Insects as a group occupy a middle ground in the biosphere between bac­ at one extreme, amphibians and mammals at the other. teria and viruses of insects present special problems to the The size and general nature study of entomology. For example, many commercially available instru­ ments are geared to measure in grams, while the forces commonly en­ countered in studying insects are in the milligram range. Therefore, tech­ niques developed in the study of insects or in those fields concerned with the control of insect pests are often unique. Methods for measuring things are common to all sciences. Advances sometimes depend more on how something was done than on what was measured; indeed a given field often progresses from one technique to another as new methods are discovered, developed, and modified. Just ofthese techniques find their way into the classroom when as often, some the problems involved have been sufficiently ironed out to permit students to master the manipulations in a few laboratory periods. Many specialized techniques are confined to one specific research lab­ oratory. Although methods may be considered commonplace where they are used, in another context even the simplest procedures may save con­ siderable time. It is the purpose of this series (1) to report new devel­ opments in methodology, (2) to reveal sources of groups who have dealt with and solved particular entomological problems, and (3) to describe experiments which may be applicable for use in biology laboratory courses.

Foreword by: R.L. Metcalf