4 MISC. PUBLICATION 511, U. S. DE'PT. OF AGRICULTURE 



most species (fig. 3, /), and a tridentate mandible (fig. 2, A) with a 

 strong retinaculum and basal setal brush. These characters differ- 

 entiate the members of this group into a distinct unit. 



The subfamily Trinodinae (fig. 1, E) is represented in North Amer- 

 America by the genera Attagenus Latr., Dearthrus Lee, and Novelsis 

 Csy. Although the members of this group possess some characters 

 similar to those found in the Dermestinae, such as the general shape 

 of the body, the possession of a retinaculum and a basal setal brush 

 on the mandible (fig. 2, B), and others, they are excluded from the 

 latter group because they lack urogomphi, have distally rounded in- 

 stead of tridentate mandibles, do not have the tenth abdominal seg- 

 ment completely encircled by a pigmented sclerotized ring, and do not 

 use this segment as a pygopod. Furthermore, the members of this 

 group possess a caudal brush (fig. 2, / and J) composed of long, 

 slender setae, and the pubescence of the body (fig. 3, G and H) and the 

 relative lengths of the segments of the maxillary palpus (fig. 3, B) 

 are unlike those found in the Dermestinae or any other group. 



The subfamily Trinodinae (fig. 1, E) is represented in North Amer- 

 ica by the single species Apsectus hispidus (Melsh.). The study of 

 its larva reveals characters which indicate a group relationship dif- 

 ferent from that noted heretofore. Unfortunately, only specimens 

 of A. hispidus were available for study, although other genera are 

 assigned to this group. If the larva of this species is representative 

 of the subfamily, as it appears to be from a study of the literature, 

 the larvae of this group are characterized by an ornamentation of the 

 epipharynx (fig. 4, G) similar to that found in the Dermestinae, At- 

 tageninae, and Thylodriinae, a four-segmented maxillary palpus (fig. 

 3, G) , a pointed and toothed mandible without a retinaculum or basal 

 setal brush (fig. 2, G and Z>), and the arrangement of the setae in dis- 

 tinct, clear, transverse areas on the tergites. They lack the caudal 

 brush and urogomphi. It would appear that the subfamily should 

 be placed near other units possessing the first two characters men- 

 tioned and not be separated from them, as is generally done, by a 

 group with a different ornamentation of the epipharynx (fig. 4, F) 

 and with a three-segmented maxillary palpus (fig. 3, E). In ad- 

 dition, A. hispidus and Thylodrias contractus Mots, exhibit a sim- 

 ilarity of the maxillary palpus, the ligula, and the antenna, and they 

 have the same number of proximal sensory papillae on the epipharynx. 

 Apparently the group should be placed near the Dermestinae, Atta- 

 geninae, and Thylodriinae. 



The subfamily Thylodriinae (fig. 1, F) contains the single species 

 Thylodrias contractus 2 — which, because of its distinctive characters, 

 both in the larvae and the adults, is set off from all other groups. 



The subfamily Anthreninae (fig. 1, G and D) is composed of the 

 tribes Megatomini, Anthrenini, and Ctesiini, the members of which 

 are characterized by the possession of hastisetae 3 (fig. 3, F) and has- 



2 Although there has been some doubt as to the systematic position of this species, a 

 study of the larva reveals that it meets all the characteristic requirements of the Dermes- 

 tidae. The species should, therefore, be retained in this family. 



3 In regard to these setae, peculiar to some dermestid larvae, Ferris (■}) states: "The 

 type is so distinct tbat it deserves a special name. * * * I have been unable to hit 

 upon anything better than to characterize it as 'pendicle setae,' the word pendicle, accord- 

 ing to the dictionary, being sometimes used to mean 'a pendant ornament.' " However, 

 the setae seem to be more than ornamental and the term "hastiseta" (hasta, spear, and 

 seta, hair or bristle) is more descriptive for these structures which sometimes have been 

 called "spear setae." 



