494 AN INTRODUCTION TO ENTOMOLOGY 



method of control by immersing the timber during the time of ovi- 

 position of the beetle was suggested by Linnaeus. 



The family MICROMALTHID^ includes a single species, 

 Micromdlthtis dehilis. This is a small beetle, measuring only 2.2 mm. 

 in length. It is elongate, piceous, shining, with the antennas and legs 

 yellow. This species is of great interest on accotmt of its remarkable 

 life-history, only a part of which is yet known. Two papers on this 

 subject have been published by Mr. H. S. Barber ('13a, '13b). 

 Briefly, this author's observations indicate that eggs are produced by 

 larva: as well as by the adult females; that there are seven or eight 

 forms of larva? ; that the two sexes of adults are developed through two 

 distinct lines of larv^a?; and that viviparous as well as oviparous 

 pccdogenesis occurs in the life-cycle. The larv^ae are foimd in decaying 

 oak, chestnut, and pine logs, where they make burrows in the decay- 

 ing wood, on which they feed. 



The family CUPESID^E includes only four American species. 

 These are found under the bark of decaying trees, and sometimes in 

 houses. The body is covered with small scales; other characteristics 

 are given in the table of families, page 471. 



The family CEPHALOID^ is a small family of which only eight 

 American species have been described. See table, page 474, for dis- 

 tinctive characters. 



The family CEDEMERID^ is composed of beetles of moderate 

 size, with elongate, narrow bodies. The head and prothorax are 

 somewhat narrower than the wing-covers; the antennae are long, 

 nearly filiform, sometimes serrate; the anterior coxal cavities are 

 open behind, and the middle coxae are very prominent. Less than 

 fifty North American species have been described. They are generally 

 found on plants, but some live on the ground near water. The larvae 

 live for the most part in decaying wood. 



The family MORDELLID^ includes a large number 



jfO^ of small beetles which are easily recognized by their pe- 



/fZ-^ culiar form (Fig. 585). The body is arched, the head 



Fig. 58s. being bent down; and the abdomen is usually prolonged 



into a slender point. Our most common species are black; 



but many are variegated, and all are pubescent. The 



adults are usually found on flowers ; the larv^ae live in rotten wood and in 



the pith of various plants, upon which they are su pposed to feed. Nearly 



one hundred fifty American species have been described. 



The family RHIPIPHORID^ includes a small num- 

 ber of beetles, which are very remarkable in structure and 

 habits. The wing-covers are usually shorter than the ab- 

 domen, and narrowed behind (Fig. 586) ; sometimes they 

 are very small, and in one exotic genus they are wanting p- .gg 

 in the female, which lacks the wings also and resembles a 

 larva in form. The antennae are pectinate or fiabellate in 

 the males, and frequently serrate in the females. The adult insects 

 are foimd on flowers. The larvae that are known are parasites, some 

 in the nests of wasps, and some on cockroaches. 



