Ticks of various species are among the most important of the pests of animals, not only because of their direct effects as parasites, but also as a result of maladies they carry. Moreover, they are predisposing agents for attacks by important secondary invaders, such as foot-rot and screw-worm flies.

In a general way, the ambushing habits and preying adaptations of Phymatidae are familiar to all entomologists. Yet, as shown by the bionomic summary for this family included by Readio (27) in his paper on the feeding methods and life history of Phymata erosa fasciata (Gray) at Lawrence, Kansas, only a handful of food records have appeared in the literature, and studies of the conditions surrounding the preying process in nature are lacking entirely.

When economic entomology concerns itself in the line of biological control further than the introduction of foreign parasites to offset the inroads of introduced pests and turns for help to our indigenous hordes of balancing agents, as it must do some day, college professors may well direct their students to Papaipema biologies. Here an easy exposition of what holds a large genus to innocuous bounds is amply portrayed and, as hosts to such a retinue which goes still further afield, proclaims them in fact helpful species of our biota.

The great basin tent-caterpillar is the most abundant form of Malacosoma found in the Rocky Mountain region of the United States. In Colorado, the species is often a serious pest of the aspen. It feeds upon a wide variety of deciduous trees and shrubs. In the foothills, Rhus trilobata and Prunus melanocarpa are frequently attacked. Whole aspen groves at higher altitudes are often defoliated by this species. In the mountains, the migrating larvae have occasionally been so numerous as to stop locomotives by greasing the rails with their crushed bodies.

Sympistis kolthoffi Auriv. originally described from Greenland (1890, Anarta kolthoffi Aurivillius, Bihand Till. K. Sv. Vet.-Akad. Handl., XV, 20, pl. 2, fig. 1) as a race of the European S. zetterstedti Staud., and has not been previously recorded from North America. Specimens of kolthoffi from Churchill, Manitoba, agree very favorably with the original description and figure, and appear specifically distinct from specimens of labradoris from the same and other Canadian localities.

Male. Wings with two brown spots in apical portion of subcostal cell. A row of about six short stout bristles on the distal half of the posteroventral surface of mid femora. Prosternum with a few hairs anteriorly and posteriorly, and a few hairs also present on the middle of the propleura in front of the spiracle. Genitalia similar to D. pictipes Loew, except the anterior claspers (see figure), which are bent forward hookwise, narrowly laterally expanded at the apex, and with a thin transparent web in the sinus of the hook.