THE HOP APHIS.

Lyttelton Times, Volume LXIII, Issue 7563, 30 May 1885, Page 6

THE HOP APHIS.

An important paper on the recent observations on the first appearance, &c., of hop aphis has been privately issued for the guidance of hop-growers and others by Miss Eleanor A. Ofmerod, F.M.S., consulting entomologist of the Koyal Agricultural Society. During the past season this lady has been in receipt of specimens and observations relative to hop aphis attack from the latter part of March to about the end of August, and though far from expressing positive certainty on a subject like this, which has been one of doubt and difficulty for at least a hundred years, yet after careful study and also comparison with the published views of entomologists who have attended to this special attack in England, Germany, and the United States of America, it appears that there is good reason for believing the course of attack to be as follows :—l. That the first attack of aphis to the hop begins in spring from wingless females (depositing living young) which come up from the hop hills. 2. That the greafe attack which usually occurs in tke form of “ fly ” about the end of May comes on the wing from damson and sloe as well as from hop, and that the hop aphis and the damson hop aphis are very slight varieties of one species, and so similar in habits as regards injury to hop that for all practical purposes •they may be considered one. ' Further, it has been shown by the result of various experiments on the hop ground at Stoke Edithpark, Hereford, allowedly the kind courtesy of the Lady Emily Foley, that the use ,of various applications round the hills in the late autumn or about the beginning of April in spring completely prevented attack to the vines of those hills ■ until the summer attack came on the wing. Among these applications paraffin was especially noticeable, as the plants treated with it were reported throughout as thriving up to the point of bearing well, and the serviceableness of mineral oil, both as a preventive and remedy, has been confirmed by the reports of experiments regarding the use of petroleum and kerosene in a diluted state published by direction of the Department of. Agriculture of the United States of America. The main points shown by the observations of the season appear to be that first attack was found as early as March, coming up from the hop hills in the form of wingless females with lice, and that this was both confirmed on a broad scale and the method of prevention shown by the circumstance of the acre of hops which. was dressed in spring with various applications (specified) to prevent attack remaining quite clean (though the rest of the garden was attacked)' until the “fly”—that is winged aphis—appeared. Also there does not appear to be any’reason to doubt thatthe hop and damson hop aphis are merely slight varieties of one species, a remark which scarcely occupies a couple of lines, but which required Constant examination of parallel condition of the two sorts from March to September, and which, if correct, lies at the root of the most important measures for prevention, save those above mentioned. Amongst measures of remedy, dressings with paraffin in any dry material by which it can be spread on the hills in spring have been shown to be useful, and so has the addition of quassia to the washings, while among methods of washing the application of steam power to this purpose opens up a possibility of carrying these operations on with a greater rapidity, and loss cost of which the further proofs will be looked for with interest.