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.......Dasyus Le Peletier and Audinet-Serville, 1828

Melolonthinae Tribes
Incertae sedis
Melolonthinae Taxa Map
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Dasyus collaris Lepeletier and Serville: homotype male.
Photo by Kerry Katovich
Dasyus Key

D. collaris: Brazil
D. variabilis: Brazil


Generic Diagnosis: This genus is recognized by its ovate body; prementum elongate, ventral surface medially grooved (Fig. 1); pretarsus of meso- and metathoracic legs with claws equal, divergent, simple; ventromedial surface of 6th ventrite with a semicircular shaped pocket, margins of which are raised (Fig. 2); pygidium subtriangular, width equal to length, posterior margin blunt.

Fig. 1 Prementum, ventral view
Fig. 2 Abdomen of male, dorsal view

Generic Diagnosis
Measurements: Prothorax at widest point 3.0-4.0 mm, elytra at widest point 3.6-5.6 mm, length 8.0-14.0 mm.

Color and vestiture: Head and abdomen black, thorax reddish-orange in males of D. collaris, black in D. variabilis males, black in all known females, covered with vestiture of short, yellowish-orange setae in all species; elytra black, reddish-orange in females of D. variabilis, black in D. collaris.

Head: Cypeus 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; 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 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; pygidium subtriangular, width equal to length, posterior margin blunt.


Dasyus is comprised of two species:

Dasyus collaris Lepeletier and Serville 1828 (type species by monotypy). Type location: presumptive syntype located at the MNHC.

Dasyus variabilis Moser 1918. Type location: holotype located at the ZMHB.


Key to species


Le Peletier, A. L. M., and J. G. Audinet-Serville 1828: In Latreille, P.A., Le Peletier, A. L. M., Audinet-Serville, J.G. and Guérin, F. E. Encyclopédie methodique. Histoire naturelle. Entomologique, ou histoire naturelle de crustaces, des arachnides et des insectes. Tome dixiéme [1825]. Paris. 832 pp.

Moser, J. 1918. Beitrag zur Kenntnis der Melolonthiden (Coleoptera). (XIV). Stettiner Entomologische Zeitung 87: 198-208.

Notes: This genus is only one of two Macrodactylini that has the meso- and metathoracic pretarsus with simple claws. The presence of the pocket on the ventral surface of the abdomen is similar to Calodactylus (Macrodactylini), however the pocket is located on a different ventrite (6th vs. 5th). Sexual dimorphism is present in this genus, primarily in coloration.


Larvae: Unknown.

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Author: Kerry Katovich
Generated on: 15/SEP/2005
..... Last modified: 01/FEB/2007
University of Nebraska State Museum - Division of Entomology