— 44 — 
THE ONION THRIPS. {Thrips striatus Osb.) 
A very small insect, slightly yellowish in color and one 
twenty-fourth of an inch in length, very active and mature, 
occurring upon onion tops in enormous numbers, causing 
them to whiten and wilt down prematurely. The insects 
Fig. 42.— Onion Thrips, adult, greatly enlarged. 
are so minute that it is often the case that the cause of the 
dying down of the tops is not disccn’ered by the owner of 
the crop. 
Remedies — At the beginning of the attack thoroughly 
spray the onions with kerosene eimiL^ion or whale-oil soap 
of the ordinary .'strengths. 
CABBAGE APHIS. (. I /)!/ i.'i hrfoixicae Linn.) 
A green plant louse on the underside of the leaves of 
cabbage, cauliflower, turnip and similar plants. The 
bodies of the lice are covered with a ti e whitish powder, 
often occurring in enormous numbers late in the summer 
and in the fall. 
Remedies — Kerosene emulsion and whale-oil soap are 
the standard remedies against these as well as other plant 
lice. It is difficult to make the application effectual, how- 
ever, on account of the curling of the leaves of the plants 
that the lice infest and the mealy covering to the lice which 
causes all liquids to run from their bodies as water runs from 
a duck’s back. To be effectual the application must be 
made with sufficient force to knock the lice from the leaves, 
in which case most of the lice will be killed. The lice live 
