CONTRIBUTION TO A MONOGRAPH OF THE INSECTS OF THE ORDER THYSANOPTERA INHABITING NORTH AMERICA. By Warren Elmer Hinds, Of the Massachusetts Agricultural College. INTRODUCTION. Very little attention has been given to the Thysanoptera of North America. So far as I can learn, descriptions or names of only twenty- three species have thus far (June, 1902) been published, besides three which have been recognized as previously descril)ed from Europe. Of the twenty-six species thus known in this country, four at least are certainly unrecognizable (Z;;y.r>^^y^>s' ^f/vY/c/ Packard, rhla'othrips mali Fitch, P. caryai Fitch, 7y//v> phylloxera Riley). Of the remaining twenty-two, six have been found identical with previously described species and therefore become synonyms—the large number is not surprising as many of the early descriptions are entirelv too brief to insure positive identification. Therefore only sixteen "species have hitherto been known to occur in this country. We may say that almost no systematic work has been done on the order ii/the United States, and, with the exception of a study of the '^Thripidse of Iowa," by Miss Alice M. Beach, most of the descriptions are scattered through different publications. I have endeavored to collect and present here such important facts as have already been published relating to members of this order, together with' the observations which I have been able to make. An attempt has ])een made to place the work upon a systematic basis, and in order to make the descrip- tions uniform, and thus comparative, all the existing types that it has been possible for me to see have been examined and redescribed. In all, thirty-seven species are thus treated in the systematic part of this paper. Other descriptions which it has not been possible for me to place are given together by themselves in the hope that some one more fortunate or skillful than myself may have material by which to identify them. Proceedings U. S. National Museum, Vol. XXVI—No. 1310. 79 NATIONAL MUSEUM. vol. xxvi. 80 PROCEEDINGS OF THE species which I "Xliere are given herein descriptions of eighteen f having been collected at believe to be'' new, all but two of them of the Massa- Amherst, Massachusetts, and within a radms of 2 miles field has not yet been chusetts Agricultural College, but even this obtained withm thoroughlv collected. The abundance of new species has been done upon this such narrow limits shows us how very little when more attention order and therefore it will not be surprising, collectors, if this small order, shall be given to these tiny insects by well as in which has been considered as insignificant in numbers as to be quite extensive in the the size of its individuals, should prove described in this paper, a number of its species. Of the new species Massachusetts Agricul- complete set of types has been deposited in the exist, has been deposited tural College; a set of cotypes, so far as they third set of cotypes I have in the Unit^'ed States National Museum; a also deposited in retained for my own use, and the remainder I have number of specimens the Massachusetts Agricultural College. The from which the species has been described follows each description. thirteen previously described American species have Eleven of the | have been been redescribed as have also a number which I believe of early stages have previously described in Europe. Descriptions | noted in each been given where known and the authority therefor description of the instance. It will be noticed that in all cases the be wanting female precedes that of the male, or the latter may | females are much more entirely:. Among the Thysanoptera the both are abundant than the males and also more characteristic when mainly known. For these reasons all of the descriptions are leased bibliography of upon the female. It would be impossible to give a references to the species of this country without including many European works. Therefore the bibliography is intended to include than for North i, the literature of this order for the world rather it could be ! America alone. Each reference has been numbered so that the whole title. referred to by number when desired without repeating references have been made by inserting the bibliographical Such ^ ' number inclosed by a parenthesis where authority for a statement is referred to, thus, (I). ol)ligations to I desire here to acknowledge that I am under many kindly those who have assisted in making this paper more complete by loaning type specimens, without the examination of which the identifi- should state, cation of several species could not have been certain. I Prof. C. H. that these types were not loaned to me directly, but to them, Fernald, who kindly took upon himself the responsibility for pleasure to but as I have been the one to profit by them it gives me kindness express my thanks to Prof. J. H. Comstock, through whose to Prof. Herbert I was able to see the type of Zimothrips poaphagus; Osborn for the privilege of examining at my leisure his type of Thrips^ NO. 1310. XORTH AMERICAN THYSANOPTERA—HINDS. 81 striata; to Prof. C. P. Gillette for the loan of his supposed Thrips striatus; to Prof. H. E. Somers for sending- the types of Miss Beach and Professor Osborn, with their kind permission, to Dr. Henrv Uzel for the positive identification of Thrips tahacl with his Thrips communis^ and finally to Dr. L. O. Howard and Mr. Theodore Pergande for giving nie access to the material in the United States National Museum collection. This paper forms the major portion of a thesis for the degree of doctor of philosoph\ at the Massachusetts Agricultural College, where it has been prepared under the supervision of Prof. Charles II. Fernald and Dr. Henry T. Fernald, Avho have charge of the work in the depart- ment of entomology. To both, for the many ways in which they have guided and encouraged me in the work of the past three years, I give my heartiest thanks. HISTORY OF THYSANOPTERA. These insects were first described b}^ DeGeer in 1744, under the name Physapus (2). Linnteus ignored this name and placed the four species known to him in a genus which he called llirqj,^, locating it in the order Hemiptera, immediately after his genus Coccus (5). In 1806, C. Dumeril raised the group to the rank of a family, which he called Vesitarses or Phj^sapodes but retained it in the order Hemiptera (11). C. F. Fallen (17), in 1814, changed the name of the family to "Thripsites,'' but did not change its ordinal position, and this name was retained by Newman (01) as the name of a "natural order," which, however, had only family value. In 1826, Latreille (50) used for them the names Thripsides and Physapi. A. H. Haliday, in 1836, published an extensive study of the British insects belonging to this group and concluded that thev should be given the rank of an order, for which he proposed the name Th^'sanoptera (68). Probably about two years later, Burmeister (69) also gave them ordinal rank, with the name Physapoda, since which time most writers have adopted one or the other of these ordinal names. Those who adopt Physapoda appear to base their preference largelj" upon the priority of Dumeril's use of the name Physapodes, Physopoda (Physapoda) being a re-formation of the term. It does not, however, seem to the writer that this position can be sustained, as at that time there was no genus Phympus^ DeGeer's name having no standing, as it was given before the tenth edition of Systema Nature." It seems therefore that Haliday was the first to give the group the rank of an order and to apply thereto a properly formed ordinal name: Thysanoptera, from Siffavog^ a tassel, and 7tTepoi\ a wing. This basing of the name upon characters of the wings is in accord with general usage in the various orders of insects. I believe that Thysan- "See Canons Y and XIII, A. O. U. Code, 1892. Proc, K M. vol. xxvi~02 6 g2 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvi. optera can claim priorit3^ and correctness of formation and should therefore be adopted. While the scientitic name of the group has been su])jected to so many changes, the most frequent!}^ used common name has persisted unchanged since the time of Linnteus. It is nothing more or less than the name which lie gave to the genus Thrips, and is now applied in the same form to any individual of the order. It is therefore incorrect to drop the '"s" when referring to an individual, as isJ frequently done. Thrips is a Latin name derived from the Greek' ^ptip, meaning a wood-louse, and is in the singular number and mas- culine gender, as will be also all generic names of which it forms the termination. Various other connnon names based upon two of the most striking characters of the group have also been used to a limited extent: Blad- der feet (Blasenfusse or Vesitarses), referring to the peculiar structure of the extremity of the leg, is appropriate and much used by German ^ writers. Fringe-wings, from Th3^sanoptera, has also been used, but much more rarely. SYSTEMATIC POSITION OF THYSANOPTERA. The systematic position of this group has undergone unusual change' since its establishment by Linnaeus. Working as he did upon the most striking superficial characters, Linnteus recognized in Thrips certain affinities with the Hemiptera-Homoptera, in which order he placed them.