Cryptolestes obesus Thomas, 2002

Zeballos, Leandro & Bento, Matheus, 2025, Discovery of the male Cryptolestes obesus Thomas, 2002 (Coleoptera: Laemophloeidae) highlights key taxonomic traits and strong sexual dimorphism, EntomoBrasilis (e 1107) 18, pp. 1-4 : 1-4

Adult of Cryptolestes obesus Thomas, 2002

( Figures 1-8 )

Material type examined. Holotype female (deposited in MZUSP; Figure 6 ) with following data: " BRAZIL: Rondonia, 63"P km. SW Ariquemes, nrH / Fzda. Rancho Grande 20-VII-1992 U. Schmitz / blacklight trap ".

Material examined. Male (abdomen dissected) deposited at MZUSP, labeled: " Brasilien, Nova Teutonia, -27.185556; -52.383333 (300-500) iv.1952, Fritz Plaumann // " MZUSP 62108 " // Cryptolestes obesus (handwritten) Matheus Bento, Det. 2024" .

Diagnosis. Body stout and robust, with dorsal surface covered with conspicuous pubescence ( Figure 1 ). Head acutely projected in front of eyes in both sexes. Frons strongly depressed anteriorly ( Figure 3 ). Male antennal scape with three digitiform inner projections ( Figure 5 ). Secondary sublateral lines of pronotum complete and equally distant from the primary

sublateral lines and lateral margins ( Figure 3 ).

Description of male ( Figures 1-2 ). Length from anterior margin of clypeus to elytral apex 1.4 mm, width at mid-elytra 0.56 mm. Coloration. Head, venter and pronotum dark reddish brown; elytra light brown. Head ( Figure 3 ) large, somewhat pentagonal, 1.25x wider than long and medially as longer as pronotum, with dorsal and ventral surface conspicuously pubescent, with moderate, decumbent pale setae inserted in deep punctures. Frons very wide, with anterior half depressed; punctures smaller than an eye facet, separated from each other by one puncture diameter; surface smooth between punctures; interocular width 8.6x transverse eye diameter. Clypeus with anterior margin broadly emargined, with emargination as wide as labrum. Antennae slightly longer than half the body length. Scape elongate, slightly smaller than pronotum, with the apex expanded, strongly concave internally, pubescent, with three digitiform inner projections separated from each other by deep incisions: ventral projection short, frontal long and dorsal smaller than frontal projection ( Figure 5 ). Pedicel globose, not projected, slightly larger than flagellomeres 3–8. Flagellomeres 9–11 larger than preceding flagellomers and forming a loose club, each slightly longer than wide ( Figure 1 ). Prothorax ( Figure 3 ) subrectangular, slightly wider than long; surface moderately setose, with conspicuous, long pale setae. Secondary sublateral line strongly defined between sublateral line and lateral margin, equally distant from sublateral line and lateral margin. Anterior and posterior angles obtuse. Elytra ( Figure 1 ) 2.8x longer than wide, with sides strongly declivous; pubescence similar to pronotum and head, with longitudinal rows of long setae. Thoracic venter. Procoxal cavities posteriorly closed. Prosternal process broad, twice wider than long, with apical margin slightly curved. Abdomen. Intercoxal process of ventrite 1 broad, as wide as metacoxa, with apical margin slightly curved. Genitalia ( Figure 7 ). Tegmen broadly rounded at base; apex with a few setigerous punctures at each side. Parameres acute, moderately setose at apical margin, setae thick. Endophallus symmetrical, with an inverted, V-shaped sclerite connected with two hooked sclerites, two sclerites parallels, curved inward, a median raspula composed of small spine-like asperities ( Figure 8 ).

Distribution. BRAZIL. Rondônia: Ariquemes; Santa Catarina: Nova Teutônia (new state record).

Remarks. Thomas (2002) described C. obesus based on a single female specimen from Rondônia state, Brazil. In the original description, he stated: "I have hesitated to describe this species, based as it is on a single female specimen. However, it is so distinctive that it should be fairly simple to associate the male when it is collected". Although uncommon for species-level taxonomy of Cryptolestes , which is based primarily on males, this female specimen described by Thomas (2002) was very different from all the other species in the genus by the body extremely stout and robust, secondary sublateral lines of pronotum complete and equidistant from the primary lines and lateral margins, and the procoxal cavities closed behind. Although a strong sexual dimorphism could also be expected for C. obesus, Thomas (2002) was right when hypothesizing an easy association with the male in this species as its diagnostic characters were not based on primary or secondary sexual features. The male of C. obesus described herein possesses all the aforementioned diagnostic traits given by Thomas (2002), by which it was easily associated with the female. However, the discovery revealed a strong sexual dimorphism in which the male presents an extremely modified antennal scape, with the apex expanded, strongly concave internally, and bearing three digitiform inner projections separated from each other by deep incisions ( Figure 5 ). The shape of the male scape of C. obesus and the endophallic sclerites diagnose this species and represent unique features among males of all the other Cryptolestes species.

Figures

Figure 1-2. Cryptolestes obesus Thomas, 2002 male: Habitus in (1) dorsal view; (2) ventral view. Scale bars: 1-2 0.4 mm.

Figure 3-8. Cryptolestes obesus Thomas, 2002,male (3-5, 7-8), holotype female (6): (3) Head and prothorax in dorsal view; (4) Head and prothorax in ventral view; (5) Scape in frontal view; (6) Habitus in dorsal view; (7) Male genitalia; (8) Endophallus. Scale bars: 3-5 = 0.2 mm. Abbreviations: eph = endophallus; teg = tegmen; prm = parameres. Holotype female provided by Gabriel Biffi (MZUSP).