446 
THE TROPICAL AGRICULTURIST. [January 2, 1888. 
risk of loss and destruction from injurius insects to 
many of the cultivated crops of this country. Thus, 
corn of all kinds, fruit trees, hop plants, clover, 
turnips, and mangel-wurzel are contiDually attacked 
by inseots, both of kinds well known and long known, 
as well as of kinds that are new, or whose ravages 
have only been recently noted, and which in certain 
cases, as the mangel-wurzel fly, Anthomyia Beta, seem 
to have been imported with the plant. The mischief 
caused by this fly has become greatly intensified even 
within the last five years. Ourtis, writing of it in 
1859, thought that its injuries would not be of much 
consequence. Again, the "turnip fly" or "flea," 
Phyllotreta nemorum, has enormously multiplied with 
the extension of turnip culture, and in some seasons 
has caused very heavy losses to farmers. Originally 
feeding upon charlock and other cruciferous plants, 
it leaves these now for more grateful food, and breeds 
rapidly in these favourable circumstances. Naturally 
this increase of insects follows pari passu the exten- 
sion of culture and the distribution of the plants which 
are the special subjects of their attacks. But it is 
found that in the case of wheat and clover and other 
crops which have been cultivated in due rotation in 
the same fields new injuries from insects have been 
noticed. It must be remembered, however, that the 
number of observers among agriculturists has increased 
of late, and the manner of observation has been 
changed and improved. It is, of course, quite possible 
that the supposed new insects may have been working 
unnoticed for generations. Admitting to an extent 
the advance of intelligent observation and the spread 
of entomological knowledge, it is quite clear that 
not only is the destruction occasioned by insects 
larger than ever it was, but that there are insects 
at work in the fields which were not there in the 
times of our forefathers. One reason for the progres- 
sive increase of insects is that a larger supply of 
food encourages the proportional propagation of in- 
sects fond of and living upon it. Another undoubtedly 
is that the systems of land treatment have completely 
changed, and become more artificial, by which the 
balances of nature, "the aggregate action and product 
of many natural laws," as Darwin has it, have been 
disturbed. Insectivorous insects, for example, may 
have been diminished by changed methods of manage- 
ment. High and altered farming may have made cer- 
tain crops more delicate and liable to insect attack. 
The slaughter of insectivorous birds and animals is 
most wholesale and indiscriminate. The hand of 
every one, to take an instance, is against moles, 
and yet farmers wonder that wireworms become more 
abundant each succeeding season. "With regard to 
new insects, there are continuous opportunities for 
their introduction into England in all kinds of agricul- 
tural produce from all kinds of climates and soils. 
Insects are probably imported into as they are exported 
out of England. Fortunately the climate of this 
country does not suit the habits of most foreign 
insects. The dreaded potato bug, Doryphora decem- 
lineata would have, without any doubt, gained a settle- 
ment here if the conditions had been suitable. But 
on the other hand, it is tolerably certain that the 
hop aphis was taken to America in hop roots or sets 
sent from England. Until 25 years ago, Professor 
Lintner states, this insect was unknown in the 
American hop plantations, and now it is becoming a 
serious trouble. Several other insects destructive to 
corn, hop, and fruit crops have been brought into 
America from Europe with seeds, plants, and fruits, and 
are threatening to become more troublesome in this 
" home of insects," as America has been called by en- 
tomologists, than they ever were in their native land. 
America has retaliated by exporting the phylloxera into 
the French vineyards, to the utter confusion and in- 
describable loss of the wine producers. Within the 
last few years scale insects have appeared in the Oali- 
fornian orange groves from Australia, and orange, citron, 
and lemon growersin other partsof the world have lately 
been exercised in their minds by the appearance of 
pests of this species. Seeing, then, these dangers 
from the spread of indigenous insects, and the fear 
of the introduction of new species from foreign countries 
it is most desirable to diffuse entomological informa- 
tion as to the habits and life history of injurious 
insects, in a simple and intelligible form, for the use 
of farmers, fruit-growers, market gardeners, and all 
who cultivate the land, and at the same time to 
give practical modes of prevention and remedies 
against their attacks. The hop plant in particular 
has many insect enemies. Some of these are most 
dangerous and destructive, and if not prevented or 
checked will soon ruin the crop. It appears as if 
the liability of hop plants to be attacked by insects 
has considerably increased during the past 30 years, 
and it is believed by hop planters that some of the 
insects which now vex them were not known in the 
hop plantations until receutly. As the planters are 
anxious to learn what has been ascertained regarding 
the insects affecting hop plants, it is considered de- 
sirable to publish this record of ten species of insects 
more or less injurious to them, giving descriptions 
of each insect, together with its life history, its mudes 
of attack, and the results of its injuries, also an 
account in some detail of methods of prevention, 
and of measures which have been found efficacious 
in stopping or alleviating injuries. 
The following insects are mentioned in Mr. "White- 
head's report: — The hop fly, Aphis humili ; the hop 
cone fly, Dilophus vulgaris ; the hop wireworm, Elater 
lineatus ; the hop jumper, Euaeanthus inturruptus ; 
the hop flea, Haltica concinna ; the otter moth, Hepia- 
lus humuli ; the thousand legs, Julus Guttatus ; the 
hop bug, Lygus umbellatarum ; the red spider, Tetrany- 
chus, Telarius ; the strig miner, Psylliodes attenuatus, 
or Agromyza fontalis[?). 
The second report relates to insects injurious to 
corn, grass, pea, been, and clover crops ; as to which 
Mr. Whitehead writes: — "It will be seen by the 
above title of this second instalment of the series 
of reports upon insects injurious to agricultural crops 
that its scope has been somewhat extended. Origin- 
ally it was intended to confine this second report 
to insects injurious to corn crops, but as the work 
progressed it was found desirable to include those 
destructive to grass crops, as some of these insects are 
common to both. Again, it seemed well while dealing 
with cereals to treat also of pulse — peas and beans — 
and to describe the principal insects that affect them, 
especially as some of these crops are liable to be 
attacked by the same insects. Besides, there would 
hardly have been enough materials for a separate 
report upon insects injurious to pulse alone, and it 
is important that their history should be given. A 
description also of a genus of insects injurious to 
various kinds of clover is added as being the most 
important enemies of this order of plants. There are 
other insects more or less injurious to clover crops, 
and many others which at times are troublesome 
to cereal and pulse crops. It would be impossible to 
include these in a work of this kind, which is intended 
merely to give a short account of insects that most 
frequently attack cultivated crops. Somo explanation 
is necessary as to the arrangement of the mo- 
nographs in this report. It would have been 
difficult to arrange them alphabetically, or according 
to the recognized scientific classification of insects, 
and it has been thought better to group them under 
the respective headings of corn and grass, peas, beans, 
and clover, and to take the insects in each group as 
far as possible in the order of their injurious effects. 
It may be objected that as the Jididm and the Vibrio, 
or Tylenchus tritici are not insects in the scientific 
acceptation of the term they should not have been 
included in the series. But these reports are written 
to convey useful and practical instruction to the cult- 
ivators of land, and are not intended to be solely for 
scientific readers. And it is only following in the foot- 
steps of the great agricultural entomologists, John Curtis 
and Dr. E. L. Taschenberg, to describe these creatures 
destructive to crops in company with true insects. 
There are other insects which are destructive to the 
various crops dealt with in this report. It is, however, 
deemed desirable to treat only of their chief pests 
and those which give most trouble and occasion most 
loss to cultivators. With regard to these it has been 
