Simon and Schuster's Guide to Insects

Chapter 1 1 ORCHESELLA CINCTASlender Sphagnum SpringtailFamilyEntomobryidaeOrderCollembolaLength 1.8 mm.Recognition marksPale yellow to blackish purple; antennae are 6-segmented. This group is very distinctive because of the large fourth abdominal segment, at least twice the length of the third segment as seen from dorsal view.HabitatFound on sphagnum moss growing in woodland pools.DistributionThis species belongs to a family of 138 species in northeastern United States and Canada.NoteSpringtails are among the most abundant of insects, yet they are very seldom seen by nonprofessional collectors. Nearly any moist soil sample will yield hundreds of individuals. If you watch the activity going on in a bowl containing wood's moss, you will see these creatures plying their way through the vegetation. Springtails undoubtedly are a main food source for many small beetle larvae and for centipedes. Very few details are known about their lives. It is known that the males place spermatophores in strategic positions on the soil so that the females will encounter them. She engulfs these gelatinous masses into her reproductive tract where the sperm are released and fertilize her eggs.2 ACERELLA BARBERISoil ProturanFamilyAcerentomidaeOrderProturaLength 1.8 mm.Recognition marksBody white; front pair of legs projected forward and used as sense organs rather than for locomotion.HabitatSoil; these insects are seldom seen.DistributionPoorly known, probably throughout eastern North America.NoteThese primitive insects need further study. Some authorities do not consider them to be insects but a separate group by themselves. They show some relationship to the springtails. Spiracles and Malpighian tubules (excretory organs), both characteristic of insects, are absent in this and similar species of the order. In addition, unlike "true" insects, they add abdominal segments during each molt. Other insects have a complete complement of segments upon hatching.3 THERMOBIA DOMESTICASilverfishFamilyLepismatidaeOrderThysanuraLength 12 mm.Recognition marksUniformly slate gray; body is covered with scales; eyes are small with separate elements.HabitatWarm, humid places, including home, but also in the wild in southern Florida and in other tropical regions.DistributionCosmopolitan.NoteThis species is often a pest in homes and libraries. It feeds on starchy materials, such as glue, but requires high humidity. It can be reared in glass jars where it will feed on oatmeal and other starchy foods. Potatoes will provide the necessary water. Do not let it mold or let the jar get too dry. Other species of this poorly known order can be captured in the wild. They are found in leaf litter and among rocks and in debris along the shore. These insects are considered to be very primitive, perhaps the most primitive of living forms. The appendages on the ventral surface of the abdomen are one indication of this even though these are not functional locomotive appendages. Silverfish might well be considered living fossils; they are much older than the dinosaurs.4 HOLJAPYX DIVERSIUNGUSSlender DipluranFamilyJapygidaeOrderDipluraLength8-10 mm.Recognition marksElongate; pale tan, with central portion of each abdominal segment darker, apical segment dark brown, with a pair of stout forceps.HabitatSoil-inhabiting species.DistributionWidespread, but local, spotty distribution.NoteAlthough all of these primitive wingless insects are rather small and devoid of attractive colors, they are worthy of study if for nothing more than the fact that so little is known about them. The wingless primitive insect pictured at the introduArnett, Ross H. is the author of 'Simon and Schuster's Guide to Insects', published 1981 under ISBN 9780671250140 and ISBN 0671250140.