Entomology 311 Lab Manual - 1st Edition, 2019

D. Leaf Search
It is very often that the search and collection of
insects is for use in identifying pest or beneficial
insects in crop systems, in which case methods that
damage the vegetation in any way may not be the
ideal method for sampling. These insects may also be
quite small and easy to damage with a sweep net
sample. With delicate or small plants and insects, a
simple leaf search is an easy way to collect and count
insects, as well as establish plant-insect
relationships and life cycle information. Many plantfeeding
insects lay their eggs directly onto host
plants, where there will be readily-available food
resources for newly hatched larvae or nymphs. For
many species, the eggs are easy to find as well,
especially if the collector is careful to inspect plant
crevices and the soil just beneath host plants (figure
1-4).
Figure 1-4: Leaf searching with forceps or an aspiration is
ideal when observing and sampling delicate species on leafs.
Image source: https://commons.wikimedia.org/wiki/
File:Fred_Coyle_searching_for_spruce-fir_moss_spiders_(8
125776694).jpg
For this technique, gently inspect the upper surface of the leaf, disturbing it as little as possible. Then gently
rotate the leaf at the stem, taking care not to dislodge any insects that may be on the underside of the leaf.
Forceps or an aspiration can be used to collect, or if the insects are very small and fragile, a paint brush can
be used to transfer insects into vials without damaging the specimens.
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