34 
FLORIDA STATE HORTICULTURAL SOCIETY 
high as 24% of ammonia. At the pres¬ 
ent prices it is, among commercial fertili¬ 
zers, the cheapest source of nitrogen. It 
is more slowly available than nitrate of 
soda, but is more lasting in its effects. 
Only in exceptional cases, such as unusu- 
allly valuable truck crops, should it be 
necessary to add any additional ammonia 
to soils treated for nematodes, for several 
months thereafter. 
THE GREEN SOLDIER BUG OR PUMPKIN BUG IN CITRUS 
GROVES 
J. R. Watson 
The control of the larger plant 
bugs presents somewhat of a prob¬ 
lem to the grower and the entomolo¬ 
gist because the adults are very resistant 
to any safe insecticide. The writer has 
used solutions as strong as ten pounds of 
soap and a pint of Black-leaf 40 in fifty 
gallons of water without killing any large 
percentage of adults, although the young 
were mostly killed. He has seen used 
the regular whitefly oil emulsions to 
which not only Black-leaf 40 but also one 
per cent of carbolinium was added, with 
like unsatisfactory results. The use of a 
stronger spray would be decidedly unsafe. 
The writer has long felt that the mechan¬ 
ical collection was the best means at hand 
and has so advised. But we have encoun¬ 
tered on the part of the growers a marked 
aversion to mechanical collecting on ac¬ 
count of the supposed expense. This aver¬ 
sion has in part been a misunderstanding 
of the implements employed. When we 
speak of hand collecting we do not as 
has often been understood, mean to pick 
these bugs off of the trees with our fingers 
one at a time. 
Several years ago we had an oppor¬ 
tunity to try out the method of collecting 
these bugs from a crop of potatoes and 
to ascertain the actual cost of the opera¬ 
tion. The potatoes were severely in¬ 
fested, i. e., there was a colony of bugs on 
about 20% of the hills. These were 
mostly the Big-footed Plant-bugs and the 
damage they inflicted was severe. One 
entering the field in the afternoon found 
the infested vines badly wilted. Using a 
pan with a little kerosene in it into which 
we knocked the bugs, we found that it 
required about an hour to collect the bugs 
from an acre of potatoes. 
One of the agreeable surprises was the 
discovery that the bugs did not move 
about much. We had rather expected 
that more would continue to come but 
this was true to only a limited extent. 
We found it necessary to go over the 
potato field but three times. 
This experience has been repeated this 
year on a patch of sunflowers. Once 
freed the plants do not generally again 
become severely infested. 
Pumpkin bugs were unusually trouble¬ 
some during the fall of 1916 not only in 
Florida but in southern Alabama as well. 
In Alabama they occasioned real alarm 
and a dread that a permanently dangerous 
