No. 4.] THE GYPSY MOTH. 297 



successful in destroying the caterpillars, and at the same time 

 the least injurious to the foliage. Experiments with Paris 

 green, repeated each year since the work began, have shown 

 that this substance, in any proportion that will not greatly 

 injure the foliage, will not destroy all the caterpillars when 

 small and only a small proportion of them when more than 

 half grown. 



The insecticides used in the experiments referred to were 

 Paris green, Paris green and lime, London purple and 

 acetate of lead, Maiden white, Moulton's insectine, wood- 

 bine kennel mixture, antinonnin, gypsine. This last sub- 

 stance proved by far the most satisfactory, since it was in no 

 way injurious to the foliage even when used in so large a 

 proportion as twenty-five pounds to one hundred and fifty 

 gallons of w^ater, and it also proved very destructive to the 

 caterpillars. Antinonnin was not received until late in the 

 season, and therefore the experiments with it were not con- 

 clusive. There can be no doubt that gypsine will prove far 

 more valuable in destroying the gypsy moth than any of the 

 insecticides in common use, because it can be used in such 

 large proportions as to prove fatal to the insect. 



In my report last year I gave a list of four species of 

 insects found destroying the eggs of the gypsy moth, and 

 nine species of true parasites living within and destroying 

 the caterpillars. To this number should be added Phivpla 

 pedalis^siy., which was omitted from the list last year, by 

 an oversight and Pimplci tenuicornis Cress., which has been 

 bred from the gypsy moth this year, thus making a list of 

 eleven different species of true parasites which live within 

 the caterpillar, but which do notremerge until after it changes 

 to a pupa and is d^d. There can be no doubt that still 

 other species will be found to attack the gypsy moth in this 

 country. Mr. L. O. Howard, a most excellent authority in 

 such matters, estimates that there are only fourteen undoubted 

 hymenopterous primary parasites on the gypsy moth in 

 Europe, one of which, Apanteles glomeratus, already occurs 

 in this country, but it has not as yet been observed preying 

 on the gypsy moth. 



Respectfully submitted, 



C. H. FERNALD. 



