50 



two yeai's later? Or, if this insect was not then in our country, when it 

 did appear in such vast numbers two years ago, why was not the same influ- 

 ence whicli occasioned its surprising multiplication then, felt also by the 

 Grain Aphis, caiising it to re-appear in our grain fields ? The two insects 

 being so intimately related, it is a mystery beyond the reach of human 

 comprehension, how some hidden influence comes to operate upon the one, 

 causing it to multiply and increase so astonishingly, whilst the other remains 

 passive and not in the least aflfected by it. 



This insect is not limited to the extensive hop plantations in the central 

 parts of this State, but appears to have everywhere overrun the hop vines, 

 both wild and cultivated. It was abundant the past simiiner in my own 

 neighborhood, and specimens were also sent mo from St. Lawrence county, 

 whereby we know tiiat its range extends to the eastern and northern con- 

 fines of the Stale, but farther than this we do not possess any definite 

 information. 



This Aphis appears to be identical with that which has long been known 

 in Europe as the worst enemy of the hop, and which sixty-five years ago 

 received its scientific name, Aphin Bumuli or the Hop Aphis, from the Ger- 

 man naturalist Schrank (I'^auna Boica, vol. ii, p. 110.) Messrs. Kirby and 

 Spencc, in their introduction to Entomology (American edition, p. 135,) 

 speak of the damage inflicted by this insect as follows: " Upon the presence 

 or absence of Aphides, the crop of every year depends; so that the hop- 

 grower is wholly at the mercy of these insects. They are the barometer 

 that indicates the rise and fall of his wealth, as of a very important branch 

 of the revenue, the ditl'erence in the amount of the duty on hops being 

 often as much as £200,000 per annum, more or less, in proportion as 

 this fly prevails or the contrary." This statement forcibly shows what 

 a direct interest our own government has in patronizing these investiga- 

 tions in which I am employed — this one little insect, in years when it is 

 numerous, taking from the revenue of the British government half a million 

 of dollars 1 



My own researches upon this insect are obviously too limited as yet, to 

 enable me to give such a particular history of its habits and operations, as 

 its importance merits. I therefore present the following account from the 

 London Gardener's Chronicle, for the year 1854, page 429: 



" As soon as the Aphides settle upon the hops, they suck the underside 

 of the leaves, and immediately deposit their young, which are viviparous, 

 and have th(i singular faculty of propagating iheir species within a few 

 hours after their birth; and in this manner many generations are produced 

 without the intervention of the fully formed Aphis fly; indeed, upon one 

 hill of hops, millions of lice arc born and die, neither parents nor progeny 

 having ever attained the condition of the perfect insect. When the first 

 attack of these flies upon the hops is severe, and early in the season, the 

 growth of the plant is commonly stopped in the course of three or four 

 weeks. If the attack be late, that is about mid-summer or afterwards, the 

 vine has then attained so much strength that it struggles on against the 

 blight, to its disadvantage, and the result is a total failure of the crop at 

 least; for the leaves fall oil", and the fruit branches being already formed, 



