Laccophilus raitti Zimmerman 1970

Laccophilus raitti
DIAGNOSIS. — L. raitti belongs to the group of species which lack a metacoxal file, have a rakelike ovipositor, and vary in whether they are irrorated or not. L. raitti would generally not be considered irrorated; but, in one female, the pigmentation is sufficiently weakened to make it appear that there is some irroration with suffusion of color between dots. The lack of a file, and the elongated front tarsi in males, the widespread teeth on the ovipositor and the long crease above the epipleura in females, and the elytral pattern in both sexes should separate raitti from other Laccophilus, except vacaensis. L. raitti is very similar anatomically to vacaensis, but the latter has the male front tarsi comparatively longer, and has a slightly different conformation of the aedeagus; also, the crease above the epipleura on the elytra does not extend as far posteriorly. If the typical elytral pattern of raitti is present, however, there will be no difficulty in separating the two species. Some L. peregrinus have elytral patterns similar to that of raitti, but the race with which it is sympatric is irrorated and that difference is enough to permit field separation. The front tarsi of males are shorter, and the crease is weaker in females of peregrinus; and it is a smaller species. L. spangleri also belongs to this group, but it differs from raitti in the ways just enumerated for peregrinus.
DESCRIPTION. — Medium (length, 4.8 mm; width, 5.2 mm) brown and yellow variegated, marmorated, or irrorated species without metacoxal file; prosternal process short; ovipositor rakelike. COLOR. Head: generally pale brownish-yellow above and beneath, but with reddish-brown occiput between the eyes. Pronotum: pale brownish-yellow except for reddish-brown anterior margin between the eyes and confluent with dark color on head; also darkened less intensely at apex. Elytra: usually variegated with dark reddish-brown on a pale brownish-yellow background, dark area usually marmorated, but may be faintly irrorated with considerable suffusion of color between the dots (one specimen in a total of 14); epipleura pale anteriorly and translucent reddishbrown in narrowed posterior part. Tergite VIII: pale yellowish-brown. Venter: variably pale yellowish-brown or light reddish-brown; proand mesosternum and their legs usually lightest; abdominal segments and hind legs darkest. Genitalia: about the same as venter, except that the right paramere tends to be dark
reddish-brown. ANATOMY. Microreticulation: head and pronotum double over much of their surfaces, but elytra weakly double in males and scarcely or not at all in females which results in a pebbling similar to females of vacaensis; inner mesh cellules of head well-defined within the larger matrix. Head: supraclypeal seam arching slightly upward at middle above margin. Pronotum: WH PW, 0.69; LP PW, 0.39. Elytra: apices slightly truncated in both sexes; in females well-defined supra-epipleural ridge extending along most of the elytral length (apparent, but much weaker in males); female epipleura without flange (none in seven specimens). Venter: prosternal process with well-defined median crest in distal three-quarters; postcoxal processes rounded and laterally projecting posterior to the midline; last visible segment of both sexes not truncated, but rounded with a produced apex in males and subtriangular in females; males with an asymmetrical median crest; females with broad, triangular crest and marginate groove along hind margin; both sexes with a few small rugae and scattered setigerous punctures. Legs: male proand mesotarsi enlarged in a dorsoventral plane and also slightly dilated laterally; fifth tarsal segment of both pair of anterior legs twice as long as corresponding fourth; palettes easily visible at 20 power magnification; profemoral setae (female, 7; male, 8 to 10). Genitalia: oval plate with produced pointed apex; its ventral median crest bent to the left; numerous raised lines on either side of the crest; aedeagus sharply angled at about one-half its total length and with small knob at tip; right paramere with produced apex; ovipositor with five pair of rakelike teeth.
VARIATION. — Among the handful of specimens of this species that I have seen, the principal pattern variation is that, instead of pigment suffusing evenly over the elytra, there is a strong suggestion of irroration. Only one specimen out of 14 was clearly irrorated, but two more were slightly so. The intensity of the pigment varies from very dark to medium reddish-brown. The non-pigmented area of the elytra vary also.
Sexes appear to be about the same size with the means of all four measurements being statistically the same (Table 15). The condition of the specimens were somewhat poor, however; and better samples (and larger ones) are needed to make a reliable conclusion. — L. raitti is known from a single locality and collection. The specimens were taken in a roadside ditch about five miles inland on the coastal plain near San Bias, Nayarit. The pond was a shallow (no more than a foot deep at any point) temporary one with mud bottom and some grass around the margin. The surrounding vegetation was tropical evergreen forest. Seven other species of Laccophilus were taken from the same locality.
Holotype male, allotype female, and a paratype of each sex with the following locality data are in the United States National Museum: 5 m. E. of San Bias, Nayarit, vii.31.62, J. R. Zimmerman. A paratype of each sex with the same data are also deposited in the California Academy of Sciences, San Francisco, the University of Michigan Museum, Ann Arbor, and the Departmento de Entomologia, Laboratorio de Sanidad Vegetal, Coyoacan, D. F., Mexico.
MEXICO. — NAYARIT. San Bias, 5 m. E., 2 6 , 2 9 , vii.31.62, JRZ (NMSU). This is the largest species of North American Laccophilus. It was described by Horn in 1871 from Texas. It is a highly variable species and, as interpreted in this paper, has a range that covers most of the central and south Plains, the Southwest, and much of Mexico. It is a polytypic species with three races that are, apparently, completely allopatric from one another. For this reason, it could easily be interpreted as three species instead of one. The species is closely related to L. inagua Young (1963) from the Bahamas. This suggests that additional collecting should turn up other populations through the West Indies. It is also very closely related to L. sonorensis n. sp. from the southwestern United States, Chihuahua, Sonora, and Baja California.
This species group is sufficiently different in size, shape, pattern and several anatomical characters from all other North American Laccophilus to pose a problem as to its origin and as to which group of species it belongs.
DESCRIPTION. — Large (length, 4.9 to 6.7 mm; width, 2.6 to 3.8 mm), brown and yellow, or black and yellow, variegated, vittate, or marmorated species; metacoxal file absent; prosternal process short; ovipositor rakelike. COLOR. Head: pale brownish-yellow or brownish-red; specimens from southern Mexico with dark reddish-brown occiput. Pronotum: same color as head, but mayae with irregular, laterally elongated darker reddish-brown discal mark in some specimens. Elytra: varying in the different races from a dark blotch with four anterior extensions on a pale yellow background to generally dark brown with a few discrete yellow markings; dark color may be solid or marmorated; epipleura always pale anteriorly, but may be dark or pale posteriorly. Tergite VIII: brown or dark brown at base, but may be pale yellow brown to brown along the posterior margin. Venter: variable from pale brownish-yellow, especially the proand mesolegs, to frequently dark reddish-brown on the metacoxal plates and the abdominal sternites. Genitalia: variable from pale brownishTexas klahoi entral
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yellow to dark reddish-brown. ANATOMY. Microreticulation: weakly double on head and pronotum with inner cellules nearly as distinct as secondary network; elytra single, and more pebbled, especially females. Head: supraclypeal seam deeply impressed and closely parallel to the margin. Pronotum: middiscal depression longitudinally elongate instead of round as in most of the North American species of the genus; posterior margin sharply deflected forming a more acute apical angle than is common in the genus; WH/PW, 0.68 to 0.69; LP ,/PW, 0.41 to 0.42. Elytra: apices somewhat truncated; epipleura of females with anterior wide portion extending posteriorly as far as the third abdominal segment instead of the first as in most of the genus; flange present in tehuanensis females. Venter: prosternal process broad and with raised median crest; postcoxal processes laterally projecting slightly beyond the midline; last visible segment in both sexes not truncated; apex produced in male; crest in both sexes poorly defined; viewed ventrally in both sexes the lateral sides of the segment slope sharply upward causing the posterior margin to be less rounded and more angular; apex of females reflected ventrally; weak marginate groove in females; numerous rugae and setigerous punctures scattered over surface. Legs: proand mesotarsi enlarged in a dorsoventral plane and also slightly dilated laterally; fifth protarsal segment twice as long as corresponding fourth and fifth mesotarsal segment more than twice as long as corresponding fourth; palettes easily visible at 20 power magnification; proand mesofemoral marginal setae very long (at least as long as femur is wide); those on profemur (usually 6) shorter and finer than those on mesofemur (usually 7). Genitalia: oval plate with elongated tip; its ventral crest distinct only near apex; numerous fine raised lines on either side of crest; aedeagus wider in distal than basal half, but narrows near apex to a small slightly bent tip; parameres of nearly equal length; right one with elongated apex; ovipositor more rakelike than sawlike, with about 1 1 pair of teeth.

Laccophilus raitti adolah kumbang dari famili Dytiscidae. Spesies ko juo marupokan bagian dari ordo Coleoptera, kelas Insecta, filum Arthropoda, dan kingdom Animalia.

Laccophilus raitti là một loài bọ cánh cứng trong họ Bọ nước. Loài này được Zimmerman miêu tả khoa học năm 1970.