312 



FOREST ENTOMOLOGY. 



" Eggs under observation were found to hatch in four days, but 

 how long they had been laid was not known. Lingerland shows 

 that the American Grape-vine Leaf- 

 hopper (Ti/phloci/ha comes) remains 

 two weeks in the egg stage, and it is 

 quite likely this is about the period 

 taken by TypMoeijha querczis. 



" The young emerge on the under 

 side of the leaf, and grow rapidly. 

 There are four moults in the nymph 

 stage. At first the young are very 

 pale, but gradually become yellowish 

 as the wing-buds develop. Towards 

 the end of nymphal life they are 

 most ravenous. The whole period of 

 growth lasts from five to six weeks, 

 the complete life-cycle probably tak- 

 ing fifty days. (See fig. 291.) 



" They kept on breeding until the 

 first week in October, but in very 

 small numbers after the middle of 

 September. 



" Until they are mature these leaf-hoppers are very sedentary, and 

 even when adult do not jump as do other members of their tribe." ^ 



i/Typhlocyba ulni 



Refprence!< to Literature consulted. 



Buckton, (Jeorge Bowdler. Monograph of the British CicacUc or Tettigida\ 

 1890. 



Edwards, James. The Hemiptera-Hornoptera (Cieadiua aud PsylUna) of the 

 British Islands. 1896. 



Theobald, Fred. V. "New Hemipterous Fruit Pests in Britain" — The 

 Journal of E^conomic Biology, 1907, vol. ii., Ft. I. 



^ "New HemijJterous Fruit Pests in Britain," by Fred. V. Theobald, M.A. 

 -The Journal of Economic Biology, 1907, vol. ii., Pt. I. 



