Insects Injurious to the Apple. 165 



Kefeeences. 



(1) Kollar, V. ' A Treatise on Insects,' p. 278 (1840). 



(2) Edtuards, J. ' The Hemiptera-Homoptera of the British Isles ,' p 247 



(1896). '■ 



(3) Ormerod, E. A. ' Handbook of Insects Injurious to Orchard and Bush 



Fruits,' p. 42 (1898). 



(4) Theobald, F. V. Report on the Orchard and Fruit Plantations of Wor- 



cestershire. (Worcestershire Education Committee) p. 12 (1906). 



(5) Theobald, F. V. Second Eeport on Economic Zoology (British Museum), 



p. 45 (1904). 



(6) Furley, K. Report on the Experimental Spraying for the Apple Sucker. 



(^^'orcestershire Education Committee) (1907). 



(7) Theobald, F. V. Eeport on Economic Zoology for the year ending 



April 1st, 1905, p. 39 (1905). 



(8) Theobald, F. V. Idem for year ending April 1st, 1906, p. 37 (1906). 



(9) CooJce, M. C. ' Vegetable Wasps and Plant Worms,' p. 304 (1892). 



(10) Bedford, DuTce of, and Pichcring, Spencer U. Eighth Eeport of the 



Woburn Experimental Fruit Farm, pp. 70 and 73 (1908). 



THE MUSSEL SCALE INSECT. 



{Lepidosaplies ulmi. Linn.*) 



The Mussel Scale, also known as the Oyster-shell Scale, was 

 first definitely described in 1758 by Linnteus as Coccus ulmi. The 

 name by which we have known it in recent years has been wrong, 

 viz., Mjjtilaspis pomonom, of Bouche (1851) ; moreover, it is now 

 shown not to be a true Mytilaspis at all, but belongs to the genus 

 Lcpidosaplus, Shimer (1868). Its correct nomenclature stands thus, 

 Lepidosaplies ulmi, Linn£Eus. It has been described under twelve 

 specific names, and six generic names according to M. E. Fernald (1). 



Scale Insects are called Coccidas, and are found living as parasites 

 on many plants in all parts of the world, especially in warnr climates. 

 They are not only unsightly, but are most injurious to the health 

 of the plant or tree which they attack. Frequently they encrust trees 

 so thickly that death results. Like the Aphis, the Scale Insect feeds 

 upon the sap of the tree, and at the same time blocks up the 

 respiratory pores (lenticels), by encrusting the trunk and boughs 

 with the scaly structures they produce, or their shrivelled bodies 

 or felted secretions. We find scale insects on all parts of trees 

 and plants, on the trunk, boughs, leaves, fruit and even on the 

 roots of some plants. 



Many species, such as the one in question, may live on many 



* Formerly known as Mytilaspis pomof'uvi. 



