18 INSECTS INJURIOUS TO GARDEN AND ORCHARD CROPS. 



insects, its hibernation, as already shown by the observations of Kath- 

 von, previously quoted, is not as complete as in the case of boreal 

 species. 



There can be little doubt that this beetle sometimes acts as a trans- 

 mitter of the bacterial wilt of cucurbits the same as is known to be the 

 case with the cucumber beetles and common squash bug, which fact is 

 to its discredit. 



The presence of the squash ladybird, although a pest of secondary 

 importance, is certainly not desirable in a field of melons, squashes, 

 or other cucurbits. With the beetles and their larvae devouring the 

 leaves, the larvae of Diabrotica at the roots, or the vine-boring Melittia 

 larvae in the stem, and the plant-louse or odoriferous squash bug sap- 

 ping the vitality of leaves and leaf stalks, this ladybird can not be 

 otherwise than harmful. Only too often several or all of these insects 

 work in unison to the detriment of a plant, hence the suppression of 

 even one of these enemies may sometimes be sufficient to enable the 

 plant to recuperate. 



REMEDIES. 



Eemedial measures that are adopted for other cucurbit pests will at 

 the same time effect the destruction of this ladybird. Its habit of 

 feeding both as larva and adult freely exposed on the leaves renders 

 it peculiarly vulnerable to poisonous applications, and of these the 

 arsenites, either dry or in solution, are the best. Hand-picking of 

 the beetles and egg masses, considering their large and conspicuous 

 appearance, is an easy manner of riddance of the nuisance if employed 

 on the insect's first appearance, and is the only measure necessary 

 under any except unusual circumstances. Both larvae and beetles are 

 decidedly sluggish in habit and hence are easily captured. 



PRINCIPAL ECONOMIC WRITINGS. 



1. Fabricius, Joh. G. <Systema entomologiae, p. 82 (fide Gemm. & 



Har.), 1775. 



Original description of the species as Coccinella borealis. 



2. Emerson, Gouverneur < American Farmer's Encyclopedia, 1858, 



p. 1012. 



A brief statement that the larva of Coccinella borealis preys upon the leaves 

 of squash. 



3. Moore, A. O. < Country Gentleman, April 1, 1858, p. 210, figs. 1-7. 



A two-column popular account with seven original figures. 



4. Osten Sacken, C. R. < Proceedings Entomological Society Phila., 



v. i, p. 125. 18G2. 



Larva hrietly compared with congeneric species described by Chapuis and 

 Candeze; stated to agree in all essential characters except that there are only 

 three distinct ocelli, the fourth being extremely minute. 



