9 
PREFACE. 
- 4 -- 
During the past season of 1890, all, or almost all, of our 
common crop insect pests were present, and their ravages 
reported to a greater or lesser extent, but only a few as being 
seriously injurious, and none as causing wide-spread attack. 
Amongst the crop attacks, which for various reasons are the 
most noticed, that of Hessian Fly has now become distributed at 
localities over most of the area of England, excepting the most 
southerly and westerly parts; but at the same time, as far as can 
be gathered from examination of specimens and from reports 
sent, the presence of the pest on the individual stalks ofWheat 
or Barley in the infested fields in the past year was slight, and 
the damage caused immaterial. 
Whether from weather effects of our insular climate ; or from 
autumn Wheat sowing being (when in regular course) after the 
time of autumn brood of the fly; or, again, from agriculturists 
being probably (in some cases) at the pains to destroy infested 
screenings ; it is obvious that, after five years of presence in the 
country, this pest in its acclimatised condition, does not 
cause nearly as much mischief as other of our com insects which 
unfortunately continue to ravage at their pleasure, because we 
have not yet found the missing link in their life-histories which 
would show us where and how they lie in our power. 
Perhaps the chief among these are the Gout Fly maggot in 
Barley heads and stalks, and Bulb maggot in young Wheat, 
caused respectively by Cldorops and Hylemyia flies. These 
yearly cause much loss, and until we know where the maggots 
of the first spend the winter, and of the second spend the summer 
or autumn, we are without the clue to lead us to thorough pre¬ 
ventive measures. This is a point on which observation is greatly 
needed for the public good. 
The attack of Stem Eel worm (Tylenchvs devastatrix ), which 
some indications have pointed to for several years back as 
possibly occurring in Bean plants, has now been found to be un- 
mistakeably present there, and stunting the growth to a serious 
extent. 
Another species of Eelworm (Aphelenchus frag arm), hitherto 
> undescribed, has been found to be the cause of destructive mal¬ 
formation in Strawberry plant growth, which even if observed 
