Plant-Diseases and Insects. 



fall plowing. All the old remedies — as salt, lime, the growing 

 of buckwheat and other supposed immune crops, soaking 

 seeds in copperas or poisons — are found to be of no avail. The 

 bulletin has added much to our knowledge of the insects, how- 

 ever, and will open the way to more intelligent experimenta- 

 tion than has been employed in the past. 



Increased attention has been given to injuries from the nem- 

 atodes, which are true worms allied to the pork trichina, and 

 they are found to cause very extensive and promiscuous inju- 

 ries. They are found to be common in the greenhouses of 

 the north, as well as in the open in the southern States, caus- 

 ing the formation of root-galls upon a variety of plants. Nema . 

 They are often very serious pests in house-grown tomatoes, todes. 

 The nematodes also attack the leaves of some plants,* as 

 bouvardia, pelargonium, cineraria, begonia, cyclamen, lily, 

 coleus, and others. In Europe the injuries from nematodes 

 are so great that an experiment station has been established 

 at Halle, Germany, for the purpose of investigating the sub- 

 ject, f 



The introduction of the lady-bird predacean (Vedalia car- 

 dinalis), from Australia to California, to destroy the orange- 

 scale, still remains one of the wonders of economic ento- 

 mology. X The scale has been almost completely destroyed 

 in many localities, and the orange industry has been given a 

 new impulse. In fact, so great has been the benefit of the 

 vedalia colonization, that the last legislature of California ap- 

 propriated $5,000 "for the purpose of sending an expert to 

 Australia, New Zealand, and adjacent countries, to collect introduc- 

 and import into this State parasites and predaceous insects." predaceous 

 This fund was placed in the hands of the State Board of Hor- insects - 

 ticulture, and Albert Koebele has been dispatched to Australia 

 to look for new insect friends. Mr. Koebele has already sent 

 several promising predaceans to California from the Sandwich 

 Islands and from Australia. He reports the finding in Aus- 

 tralia of important enemies of the serious red scale, and 

 they have been sent to America. These predaceans are mostly 



*See "Eel- worms in Leaves ofCultivated Plants," by B. D. Halsted in American Garden, 

 xii. 410 (July, 1891). Also Atkinson, Insect Life, iv. 31. 



fSee Jahresbericht der Versuchstation fur Nematoden — Vertilgung, by Dr. M. Holl- 

 rung, 1890. 



tFor an account of the introduction, see Annals for 1889,62. Also, Annals for 1890, 

 103. 



