Trigonops, Guérin-Méneville

Zimmerman, Elwood C., 1942, Curculionidae of Guam, Insects of Guam I, Honolulu, Hawaii: Bernice P. Bishop Museum, pp. 73-146 : 82-83

KEY TO THE SPECIES OF GUAM TRIGONOPS

1. Elytra conspicuously uneven, with numerous irregularities on the disk; intervals 5, 6, and 7, especially 5 and 6, rather prominently and irregularly elevated at the top edge of the lateral declivity; prothoracic puncturation very coarse and dense, the punctures tending to be longitudinally confluent, the interstices irregular, some broader, many narrower than the punctures (length 5 to 8 mm.).............................................2. T. inusitata Zimmerman.

Elytra not so formed; prothorax not very coarsely punctate, the interstices almost always broader than the punctures; if the prothorax is comparatively coarsely punctate and elytral intervals 5, 6, and 7 elevated, then the disk of the elytra is never irregular and the length is less than 5 mm. 2

2(1). Pronotum obviously depressed above, distinctly angulate at the sides of the disk at base in front of elytral intervals 6 and 7, the angulation formed by a low, rounded, short, longitudinal carina that is covered with paler scales in fresh specimens, disk, when denuded, densely and conspicuously granulate and with scattered indistinct punctures.......................... 3. T. inaequalis Zimmerman.

Pronotum usually quite distinctly convex above and not obviously depressed, without a baso-lateral carina before elytral interval 6..................................... 3

3(2). First funicular segment obviously longer than second, fully a fourth or a third longer than second................................................................................................ 4

First funicular segment as long or just perceptibly longer than second, never a quarter longer (usually between 15/13 or 12/11 as long).............................. 5

4(3). Prothorax as long or slightly longer than broad; scales on dorsum each appearing hard, smooth, convex and shiny.......... 4. T. subfasciatus (Boheman) . Prothorax broader than long; scales of dorsum not smooth, convex and shiny, but appearing soft and spongy, each coarsely reticulate or farinaceous........................................................................................ 5. T. hirsuta Zimmerman.

5(3). Entire elytra including disk bristling with long, almost straight conspicuously erect or but slightly curved, black, hairlike setae; disk of pronotum with short erect setae............................................................ 6. T. impura (Boheman) . Elytral and pronotal disks with decumbent or prostrate setae only, never with conspicuously erect setae...................................................................................... 6

6(5). Discal elytral intervals without any setae on basal half...................................... TODO TODO TODO TODO Discal elytral intervals with setae on basal halves.................................................. 7

7(6). Eyes not strongly convex and not protuberant (as in fig. 1 , a), as long or slightly longer than distance between them; distance between median angle of interocular suture and apex of transrostral carina more than three fourths to fully as long as narrowest interocular breadth; setae on mid and hind femora closely appressed to derm, with their recurved tips usually touching or almost touching the derm.......................... 8. T. convexa Zimmerman. Eyes strongly convex (as in fig. 1 , b), shorter than distance between them; distance between median angle of interocular suture and apex of transrostal carina much shorter than narrowest interocular breadth; setae on mid and hind femora, especially along lower edge, slanting rather distinctly away from derm and giving lower edge of femora a rather spiny appearance............................................................................................9. T. vulgaris Zimmerman.

Figures

FIGURE 1.-0utlines of structures of Curculionidae: a, b, outlines of heads of (a) Trigonops convexa and (b) T. vulgaris, showing convexity of eyes; c, d, lateral outlines of aedeagus of (c) Microcryptorhynchus guamae and (d) M. premnae; e, f, dorsal outline of aedeagus of (e) M. premnae and (f) M. guamae; g, h, apices of mesotibiae of (g) Choerorrhi1wides flavisetosus and (h) C. marshalli.