Tragidion gracilipes Linsley

Swift, Ian & Ray, Ann M., 2008, A review of the genus Tragidion Audinet-Serville, 1834 (Coleoptera: Cerambycidae: Cerambycinae: Trachyderini), Zootaxa 1892, pp. 1-25 : 20-21

Tragidion gracilipes Linsley

( Figs 4 B–C, 7B)

Tragidion gracilipes Linsley, 1940:136 ; Hovore and Giesbert, 1976:353. Type locality: Napa County, California.

Material examined: 10 specimens, including the type at CASC.

Diagnosis. This species is closely related to T. armatum and T. agave . It can be separated from both species by the narrower metatarsi, in which the first tarsomere is longer than the following two together, and the 2nd tarsomere longer than broad and distinctly more elongate than 3rd, and the tarsal claw is inserted into the 3rd tarsomere distinctly less than half its length; the basal black band is narrow and confined to the humeral margin; the antennal scape, which is enlarged and 2 × the width of 2nd antennomere at its apex, as well as being more or less equilateral in shape. Tragidion armatum and T. agave have the more robust tarsi; lack any basal black band; and the scape is subconical, tapering anteriorly. T. gracilipes can also be distinguished from T. armatum (but not T. agave ) by the long antennae, which exceed the elytral apices by at least three whole antennomeres.

Distribution ( Fig. 7 B). From the material examined, this species appears to be endemic to the California Floristic Province, with most specimens from northern and southern California. A specimen of this species from Ensenada, Baja California, Mexico (MCZC) represents a new country record.

Ecology. This species is known to infest Rhamnus californica in northern California, however, it has also been reared from fire-killed Adenostoma fasciculatum ( Swift 2008) . The biology of the larvae is similar to that of T. annulatum .

Figures

FIGURE 4. Dorsal habitus photos of Tragidion spp. A, Tragidion dichromaticum (female); B, T. gracilipes (male); C, T. gracilipes (female).

FIGURE 7. Distribution map of Tragidion spp. A, Tragidion agave; B, T. gracilipes; C, T. annulatum; D, T. deceptum; E, T. densiventre; F, T. auripenne.