Article beginning on page 221.
Psyche 10:221-223, 1903.

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NOTES ON ACANTHOTHRIPS,
BY H. J. FRANKTAW, B. S., AMHERST, MASS. On the 9th of September, 1903, five females and one male Acmihothrips qnafemordi~ Hinds, were found under the loose bark of a sycamore tree near the college grounds. Since then, a large number of specimens have been found on the same tree. While I have not found them on other sycamores in the neighbor- hood, their numbers on this tree would seem to indicate that the sycamore is their food plant. It is possible, however, that they fed, during the summer, on plants near this tree and that they were simply preparing to hibernate under its bark. Acanthothrips magnufemora//i was originally reported from Miami, Florida. Dr. Hinds gave a very good description of the male of this species from a single specimen and, since
that time, no further account of the insect seems to have appeared and no description of the female has been published. Female.- The female, although generalb larger, more robust, and with a more swollen abdomen, closely resembles the male in most respects. Length 2.28 mm. (2.1 to 2.7 nim.); width of mesothorax 0.49 mm. (0.47 to 0.52 inin.). Relative lengths of the segments of the antennae as follows : Number of segment, I 2 3 ;I 5 6 7 8
- - -- - - -- - .- --
Spaces of micrometer, 12,3 18.4 37 34 29.6 18.4 18.2 10.5 Described from nine specimens.
Two cotypes (two slides) have been deposited in the United States national museum.
Three cotypes (two slides) have been deposited at the Massachusetts agricultural college. I have retained four cotypes (one slide). The color of the male and female both is mole or less tinged with red, as seen by transmitted lighi, croing to the presence of scattered hypodermal pigmenta- tion. Fore femora strongly compressed ; two apical segments of the antennae of bolh sexes with a straight, longitudinal row of about ten setae seen on the outer side of the segments above, when the antennae are antciiorly directed, beginning at the apex of the last segment; surface of the abdominal segments reticulated. The description of this insect by reflected light is, in many respects, quite dif- ferent from that by transmitted light.
By reflected light, the general color of the body above is seen to be light gray- ish tinged with red; the eyes and ocelli are brick-red in color; the last two segments of the abdomen before the tube are pale yellow and the outer two thirds of the tube is black. There is a dark brown, longitudinal, median basal stripe on the head above and the fore femora usually bear one or two isolated brown dots. A broad,




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2 22 J'S YCIIE [Oct.- Dec.
Y-shaped, dark brown stripe begins on the mesothorax, crosses the nietathorax, and extends on the dorsum of the abdomen to the posterior margin of the seventh segment. The base of the stripe is median on the dorsurn of the abdomen and grows gradually wider anteiiorly ; it is narrowed between the segments. The arms of the Y nearly reach the anterior angles of -the mesothorax. On the thorax, the stripe is somewhat lighter in color having a distinct reddish tinge. The pos- terior angles of all the abdominal scgrnents above, except the last three, are dis- tinctly flecked with pure white. There is also a somewhat indefinite white spot on each side of the dorsal stripe on each side segment. The appearance of the ven-
tral side of the imsect is the same by reflected as by transmitted light. Lawn.- On the 23d of October, 1303, several specimens, apparently all bhiiging to the same larval instar, were found congregated together with a num- lwr of adults.
Length 1.2 nini.; "iidth of meso-thorax -56 mil}. General shape fu6ifonn; color red. llead quadrate and lighter in color thim hod? ; cheeks straight and p:irallel ; post-ocular bristles prominent and knobbed. The head also bears four other bristles which are similar to those behind the eyes; two of these are situated between the eves, one on eacli side, about half-wily between the middle of the head :iml he margin of the eye ; the other two rtt-e situ- iiteci about half-way between these and the margin of the thorax. The eves are small, round, black in color, and very widely separated. Antenuac consisting of seven segments, light- brown in color, the third segment the 1011gccyt; second segment bearing knobbed hairs, fourth iind fifth segments bearing ;seii.se cones: apical segment bluntly pointed and beiirii'ig a long, slender, acute hair at its end.
Thorax red, with it'regiiliii" and indefinite transpasent markings; bearing knobbed hairs like those on the head on nil thi-i.'e cyc'gmenLs. 1.e~ very light brown in color; femora bear- ins knobbed hairs ; ti~rsi hearing- two *ti-ong clau-s. Abdomen about one-half the length of the hodv, tapering grad~ially to the end of the tube; red in colov, with irregular transparent mm-kings ; lii-st segment transparent, fourth segment somewhat lighter thm ihe others. All Ihc segments, except the last two, bear knobbed hairs. Toward the posterior part of the abdomen, the hairs gmdi.iiilly grow longer. Around the posterior inargir oi the yi11 segment there is a circlet of long spines which are strongly bent near their tips. The tube is about two thirds the length of the head, tapers gradually from bzse to apex. is li,qht brown in color; and bears a circlet of acutely pointed spines at its tip: oii1~- two of the eight exlremely long hairs xen in the adult are dei-eloped- and these are on Llie vcntral side ot the tube in all iny specimens. On October 31x1, loo-;, I found a liirgc female Aca1zthothrips viodzrornis Reut. also under the buk of the sycamore.
'I'liis is the species on which Uzel founded the genus and it docs not seem to have been ~eporLecl lieietofore in this country. It would be useless for one to attempt to redescribe the species from one specimen, but this species may be readily distinguished from magnar/no/-ali-s by its larger size and dark brown color. The last three abdominal segments are dark



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brown and the tube does not bear a circlet of eight very long hairs as in magna- femoral2.r. There is a very distinct white fleck, seen by reflected light, on the ante- rior corners of all the abdominal segments above, except the two basal and the two apical.
Uzel gives the average length of the females of the species as being 2.4 nun. My specimen is a very large one measuring about 3 mm. in length. The foregoing studies were made at the Entomological laboratory of the Massa- chusetts agricultural college.




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