Aglyptinus tumerus Seago and Wheeler

Seago, Ainsley E. & Wheeler, Quentin D., 2004, Two New Species of Aglyptinus Cockerell with Unusual Sexually Dimorphic Antennae and Diffraction Gratings (Coleoptera: Leiodidae), The Coleopterists Bulletin 58 (2), pp. 235-244 : 237-242

Aglyptinus tumerus Seago and Wheeler , new species

( Figs. 1 , 2 , 6 , 9–11 )

Holotype. Male. Panama: Chiriqui Province, 19 km NW Boquete , 2 October 1975, D. S. Chandler, sifted; under tree bark. With red label ‘‘ Holotype, Aglyptinus tumerus Wheeler & Seago, 2002 .’’ Deposited in American Museum of Natural History .

Paratypes. 16 males, 2 associated females from ‘‘ Panama: Chiriqui Province, Bajo Grande , 2 miles SE Cerro Punta, 6.VIII.1978, Q. D. Wheeler lot no. 7843, on myxomycete plasmodium under bark of log ( AMNH).’’ 6 males: ‘‘ Costa Rica, Puntarenas, Monte Verde , ca. 1,600 m, 11.III.1986, M. Sorensson’ ’ ( ZMLU) . 3 males: ‘‘ Costa Rica, Puntarenas, Reserva Biologica de Monteverde , 1,580 m nr. Quelorada cuecha, on Senero Rio by J. Ashe, R . Brooks , R . Leschen , 13 May 1989. Snow Ent. Mus. Costa Rica Expedition #149.’’ ( SEMC)

Diagnosis. Aglyptinus tumerus and A. phymaphorus differ from all other species of the genus in having expanded stem antennomeres V–VI present in all males. Aglyptinus tumerus may be distinguished from A. phymaphorus by its cuplike, asymmetrically expanded male antennomere V, enlarged antennomere VI, and unmodified antennomere IV ( Fig. 2 ).

Description (male). Broadly oval, moderately convex, length 1.9–2.3 mm, width 1.4–1.8 mm. Color golden testaceous to reddish-brown, aenescent; elytra semi-translucent, often pale along suture. Elytra with spectral iridescence on apical half, with subtriangular dark brown spots subapically; spots more opaque than surrounding cuticle, sometimes faded to light golden color. Elytral microsculpture of iridescent regions comprises numerous close-packed, short, parallel ridges ( Figs. 9–11 ). Head broad, subquadrate; minute swelling of anterior margin above antennae; surface smooth, shiny, with sparse, minute setiferous punctules ( Fig. 1 ). Antennae with 7- segmented club composed of antennomeres V–XI, interrupted by small antennomere VIII; V largest, cuplike with deep groove containing several large setae, more than 2 3 width VI; VI about 1.5 3 width VII; VII–XI as in other Aglyptinus ( Fig. 2 ). Pro- and mesobasotarsomeres about 2 3 the width of other tarsomeres, with ventral spatulate setae; length basal tarsomere less than next two combined. Median lobe of aedeagus with apical 1/4 slightly curved in lateral view; reservoir at base of flagellum less than 1/6 length median lobe ( Fig. 6 ). Due in part to the extreme difficulty of dissecting the aedeagal parameres intact, these appendages were not examined; they have not been included in past treatments of the genus (e.g., Hlisnnikovsky 1964) and will not be introduced into this analysis.

Variation. While all observed specimens fell within the range indicated above, there appeared to be two size classes, one ‘‘large’’ (about 2.2 mm) the other ‘‘small’’ (about 2.0 mm). Color varies from pale aenescent to deeper testaceous.

Etymology. From the Latin tumor, a swelling, in reference to the enlarged antennomeres V and VI.

Aglyptinus phymaphorus Seago and Wheeler , new species ( Figs. 3 , 5 )

Holotype. Male. ‘‘ Costa Rica, Tres Rios , 8.xii.1955, B. Malkin, in mushrooms on trees.’’ With red label ‘‘ Holotype, Aglyptinus phymaphorus Seago & Wheeler, 2002 .’’ Deposited in EMEC .

Paratype. Male. ‘‘ Costa Rica, Cartago, 5 km S El Palme , 14.VII.1973, J. Doyen and P.A. Opler. ’’ Deposited in EMEC .

Diagnosis. Aglyptinus phymaphorus may be distinguished from A. tumerus by its asymmetrically expanded antennomeres IV, V, and VI, antennomere V not having deep groove as in A. tumerus .

Description (male). As in A. tumerus , except as follows. Length 2.2 mm, width 1.6 mm. Color golden brown; as material examined was both aged and dried, this lighter hue may be an artifact of preservation and subject to the variation of pale to darker brown observed among A. tumerus . Elytra with spectral iridescence on apical third, likely due to microscultpure as in A. tumerus . Antenna with 8-segmented club composed of antennomeres IV–XI, interrupted by small antennomere VIII; VI largest; V and VI about 3 3 width of III, nearly palmate, narrow at base; no antennomeres cuplike ( Fig. 3 ). Median lobe of aedeagus with apical 1/4 more curved in lateral view than in A. tumerus ; reservoir at base of flagellum less than 1/5 length median lobe ( Fig. 5 ).

Figures

Fig. 1. Head of Aglyptinus tumerus Seago and Wheeler, dorsal view.

Figs. 2–4. Antennae of males. 2) Aglyptinus tumerus; 3) A. phymaphorus; 4) associated unmodified male, Aglyptinus sp.

Figs. 5–7. Median lobe of male genitalia. 5) Aglyptinus phymaphorus; 6) A. tumerus; 7) Aglyptinus sp.

Figs. 8, 9. Elytral microsculpture (26203). 8) Non-iridescent female; 9) iridescent male.

Figs. 10, 11. Diffracting microsculpture of male A. tumerus (54503). 10) Dorsal view; 11) lateral-oblique view.