Other like instances illustrating the probable fact that this scale is much more widely disseminated over the Eastern States than we have any knowledge of might be given, but these two will suffice to illustrate the point that we first need systematic inspection before we shall be able to form any comprehensive idea of the task we have before us in suppressing this pernicious insect.

We have the barest general idea as to the nurseries which are infested outside of the State of New Jersey and Long Island, New York, where doubtless Professor Smith and Mr. Sirrine have done the best work in the way of inspection of nurseries that has been done in the East.

My experience in Virginia leads me to believe that there are a large number of small nurseries, especially those which have dealt largely in rehandling New Jersey and Maryland grown stock, scattered all over the Atlantic States which are more or less infested and are acting as distributing centers for this insect.

Only six of the Eastern States are reported to me as having infested nurseries, and in none of these does it appear that any thorough system has been adopted, or at least executed, for the proper control of nursery stock to prevent the dissemination of this scale.

Only four of the fourteen Eastern and Middle States now reported as infested have any legislation which at all relates to the control of this pest, and in these States, so far as I am aware, but little has been done to make the law effective. Back of this lies the real and strong question as to whether these laws can, under the present aspect of the question, be made effective.

To speak definitely of my own State, I may say that we have a law which gives us ample power to inspect all premises, whether nurseries or fruit plantations, and to take drastic measures to secure the destruction of infested stock, or its treatment where such is deemed advisable; but the general public knows that no similar measures are being executed with any thoroughness throughout the Eastern States, and are very much inclined to oppose the execution of any law and to cover up the fact of the existence of the scale.

Prior to the passage of our law I had for three years done all I could to ascertain infested localities and gain information concerning the insect, but practically little came of my efforts. Only one point of serious infection, that at City Point, was discovered by me during this time, and this came about through no direct effort of mine. In fact, it was simply an incident in the ordinary course of my correspondence which led me to detect it.

Shortly after the Virginia law was passed empowering us to deal with this question I issued a pamphlet of general information and began a much more thorough investigation of this subject. Prior to this time we felt quite convinced that there were only two districts in the State seriously infested, but in a very few weeks after we began serious work the scale was located in three new districts and the extent of the premises infested in each was found to be far beyond our

expectation. In fact, we were at once convinced that the execution of our law, as drawn, would be impossible, and that any attempt to isolate and eradicate the scale from the numerous premises which were found to be infested would involve an outlay of time and money much greater than our station could possibly undertake.

To speak plainly, our investigations thus far have shown that this insect has gained such a wide dissemination in the State that no action which a single official could possibly take would have much effect in eradicating it, and we have come to believe that the proper duty of the experiment stations or of such State authorities as attempt to control this insect is not to put forth further personal effort to control the scale wherever it may be found in individual localities, but to strike deeper and to at once put the nurseries under such a system of surveillance that its further dissemination from them will be checked with certainty. However, the work of clearing the fruit plantations already infested must not be neglected, but its accomplishment must rest largely with the individual growers in the several communities interested.

A State officer can very properly, and with great profit to the locality interested, supervise and direct the general work; but unless the individual growers will actually engage in executing the orders or directions which may be given them there is no hope that the insect can be checked.

If I am right in believing that the first duty of the official entomologist is to check the dissemination of this pest through the nurseries; then the question of the cooperation of the several States is a prime point, and must be made the basis of all effective work. Certainly all will agree that it is quite useless for the nurseries of one State to be inspected and subjected to drastic control if nurseries just across the border in another State can with impunity ship infested stock into the neighboring State. This it appears is exactly the present status of the case, and hence nurserymen in those States which have laws providing for inspection and eradication of the scale properly enough feel that they will be subjected to great annoyance and probable pecuniary loss by the execution of any drastic law when their competitors in a State where such laws are not enforced are permitted to enter their State and sell stock free of all control. It is a delicate and important question to say how far or in just what lines cooperation is practicable or shall be undertaken.

The legislation of the several States is so at variance, even in the laws already passed, and methods of executing laws within the several States also are so at variance, that a serious question arises whether any real security will be attainable by legislation of this sort.

Every person, and especially every entomologist, who has had any thing to do with the execution of special enactments of this nature knows that the people resent and very often rebel against what they consider improper interference with their private affairs.

It is very well to say that the people must be educated, but it is another matter to accomplish this fact, and in the meantime we are in the presence of a real and serious danger.

Every person to whom I have written on this subject, except one, believes in cooperation among the several States, but few indeed are clear as to what lines or under what general plan we could undertake cooperation.

For my part, I am of the opinion that any cooperation that may be undertaken should deal solely with the nursery question, as the question of local infection is a matter for the individual States to deal with.

Whether we could secure the enactment of a general law in all the infested States is to me a question of very grave doubt; in fact, I feel almost certain that it would be impossible to secure a law under which the several entomologists could act in unison. Consequently I am led to suggest that if there can be some scheme devised by which we can secure thorough and critical inspection of all nurseries and full publication of the facts we may be able to accomplish the desired result much more speedily and with vastly less cost than to wait for special legal enactments by the several States. But this step if undertaken would need to be surrounded with proper safeguards. This inspection would become a matter of such critical importance that every possible care would need to be observed to make it absolutely fair and impar tial. And then the publication of such data could not, in justice to the commercial interests of the several States, be left to the individual stations, colleges, or boards of agriculture, but should be made a conjoint affair and only issued after the most painstaking efforts to verify every observation reported. In fact, it seems to me that here is an instance in which the Department of Agriculture at Washington, acting as a central authority, should take up the work and publish such a report as I have indicated above. If a thorough inspection could once be completed it would thereafter be quite a simple matter to keep tab on the nurserymen and publish from time to time a blacklist of such as refuse to follow out proper regulations to insure the character of the stock disseminated by them.

The foregoing thoughts cover in a general manner the problem as it presents itself from my brief experience in Virginia. I hope the association will give me the benefit of their best suggestions, and if any worker has really faced this matter and found out how we are to suppress this dangerous pest without cooperation, so far as relates to its dissemination on nursery stock, I will be delighted to learn the facts. At the meeting of the American Association of Agricultural Colleges and Experiment Stations next November in Washington, I hope to be present and read a paper on my experience in attempting to sup. press this insect in Virginia. I wish this association here present might take some action looking toward carrying this question of cooperation before that meeting by report of a committee or otherwise, as may be deemed best.

THE DEVELOPMENT OF THE MEDITERRANEAN FLOUR MOTH.

By F. H. CHITTENDEN, Washington, D. C.

In the article on insects injurious to stored grain prepared by the writer for the Yearbook of the United States Department of Agriculture for 1894, the following statement was made on page 285 concerning the development of the Mediterranean flour moth (Ephestia kuchniella Zell.): "From experiments conducted during the year at Washington it is estimated that under the most favorable conditions, i. e., in the warmest weather, the life cycle consumes about five weeks." This estimate was given in comparison with the record of M. J. Danysz who conducted observations on the development of this species in France. M. Danysz gives on page 11 of his memoir on this moth* a brief statement showing that from moths that issued under his observation from the 15th to the 20th of August a second generation of moths developed from the 13th to the 18th of October. He concludes with the statement: "Thus we have obtained a complete evolution in about two months, from the 15th of August to the 15th of October."

My estimate of five weeks is quoted by Mr. W. G. Johnson in his excellent article on this species recently published as an appendix to the Nineteenth Report of the State Entomologist of Illinois (p. 28) in contrast to experiments conducted by that writer "during midsum mer, under the most favorable conditions in California and Illinois," whereby he was unable to obtain a full-grown larva in less than five weeks from its emergence from the egg, his shortest period from the deposition of the egg to the issuance of the adult being placed at fiftynine and one-half days.

This experiment, according to Mr. Johnson's table on page 29, was, I judge, conducted at Champaign, Ill., from April 29 to June 28, 1895. My estimate has gone on record without the details to substantiate it, the limited space allotted me for my Yearbook article having been insufficient for the purpose.

With a view to the ascertainment of the exact truth, a series of experiments was undertaken the present year as soon as the weather promised anything favorable in the way of obtaining minimum developmental periods.

In my experiments to determine the life history of insects affecting stored products a special effort has been made to determine the minimum period of each stage. The reasons are these: With but few exceptions, indoor insects are of tropical origin and attain their highest development and are consequently most troublesome in warm climates. Again, with scarcely an exception, the different species cause, by their ravages in cereals and other products, a certain amount of decomposi

*

Mémoires du Laboratoire de Parasitologie végétale de la Bourse de Commerce, Vol. I, 1893.

tion, which induces a high degree of temperature, often of 90° and over, in cold weather many degrees higher than in the surrounding atmos phere. Under certain conditions this temperature may be maintained the year round, and it is therefore necessary to know the minimum periods before we can determine or even estimate the number of generations that may be developed in a year.

The following account of my experiments is given:

PERIOD FROM EGG TO ADULT.

Experiment No. 1.-Newly hatched larvæ from eggs deposited April 18 were placed in corn meal. June 2 one had transformed to pupa, the moth issuing June 9. Two more moths appeared, the day following, a total of fifty-two days as the life cycle for this period, which happened to be cooler than normal for this latitude.

Experiment No. 2.-Moths placed in corn meal April 30 produced the first members of another brood June 14, or in forty-six days. Weather normal.

Experiment No. 3.-Adults confined with corn meal at midday, June 10, 1896, and four moths of the new brood were found to have issued July 20. The exact date of issuance was not ascertained owing to the writer's absence from the office Sunday, but from their appearance they had bred either during the night of July 18 or 19, and the duration of the period was between thirty-eight and thirty-nine days. The temperature for this period, although not unseasonably cool, was not as warm as in previous years, the indoor temperature not ranging above 82° F. except on three or four days.

Experiment No. 4.-Moths placed in corn meal June 22. Two fullgrown larvæ left the meal July 20 to seek a place for transformation, and the following day about 20 followed suit. Three moths issued dur ing the night of July 30, being found early on the morning of the 31st, and giving nearly the same period from the egg to moth as in the preceding experiment, thirty-eight days.

INCUBATION.

An experiment to determine the minimum period of incubation began on the afternoon of April 18, when a few moths were placed singly in vials for the purpose. These were examined at 6.30 p. m. and at 11 p. m. and a large batch of eggs found to have been laid in one of the vials in the interim. A considerable proportion were found to have hatched early in the afternoon of April 23, or about four and one-half days from the time of deposition. Weather the first day very hot, the sec ond quite cool, the remaining time seasonable, the indoor temperature ranging from 91° to 66° F.

In colder weather the egg state may last as long as two weeks. In Mr. Johnson's experience it lasted from seven to nine and one-half days, the eggs having been deposited in April, August, and October.