81 



Cabbage, Chestnut, Arbor Vitae, Yew, Ilex, Pine, Mespilus, Peach, 

 Millet, Plane-tree, Hawthorn, Mulberry, and Strawberry. 



An interesting point in connection with their ability to feed on so 

 great a variety of plants is the facility with which they can be changed 

 from one food-plant to another. I have fed a number of larvae all from 

 a single mass of eggs, the food-plant of every one of which was differ- 

 ent, and with others have changed the food-plant every day during 

 their entire larval history. The larvae of Ocneria are frequently found 

 with the eggs of a Tachinid attached to them. Generally there is but a 

 single egg 1 though sometimes two, three and four have been observed; 

 they are usually on or near the head. In most of the cases that came 

 under my observations the Ocneria moulted before the eggs of the 

 Tachinid hatched. Two of the Tachinids which pupated August 19, 

 gave imagos September 2. AnotLer fact which must lessen the value 

 of this Tachinid as a destroyer of the Ocneria is a habit the larvae 

 have of rubbing the head against some hard substance. This was 

 observed several tiroes, and in some cases 1 he eggs though not detached 

 were injured. Although I can not state that Pimpla pedalis is parasitic 

 upon the Ocneria it has been very abundant in the infested region this 

 year, and I think it very probable that it will be found among the para- 

 ites of the Ocneria. 



Doubtless many birds will be found feeding upon the Ocneria. At 

 this time there are but two species, the Yellow-billed Cuckoo and the 

 Black-billed Cuckoo (Coccyzus americanus and C.erytlirophthalmus), that 

 I can name as aiding quite materially in the destruction of the larvae. 

 Among invertebrates the following can be named: Cicindela 6-guttata, 

 Camponotus herculaneus, Sinea diadema, an undetermined Syrphus, and 

 Chrysopa, Lithobitis forficatus; also the following spiders : Epeira strix, 

 Steatoda borealis, Lycosa sp., Drassus sp., Agalena nwvia, Phidippus gal- 

 athea (mystaceus), Epiblemum scenicum, Marptusa familiar "is, and Tho- 

 mixus sp. 



While the original creation of the Commission and the subsequent 

 transfer of the work to the State Board of Agriculture were warranted 

 by the nature of the emergency, it was undoubtedly a mistake to appoint 

 men to look after such important work — work demanding, in the words 

 of the appointing power, " prompt, judicious, and energetic action" — who 

 were already more than occupied with other work. The fact that they 

 were appointed with the distinct understanding that their services 

 should be given gratuitously, while not equivalent to saying that their 

 services would be slight, does indicate that they would be secondary 

 to more important affairs. 



And while it is only just to the present committee to state that they 

 have devoted more time to their work than could have been asked or 

 expected, it is interesting to note that one of them is now in favor of 

 at least a per diem compensation, and recently so testified before a leg- 

 islative committee. 



21382— JSTo. 26 6 



