sap from plants. The adults measure anywhere between 0.3 to 1.0 millimeters in length. The average eriophyid mites found on plants are usually orange, red, pink or yellow in color with a spherical shaped body. The reproductive habits of eriophyid mites are very similar to those of spiders and ticks. The male eriophyid mite has no digestive system and dies soon after mating. Females have a spherical shaped body and are immobile for most of their life. They can only be found feeding on plants and plant tissues. It is very rare, however, to find a female that is not attached to a leaf or some other plant part.
Eriophyid mites feed on the plant’s nutrients. They suck the sap from plant cells, injecting enzymes to break down cell walls so they can suck up the contents. The infested leaves of plants may wilt and turn yellow or even brown, while the eriophyid mites themselves may become covered in a white fluffy wax.
The fluffy wax is a mixture of the plant sap and their own feces. It is secreted by tiny wax glands in the skin of the mite.
Eriophyid mites are most active during the warmer months of the year. The adult mites will feed and mate on leaves and other parts of plants. The females will lay their eggs either on the underside of leaves or in the branches of plants.
The eggs are small, white and almost invisible to the naked eye.
Sources & references used in this article:
An Illustrated Guide to Plant Abnormalities Casued by Eriophyid Mites in North America by HH Keifer – 1982 – books.google.com
Effectiveness of eriophyid mites for biological control of weedy plants and challenges for future research by L Smith, E De Lillo, JW Amrine – Experimental and Applied Acarology, 2010 – Springer
The Dispersal of Aceria tulipae and Three Other Grass-Infesting Eriophyid Mites in Ohio by LR Nault, WE Styer – Annals of the Entomological Society of …, 1969 – academic.oup.com
Climbing of leaf trichomes by eriophyid mites impedes their location by predators by K Michalska – Journal of Insect Behavior, 2003 – Springer
Behavioural responses to potential dispersal cues in two economically important species of cereal-feeding eriophyid mites by A Kiedrowicz, L Kuczyński, M Lewandowski… – Scientific reports, 2017 – nature.com