The More Important Apple Insects. ae 
APPLE FLEA-BEETLES.” 
The so-called apple flea-beetles, in common with other flea-beetles, have 
strongly developed hind legs with which they are able to jump somewhat after 
the manner of fleas. Generally speaking, the two species here treated are 
not particularly destructive to bearing apple orchards, but young orchards and 
nurseries may sometimes be attacked so severely that special remedial meas- 
ures are desirable. The overwintering beetles begin their attack upon the 
foliage in late spring to early summer, and when abundant eat many small 
holes through the leaves, giving them a perforated appearance. The larvé 
appear during midsummer and feed upon the scft leaf tissue, skeletonizing 
the foliage. 
The life histories of these insects have not been studied in detail. They pass 
the winter as bright, metallic green beetles, about one-sixteenth of an inch 
long. The eggs are yellowish, more or less elongate in outline; and are about 
one-twenty-fifth of an inch in length. The full-grown larve are generally black 
in color, about one-fourth of an inch long, and when grown pupate in fragile 
earthen cells just below the surface of the ground. Later the beetles issue 
and hibernate, there being but one generation annually. 
Since flea-beetles are chewing insects, they may be controlled by an applica- 
tion of arsenate of lead of the usual strength in water or fungicide, as lime- 
sulphur solution or Bordeaux mixture. The application should be made as 
soon as the beetles are discovered. Orchards and nurseries properly sprayed 
for other chewing insects will seldom require special treatment for this pest. 
SPRING CANKERWORM.” 
Cankerworms, also known as measuring worms, loopers, or spanworms, have 
long been known as defoliators of apple and certain shade trees, and during 
cankerworm years may cause very important injury, especially in orchards 
net usually plowed or sprayed. In common with many other insects, canker- 
worms have their periods of abundance, usually lasting 4 or 5 years, after 
which they practically disappear, due to the combined effects of parasites, cli- 
mate, etc. The damage is done by the larve feeding upon the foliage, which 
they ccnsume, except the midribs and larger veins (fig. 57). By the close of 
the feeding period. orchards may be so defoliated that from a distance they 
appear brown and scorched as if swept by fire (fig. 58). Cankerworms are 
most often troublesome in neglected orchards and on unsprayed trees growing 
in sod around the home, and when once established under such conditions may 
defoliate the trees several years in succession. 
The spring cankerworm is native to North America, occurring in Canada 
and the northern United States, ranging southward through the Mississ‘ppi 
Valley and westward to Kansas and Texas. It is present also in California. 
Its principal host plants are the apple and elm, although it also feeds on cherry, 
plum, prune, apricot, linden, etc. The winter is passed in the pupa stage (fig. 59) 
just below the surface of the ground. If the weather conditions are warm the 
moths will sometimes emerge as early as February, but, as a rule, emergence 
does not take place until early spring. The wings of the female moths are very 
much dwarfed and are useless for flying, and this necessitates their crawling 
up the trees in order to deposit their eggs. These are laid in patches along the 
trunk or larger limbs or in any convenient crevice. The females (fix. 60) are 
grayish, with a dark stripe upon the back, and measure about five-sixteenths of 
*1 Altica foliacea LeConte ; Altica punctipennis LeConte. = Paleacrita vernata Feck. 
92300°—22 3 
