Hister guanacaste, Caterino, Michael S., 2004

Caterino, Michael S., 2004, Taxonomy of the Hister criticus group, with description of a new species (Coleoptera: Histeridae), Zootaxa 601, pp. 1-16 : 12-14

Hister guanacaste n. sp. ( Figs. 2 , 4 D, 5C, 6B, 7A, 8A)

Types: HOLOTYPE male (dissected by the author): "Est. Palo Verde, 10 m, P. N. Palo Verde, Prov. Guan., COSTA RICA, 4 a 7 may 1992. U. Chavarría. L­N­259000­388400" [INBIO CRI001 213387]; PARATYPES (28): 11: same data as type (INBIO #'s CRI001 213361, CRI001 213363, CRI001 213368, CRI001 213370, CRI001 213372, CRI001 213398, CRI001 213400, CRI001 213403, CRI001 213404, CRI001 213405, CRI001 213431); 5: "Est. Palo Verde, 10m, Ref. Nac. Fauna Silv. R. L. Rodriguez, Prov. Guan., COSTA RICA, U. Chavarría. Jun 1991. L­N­259000­388400" (CRI000 573317, CRI000 573318, CRI000 581027, CRI000 581031, CRI000 581064); 4: identical data as preceding except collected May 1991 (CRI000 346418, CRI000 346473, CRI000 346474, CRI000 510745); 2 identical data as preceding, except collected in Jun 1991 by D. Acevedo (CRI000 449970, CRI000 449978); 3: " 3 km NO de Nacaome, 100m, P. N. Barra Honda, Prov. Guan., COSTA RICA. 3 a 30 may 1993. M. Reyes. L­N­239000, 386000" (CRI001 401381, CRI001 402254, CRI001 401926); 3: “Sect. Palo Verde, Prov. Guana, COSTA RICA, 10m, 4–24 ABR 1995. E. Navarro, Interseccion, L N 259150 388500 #4616” (CRI002 184890, CRI002 184891, CRI002 184904).

Diagnosis: This species is closely related, and similar in most respects, to the following ( H. foveipygus ). Its most distinctive feature is the almost entirely impunctate pygidum and propygidium, the latter with only small punctures along its anterior margin ( Fig. 4 D). It also has the third elytral stria characteristically interrupted, absent from most of the apical half of the elytron, though invariably with a very short apical appendix. In H. foveipygus (as well as some individuals of H. criticus ) this stria is barely or not at all interrupted.

Description: Average length: 4.0 mm (range 3.8–4.4); Avg. width: 3.8 mm (range 3.4– 4.2); body black and shining, ovoid, outline not interrupted at the pronotal/elytral junction; frons broad, convex, minutely punctulate; frontal stria bisinuate, strongly impressed, ending at dorsal margin of eye, frons depressed within; supraorbital stria absent; epistoma convex, narrowed anteriorly, emarginate; labrum rounded, convex, about two­thirds as long as wide, anterior margin recessed; mandibles depressed at anterobasal angles, dorsal surfaces flat, incisors lacking teeth; antennal scape about as long as mandible, curved; funicle gradually expanded, to about two­thirds maximum width of antennal club; club ovoid, flattened, with annuli oblique, lacking sensory plaques.

Pronotum with sides rounded, converging; marginal pronotal stria ending behind eye; outer lateral stria absent, inner stria slightly abbreviated at base, continuous with anterior marginal behind head; lateral pronotal margin weakly but noticeably convex; pronotal disk with few small punctures along basal margin, elsewhere no more than minutely punctulate; prosternal keel lacking striae (with basal fragments in few individuals); prosternal lobe rather narrowly rounded anteriorly, with one complete marginal stria, and second abbreviated stria in basolateral half, extended to hypomeron by narrow, sinuate alae. Protibia tridentate, apical tooth bispinose, with complete submarginal carina, bearing a few small spinules, including one or two along apical tibial margin; apical spurs prominent (though often worn) ( Fig. 5 C).

Elytra lacking inner and outer subhumeral striae; striae 1 and 2 complete; stria 3 rarely complete, usually present only in basal one­third and apical one­sixth; striae 4 and 5 absent; sutural stria present in apical one­half or slightly more. Mesosternum shallowly emarginate, with one complete marginal stria, and fragments of an additional stria in anterior corners; metasternal postcoxal stria extending from end of mesosternal stria to mesepimeron; lateral metasternal stria originating near inner edge of mesocoxa, extending obliquely to near metacoxa, then bending at nearly right angle forward to metepisternum. 1st visible abdominal sternite with one stria extending from anteromedial corner of metacoxa almost straight back to posterior margin of sternite, with a second strial fragment near posteromedial coxal corner. Meso­ and metatibiae weakly arcuate, with two series of marginal spines; apicoventral margin of basal tarsomeres of meso­ and metatarsi with 2 inner and 1 outer spines, tarsomeres 2–4 with single pair of marginal spines.

Propygidum and anterior half of pygidium ( Fig. 4 D) with conspicuous transverse microsculpture; propygidium nearly flat, very shallowly depressed on either side of middle, with small punctures separated by slightly more than their widths along anterior margin (slightly finer and sparser at middle), becoming nearly impunctate posteriorly; pygidium strongly convex, evenly inconspicuously punctulate throughout.

Male ( Fig. 6 B): aedeagus slender, tegmen expanded apically, with unique, deep apicoventral emargination.

Female ( Fig. 8 A): Ovipositor short, well sclerotized; coxite apically bidentate, twofifths entire ovipositor length; bursa reduced, flattened, weakly sclerotized; 5 linear, slightly apically bulbous spermathecae attached to oviduct near base of bursa, four of them approximately equal in length to bursa, the 5th reduced, about one­third length of others.

Remarks: This species, named for the province of Guanacaste , is only known from lowland areas near the Gulf of Nicoya in northwestern Costa Rica.

Figures

FIGURE 2. Map of specimen records for Hister guanacaste and H. foveipygus.

FIGURE 4. Photographs of propygidium and pygidium of Hister spp. A. Hister criticus; B. H. laevimargo; C. H. latimargo; D. H. guanacaste; E. H. foveipygus.

FIGURE 5. Posterior view of protibiae of Hister spp. A. Hister criticus; B. H. latimargo; C. H. guanacaste; D. H. foveipygus.

FIGURE 6. Dorsal view of components of aedeagus of Hister spp. A. Tegmen of Hister criticus; B. Tegmen of H. guanacaste; C. Tegmen of H. foveipygus; D. Median lobe of H. foveipygus.

FIGURE 8. Lateral view of valvifer and coxite (ovipositor) of Hister spp. A. Hister guanacaste; B. H. foveipygus.