Lagocheirus araneiformis flavolineatus Aurivillius, 1921

Toledo, Víctor H. & Hovore, Frank T., 2005, Notes on the genus Lagocheirus Dejean: records and descriptions (Coleoptera: Cerambycidae: Lamiinae: Acanthocinini), Zootaxa 1021 (1), pp. 29-36 : 32-34

Lagocheirus araneiformis flavolineatus Aurivillius, 1921 , new status

(Figure 2a)

Lagocheirus flavolineatus Aurivillius, 1921: 52 , pl. 2, fig. 10

Remarks. When Aurivillius described this species from Colombia, he noted that it differed only slightly from Lagocheirus araneiformis , the primary distinguishing characteristics being the distinctive dorsal pattern of pale yellowish vittae, forming an X­shaped marking across the elytral disk, and by the larger blackish tubercles of the elytra. Dillon (1957) summarily — and incorrectly — synonymized flavolineatus with L. rosaceus Bates , without comment as to how he arrived at that determination. Dillon may not have seen either the type specimen of flavolineatus nor the original description and illustration, as flavolineatus clearly does not fit within Dillon’s characterization of rosaceus , nor would it key to that species in his revision, having the median portions of the pro­, meso­ and metasterna, and abdominal sternites densely pubescent (a “group” character that it shares with araneiformis ). Also, Lagocheirus rosaceus has a very different dorsal pattern (Figure 5), primarily formed by reddish­orange vittae, a much broader, more inflated­appearing pronotum, and much shorter antennae, with annulate distal segments. Toledo (1997) did not review South American taxa in his regional study of the genus, and so did not comment upon the synonymy of flavolineatus with rosaceus , but the two taxa clearly differ from one another, and flavolineatus is hereby removed from synonymy with rosaceus .

The relationship of flavolineatus to araneiformis is more difficult to resolve, however, as the two taxa appear to intergrade within northern Amazonian Ecuador. A series of specimens from Napo Province ("km 11, Loreto Road, 1,200 m " E.F. Giesbert) (Figure 2a) (FSCA), exactly match the type specimen of flavolineatus in coloration and the extent of the elytral pattern, and are readily distinguishable from araneiformis ypsilon (Voet) (from Central America) and araneiformis fulvescens Dillon (from northern South America) both of which lack the distinctive dorsal pattern, yellow pubescent antennae, and coarser, basal elytral sculpturation. Three specimens from Sucumbios Province: " 5 km W Nueva Loja " [= Lago Agrio], T.C. MacRae (FTHC) (Figure 2b) (approximately 120 km E of the Loreto Road locality, and several hundred meters lower elevation), possess the apical portions of the flavolineatus elytral pattern, but on the basal portion of the elytra the pattern ranges from indistinct to absent, and the antennae are less­brightly yellow­colored. Specimens from a lower elevation site in Napo Province: 21–25 km W Atahualpa, F.T. Hovore (FTHC) (Figure 2c) (approximately 40 km south, and 900 m down­slope from the Loreto Road locality) have typical araneiformis dorsal patterns, but with elytral sculpturation and antennal coloration closer to that of flavolineatus . Specimens of araneiformis examined from further south in Ecuadorian Amazonia, and from mid­elevation sites in French Guiana (± 300m) (Figure 2d) exhibit no intermediacy with the flavolineatus phenotype.

The distinctive flavolineatus pattern apparently occurs populationally in montane Amazonian Ecuador, and presumably also in Colombia, where it may represent a discrete taxon within the araneiformis species group. Because material from nearby lower elevation sites in Ecuador exhibits phenotype intermediacy with araneiformis , it seems prudent at present to regard flavolineatus as a subspecies of Lagocheirus araneiformis .

The type of L. flavolineatus is in the Entomology Collection of the Swedish Museum of Natural History .

FIGURE 4. Lagocheirus giesberti ; a: male, Costa Rica; b: female, Costa Rica

FIGURE 5. Lagocheirus rosaceus , male, Costa Rica

FIGURE 6. Lagocheirus obsoletus obsoletus , male, Costa Rica