THE CICADA OR TETTIGID^E OF GUERNSEY. 



BY MR. W. A. LUFF. 



In a paper read before the Society in 1890, 1 gave a list of the 

 Hemiptera-Heteroptera of this island, a group forming the 

 first division of the order Hemiptera, insects characterized by 

 a sucking rostrum instead of cutting jaws, and by their 

 undergoing an incomplete metamorphosis. 



The insects now under consideration (The Cicada?) are 

 included in the second divison of the Hemiptera, under the 

 title of Hemiptera-Homoptera, and differ from the Heterop- 

 tera by the elytra or forewings being membranous and 

 naked, and not overlapping each other at the apex, and the 

 rostrum springing from the posterior portion of the under 

 side of the head, near the base of the fore-legs. 



To this group also belong the numerous species of 

 Aphides or greenflies, so destructive to our plants in gardens 

 and greenhouses, and the scale insects, which include such 

 species as the Cochineal insect (Coccus cacti), a native of 

 Mexico, the lac insect (Coccus lacca), of the East Indies, and 

 the common scale insect (Coccus adonidum) so well known 

 in our hot-houses and conservatories. The curious ant's nest 

 species Ripersia Tomlinii, recently discovered for the first 

 time at Moulin Huet Bay also belongs to this family. 



The Cicadae of the Tropics are often of a very large size, 

 some of them measuring as much as seven inches across the 

 wings. Many of the species possess an apparatus for the 

 production of a rather sharp and rattling sound, which is 

 sometimes so loud as to be heard at the distance of a mile. 



The musical or sounding organs, which exist only in the 

 male, are situated on the sides of the insect, just behind the 

 wings. They consist of drum-like membranes stretched over 

 small cavities; attached to the inside of these are powerful 

 muscles which serve to vibrate the membrane with inconceiv- 

 able rapidity. The noise is sharp, monotonous and tiresome 

 from its constant repetition. 



It is on account of its song that the Cicada has been 

 mentioned so much in the literature of the countries in which 

 it occurs. 



