Dasyus collaris: homeotype male. Photos by Kerry Katovich. .
Dasyus collaris: female. Photo by Kerry Katovich
left lateral view caudal view
Genitalia of Dasyus collaris.
Distribution of Dasyus collaris.

Melolonthinae Catalog

Diagnosis: this species is recognized by its distinct coloration and size, male pronotum reddish-orange, and elytra black, females have a black pronotum and elytra. Total length (8.0 mm) and width (5.6 mm) of D. collaris is approx 1/2 that of D. variabilis.

Description:
Measurements: Prothorax at widest point 3.0 mm, elytra at widest point 3.6 mm, length 8.0 mm.

Color and vestiture: Head, thorax and abdomen black, (thorax reddish-orange in males), thorax covered with vestiture of short, yellowish-orange setae, elytra black.

Head: Eyes large in dorsal view (ocular width 1/2 interocular width); clypeus coplaner with frons, frons angled at 30°; labrum in frontal profile narrowly ovate, weakly emarginate, slightly produced anteriorly from clypeus, labrum not coplaner with clypeus; labium with prementum elongate, ventral surface with medial groove; antennae 9-segmented, segments 7-9 forming the elongate club, equal to length of segments 2-6 combined.

Prothorax: Pronotum oblong, transverse, widest medially, posterior angle obtuse, posterior margin convex, medially lobed; prothoracic leg with coxae elongate; tibia lacking teeth, medially with a stout spur; pretarsus with claws strongly divergent, equal in length, both claws narrowly split.

Mesothorax: Scutellum subtriangular; elytra ovate, width equal to length, elytral epipleuron forming a rounded bead, margin with a slight membranous border, dorsal surface smooth, punctate, punctures in distinct vertical lines, anterior umbone prominent, posterior umbone moderately produced; pretarsus of mesothoracic leg with claws equal, divergent, simple.

Metathorax: Metathoracic leg with coxae clearly separated; femur broadly ovate, widest medially; tibia subtriangular, widest medially, narrow proximally, posteroventral margin with a pair of long, stout spurs; pretarsus with claws similar to mesothoracic legs.

Abdomen: Ventrites 2-4 subequal in length, 5th visible ventrite (=propygidium) equal in length to ventrites 2-4 combined, ventrite and sternite of 5th abdominal segment lacking a complete suture, 6th ventrite equal in length to 5th ventrite length; ventromedial surface with a semicircular shaped pocket, margins of which are raised, posterior margin sinuate; pygidium subtriangular, width equal to length, posterior margin blunt.