80 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 85 



In illustration of the factor of hardness as related to bird food the 

 three genera Lixus, Thecesternus, and Sphenophoriis, representing 

 as many families of weevils, may be discussed. Lixus is so hard that 

 the entomologist usually finds drilling a necessary preliminary to 

 pinning ; moreover the species are full of vitality, sometimes living 

 through 24 to 36 hours in the cyanide bottle. Records of this genus 

 in our tabulations total 102, distributed among 27 species of birds. 

 No fewer than 18 specimens were found in a single stomach of a 

 nighthawk. Thecesternus. a weevil with unusually thick and hard 

 integument, was identified 151 times in the stomachs of 22 species of 

 birds. Twelve specimens were taken by a meadowlark at a meal and 

 15 by a robin. The billbugs of the genus Sphenophoriis not only are 

 hard, but like Lixus have much ability to resist the fumes of cyanide 

 and prolonged submersion in water. However 1,397 determinations 

 were made representing 34 species of these weevils. They were found 

 in the stomachs of no fewer than no species of birds. Some of the 

 larger numbers taken from single stomachs were: 10 in the cases of 

 the upland plover, clapper rail, and yellow-headed blackbird ; 11 in a 

 robin ; 12 in an avocet ; 17 in a crow blackbird ; 20 in a killdeer ; 33 in 

 a crow ; and 34 in a magpie. 



Hardness thus appears to be of no consequence as a defense. Brief 

 attention may be paid to a few other of the so-called protective devices 

 of weevils. One of the obscurely colored genera, with the habit of 

 dropping to the ground and feigning death, is Rhinoncus ; such weevils 

 are said to resemble seeds, but what good this would do, since most 

 birds eat seeds, theorists have left unexplained. Rhinoncus has been 

 identified y^ times from the stomachs of 30 species of birds, of one 

 of which, the olive-backed thrush, an individual had eaten 20 of these 

 weevils. Rhodohacnns, our only conspicuous red and black weevil, 

 was identified 14 times in the stomachs of 10 species of birds, and 

 Tyloderma, black weevils with whitish or yellowish markings, 133 

 times in 48 species of birds. Fifteen specimens of Tyloderma were 

 taken from the stomach of a meadowlark. 



To mention the relations of birds to a few representative genera of 

 weevils, we may record that the rare Otidoccphalus were identified 

 six times in the stomachs of an equal number of species of birds ; that 

 the minute Apion were taken 91 times by 36 species ; the nut weevils 

 (Balaninns) 380 times by 85 ; the cotton-boll weevil (Anfhonomus 

 grandis) 348 times by 43 species of birds (23 other species are re- 

 corded as enemies in the literature) ; the alfalfa weevil (Hypcra 

 murinits) 2,222 times by 50; the clover root weevils (Sitona) 1,611 



