LOSSES CAUSED BY IMPORTED TREE AND PLANT PESTS 



79 



This Act also yivcs power of control within the United 

 States of new and dangerous plant pests by quarantine 

 or regulation of movement. This power is, however, now 



limited by the ne- 

 cessity of actually 

 determining the 

 presence of the in- 

 sect or disease to be 

 quarantined against 

 in the State or dis- 

 trict made subject 

 to the quarantine. 

 An enlargement of 

 this power to be 

 able to effectively 

 quarantine against 

 such a widespread 

 disease as the white 

 pine blister rust is 

 now being sought. 



The powers of 

 this act in relation 

 to the exclusion of 

 foreign plant ene- 

 mies has hitherto 

 been directed to- 

 wards specific dan- 

 gers which could be 

 shown by the Fed- 

 eral or State experts 

 in relation to par- 

 ticular plants or 

 plant products. In 

 view of the tremen- 

 dous losses which 

 are now being oc- 

 casioned by intro- 

 duced plant pests 

 and the additional 

 losses which are now 

 threatened by the 

 many new plant 

 pests likely at any 

 time to be intro- 

 duced, as herein 

 shown, it is perhaps 

 opportune now to 

 seriously consider 

 the advisability of 

 very much restrict- 

 ing the further en- 

 try of all foreign 

 plants and plant 

 products capable of 

 being the agency of 

 such introductions; 

 in other words, to 

 put all such intro- 

 ductions under def- 

 inite Federal con- 



trol and supervision, with power of exclusion wherever a 

 reasonable risk is known. This need is emj^hasized just 

 at this time by a number of important illustrations, al- 

 ready alluded to, of recently introduced pests, including 

 the pine blister rust, chestnut blight, citrus canker, pink 

 boll worm of cotton in Mexico, and a new peach pest from 

 Asia which has scarcely yet come to jmblic knowledge 



PUPATING LARVAE OF THE ASIATIC 

 LADYBIRD {CHILOCORUS SIMILIS) 



This beneficial insect, which is a voracious 

 feeder on the San Jose scale in China and 

 Japan, was introduced into the United States 

 to assist in the control of this scale insect, 

 and is helping to prevent destruction amount- 

 ing to several hundred thousand dollars a year. 



AX IMPORTANT NEW INSECT ENEMY OF THE PEACH 

 (LASPEYRESIA MOLESTA) 



Observations during the summer and fall of 1916 seem to indicate that another 

 formidable insect enemy of the peach and other deciduous fruits has become 

 established in America. Larvje of this insect have been observed injuring the 

 twigs of peach, plum, cherry, and fruit of the peach. No. 1 shows a peach twig 

 with a mass of dried gum and leaf fragments due to attack by the caterpillar. 

 No. 2 shows a peach shoot cut open exposing the larva in its burrow. No. 3 

 shows the cavity excavated in the peach by larva entering at the side. 



but which threatens our peach crop with greater losses 

 than perhaps any of the older established peach pests. 

 It would certainly appear that the enforcement of much 

 more restrictive measures than are now possible is amply 

 justified. 



