LIFE-HISTORY. Ixix 



Typhlocijha one single ovum sometimes occupies the 

 entire cavity of the abdomen, and this has much the 

 appearance — but of course not the significance — of 

 the egg of the true female of Aphis. 



The females of the true Tibicina3 are very prolific, 

 each yielding, as before noted, from two to three 

 hundred eggs. Probably some American species exceed 

 this number, and may approach nearly to the fecundity 

 of the locusts. It is probable that some species of 

 Tettigidae have more than one brood in the year. Thus 

 Tj/phlocijha mdissce may be taken in early September 

 on the leaves, and quite late in December, under the 

 roots of thyme. Even when the thermometer marked 

 20° of Fahr., and the snow was an inch deep on the 

 ground, I found many young larvse very active and 

 leaping vigorously, this low temperature apparently 

 not afi'ecting them or freezing their juices. 



The Tettigidee can hardly be considered gregarious 

 in habit ; nevertheless numerous specimens of Euacan- 

 thus intemtptus may sometimes be taken on a single bush 

 of the Ukx. Five or six individuals of Fhikenus may be 

 taken occasionally within one mass of spume ; and 

 yet, again, small showers of Typhlocybidae may be 

 started from the hazel bushes (Corylus), or the rose 

 trees. As a rule, however, examples are more or less 

 isolated, and in this respect they are unlike Ajihis and 

 Coccus. After the Tettigidae attain the imago state, 

 their chief occupation appears to be to chirp all day to 

 their mates, to enjoy their short lives, then to oviposit 

 and die. 



With the exception of the Aphrophor^, which 

 attack almost all kinds of trees and plants, the Tetti- 

 gida) are much restricted as to their choice of food. 

 Some kinds exclusively affect the oak, others the 

 elm, the maple, the poplar, and the willow ; others 

 nestle amongst low plants on dry or sedgy moors ; 

 some live on hot and sunlit banks, whilst others 

 hybernate at the roots of furze and heath. Even the 

 tops of high cliffs, like those of the Isle of Wight 



