io6 First Report on Economic Zoology, 



tlitit do harm, viz., Onisci/s asclli's, Linn., and ArmadiUidium vulgare, 

 Lat. Oniscus aseUus is omnivorous, but does nuich harm in liot-liouses 

 and to soft wall-fruit ; it also eats away at strawberry roots. This species 

 rolls itself up into a ball and can be told from the ArmadiUidium and 

 Porcellio by having eight-jointed antennse, the two latter having seven- 

 jointed ones. 



ArmadllUdium vidgare is larger and of a uniform slaty blue and rolls 

 itself up very readily. 



Porcellio scaler is brown, much variegated in colour, with a rough 

 shell and two long spines behind. 



Probably they have been spread in the manure from the heap you 

 refer to. 



You might cover the manure heap with lime — gas lime (hot) in 

 preference — but it must be left on the heap for some four weeks before it is 

 put on the land. J should put a layer an inch thick of gas lime over the 

 heap and let it stand for some time. 



Woodlice may easily be trapped along borders by putting here and 

 there pots filled with moss and horse dung. They can be collected in the 

 day-time and so destroyed. 



Many plants are harmed by these pests ; as a rule the harder the leaf 

 the more the plant escapes. 



There are some twenty species of Woodlice found in Great Britain. 

 These land isopoda are included in twelve genera. They may mostly 

 be found under moss, decaying wood, and leaves, both out-of-doors and in 

 greenhouses. Some few, such as Ligia ocecmica, Linnaeus, and Fhiloscia 

 Gouchii, Kinahan, seem to be partial to the neighbourhood of the sea. 



A New Phytoptid Disease in Violas. 



Quite a new disease in violas has Ijeen reported by Mr. Charles J. 

 Gleed, of Cliveden Gardens, Maidenhead. The specimens sent had 

 most of the leaves curled tightly over at each side and were quite 

 hopelessly deformed. 



Mr. Gleed wrote that he " thought it was the cold weather ; but 

 the attack is not general, two or three plants here and there, about 

 30 per cent, of the plants and both young stuff struck this spring, 

 and old plants off which cuttings have been taken, are attacked 

 indiscriminately." 



At first sight one would say the damage was due to Biplosis 

 violicola — the Violet Gall-Midge described by Mr. Chittenden * and 

 excellently figured — but an examination soon revealed the real cause 

 of the disease. There were found in all the leaves examined a 

 number of short, thick green phytopti which seemed especially to 

 congregate towards the apex of the leaves. As many as fifty of this 

 large species were counted in one leaf. It is larger than the Currant 



* " Some Insects inju'ions to the Violet, Rose, and otiier Oraaiiiental Plants," 

 Bull. 27 (N.S.), U.S. Dep. of Agriculture, 1901, p. 47. 



