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AN INVASION BY THE CLOVER-LEAF BEETLE. 



By J. B. Smith. 



This insect has aot been heretofore known as a troublesome species 

 in ^ew Jersey. During the season of 1889 larvae and pupae were sent 

 from the northern part of the State, and there was an abnormal increase 

 all around the State. In Philadelphia, where most of the collectors had 

 never taken it, it became suddenly the most common species. Every- 

 thing pointed to an injurious invasion of the species, and such I pre- 

 dicted in my report for 1889. Early in the season of 1890 I received 

 complaints of a caterpillar on clover in enormous numbers. Specimens 

 sent, in response to my request, reached me in a defunct condition, evi- 

 dently killed by a fungus disease. Meanwhile the same complaints 

 were made in other parts of the State, and the newspapers reported 

 them as being gathered by the bushel. I could not get hold of a 

 living specimen, and all the reports stated that they crawled up to the 

 tops of grass blades and coiled themselves up. In Gloucester County I 

 finally found the larvae myself, and after some search found also a few 

 living specimens which I recognized as the larvae of the clover-leaf 

 beetle ; but before I could get them home they were killed by the fun- 

 gus, and some put in weak alcohol were discolored by the disease and 

 distorted so as to be useless as specimens of the species. 



Afterward I found the remains of these same larvae in clover fields 

 in all parts of the State visited by me, but nowhere a living larva. The 

 specific effect of the disease caused by Empiisa sphwrosperma seems 

 to be inducing the larva to crawl to the tops of grass blades and coiling 

 themselves around the extreme tips or as near as they could get to it. 

 What promised to be a terrible destructive attack was happily pre- 

 vented by the effects of this disease, which almost completely exter- 

 minated the larvae. There were two remarkable things : First, the enor- 

 mous numbers in which the larvae appeared all over the State where 

 no beetles were observed last year — I did not find one near New 

 Brunswick — and yet the larvae were here in destructive numbers this 

 spring; and second, the equally widespread disease, which was in all 

 places at the same time. 



That some larvae escaped is proved by the fact that at Long Branch 

 Beach I found the beetle very common in midsummer. Near Philadel- 

 phia, 1 am informed, the beetle has been very rarely seen this year. 



Mr. Howard mentioned a similar attack in Lancaster County, Pa., 

 and stated that Professor Riley had recently received a larva indistin- 

 guishable from this which had been found feeding on timothy. 



Mr. Woodworth said that he had in Arkansas observed three epi- 

 demics among insects which seemed to stamp out the infested species 

 almost entirely. On one occasion the tomato worm was utterly exter- 

 minated. 



