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ENTOMOLOGICAL WORK IN CENTRAL PARK. 



BY' E. B. SOUTHVVICK, NEW YORK, N.Y. 



[Authox^'s abstract.] 



The work of the entomologists of the department of public parks is in the care of 

 trees, shrubs and plants, under the directions issued by the president of the board of 

 commissioners. 



The work of removing the egg masses of Orgyia leucostigma was the first done in this 

 department, when twelve men were employed to clean the trees, benches, walls, and stone- 

 work in the parks. The first autumn of our work we collected thirteen bushels of these 

 cocoons and egg masses, leaving those cocoons that were apparently parasitized until the 

 final cleaning. The large elms on the Mall were thoroughly cleaned with steel brushes 

 made for the work, and each tree received a wash to destroy any insects that might be in 

 the crevices of the bark. This work of collecting (and burning in the furnace) has been 

 carried on each year as the force would allow, in this way keeping them in subjection. We 

 now treat them in four different ways : 



(1st) By hand-picking, of which bushels are each year taken from the trees with 

 tools especially adapted for this work. 



(2nd) By jarring the larv;e down with a pole, so arranged that a blow from a mallet 

 on a projection placed at the large end of the pole will jar any down that may be on the 

 branches. With a sudden blow most of them will fall to the ground, where they can be 

 crushed. 



(3rd) By poisoning the foliage with London purple, which is quite effective and usedi 

 especially on very large trees that can not be treated otherwise. 



(4th) By poisoning or spraying the trunks of large trees with an emulsion of 

 petroleum and carbolic acid. This penetrates most of the cocoons sufficiently to kill the 

 inmates, the disadvantage being that it kills the parasites too. This method is only 

 resorted to when the egg masses are very numerous and we are short of help, and as a 

 means of reducing the next'brood. Large numbers of trees were so treated this season to 

 arrest the late summer hatchings. 



The next insect in abundance and destructive working was the Bag Worm, Thyri- 

 dvpteryx ephemercpformis. Whole portions of the parks were literally stripped of their 

 foliage • many of the trees on the drives were nearly as bare as in winter. So abundant 

 were they that the branches were strung with their cases, and with one push of the instru- 

 ment prepared for collecting them, a handful of these cases would be taken. Four kinds 

 of tools were made for this work, and the cases were collected and destroyed. In this 

 way nearly twenty-two bushels have been collected and destroyed. 



The Datanas have always been abundant in the parks, and as many as fifteen 

 pounds of caterpillars have been taken from a single tree. These are collected while 

 massed, as is their habit, and then destroyed. 



Hyphantria cunea is very abundant in our parks and has been destroyed by cutting 

 down the webs as far as was possible. If the tree was too valuable, they have been twisted 

 out with poles made especially for this work. In some cases spraying has been resorted 

 to, but as this does not remove the unsightly web, the most practical thing to do is to 

 remove the whole colony. 



Clisiocampa americana has this year appeared in our parks for the first time, and in 

 great abundance. The webs that appear on the trees before they are in full leaf can be 

 easily i-emoved, and in this way the finer trees can be protected. The eggs are alsO' 

 removed in the late autumn and winter, as they are very conspicuous. 



