INSECTS INJURIOUS TO CUCUMBER, MELON, ETC. 175 



occurring abundantly in the Gulf States. The "worms" of 

 these two species are frequently confounded because of their 

 similar appearance. Both feed in the same fields and their life 

 habits exhibit little variation. 



Remedies mentioned for the pickle worm are applicable, as 

 the melon caterpillar can be killed readily by an arsenical spray. 



Miscellaneous Pests. — The onion thrips, considered on 

 pages 89 and 90, the wheat thrips (page 90) and the red spider 

 (page 91) are all important enemies of 

 cucumbers grown under glass, as is also 

 the greenhouse white fly (Aleyrodes 

 vaporarioriim Westw., fig. ii4.r). In- 

 deed in the case of the last mentioned 

 pest it would be impossible to grow this 

 crop in forcing houses without the em- 

 ployment of remedial measures. 



This pest can be held in control by 

 vaporization or fumigation with tobacco 

 or nicotine extracts, or by spraying with 

 kerosene emulsion or the so-called whale- 

 oil (fish-oil) soap. Care is necessary in 

 using the extracts that the smudge does Fi&. lUx -Greenhouse 



, ^1 J • • it. white fly. Adult above, 



not become too dense and mjure the p^p^ beiow-highiy mag- 

 plants. Before applying this remedy on "ified. (After Morrill.) 

 a large scale a preliminary trial should be made following the 

 directions on the packages, and reducing the amount if any ill 

 results follow. Hydrocyanic acid gas properly used is an ex- 

 cellent remedy.^ 



1 See Circ. 57, Bu. Entom.. U. S. Dept. Agr., and Fumigation Methods, by 

 Prof, W. G. Johnson, publislied by Orange Judd Company, New York. 



