PROC. ENT. SOC. WASH., VOL. 23, NO. 2, FEB., 1921 45 



Systematic Position of Sandalus Larva. 1 



Sandalus has been placed in the family Rhipiceridae together 

 with Zenoa and Callirrhipis and other exotic genera. Larvae of 

 both these latter genera have been studied and their association 

 with Elaterid-like forms has been recognized. The larva of 

 Sandalus presents so many structural differences from the two 

 genera just mentioned that it can not be regarded as belonging 

 to the same family. It might be contended that this parasitic 

 larva, of which only the last instar is known, may have very 

 different structures and appearance in the earlier instars. This 

 of course may be the case in all such parasitic forms known (as 

 in the families Staphylinidae, Carabidae or Meloidae) the funda- 

 mental structures, however, do not vary as much as is generally 

 believed and the family characters usually are recognizable 

 throughout the various stages. The form, reduction of legs, 

 antenna and palpal joints can be regarded as adaptations to a 

 parasitic habit, and a difference in these structures from allied 

 genera are to be expected. The larva can be differentiated from 

 Zenoa and Callirrhipis by the presence of a divided mala, which 

 will also distinguish it from all other parasitic types of larvae 

 known. The spiracles are identical with those of the Elateridae 

 and Sandalus is possibly most closely related to this family. 

 Many characters suggest, however, that it has developed from 

 Malachiid or Dermestid types which are regarded as less special- 

 ized larvae than the Elaterids. 



For the above reasons this genus is characterized as belonging 

 to a distinct family, Sandalidae, based on Sandalus niger Knoch . 



Characterization of the Family Sandalidae. 



Larvae. White, fleshy, fusiform, provided with solid, chitinous, conical cerci; 

 head globular, probably hypognathous; gula large, rectangular; labrum present; 

 antenna large, conical, one-jointed; mandible of simple grasping type, conical 

 and acute, without molar structure, retinaculum, prostheca or hairfringes; 

 ventral mouth parts retracted, fleshy and somewhat swollen, fused into a unit 

 through loss of maxillary articulating area and union of menturn and maxillary 

 stipes; inner margin of maxillary stipes and region of cardo slightly chitinized; 

 maxillary palp two-jointed; galea andlacinia present, conical, latter more obtuse; 

 labial stipes conical, palp one-jointed; ligula small; hypopharyngeal bracon well 

 developed but only lightly chitini/ed and united with large fleshy hypopharynx; 

 occipital foramen posterior; legs weak, conical, no chitinous articulations, three- 

 jointed, tarsus chitini/ed and hooklike, coxa widely separated; intersternal 

 rings of mesothorax and metathorax well developed, no hypopleural chitini/a- 

 tmns of thorax; abdominal and thoracic areas indistinct; spiracles bifore; tenth 

 abdominal segment ventral, wart-like. 



'The following taxonomic discussion is based on a joint study of the character- 

 ization of Coleopterous larval families undertaken by Dr. A. G. Boving and the 

 writer. 



