1908.] 



Bulb Mite. 



679 



2. That some species of the genus Eriophyes are found feeding 

 each on several species of the same genus of plant. 



3. There are recorded cases of a species of Eriophyes attacking 

 plants of different genera of the same natural order. 



4. That examples of the same species of Eriophyes infesting 

 plants of a different but related natural' order are so rare as to 

 be exceptional. 



It still remains to prove from microscopic examination and 

 experimentally that the same species of mite will infest plants of 

 two different and not related natural orders, giving rise on these 

 plants to the same kind of gall or damage. 



R. Stewart MacDougall. 



In reference to the article on the Bulb Mite (Rhizoglyphus 

 echinopus) which appeared in this Journal for March, 1905, 

 the methods of treatment there given 

 The Bulb Mite (Rhizo- have now been revised and should read 

 glyphus echinopus). as follows : — 



1. This pest is very difficult to combat 

 because the extremely tiny mites feed not only on the outside of 

 the bulbs, but between the leaf scales of the bulb, feeding and 

 laying their eggs in the interior, where they can scarcely be 

 reached. The best plan is to burn badly infested bulbs, 

 for the mites which have penetrated into bulbs cannot be 

 reached. Infested soil should not be used for other bulbs. 



2. In the case of mites which are more external the bulbs 

 should be sprayed with paraffin, the treatment being repeated 

 a fortnight later ; or the bulbs may be washed in sulphide of 

 potassium (liver of sulphur), 1 oz. to 1 gallon of water, or 

 brushed with this after removal of the outside scale leaves. 

 This treatment is useful against fungi which follow the attack 

 of the mite.* 



* At a meeting of the Scientific Committee of the Royal Horticultural Society (see 

 Gard. Chron. s Dec. 20, 1902, p. 465), Mr. Saunders, in the course of a report on 

 hyacinth bulbs containing a large number of R. echinopus, stated that "When bulbs 

 are thus infested with these mites nothing can be done to save them. When only a 

 few mites are at the base of the bulb, where the attack generally commences, they 

 may be killed by immersing the bulbs for five minutes in water at a temperature of 

 115° to 120° Fahr. If some sulphide of potassium (6 oz. to the pint) be added to the 

 water, this remedy would be all the more efficacious ; indeed it is said that soaking 

 the bulbs in this solution cold for twenty minutes will kill the mites." 



