94 



GOOSEBERRY. 



Gooseberry and Ivy Red Spider. Bryohia pratinsa, C. L. Koch. 

 Also Bnjobia ribis, u. sp., of Dr. Friedrich Thomas. 



5^^ 



Beyobia pr-etiosa, from life ; B. speciosa (outline figure after Koch) : both 

 magnified. Leaf infested by " Bed Spider," natural size. 



During the spring and early summer of 1893 Gooseberry 

 leafage was infested to a very unusual extent by a small 

 Acariis, or "mite," commonly known as "Ked Spider." This 

 mite is of a different species to the well-known "Red Spider" 

 of the Hop, and is very commonly to be found on Ivy leaves ; 

 but in this year, without apparently being less present on 

 Ivy, it extended its infestation to Gooseberry leafage to an 

 amount causing serious loss to growers in many localities. 



This very unusual prevalence was almost certainly owing 

 to the very unusual drought, which, as we all know, is favour- 

 able in various ways to increase of "Red Spiders," and 

 demonstrably so from a great number of these mites not 

 being washed off, or otherwise injured, by soaking moisture, 

 or heavy driving rain-storms. 



In the following year (1894) this " Red Spider " infestation 

 reappeared as early as the 24th of February, but passed away 

 much earlier than in the preceding year, no observations of 

 its presence being sent me after April, whereas in 1893 pre- 

 sence of the pest was reported up to the 21st of June. 



In 1895 the infestation again appeared in some considerable 

 quantity, with some hot bright weather, but disappeared 

 again (in the localities reported) with the occurrence of cold 

 and wet, and (excepting where no means were taken to keep 

 the attack in check) it was neither so widely spread nor so 



