Genus - Lixus

Taxonomic Hierarchy for University of Alberta E.H. Strickland Entomological Museum


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4 results for "Lixus"

Lixus rubellus

University of Alberta E.H. Strickland Entomological Museum

SeasonalityStrickland Museum specimens (mostly from Alberta) were captured from May-July, with most in June. IdentificationLeConte (1876) identified this species as being very long and slender in overall shape, and of intermediate size (approx. 8 mm). Its cuticle colour is described as brownish-black (with Strickland Museum collections specimens appearing much closer to reddish-brown), and this is veiled by a sparse coat of very short hairs that become more dense in lateral and ventral positions. The pubescence is grey in colour, but becomes somewhat yellowed in patches - on elytra tips the pubescence becomes so fine that it takes on a powdery appearance. The rostrum of this species is fairly slender, is slightly shorter than the prothorax in length, and bears slender antennae near its tip. The antennae possess a first joint of the funicle (antennal segments between basal scape segment and clubbed tip) that is broader than the second joint. The prothorax is longer than wide, with a gradual anterior taper. Its sides are almost straight, and its back edge forms a broad arc adjacent to each elytron, creating broad medial angle (backwards projection along the midline). A shallow median depression is situated directly ahead of the medial angle. Femora on the legs of this species are slender, and the legs are brown in colour. The distinctive elytral tips are drawn out into extended, divergent points with minor rounding on their tips. Punctures (pits) are fine and dense upon the rostrum, with interspersed large punctures and one large frontal puncture. The prothorax bears minute 'wrinkly' punctures, and some moderately sized shallow ones, while the elytra bear fine 'wrinkly' punctures in tightly-packed rows. Observation of specimens in the Strickland Museum collections suggests that the extended elytra tips, general reduction in pubescence dorsally, and close spacing of elytra punctures are the most diagnostic characteristics for this species.

Lixus musculus

University of Alberta E.H. Strickland Entomological Museum

SeasonalityMuseum specimens were taken sporadically throughout the summer and fall months. IdentificationSay (1831) noted that adult specimens are large (approximately 8.8 mm), with underlying cuticle that is pitch black and covered with numerous short, white hairs. The general body dimensions are fairly ovate in dorsal view (comparatively short and stout), with a tubular, arched rostrum, and a head that is slightly constricted between the eyes. The prothorax is wider than it is long, is strongly rounded at its front, and has fairly rounded sides. The medial angle (at the back of the thorax, along the midline) is depressed, and a broad and shallow longitudinal depression arises just anterior to the medial angle, fading as it heads forward. Punctures on the cuticle are small and dense on the sides of the rostrum's base, comparatively small and dense across the thorax, and larger on elytra, but progressively smaller and constrained to longitudinal grooves near the posterior tip of the elytra. Say's original diagnosis has been supplemented with a few characters suggested by LeConte, (1876) in the identification above.

Lixus parcus

University of Alberta E.H. Strickland Entomological Museum

Common NameKnotweed Weevil SeasonalityMuseum specimens were all captured in April-June, in Alberta, and are post-emergence adults. IdentificationLeConte (1876) diagnosed this relatively small species as one in which the underlying cuticle is black and covered by a thin coat of grey pubescence - Stickland Museum specimens appear to have a much more reddish-brown coat on dorsal surfaces, but this is simply because their emergence coat has not rubbed off yet (Essig, 1958). This species is distinguished by its thick rostrum, which is as long as its prothorax, and bears coarse punctures (laterally), and a prominent fovea (shallow central pit) and shallow transverse depression on its front. Antennae are situated very close to the tip of the rostrum. The overall body shape is relatively ovate (in dorsal view). The prothorax has fairly round sides, is wider than it is long, and has broad indentations in its posterior edge (for accepting leading edges of elytra). These indentations meet along the midline of the prothorax to form a very broad triangle at the medial angle. The legs of this species have femora that are moderately slender and uniform in thickness. The elytra are significantly wider than the prothorax, with moderately deep depressions where they meet the prothorax, and rounded posterior tips. Punctures in the cuticle are minute on the prothorax, with sparse, coarser punctures interspersed. The elytra have much coarser punctures in a widely spaced distribution, but arranged in longitudinal bands (striae).

Lixus terminalis

University of Alberta E.H. Strickland Entomological Museum

SeasonalityApril-August (plus one questionable January specimen) in collections, most from April-June. IdentificationLeConte (1876) diagnosed this species as moderately large (9-11 mm), generally slender, and with a black cuticle overlain by fine, somewhat patchy, ashen-grey hairs. The background cuticle colour appears much closer to walnut-brown in our museum specimens. Separated, rounded posterior elytra tips are the key distinguishing feature for this species, it is otherwise fairly similar to Lixus rubellus Randall 1838. Within L. terminalis, the rostrum is as long as the prothorax, relatively thickened, and bears antennae near its anterior tip (1/5th of the way from the tip). The antennae have a first joint of their funicle (antennal segments between basal scape and clubbed tip) that is broader than the second joint. The prothorax is longer than it is wide, is dorsally rounded but with straight sides, and is broader than the elytra. Notches for accepting the fronts of the elytra appear almost straight in their lateral extremes, and the anterior constriction of the prothorax is gentle, giving it a rather boxy appearance. The medial angle (backwards projection along the midline of the prothorax) is small and pointed, and is situated just behind a dorsal impression which itself becomes shallower anteriorly, almost reaching the anterior edge of the prothorax. The femora of the legs are slightly club-shaped. There are punctures (pits) that are fine and dense upon the rostrum (becoming coarser on its sides). Punctures upon the prothorax are a mixture of interspersed fine and coarse pits; and are coarse, moderately deep, and widely spaced in a linear arrangement upon the elytra.

Taxonomic Hierarchy for University of Alberta E.H. Strickland Entomological Museum