Amino acids, the main constituents of protein, are needed by animals for the synthesis of the new body tissue during growth and for the regeneration of old tissues in the adult. They take part in the formation of almost all substances in the body and perform an important function in many physiological processes. When these acids are not available to the animal in sufficient quantities, characteristic metabolic disturbances and pathological conditions result. Amino acids have a similar role in insect physiology and hence have an important bearing upon problems related to insect pathology, toxicology and ecology. Unfortunately, however, very few attempts have been made to investigate the importance of amino acids in the diet of insects.

During a study of the species of Tubifera known to occur in Maine the author noted that certain specific key characters were not always constant, and often a long series of several species was required before identification was certain. In search of taxonomic characters to supplement those given in literature the author extracted and compared the male hypopygia of several known species of Tubifera. It soon became apparent that this structure deserved more emphasis in the taxonomy of this interesting genus.

One of the few Canadian entomologists to study thrips was R. C. Treherne who was one of the group of workers to investigate the pear thrips when it first became an economic pest in North America. In the course of his work he collected and studied thysanoptera. His collection, supplemented by exchanges with other workers, formed the basis for the material now in the Canadian National Collection at Ottawa. The writer is indebted to curators of this collection and particularly T. N. Freeman, for the generous loan of valuable specimens for study, particularly the types of Treherne. The Moulton collection is now deposited at the San Francisco Academy of Science, Golden Gate Park, San Francisco, California. We also wish to thank Dr. E. S. Ross, curator, for the opportunity of studying the types of Taeniothrips tahoei Moulton, Tae. pingreei Moulton, Tae. aureus Moulton, and Frankliniella californica Moulton.

The taxonomic status of Ephemerella excrucians Walsh was recently discussed by Burks (1947), who also stated that destructive ecological changes have drastically altered the type locality of the species. Special interest attaches, therefore, to two male specimens of Ephemerella which I reared from nymphs taken in the Au Sable River, Crawford County, Michigan, and which Dr. Burks has determined as E. excrucians.