Important and Selected Orders of Forest 
Insects 
The major section of this book. which follows, discusses the most important 
insects affecting forest and shade trees, shrubs, and wood products. The discussion 
includes brief descriptions of the insects and their habits, primary hosts, economic 
impact on forests, and possible control measures. Also included are a number of 
other insects that are abundant in the forest but usually are not thought of as forest 
insects. Given the ever-increasing use of forested areas for recreational purposes 
and the growing public concern about our wildlife resources, it seems appropriate 
to include such insects and describe their importance as pests of humans or other 
forms of animal life. 
Order Thysanura—Bristletails 
Bristletails occur abundantly in the forest in rotting wood and debris, under 
stones, and among fallen leaves, but none is injurious. They are distinguished by 
the stylelike appendages on some of the abdominal segments, by the two or three 
taillike appendages at their posterior ends, and usually by their elongate bodies. 
Order Collembola—Springtails 
Springtails are very small, primitive, wingless insects. The body is covered by a 
soft exoskeleton and there is a single pair of antennae, each normally consisting of 
four segments. The mouth is located ventrally, and the mandibles and maxillae are 
either toothed for chewing or styliform for sucking. There are three pairs of legs, 
each typically terminating in one or two claws. The first abdominal segment bears a 
ventral tube or collophore; there is a pair of small appendages fused basally on the 
venter of the third segment; and a furcula is appended to the ventral surface of the 
fourth. The latter operates as a spring and 1s capable of propelling the insect into the 
air as much as 10 cm (835). 
Springtails are widely distributed and are among the most abundant of insects. 
They are found in all kinds of places—many unexpected, such as on the surface of 
snow and on the surface of water. In the forest they are found in moist soil, among 
dead leaves. in dead and decaying logs, under loose bark, and in bark crevices of 
living trees. The majority feed on algae, fungi, and lichens and other living or dead 
plant matter. Pollen from conifers is favored by some species in the spring. Some 
may be attracted in large numbers to decaying fruit and animal matter. Others may 
be attracted to sap flowing from trees in the spring. 
Springtails tend to be beneficial in the forest because they help to reduce litter 
and form humus. Keys to Collembola occurring in eastern North America are 
available (88, 429, 535, 862, 1359). 
Order Ephemeroptera—Mayflies 
Mayflies are frail, delicate insects with medium-size soft bodies that end in three 
long threadlike tails, or caudal setae. The wings are membranous and many-veined 
and are held upright while at rest. The front pair is large and triangular: the hind 
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