8 Transactions of the Academy of Science of St. Louis 
Folsom (1933), in discussing the economic importance of 
Collembola, states that there are forty species that are important. 
He says, “The greatest damage by springtails is done to young, 
tender plants, especially seedlings. The springtails make holes 
in leaves gradually piercing leaves completely and characteristic- 
ally leaving the epidermis at the end of the puncture intact. They 
feed also on wounds made by flea beetles, potato beetles, and 
other insects. Many species injure the stems of plants just be- 
low the surface of the ground and cut through them. On the 
roots springtails cause injury by gnawing pits and by destroying 
root hairs and small rootlets.” 
The genital apertures of both sexes are ventral to the fifth 
abdominal segment and the anal opening is ventral to the sixth. 
There is an enlarged somewhat flattened papilla on the male on 
the end of which is a round genital opening. In the female 
the homologous opening is transverse with a posterior and an 
anterior lip. Since this characteristic of the sexes is difficult 
to distinguish and since the sexes are otherwise alike no mention 
is made in descriptions as the sex. 
There are six or seven nymphal instars before the imago 
appears (Davis and Harris 1936; Maclagan 1932). The nymphal 
stages resemble the adult so much externally that little or n° 
mention is made in descriptions of species as to which stage 
is used. 
ORDER (Collembola) Lubbock, 1870 
The species belonging to this order are without a noticeable 
metamorphosis. At no stage are wings present. The abdomen 
has three appendages; the ventral tube on the ventral side of 
the first abdominal segment, a tenaculum on the ventral side 
of the third segment, and the springing organ, the furcula, at 
the end of the fourth or fifth. The proximal part of the furcula 
is known as the manubrium, the distal half as the dentes and 
the tip of the dentes as the mucro. The legs are composed of 
