Colpoptera falx Bahder & Bartlett, 2025

Colpoptera falx Bahder & Bartlett View in CoL sp. nov.

( Figures 12–16 View FIGURE 12 View FIGURE 13 View FIGURE 14 View FIGURE 15 View FIGURE 16 )

Type locality. La Selva Biological Station , Heredia Province, Costa Rica ( 10.431269, -84.005961) ( Fig. 1 View FIGURE 1 ) GoogleMaps .

Diagnosis. Dark species, body generally uniformly fuscous, slight less fuscous around eyes and along anterior margin of mesnotum, forewing fuscous, less fuscous along costal vein and distal third, face without markings. Aedeagus lightly sclerotized, nearly symmetrical, pair of strongly bifurcated dorsal processes of moderate length arising subapically on lateral margins and pair of large, broad and hooked processes on ventral margin that cross distally.

Description. Dark species, body generally uniformly fuscous, slight less fuscous around eyes and along anterior margin of mesonotum, forewing fuscous, less fuscous along costal vein and distal third, face without markings ( Fig. 12 View FIGURE 12 ).

Structure. Body elongated, length male (with wings) 5.2–5.3 mm, female 5.4–5.6 mm ( Table 4).

Head. In dorsal view, vertex nearly rectangular, anterior margin slightly curved, approximately level with anterior margin of eyes, posterior margin concave, median carina absent, transverse carina at fastigium evident ( Fig. 13A View FIGURE 13 ). In lateral view, generally rounded, slightly angled at fastigium, vertex slightly projected above eyes, frons curved dorsad ( Fig. 13B View FIGURE 13 ). In frontal view, transverse carina at fastigium evident, lateral margins expanding from dorsal margin, reaching widest point just below antennae then constricting strongly ( Fig. 13C View FIGURE 13 ).

Thorax. Pronotum in dorsal view widest at midpoint with anterior margin moderately convex, posterior margin moderately concave, tricarinate, carina at midline continuous from anterior to posterior margin, lateral carinae extending from anterior margin of pronotum, laterad, becoming obsolete ventrally ( Fig. 13A View FIGURE 13 ). Mesonotum approximately as wide as long at midpoint, intiatially unicarinate at anterior margin, two additional carinae arising at mid carina near anterior margin, extending diagonally to just beyond lateral carinae, slightly sinuate ( Fig. 13A View FIGURE 13 ). In lateral view, greatly raised, angled where diagonal carinae arise at mid carina ( Fig. 13B View FIGURE 13 ). Hind tibiae with single lateral spine approximately 3/4 distance from femoral-tibial joint, spinulation 6-7-2.

Forewing reticulate, broadest basally, constricting at claval apex, expanding slightly, apex broadly rounded ( Fig. 14 View FIGURE 14 ).

Male terminalia. Pyfoger in lateral view nearly uniform width along entire length, anterior margin sinuate, posterior margin slightly sinuate, dorsal and ventral margin equal length, slightly sinuate, medioventral process lacking ( Fig. 15 View FIGURE 15 ). Gonostyli in lateral view generally rounded with large dorsal process arising basally, with helical sclerotized ridges, apex blunt with posterior corner rounded, anterior corner hooked ( Fig. 15 View FIGURE 15 ). Aedeagus nearly symmetrical with two pairs of processes ( Fig. 16 View FIGURE 16 ); first pair (A1 & A2) arising on subapical lateral margin, strongly bifurcated with dorsal projections (A1a & A2a) curved cephalad basally, straight distally, ventral projections nearly straight, angled cephalad, extending just beyond apex of A1a and A2a ( Fig. 16 View FIGURE 16 ), second pair (A3 & A4) arising on inner ventral margin just basad of A1 and A2, curving dorsad and cephalad, broadly flattened, narrowed basally, expanding immediately, lateral margins subparallel, apex strongly curved mesad (approximately 90°), reaching aedeagal base. Anal segment elongate, irregularly sinuate on dorsal and ventral margins, dorsal margin angled ventrad approximately ¼ from base, ventral margin with strong invagination approximately 2/3 from base, apex distad of invagination comma-shaped.

Plant associations. Unknown, collected sweeping trailside vegetation.

Distribution. La Selva Biological Station, Heredia Province, Costa Rica.

Etymology. The specific epithet ‘ falx ’ is a reference to the large, scythe-like ventral process of the aedeagus.

Material examined. Holotype male “ Costa Rica, Heredia Pr. / La Selva Biological Station / 12.VI.2018 / sweeping weeds / Coll.: B.W.Bahder // Holotype / Colpoptera falx ♂ ” ( FLREC) . Paratypes ( 3 males, 4 females); same data as holotype .

Sequence Data. For the COI gene, 18S gene, and for the 28S D8 and D9-D10 expansion region, sequence data was successfully obtained and accessioned ( Table 2). There was strong to moderate bootstrap support (100, 89, 99 respectively for 18S, D8 and D9–D10) for the monophyly of Colpoptera relative to out-groups with all new taxa resolving within Colpoptera ( Fig. 17 View FIGURE 17 ). Based on COI, C. acinaces sp. nov. and C. falx sp. nov. resolve adjacent to eachother with strong bootstrap support (100). Additionally, C. alacutus sp. nov. resolves adjacent to C. japortla with moderate bootstrap support (60) for COI. These relationships were also reflected in the consensus tree based on concatenated data for all markers with strong bootstrap support for both the relationship of C. acinaces sp. nov. to C. falx sp. nov. (99) and C. alacutus sp. nov. to C. japortla (93) ( Fig. 18 View FIGURE 18 ). Finally, the consensus tree based on concatenated data for all loci analyzed for available taxa show strong bootstrap support (100) for the genus Colpoptera based on the taxa analyzed ( Fig. 18 View FIGURE 18 ).

Remarks. The general habitus of C. acinaces sp. nov., C. alacutus sp. nov. and C. falx sp. nov. appears similar to many described species of Colpoptera . Additionally, both the form of the terminalia and geography appear to exclude the other described genera in the Colpopterini (most genera are Antillean). Of the novel taxa, C. alacutus sp. nov. possesses an aedeagus that is similar to many taxa within the Colpoptera (dorsal pair of processes that are deeply bifid and small ventral pair of processes that are all generally symmetrical). However, the wing shape of C. alacutus sp. nov. is more pointed than many of the described taxa. The only species with somewhat pointed apical margins of the forewings are C. acutata and C. caldwelli , both of which have similar structure of the genitalia. However, C. caldwelli is a very dark/fuscous species whereas C. alacutus sp. nov. is very pale. Despite color, C. caldwelli has an aedeagal structure more similar to C. alacutus sp. nov. than does C. acutata . Additional differences that preclude the novel taxon from C. caldwelli is the shape of the anal segment, where it is long and slender in C. alacutus sp. nov. and more robust with a truncated apex in C. caldwelli (where it is tapered in C. alacutus sp. nov.). Finally, the shape of the anal segment differs between C. alacutus sp. nov. and C. acutata as well as the color patterns described, where C. alacutus sp. nov. is lighter in color and lacks the white markings on the frons observed in C. acutata . Both C. acinaces sp. nov. and C. falx sp. nov. also superficially resemble many species of Colpoptera based on body shape and general color pattern (resembling C. marginalis and C. sinuata most noticeably based on original descriptions, however being darker than these species), the aedeagus of these novel taxa is significantly different from the structure observed in any other taxa. In both C. acinaces sp. nov. and C. falx sp. nov. the ventral processes are very broad, flattened and curved mesad, beak-like when paired and individually resembling swords. The two species differ primarily from each other in the size of these ventral processes with C. acinances sp. nov. having ventral processes only reaching the midpoint of the aedeagal shaft whereas the processes in C. falx sp. nov. extend to the base of the aedeagus. Potentially related to this difference is the size of the dorsal processes, where C. acinaces sp. nov. has larger dorsal processes compared to C. falx sp. nov. which inversely has large ventral processes. There are also subtle differences in the form of the anal segment (primarily the apex) that also separate these species. The similarity of the ventral processes in these two species appear to be reflected in the phylogeny generated based on the loci analyzed. These taxa resolve adjacent to each other with strong support (and lower than normal variance COI compared to other taxa) and the similar form (differing mainly in size) of structures indicate these taxa are very closely related.

While females were unavailable for C. alacutus sp. nov., the terminal sternites for females of C. acinances sp. nov. and C. falx sp. nov. ( Fig. 19 View FIGURE 19 ) were observed. The overall general form among the two species is very similar, with the only noticeable difference being that the apex of the tergite of C. acinaces sp. nov. is rounded whereas it is slightly truncated in C. falx sp. nov. Because these novel taxa are very similar in appearance, male morphology and genetically, it is not unexpected that this feature in females does not differ significantly. In Caldwell (1945), this character appears useful in distinguishing species, and for more distantly related species appears so. However, based on the observations of this structures here, this feature may not be reliable for closely related taxa.