294 TEXT-BOOK OF ENTOMOLOGY 



4. Rasping sounds produced by friction : 



a. Rubbing of the pronotum on the mesonotum (Cerambycidae except 



Spondyli and Prionus). 



b. Friction of the prosternum on the mesosternum (Omaloplia brunnea). 



c. Elytra with a rasp at the end (Curculionidae, Dyticidae, Pelobius). 



d. With a coxal rasp (Geotrupes, Ceratophyus) . The male of Ateuchus 



stridulates to encourage the female in her work, and from distress 

 when she is removed. (Darwin.) 



e. Friction of the edge of the elytra against the femur (Chiasognathus 



grantii}. 



f. Pygidium with two rasps in the middle (Crioceris, Lerna, Copris, Oryctes, 



Necrophorus, Tenebrionidse). 



g. Abdomen with a grating ridge and four grating plates (Trox). 



h. Abdomen with two toothed ridges rubbing on a rasp on edge of wing- 



cover (Elaphus, Blethisa, Cychrus). 



i. Rubbing the elytra on a rasp on the hind wings (Pelobius hermanni). 

 j. Friction of the wing against the abdominal segments (Melolontha fullo). 



Mutilla makes a rather sharp noise by rubbing one abdominal segment 

 against another. Ants (Ponera) have a stridulating apparatus, and other 

 genera numerous (20) ridges between the segments. 



Even certain moths and butterflies emit a rasping or crackling noise. The 

 death's-head moth and other sphinges cause it by rubbing the palpi against the 

 base of the proboscis. These and certain butterflies are provided with parallel 

 ridges forming a rasp on the " basal spot " of the inner side of the basal joint of 

 each palpus (Renter). A South American butterfly (Ageronia feronia) can be 

 heard for several yards as it flies with a crackling sound. Hampson finds 

 that the cause of the clicking sound is due to a pair of strong chitinous hooks 

 attached to the thorax, against which play the spatulate ends of a pair of hooks 

 attached to the fore wings. An Australian moth (Hecatesia) flies with a whiz- 

 zing sound ; Vanessa is said to be sonorous. 



The males of Orthoptera produce their shrill cries or chirping noises, 1 , by 

 rubbing the thighs against the sides of the body (Acrydiidse) ; 2, by the fric- 

 tion of the base of the fore wings on each other (Locustidse) ; 3, by rubbing 

 the base of the upper on the base of the hinder or under pair (Gryllidse), in 

 the two last there being a shrilling apparatus consisting of a file on the hind 

 wings, which rubs on a resonant surface on the fore wings. The females are 

 not invariably dumb, both sexes of the European Ephippigera being able to 

 faintly stridulate. Corixa also produces shrill chirping notes. (Carpenter.) 



Certain insects also hum, and have what may perhaps be called a 

 voice. The cockchafer, besides humming with the wings, produces a 

 sound almost like a voice. In the large trachea, just behind each 

 spiracle, is a chitinous process, which is thrown into vibrations by 

 the air during respiration, and thus produces a humming noise. 

 (Lubbock.) Such is also the case with flies, the mosquito, dragon- 

 flies, and bees. In flies and dragon-flies the " voice " is caused by 

 the air issuing from the thoracic spiracles ; while in the humble-bee 

 the abdominal spiracles are also musical. The sound made by the 

 spiracles bears no relation to that caused by the wings. Landois 



