APPENDIX. 379 



that the climate of California is sufficiently mild to enable many of the pre- 

 datory species to multiply uninterruptedly the year round. The twice- 

 stabbed ladybird, he says, ' occurs on plants throughout December and 

 January in great numbers in all stages. 



Valuable as these natural enemies undoubtedly are, however, they will 

 be efficient only at intervals, and thei-e will always be considerable period.s 

 when, for one cause or another, they will be less numerous, and the scales 

 will then have a chance to multiply. In fact, after the scale has once 

 become established, and the balance between it and its natural enemy has 

 been reached, we may expect with more or less regularity periods of abund- 

 ance and scarcity of the scale insect. The possible usefulness of parasitic 

 and predaceous insects should, therefore, at least in the east, not be allowed 

 for a moment to interfere with active operations with remedies nor blind 

 one to the importance of the San Jose scale and the extraordinary pre- 

 cautions which should always be taken to prevent its wider dissemination. 

 We have, nevertheless, as an experiment, arranged to introduce certain of 

 the Australian ladybirds into affected Maryland orchards the coming 

 spring.* 



THE RED SPIDER. 



By Pkof. a. B. Cordlev. 



This mite is probably the well-known " red spider"' of the greenhouse. 

 Tetranyckus telarius. At Corvallis it is even more abundant upon prune 

 trees than is the clover mite, but it does not seem to have attracted such 

 general attention in other parts of the state. To the unaided eye it appears 

 very similar to that mite, and the general api^earance of infested trees is 

 the same. The clover mite, however, is rarely found in the adult stage 

 upon the leaves, and the eggs are always deposited upon the branches or 

 trunk, while the "red spider " may be found in all stages upon the leaves— 

 the eggs, the young in all stages and the adults being protected under a 

 delicate web on the undersides of the leaves. 



The winter eggs are deposited upon the trunks and branches, as are those 

 of the clover mite, and when abundant give the bark the same ' ' rusty ' ' ap- 

 pearance. 



Itemed;/— Spray with sulphur, lime and salt in the fall as soon as the leaves 

 have fallen. 



* Since this paragraph was written, we learn that the New Jersey State Board of 

 Agriculture has passed a resolution calling upon the state legislature to appropriate the 

 sum off 1,03J for the purpose of introducing ladybirds from California into affected New 

 .Tersey orchards. If the bill should pass, the attempt will be made in the spring of 189(5. 



For remedies most efficacious in Oregon, see Spray Calender of this report.— Henry 



E. DOSCH. 



