Mesothrips guamensis Moulton 1942, new species
Creators: name: Moulton, Dudley
Publisher: name: Zenodo
Year: 1942
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Thysanoptera
Phlaeothripidae
Mesothrips
Mesothrips guamensis

description: 18. Mesothrips <i>guamensis</i>, new species. Male holotype: blackish brown, only joints of legs and fore <i>tarsi</i> lighter; wings brownish. <i>Head</i> 1.8 times longer <i>than</i> wide, sub-rectangular in shape, cheeks straight, slightly narrowed posteriorly and with a basal thickening; eyes broadly rounded, not protruding; cheeks with several scattered small spines; postoculars longer. <i>than</i> eyes, pointed. Mouth cone reaching two <i>thirds</i> across prosternum, narrowed near the middle and from there more or less pointed to tip. Antenna! segments 3 to 5 broadly clavate, 6 and 7 subovate but narrowed at base, 8 broadly spindle shaped. Segment 3 with two sense cones, 4 with five sense cones. Anterior margin of prothorax deeply concave, <i>with</i> a median thickening extending from lower line of crescent to a strong <i>transverse</i> line in front of posterior margin, forming an <i>inverted</i> T. All normal spines present, the outer pair at posterior angles longest, inner pair somewhat shorter, midlaterals still shorter and those on anterior margin and <i>angles</i> much smaller. <i>Fore</i> legs greatly enlarged, each fore tarsus <i>armed</i> with a <i>broad-seated</i> tooth. <i>Wings</i> long, slightly narrowed in the middle, each forewing with 34 double fringe hairs. Spines on posterior angles of abdominal segments 5, 6, 7 and 9 very long. Tube approximately 0.8 as long as head and 3.5 times longer <i>than</i> width at base. Total body length 3.5 mm.; head length 0.47 mm., width across eyes 0.264 mm.; near posterior margin 0.22 mm. <i>Prothorax</i> length measured from a <i>transverse</i> line connecting anterior angles 0.308 111111.,and 0.235 111111.when measured from the lower middle point of the anterior margin crescent; tube length 0.367 mm., width at base 0.102 mm. Antenna! segments length (width): I, 50 (50); II, 76 (40); III, 113 (46); IV, 116 (SO); V, 106 (43); <i>VI</i>, 66 microns. Segments 7 and 8 are not in position to be measured accurately. <i>Length</i> of spines: postoculars 150; those on anterior margin and angles subequal, 66; midlaterals 83; on posterior angles outer 133, inner 100; on ninth abdominal segment 367, at tip of tube 294 microns. Length of fore femora 0.455 mm., width near middle 0.176 mm. Upi, May 5, under bark of <i>Hibiscus tiliaceus</i> along with <i>Mesothrips swezeyi</i>, holotype male, Swezey (5465). This species, although having the same general appearance and color as swezeyi is easily separated by the crescent-shaped fore margin of prothorax. From <i>jordani</i> it may be separated by its uniformly dark brown antenna; from <i>setidens</i> by its broadly triangular tarsal tooth without setae; and from <i>alluaudi</i> Vuillet which has a clear yellow third antennal segment (in <i>guamensis</i> the antenna is uniformly dark brown).
description: Published as part of <i>Moulton, Dudley, 1942, Thysanoptera: Thrips of Guam, pp. 7-16 in Insects of Guam I, Bernice P. Bishop Museum Bulletin</i> on pages 13-14, DOI: 10.5281/zenodo.3634035