Beating sheets and cards.Non-flying and slower-moving insects, particularly those the feign death are easily-collected using some type of beat sheet or card (also see Beat bucket). In their simplest forms, beat sheets can be a bed sheet laid under a plant so that when the plant is beaten with a stick or by hand, dislodged insects fall on the sheet so they can be easily seen. Similarly an inverted umbrella can be used to collect dislodged insects. As a population level monitoring tools, the number of specific arthropods can be counted for each sample taken. When repeated over space or time relative differences in population levels can be documented.
Beating cards.Collecting and monitoring tiny insects on plants is easy using an off-white card such as a yellow paper pad. Held underneath foliage or flowers while
beating the plant parts, aphids, spider mites, scale insect crawlers and thrips will be dislodged and land on the paper where they can easily be seen and collected with an alcohol-soaked cotton swab (Q-Tip®) and put in a vial of alcohol. Note: Wear a glove when beating plants with spiny leaves.
Drop cloths and beat sheets. In row crops like soybean fields, insects that do not fly or quickly run away (e.g., caterpillars, true bugs, many beetles) can be collected and monitored by placing a piece of cloth, generally 3 ft wide, between the rows of plants (see design). Sticks or rods affixed to the ends of the cloth allow the cloth to be rolled up for transport and storage. The plants are then beaten to dislodge insects so that they land on the cloth where they can be collected by hand-picking, a jar or using an aspirator.
In broadcast-planted soybeans or vegetation where there are no open spaces, a vertical beat sheet has been designed to be used as a collection and monitoring tool (see design from Drees, B. M. and M. E. Rice. 1985. The vertical beat sheet: a new device for sampling soybean insects. J. Econ. Entomol. 78(6): 1507-1510). This device allows insects collected to be “poured” into a sack or bag for freezing and procession later.
For collecting insects in trees and bushes, a beating sheet can be made using flexible support rods (bamboo is an ideal material) that fit into pockets made at each corner of a share cloth (see design). The cloth can then be held by the center of the “X” of the rods while a stout rod or bat is used to beat branches about the suspended cloth to dislodge arthropods. This is the tool of choice for collecting insects like long-horned beetles, walking sticks, tree crickets and tree or nut-feeding weevils.
Some researchers and as depicted in early scenes of the movie, “Arachnophobia”, a sheet has been placed underneath trees that were then fumigated with a quick knock-down insecticide like sprays containing pyrethrins. Dying insects fall out of the trees and can be collected from the cloth. This technique is an effective way to quickly document insect diversity in hard-to-reach places like rain forest canopies.