Read: more details in Agricultural Research.

Mites—New Technology Aids Identification

The 200-year-old study of mites--the science called acarology--is being transformed.

Agricultural Research Service experts on mites are using state-of-the-art technology to study these microscopic insects. Recently, ARS scientists from the Systematic Entomology Laboratory, working with colleagues at the Nematology Laboratory--both at the Henry A. Wallace Beltsville (Md.) Agricultural Research Center--applied newly developed technology, called low- temperature-scanning electron microscopy (LT-SEM), to study mites.

Because of their small size--some no bigger than the point of a needle--mites are difficult to study biologically. They have many sensory organs, mouth parts and other body parts so complex that systematists have difficulty comparing those of closely related species.

Unlike conventional microscopes, LT-SEM images of a specimen are formed and magnified by electrons passing through a magnetic field that functions as a lens. The images can be displayed, and thus recorded, on a cathode ray tube similar to a TV screen.

The LT-SEM was used to obtain, for the first time, clear, three-dimensional images magnified more than 50,000 times. These reveal delicate structural forms and intricate details of intact mites and how they interact with and attack plant and insect hosts. Such information helps scientists to better understand mites' behavior and how different parts of their body structure actually function. It is also used to name and classify them.

Often, a lack of detailed information about mites' correct identity, biology and ecology causes serious consequences to U.S. agriculture. More than 6,000 mite species infest nearly every agronomic and horticultural plant important to agriculture. They cause annual economic losses estimated in the billions of dollars from decreased food, fiber and ornamental production.

For more details, see the October issue of Agricultural Research.

ARS is the chief research agency of the U.S. Department of Agriculture.

Scientific contact: Ronald Ochoa, ARS Systematic Entomology Laboratory, Beltsville, Md., phone (301) 504-7890, fax (301) 504-6482, rochoa@sel.barc.usda.gov.