Sampsonius is a genus of beetles belonging to the family Curculionidae.[1]
The species of this genus are found in Southern America.[1]
Diagnosis: Characterized by a notably elongated and pale body. The pronotum is distinctly elongated with long paired serrations along the anterior edge and emarginate sides. The elytral declivity features spines and/or tubercles, often accompanied by long, dense setae. The antennal club is flattened, with the first and second sutures slightly to moderately curved and the first two segments sclerotized.
Biology: Sampsonius species are domicile parasites that do not create their own galleries. Instead, the female seeks out the newly excavated gallery of another ambrosia beetle, often a Dryocetoides species, enters it, and consumes the original occupant. The female then uses this gallery to rear her brood. These species are typically found in seedlings or branches ranging from 2 to 8 cm in diameter.[2]
Taxonomy[3]
Detailed Description:
Eyes are shallowly emarginated, with the upper portion smaller than the lower. The antennal club is approximately circular and classified as club type four (not truncated, with the first segment smaller than the second and both convex). Segment 1 of the club is straight on the anterior face, though it may be slightly concave or convex; its margin is mostly costate and appears softer on the posterior face. Segment 2 is corneous on both sides but not circular, preventing the antenna from appearing tall or "telescopic." Segment 3 is clearly visible on both sides of the club. The first segment of the antennal funicle is shorter than the pedicel and the funicle itself is four-segmented. The scapus is regularly thick.
The frons above the epistoma is mostly smooth and alutaceous, with minor punctures, or may be rugged and coarsely punctate. The submentum is flat and flush with the genae, shaped like a narrow triangle. The anterior edge of the pronotum features two distinct flat denticles protruding anteriad, and the entire margin extends forward, forming a noticeable "hood" over the head. The pronotum appears long from the lateral view (type 9) and is conspicuously long and angulate or rounded from the dorsal view (type b). The pronotal disc is shiny or smoothly alutaceous, with small punctures, while the lateral edge is obliquely costate.
Procoxae are contiguous, and the prosternal posterocoxal process is short and conical or flat and inconspicuous. There are no tufts on the pronotal base associated with the mesonotal mycangium, nor setae on the elytral bases linked to the elytral mycangium. The scutellum is flat and flush with the elytra. The bases of the elytra are straight with an oblique edge, and the elytral disc is longer than the declivity, being convex or bulging. Punctures on the elytral disc are arranged in strial lines, which may be difficult to discern. The boundary between the elytral disc and declivity is distinct, with the lateral profile of the elytral declivity excavated. The dorsal profile of the elytral apex is prolonged, appearing attenuated, angulate, or concave, and emarginate. The elytral declivity is covered with dense erect setae, often more abundant than the strial punctures.
The posterolateral declivital costa is elevated, reaching beyond the fifth interstriae and often completely surrounding the entire declivity. The surface of the declivity features a pair of tubercles on the elevated costa, making their assignment to interstriae challenging, or it may have a pair of long projections on each elytron. The first interstriae are parallel, sometimes slightly broadened towards the elytral summit. Striae and interstriae on the upper part of the declivity are even and flush with the surface. The protibia is slender and not distinctly flat, with the posterior side flat and bearing only setae. Protibial denticles are small, with their bases slightly elevated, and the protibial margin rounded, having fewer than six denticles. The metatibia is of normal size. The coloration is uniformly light brown or reddish, with the pronotum sometimes being slightly lighter. Length ranges from 3.1 to 8.0 mm.
Sampsonius | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Coleoptera |
Family: | Curculionidae |
Genus: | Sampsonius Eggers, 1933 |