Mesovelia pacifica, Mulsant & Rey, 1852

Usinger, Robert L., 1946, Hemiptera Heteroptera of Guam, Insects of Guam II, Honolulu, Hawaii: Bernice P. Bishop Museum, Bulletin 189, pp. 11-103 : 93-94

87. Mesovelia pacifica ,new species ( fig. 25 , a).

Elongate, slender, the head slightly longer than broad across eyes, eyes sinuate at inner posterior margins, anterior angles of pronotum only briefly rounded, mesonotum less than twice as long as metanotum at middle, hind femora without spines beneath, first genital segment in male without spines or processes but with 6 to 8 stiff black bristles on either side of middle, the bases of these bristles concealed when the genital segment is retracted in its normal position. Male genital claspers abruptly bent at basal third, directed forward and tapering apically. Second segment of posterior tarsi distinctly longer TODO TODO

Male: head longer than broad across eyes, 23: 20; the eyes half the width of interocular space, sinuate on inner posterior margins. Rostrum reaching almost to apices of hind coxae. Antennae almost as long as body, 84: 86; first segment only about two thirds as long as head, 18: 23; proportion of segments 18: 13: Z7: 26.

Pronotum one third as long on median line as head, 7: 21; three times as broad as long, 21: 7; hind margin feebly but distinctly sinuate; anterior angles briefly rounded. Mesonotum a little longer at middle than pronotum, 9: 7, the hind margin curved forward sublaterally. Metanotum over half as long as mesonotum, 5.5: 9, the hind margin nrarly TODO

Abdomen only moderately expanded, the connexival plates a little over one third as wide as dorsal abdominal disk at the same level, the connexivum only moderately reflexed, the entire abdomen slightly narrower at widest part than greatest width of thorax.

First genital segment almost as long above as broad at base, 10: 12, less than half as long beneath as broad, 5: 12; with 6 to 8 stiff black bristles on either side of middle ventrally, the bristles covered basally by the preceding segment. Claspers very broad and abruptly but roundly bent subbasally, slender and tapering to acute apex on apical half.

Legs simple, the femora without distinct spines on under surface. Second segment of hind tarsi longer than third, 23: 20.

Female similar to male in most body proportions but relatively broader, the abdomen in particular broader, the greatest width across connexival margins one sixth greater than width of thorax, 31: 26.

Color yellowish or greenish ochraceous with variable brown markings. Palest specimens with a brown stripe on either side of middle of metanotum, brown on all of second tergite, the middle of third and the middle of fourth tergites, and with brown dorsal abdominal sutures. Connexival plates pale with narrowly brown lateral edges. Eyes brownish. Antennae more or less infuscated, especially apically. Abdominal venter with a sublateral longitudinal line. Rostrum brown at apex. Legs pale brown especially at joints. Erect bristles of legs brown. Darkest specimens almost entirely brown above, pale only on anterior portion of pronotum, middle of mesonotum and metanotum, laterally on fourth and generally on seventh tergite, posteriorly on eighth tergite and on middle of connexival plates. Under surface testaceous at middle, brownish laterally. Legs pale basally, brownish elsewhere.

Size: male, length 2.25 mm., width (abdomen) 0.6 mm.; female, length 2.6 mm., width (abdomen) 0.8 mm.

Holotype male, allotype female, and three paratypes, all apterous, Mt. Chachao , May 16, Usinger.

Runs to thermalis in Horvath's key (Hist.-Nat. Mus. Nat. Hung.,.Ann. 13: 544, 1915) but lacks the two subbasal black tubercles of the first genital segment of that European species. M. orientalis Kirkaldy is superficially quite similar but has a distinct median tubercle on the first genital segment. The present species differs from indica Horvath, in which the second segment of the hind tarsus is shorter than the third and the eyes are not sinuate at inner baJ,es, and in which no mention is made of the black bristles found in pacifica on the first genital segment. M. hungerfordi Hale from Australia is larger and has "two elevated tufts of brownish-black spines on the venter of the first genital segment" (Hale, South Austr. Mus., Rec. 3: 200, 1926) as in mulsanti,thermalis,andsubvittata. Thespinesthatcompriseth!ise "tufts" arevery short and dense in contrast to the long, posteriorly directed bristles of pacifica .

The only other Mesovelia reported from an oceanic island in the Pacific is mulsanti White ( fig. 25 , c), a common species in taro patches in the lowlands of the Hawaiian Islands. This was doubtless introduced quite recently from America. I have seen a Fijian Mesovelia in the recent collection of E. C. Zimmerman and New Caledonia specimens in the collections of F. X. Williams.

Figures

FIGURE 25.-Mesovelia species, details of ventral surface of first genital segment: tt, pacifica; b, orientaUs; c, mulsanti