8 INSECTS AFFECTING VEGETABLE AND TRUCK CEOPS. 
what better than in dried specimens. It is singular that this park 
should have been so badly infested by this species, while only one 
individual could be found in a long search on the grounds of the 
Department of Agriculture. The difference in distance is not more 
than 1J miles. 
THE SPINACH FLEA-BEETLE. 
(Disonycha xanthonvelwna Dalm.) 
During the year 1912 beets as well as spinach grew very rapidly 
in the District of Columbia during rainy days, succeeded by warmer 
ones, but owing to press of other work the writer was unable to give 
them and their insect enemies as much personal attention as they 
deserved, and another reason was that the species involved, Disonycha 
xanthomelcena Dalm., has already been written up with considerable 
care. 
Nevertheless there is always something new to learn, as there will 
be of all species, as long as we continue to observe them under dif- 
ferent environments and atmospheric conditions. The table beets 
grew so rapidly that in spite of the larvae and adults of the spinach 
flea-beetle, which " peppered them full of holes," they made consid- 
erable progress. 
The spinach began to die rapidly about the beginning of the third 
week of June, and in four days nearly every plant appeared as if dying. 
In addition to the spinach flea-beetle, the spinach aphis (R7wpaJosi- 
phum dianthi or Myzns persicce auct.) was also present, but, as 
affirmed by Dr. Erwin F. Smith, who, with the writer, examined 
the plants June 25, there was no evidence of disease or of malnutri- 
tion. If the plat of spinach had been a field, the plants would un- 
doubtedly have perished, owing to the combined attack of the flea- 
beetles and the aphides, and this in spite of the fact that the aphides 
were being rapidly destroyed by ladybirds. 
To determine the extent or degree of injury, comparison was made 
of a beet root taken from our experimental plat, which had been very 
little affected by this flea -beetle, with another lot which had been 
badly affected, with the result that it required nine of the affected 
roots to equal the weight of one that was practically unaffected. 
The small roots were picked out at random by the writer from the 
place most badly affected, which was at the sunny end of the plat. 
It should be mentioned in this connection that plants growing 
where they were shaded by hedge plants were comparatively little 
affected by insects. This same observation has been made in connec- 
tion with the imported cabbage caterpillar (Pontia rapce L.), which is 
not disturbed by wasps when feeding in shady places. 
