56 
scrioti™ n? £ re t ter ? a - rt ?! th ° Se “swerins to the above de- 
acnption to be found m the corn field, will usually be olant 
hce (aphides); and will mostly belong, in fact, to a^simde spe- 
; es 5 the coin root aphis; but a few may be “mealv blip’s” 
(genus Dactylopius family Coccidm), recognizable aMuch^v 
then general lesemblance to the kinds of “mealv buo-s” common 
lTce gl bv n the'ir e tlnV| 1 -e‘ V T* b? distin g ui «hed from the plant 
mentarv size t ’ f'ms.er bod.es, and by the almost rudi¬ 
mentary size ot their legs and antennae. They are a I wavs mv 
<ered with a mealy or powdery excretion of minute particles of 
wax, and never have honey tubes, or cornicles, on the back of 
the abdomen—both characters in which they agree however 
nlant^Wtl the 0 "', er P lant . Iice - From all'the corn-infesting 
pant lice they may be technically separated by the fact that 
whlll thTidant'Ih 6 and b ® ar but a single tarsal claw, 
a pair of £al claws ’ S gr ° UP h&Ve two tarsal &*** aad 
Plant lice are among the most prolific of insects* producing 
several generations annually, but thev are commonlv held 
severely m cheeky by climatic, meteorological, and biological 
parasites 8 ’ Th^v Ife b '’ season ’ weather, and plant or ammal 
parasites, they are, consequently, capable of rapid and enor 
mous increase when any of these 'checks are' temporarily 
bltbltlL nurflm el l l! ]erf '/ > a degree ' As the -^ affeot th e Plant 
!len; „p a ti g the elaborated sap upon which its vital activity 
this o ifinjury done is usually general, and especially is 
in addition trfti 0-0 e the part infested. Some species, however, 
' “SiPt ,this general dram upon the life of the plant, cause 
a listmct lod defomrty to root or leaf in the nature of a o- a l] 
which protects them at the same time that it secures them food.’ 
- u .y «lop liable to their attack in force is never long free from 
mal 8 dis-Inneal 11 1 16 han( t a see,nin gl.v irresistible outbreak 
may disappeai as quickly as it came, a slight and almost im 
of r Zsfd e ehcafe g 1n°secte.t dlti ° nS **** taldUg tremendous 
w?noN ^fil-fi 1 01 c some P art some generation, may grow 
be wlthmlt” 8 - t!1 ®T for ,apid dissemination, or the species may 
be without winged representatives. They may live through the 
of 'tlil limit' ?{. their aetive lif e above ground, on exposeefparts 
C oi' they may alternate, spreading eacV year 
naito thf .Ini/® I' and t T a,ld back again. Whatever 
pait or the plant they infest, they may live on a sino-le host 
species, they may spread indefinitely from one to severa? other s, 
-in a single year ( ?Scfence e yol'^fxi y 1ST? n e .iK?- °^i a * ouse iMyzuz achyrantes ?) 
Aphides, Yol. L, p?80) that asingle rose ?nh! : ^w Buckt / m shows (A Monograph of British 
Sx t U I In5g! >r «a%e S^ve h nt^n“h 
