CHAPTER XVIII
LETTERS TO PROFESSOR RILEY AND DR. HOWARD
Flour moth and Winter moth—Orchard growers’ Committee—John Curtis—Entomology in Cape Colony—Handbooks and Reports—The General Index—The LL.D.
The letters addressed to the two distinguished United States officials are unlike most of those we have passed. Miss Ormerod writes, as usual, in courteous and even in deferential terms to the two acknowledged chiefs among Entomological authorities in America. The considerable variety of subjects touched upon are dealt with in less simple language, and minor details give place to discussions on the higher polity of Economic Entomology. The letters contain internal evidence of the esteem in which her work was held by her correspondents.
1, Moth, with wings expanded; 2, moth, at rest; 3, caterpillar; 4, chrysalis—all magnified; lines showing natural length.
FIG. 41.—MEDITERRANEAN FLOUR MOTH, EPHESTIA KUHNIELLA, ZELL.
To Professor Riley, Entomologist to the Agricultural Department, Washington, U.S.A.
Torrington House, St. Albans, England.
March 6, 1889.
Dear Professor Riley,—We have got a flour caterpillar in England, newly arrived in the last two years, which is so very troublesome and injurious where it establishes itself that I should like to place a short account of it in your hands, hoping that at your leisure (I should rather say at your best convenience, for leisure you have none) you may kindly tell me whether you have it in the U.S.A., and, if so, whether you manage to keep it in check. The caterpillars were first observed in Europe in 1877 by Dr. Jul. Kuhn, of Halle, doing much mischief during the process of grinding some American wheat. The imagines from these larvæ were placed by Dr. Kuhn in the hands of Professor Zeller, who considered them to be Ephestia of a species previously undescribed, and they were named by him kuhniella (fig. [41]) specifically after their observer. All this most likely you know well, but it is the appearance of this “pest” here which I am more particularly writing to you about. In 1887 the caterpillars did great harm in some large stores in London, and last year the attack established itself in a wheat-flour steam-mill in the North of England. The great harm caused is by reason of the caterpillars “felting” up the meal or flour by the quantity of web which they spin in it. They feed, of course, but this is not so injurious as working up the flour together, as thus they clog the mill apparatus to a very serious extent. I have much reduced their numbers by getting the manager of the steam-mill to turn on steam to scald them; and cleaning, whitewashing, and some use of paraffin have done good. The real cure would be to change the material ground. If we could use ryemeal for a few weeks we could clear out effectually this wheat-flour-feeding caterpillar. Unfortunately, however, the delicate apparatus of our recently arranged wheat “roller” mills does not allow of this. One point that would help us in preventive measures would be to know where the attack comes from. I am told it is a “scourge” amongst the flour (or rather the meal, as it prefers the more branny parts) in wheat from Russia and Hungary at the Mediterranean ports, so I am making inquiries; but Dr. Lindeman is not aware of this attack having been noticed in Russia. Under these circumstances I thought that I would write to you about it, and if you are acquainted with this moth and the larval working, and, still more, if you know how to destroy it, I should feel greatly favoured and obliged by any information that you may kindly give. I believe that unless it has very recently been placed on your American lists of Lepidoptera it is not noted as known there, and I am trying to persuade myself that it is not all selfishness which makes me trouble you thus, but that if by any possibility you may not chance to have heard of the serious nature of the work of these larvæ, you may care to have a few lines about them. The moth is about ¾ in. in spread of the fore-wings, which are of pale grey with darker transverse markings; the hinder wings remarkable for their whitish semi-transparency with a darker line from the point along a part of the fore edge. The larvæ, when full-grown, as far as I see, are about five-eighths of an inch long. You will not care to have full description, but they have surprising instinct for travelling, and amazing strength. One that I watched to test this power escaped from under a little smooth-edged cardboard frame which I had placed on a woollen cloth on a quite flat table and pressed down with a one pound weight.
I hope before long to forward my twelfth Report for your acceptance and that it may meet your approval.