356 Insect Pests. 



TJiey take a week to hatch. I have never found them except in 

 the leaves, but Parrott (4) has found them in America at the base of 

 the bud scales and in the pubescence of the buds. 



The adult varies in colour from clear white to translucent white, 

 and now and then with a pinkish tinge. The cylindrical body is 

 annulated. 



The general characters are seen in the figure (234). The size 

 varies very much, JSTalepa giving it as 0-2 mm. in the female, 0-175 

 in the male. 



The larval stage is much like the adult, but the annulation and 

 markings are not so distinct, and it lies in a semi-curved position 

 buried in the substance of the galled tissues. 



The earliest record was by Scheuten (6), who called the supposed 

 adult Tyfhlodromus pyri ; this was nothing more than a Gamisid mite, 

 probably feeding on the Eriophyes, having no connection with the true 

 gall former, which was first named by Pagenstecher (7) Phytoptus pyri. 



Prevention and Eemedies. 



There is no doubt that this pest is spread with nursery stock, and 

 it is therefore very essential that such should be fumigated before 

 being planted. 



Hydrocyanic acid gas has been found quite effectual for this 

 purpose at the strength used for fumigating young dormant stock 

 {vide Appendix 0). 



In small attacks in gardens the galled leaves should be hand-picked 

 as soon as the signs of the disease appear, by so doing in a year or so 

 it will disappear. 



Slingerland has found in America that spraying with kerosene 

 emulsion diluted with five to six parts of water exterminates it, and 

 Lounsbury has found the same of benefit at the Cape. This lias been 

 tried in Britain, and although it reduced the attack it did not by any 

 means exterminate it. 



In 1898, the kerosene emulsion, paraffin-naphthalene wash, and 

 the lime-salt-sulphur washes were tried at Wye, and the latter proved 

 (I) by far the most successful. Since then experiments in America (4) 

 have conclusively proved that a modification of this wash, namely, 

 lime-sulphur-caustic soda, is best for combating this disease, or the 

 boiled lime- sulphur wash. 



Paraffin emulsion may be used where apple is attacked, diluted 

 with five parts of water. This is best used in late autumn and early 

 spring. Prom observations made here, either the lime-salt-sulphur 



