Laccophilus youngi Zimmerman 1970

Laccophilus youngi
DIAGNOSIS. — The unique combination of a non-irrorated, variegated, or marmorated elytral pattern, metacoxal file in the male, intermediate prosternal process, and size makes this one of the most distinctive species in North America. Only L. pictus and L. gentilis suavis are not irrorated and possess files; but the first has a black and yellow pattern, and the second is a much smaller species with a subbasal fascia. In a total of 50 females an epipleural flange was always present. Other Laccophilus that possess the character that frequently are all irrorated — L. maculosus shermani, L. fuscipennis, and L. vacaensis chihuahuae. L. quadrilineatus and L. raitti have variegated or marmorated patterns; but files are lacking, and the females have rakelike instead of sawlike ovipositors.
DESCRIPTION. — Medium to large (length, 4.6 to 5.4 mm; width, 2.7 to
3.0 mm), variegated, light and dark brown species; coxal file present; prosternal process intermediate; ovipositor sawlike. COLOR. Head: pale brownishyellow above and beneath except for reddish-brown occiput; appendages pale except mandibles. Pronotum: mostly pale brownish-yellow, but with large dark reddish-brown to nearly black blotches on the anterior margin between the eyes and continuous with the occipital dark area; posterior margin translucent brownish-red. Elytra: large dark brown or nearly black blotch over most of the disc on a pale brownish-yellow background; pattern tending to be marmorated with anterior and posterior extensions from the central blotch; epipleura generally pale except for the light reddish-brown translucence in posterior half. Tergite VIII: pale yellowish-brown. Venter: generally light yellowish-brown with slightly darker reddish-brown tinges at coxal bases and on the hind legs. Genitalia: variably reddish-yellow brown. ANATOMY. Microreticulation: double on head, pronotum, and obviously so on elytra. Head: supraclypeal seam diverging upward at midline instead of remaining parallel to margin. Pronotum: epipleural flange nearly always present on females: apical truncation slight in females; not clearly distinguishable in males. Elytra: WH PW, 0.68; LP, PW, 0.41. Venter: coxal file prominent in males, composed of about 19 coarse lines; prosternal process intermediate with apex reaching almost to a line drawn even with the posterior margins of the mesocoxal cavities and with a sharply defined crest on apical expanded portion; lobes of postcoxal process rounded, projecting laterally well beyond the midline; last visible abdominal segment of male evenly rounded, with numerous prominent rugae and a weakly defined, nearly symmetrical ventral crest; scattered setigerous punctures and a few thick, short hairs at ventral lateral margin; female with the apex tending to be triangular in outline and with a groove or impressed line forming a margin on either side of the apex; rugae, setigerous punctures and hairs as in male. Legs: proand mesotarsi enlarged in a dorsoventral plane; fifth tarsal segments about one and one-half to one and two-thirds as long as corresponding fourth; profemoral setae (7) about half as long as mesofemoral (7 to 9) ones; longer metatibial bifid spine nearly as long as first two metatarsal segments. Genitalia: oval plate produced to point; its ventral crest apparent near tip, numerous weak lines on either side of crest and diverging away from midline; aedeagus widened at about three-quarters its length, then narrowing to a blunt tip; ovipositor with about 13 pair of sawlike teeth. — Laccophilus youngi occurs on the western side of the continent from Nayarit to Guatemala (Fig. 23). There is also a single male from Poza Rica, Veracruz. It is found in tropical deciduous forest at about 2000 to 3000 feet, and I have collected it almost entirely in deeply cut mountain valley streams with strong current. This probably accounts for its rarity in collections since most Laccophilus avoid strong currents. It is also one of the few species that occurs
where there is a heavy shaded canopy over the stream. It uses grassy margined and gravelly bottomed, silted streams — as well as those with solid rock bottoms. They apparently can make use of any kind of debris to maintain their position in the stream. Holotype male, allotype, and four male and four female paratypes with the following data are in the United States National Museum: 3 miles north of La Resolana (Casimiro Castillo), x.26.66, A. H. Smith and J. R. Zimmerman. Other paratypes distributed as follows: three males and nine females, 29 miles northeast of Colima, Colima (in Jalisco), xii.3.48, H. B. Leech, and two males and one female, Sierra de Zapotan, xi. — .42, Eugenio Paredes, are in the California Academy of Science, San Francisco, and a male and female, same data, in the University of Michigan, Museum of Zoology, Ann Arbor; and one male and one female with the same data as the holotype, Departmento de Entomologia, Laboratorio de Sanidad Vegetal, Coyoacan, D. F., Mexico.
MEXICO. — CHIAPAS. Arriaga, 1 9, vii.22.65, P. J. Spangler (USNM). Cuahtemoc, 1 $, 1 5, viii.30.63, JRZ (NMSU). COLIMA. Trapechi, 1 9, vii.29.62, JRZ (NMSU). JALISCO. Autlan, 9 m. SW., 4 $ , 7 9 , x.24.66, A. H. Smith & JRZ (NMSU). Colima, 29 m. NE. (given as state of Colima, but this would have to be Jalisco), 3 S, 9 2, xii.3.48, H. B. Leech (CAS). La Huerta, 5 m. N., 3 9, 6 m. N., 1 $, 6 9, x.25.66; 22 m. N., 12 $, 14 9, x.26.66, A. H. Smith & JRZ (NMSU). NAYARIT. Sierra de Zapotan, 3 S, 2 9, xi. — .42, Eugenio Paredes (CAS). OAXACA. Tapanatepec, 2 $ , ix.1.63, JRZ (NMSU). VERACRUZ. Poza Rica, 1 $, viii.27.65, P. J. Spangler GUATEMALA. — Quiroga. 1 9, viii. 14.65, P. J. Spangler (USNM). This polytypic species is composed of three races which have ranges that extend from the southwestern United States to Guatemala. Each race has been considered a separate species. L. pictus Castelnau was described in 1834 from Mexico, L. insignis Sharp in 1882 from Texas, and L. coccinelloides Regimbart in 1889 from Arizona. Intergrade populations have been found between pictus and insignis in Veracruz and between pictus and coccinelloides in Jalisco. Intergradation is restricted to two very small areas.
Although L. pictus males possess metacoxal files, the species appears to be rather far removed from other North American species with files. The bright yellow and black elytral pattern contrasts sharply with the dull irrorated brown or dark brown found in most of the others. Other differences are the strongly double microreticulation
— tN — CN — tN -H<Nl
and the long pronotal apex. The relative length of the pronotum exceeds any other North American Laccophilus.
DESCRIPTION. — Medium to large (length, 4.2 to 5.9 mm; width, 2.5 to 3.4 mm), black and yellow species; metacoxal file present; prosternal process short; ovipositor sawlike. COLOR. Head: pale brownish-yellow in front; occiput, inner eye margin and mandibular margins black; other appendages yellow. Pronotum: disc to lateral margins pale brownish-yellow, but entire anterior and posterior margins black filling in the entire "V" at the apex. Elytra: strikingly marked with yellow and black; epipleura black or dark reddish-brown. Tergite VIII: pale yellow-brown tinged with red. Venter: entirely pale in shades of brownish-yellow variably tinged with red. Genitalia: same as venter. ANATOMY. Microreticulation: strongly double on head, pronotum and elytra; individual cellules often not visible; pronotum roughened. Head: supraclypeal seam closely parallel to margin. Pronotum: relatively longer from head to apex due to the more acute angle formed by the adjacent margins of the pronotum and elytra; WH/PW, 0.67; LP/PW, 0.44-0.46. Elytra: epipleural flange common in insignis, but rare in the other two races; truncation of apices marked. Venter: coxal file prominent in males and weakly present in females, composed of about 25 relatively coarse lines, and about 8 to 10 much finer ones; prosternal process with well-defined crest in apical half; lobes of postcoxal processes rounded and laterally projecting well posterior to midline; last visible ventral abdominal segments not truncated (discussed under subspecies). Legs: male proand mesotarsi noticeably enlarged in a dorsoventral plane; first three segments with lateral distal corners produced; palettes large enough to be easily distinguished at 20 power magnification; fifth tarsal segments on front and middle legs about one and two-thirds as long as corresponding fourth; mesofemoral setae (6 to 8) about twice as long as profemoral ones (6 to 7). Genitalia: oval plate with produced acuminate tip and with prominent ventral crest extending anteriorly and bending slightly to the left; numerous raised lines on either side of the crest, but longer and more numerous on the right; right paramere less triangular than in maculosus (fig. 129) and nearly as long as left; aedeagus narrowing abruptly near the tip; ovipositor with about 12 sawlike teeth.