That in Europe, where the disease is present, it is taking many, many trees. We have a man over there from the Bureau studying the bark-beetle situation and trying to get all the pointers he can to help us out here in our eradication program. But we know that the disease may be present in a tree for as many as 5 years. That is the longest period that we have known of the disease being present without outer manifestation. Then suddenly the disease will manifest itself and the tree dies. In other words, we may be passing trees as not being infected today that may have had the disease, as a matter of fact, in the tree for 3 or 4 years and then come out after we get by. Mr. CANNON. Each year you have gone back over the same area and cut down trees that you left the year before, and each year the number of elm trees in the infected district decreases. Mr. STRONG. We have not been working on this very long. The first year we had any funds at all we did not know what the extent of the infected area was. It was pretty much of a hit-and-miss proposition. This year we have considered, in these large acreages where elms are grown and where there is a number of dead and dying trees, in order to avoid this thing of going back over as much as possible the next year and finding trees that are diseased, that we take all those trees outright. In other words, the large area is being clean-cut. We have cut down so far in this program 918,271 elm trees. That is of all sizes, large trees and medium-sized and small trees. A great many of them have been mixed up with these buildings and wires so that we have had to take them down piece by piece. Mr. CANNON. Could you not require the owners to destroy those trees, just as you require the owner of a mad dog to destroy his dog? Mr. STRONG. No; I do not think we could. We could not get anywhere. We could make an inspection and tag the infected trees that we find and then tell the State, "Here is a dead tree, you had better take it out." But that does not protect the elm trees that are outside of that area from infection, if the owner does not take it down. DUTCH ELM DISEASE IN EUROPE Mr. CANNON. If Europe has been unable to control the disease, what leads you to believe that you can control it here? Mr. STRONG. Europe has not tried. There have not been any real eradication measures carried on. I think Holland now is taking an interest in that and probably they have cut down a great many trees. In England the disease has been more or less allowed to just run its course. Mr. CANNON. England, Germany, Holland, and other European states would not lightly abandon a national resource of such value. It is evident that they realize the hopelessness of controlling the disease. Mr. TARVER. With reference to the statement you made a few moments ago, how can you determine that the disease has been present in a tree for four or five years before it is made manifest? Mr. STRONG. When the disease manifests itself, we take a section of the tree, and we can go back to the ring of the year that the tree was infected and determine that it had the diseases from that year on. We have to make laboratory cultures of all suspected specimens that are sent in. We cannot determine just offhand by looking at the tree. There are other diseases that do resemble this and we have to culture the specimens in the laboratory to determine definitely. TRUCK CROP AND GARDEN INSECTS Mr. CANNON. The next item is as follows: Truck crop and garden insects: For insects affecting truck crops, ornamental, and garden plants, including tobacco, sugar beets, and greenhouse and bulbous crops, $361,418. Mr. STRONG. The following is presented for the record: WORK DONE UNDER THIS APPROPRIATION General. The work done under this appropriation deals with the study of insects and the development of means of control of the forms injurious to truck crops and garden plants, including vegetables, flowers, bulbous plants, potted ornamentals, and plants grown under glass, as well as such related crops as strawberries, raspberries, blackberries, sugar beets, and tobacco. It also provides for investigations on the European earwig, pest of mushrooms, and soil insects such as wireworms and white grubs attacking vegetables. Field laboratories are maintained in certain of the more important trucking regions and in localities where bulbs and other ornamental plants are produced. Truck crop insect investigations.-The activities conducted under this project are concerned with insects affecting truck crops such as beans, peas, melons, potatoes, sweetpotatoes, onions, cabbage, etc. Investigations are now being conducted on the European earwig in the Pacific Northwest, cucumber beetles, pepper weevil, vegetable weevil, Puerto Rican mole cricket, pea aphid, sweetpotato weevil, celery leaf-tier, and various wireworms and white grubs injurious to truck crops. Certain phases of these investigations are conducted in cooperation with the Bureau of Plant Industry and the Bureau of Agricultural Engineering. The studies are carried on at 17 field laboratories located in various parts of the country. For the most part the investigations conducted at a laboratory cover a variety of problems, and the laboratory may be considered as regional headquarters for work on truck-crop pests. For example, the pests of cole crops are studied at five different stations. The development of satisfactory methods for the control of insects affecting vegetable and garden crops has assumed greater importance in recent years than at any time in the past. The development and expansion of the vegetable industry in the South and Southwest, the increased consumption of green food products, and the demand that these be free from insect damage and insecticidal residues are factors which have contributed to the increasing importance of this work. With the concentration of crops in certain areas old pests have increased in abundance and distribution. The pepper weevil, previously known in the country only in the West, has recently been discovered in parts of Florida. The tomato pinworm has been found in new areas and is causing heavy losses. Certain recently introduced pests, such as the Puerto Rican mole cricket and the vegetable weevil, are causing damage over larger areas. The mole cricket is proving to be an especially destructive pest in parts of the Atlantic coastal plain, where it injures seed beds by its habit of tunneling through the soft soil. No fully effective control is yet known; the baits suggested are only partly effective, and more work is necessary on the habits before the baits can be greatly improved. Many of these remedies which have been developed for the control of certain pests of truck crops involve the use of insecticides containing arsenic. Where heavy infestations occur the pests cannot be satisfactorily controlled without leaving excessive residues. This coupled with the careless use of insecticides by growers emphasizes the need for developing methods of control which will not leave harmful residues. The activities under this project cover a wide variety of pests and crops. They affect not only the work of large industries, including canners and producing and marketing agencies of important food crops, but also practically all home gardeners. The interest in home gardens has been greatly expanded, and with it there is an increasing demand for information on the control of insect pests and an appreciation for the use of remedies which will not leave objectionable spray residues. The requirement that canned vegetables be free from insect pests has emphasized the need of developing controls which will be highly efficient. Even if insects are present in such small numbers as to cause little visible damage, they may occur in sufficient number to cause rejection of the crop by the canner, with corresponding loss to the grower, or condemnation and seizure of the canned product. The development of the canning industry in the Pacific Northwest has brought demands for effective control measures for various pests, particularly certain insects attacking peas, a product receiving considerable attention. Berry insect investigations.-The work under this project is concerned with the study of insects injurious to the small fruits known as berries and including strawberries, raspberries, blackberries, etc. Work is carried on at two field laboratories, one at Puyallup, Wash.; for problems in the Pacific Northwest, and one at Chadbourn, N. C., for problems in the strawberry sections of the eastern coastal plain. In the Pacific Northwest special attention is being given to development of measures to control the raspberry fruit worm and the raspberry mite. The work on these two pests is directed to the application of insecticides which do not leave objectionable residues and the method of applying them so they will be effective. Other important problems await study. Recently a European pest which attacks the ripe strawberry just beneath the cap has been causing damage in parts of the Pacific Northwest. The occurrence of large numbers of minute insects called thrips in cans of raspberries and related fruits produced in the Pacific Northwest emphasizes the need of studies to determine methods of controlling this pest, the occurrence of which has recently attracted particular attention. At the Chadbourn Laboratory, in the eastern coastal plain, special attention is being devoted to the control of the strawberry weevil and the strawberry root aphid. Work on the root aphid, which causes material losses and is apparently associated with one of the important strawberry diseases, is carried on in cooperation with the Bureau of Plant Industry. When the strawberry weevil occurs in such numbers that it cannot be controlled by cultural practices, it is necessary to apply insecticides. The present investigation is concerned largely with the use of derris and pyrethrum, which do not leave objectionabie residues. Sugar beet insect investigations. This project is concerned almost entirely with investigations on the sugar-beet leafhopper, which is the most important pest of sugar beets in the western part of the United States, and also damages vegetables. Its periodic attacks result in almost complete failure of beets, tomatoes, beans, and squashes in certain areas and cause marked reduction in the yields every year. The sugar-beet leafhopper transmits the destructive disease known as curly top. One insect may transmit the disease to a number of plants. The leafhoppers invade fields in large numbers in the migration periods and direct control in the fields has not been found practicable. The work on this insect in the different sections varies in scope and is divided into two work projects. In the Intermountain Region the investigations are carried on from laboratories at Twin Falls, Idaho; Grand Junction, Colo.; Phoenix, Ariz.; and Salt Lake City, Utah. It consists principally of surveys made to determine the abundance of the beet leafhopper and the availability of its favorite host plants in its natural breeding areas, studies to determine the value of sprays and trap crops, field studies and surveys to outline the main breeding areas, and modifications of these due to natural or artificial causes. In California the studies are concerned with the determination of the value of spraying wild host plants and the elimination of breeding areas as a means of control, and the relation that populations of the leafhopper have to damage to tomatoes and other truck crops and the production of beet seed. Tobacco insect investigations.-The work under this project is concerned with the study of insects injurious to tobacco both in the field and in storage. It involves studies of the life history, habits, and methods of control by the use of insecticides, attractants, baits, fumigants, cultural practices, etc. The activities are divided into four work projects, three of which are closely related, as they are concerned with insects attacking tobacco in the field. The Agricultural Appropriation Act for 1936 provided an increase of $33,000 for investigations on insects attacking tobacco in the field. The work on insects attacking tobaco in the field is now carried on in three of the main areas which produce various types of tobacco. The work in the dark fire-cured area is located at Clarksville, Tenn.; that in the flue-cured area at Oxford, N. C., supplemented by seasonal work at Florence, S. C.; and that on insects attacking shade-grown tobacco at Quincy, Fla. Satisfactory controls that will not leave objectionable residues are not available for the control of many of the important pests, such as the hornworm and flea beetle. Concerns purchasing tobacco for manufacturing purposes are giving attention to the amount of visible residue that may occur. This emphasizes the need of the development of controls which will eliminate objectionable residues. In the dark fire-cured area tests are under way to determine the practicability of the use of poison-bait feeders as an aid in the control of the hornworm moth. Experiments to determine the effect of such insecticides as derris are also under way, as well as studies to determine the possibility of using pyrethrum or other organic compounds. The type of bait most effective for the control of the sod webworm is also receiving some attention. During the past season work in the flue-cured area has, for the most part, consisted of a survey to determine the abundance of the principal insect pests. Funds for work in this section did not become available until the active season was well advanced and it was not practical to start any intensive experiments for determining the value of various controls. Tests to determine the practicability of control by cultural practices, however, are now under way, as well as experiments to determine needed facts about the hibernation of important species. Surveys have been conducted to determine the status of the various insect pests, not only from the loss in the field but also the effect insect injury has on the price the farmer receives for his crop. These include not only the reduction because of visible injury but also the reduction due to loss in weight. In the shade-grown tobacco section the most important pest is the tobacco flea beetle. The practicability of using barium fluosilicate has been tested, and during the past season particular attention has been directed to the use of derris and cube dusts. Preliminary results indicate that it is practicable to control this insect, at least in seedbeds, by the use of these materials. Attention is also being directed to methods of control of the tobacco thrips. Investigations on insects affecting tobacco in storage which have been under way for a few years were undertaken in response to the demand of the tobacco trade of the United States. They are chiefly concerned with the development of methods of controlling the recently introduced tobacco moth and the tobacco heetle in both the closed and open type of warehouses. Some very useful and interesting information has been secured, and such conclusions as to control measures as have been developed have been made available to the trade. Aside from the protection of tobacco produced within the United States, these investigations have a bearing on the production of a product sufficiently free from insects to meet the requirements of countries to which American tobacco is exported. The infestation in closed storages can be materially reduced by the use of traps and fumigants. It is not practical to apply these methods in the open storages, and studies are being made to determine other measures of control. such as the use of contact sprays. The practicability of using low temperatures is also being studied. Investigations of insects affecting greenhouse and ornamental plants.-The work under this project deals with investigations to determine methods for controlling insects attacking flowering garden plants, such as narcissus, tulip, dahlia, etc., and household and ornamental plants; insects injurious to flowers and all kinds of plants grown under glass; and insects injurious to mushrooms. There are many pests of these plants, and in many cases the control which may be used successfully on one kind of plant cannot be used on other kinds of plants. In determining controls for a given insect pest it is necessary to test them on most of the kinds of plants attacked and to study the control in relation to the culture of the plant. Some of the pests of greenhouse and ornamental plants now receiving special attention are: (1) The cyclamen and broad mites, insects extremely difficult to control, which, according to a conservative estimate, cause annual losses to greenhouse interests approximating $1,000,000. (2) Insect veetors of important mosaic diseases of rose and narcissus; it seems likely that certain of these diseases are transmitted by insects which may be fairly easily controlled. (3) The iris thrips, a widely distributed pest especially difficult to control where the tubers are left in permanent locations. (4) The Mexican mealybug, a pest attacking a large variety of plants, recently established in commercial greenhouses, which resists the treatments ordinarily used for the control of greenhouse insects. (5) The greenhouse red spider, a pest which attacks a wide variety of plants and causes losses throughout the country. (6) The gladiolus thrips, a limiting factor to the successful product.on of this favorite garden flower. (7) Bulb mites; there are a number of mites which seriously injure narcissus bulbs and flowers for which satisfactory control measures are not available, and additional facts are needed before all varieties of bulbs can be d sinfected to eliminate mites. (8) Narcissus bulb flies; effective methods for disinfecting narcissus bulbs have been developed, but present methods of controlling the pest in the field are not fully effective. The most important pest problems confronting the producers of mushrooms are maggots and mites. The control measures now available to the commercial producer are not fully effective. Conditions that must be maintained in the house for the satisfactory growth of mushrooms make it difficult to fumigate. Mite control is especially difficult, because the fumigants ordinarily used do not penetrate the compost and reach the mite without injury to the mushroom. A sulphur burner has recently been devised which material y increases the opportunity for using sulphur in fumigating houses. Progress has also been made in the development of light traps. Further work, however, is necessary to make these results available to the producer. The chemical problems are being studied in cooperation with the Insecticide Unit. Mr. CANNON. You are asking for no change in this item? Mr. STRONG. That is right. CEREAL AND FORAGE INSECTS Mr. CANNON. The next item is "Cereal and forage insects", follows: as Cereal and forage insects: For insects affecting cereal and forage crops, including sugarcane and rice, and including research on the European corn borer, $372.229, including not exceeding $15,000 for investigation of the means of control of the Mormon cricket. Mr. STRONG. The following statement is presented for the record: Appropriation Act, 1936. Reappropriated by Second Deficiency Act, 1935, from 1935 appropriation for "Grasshopper control" (to provide for a cooperative grasshopper survey ) --- $347, 229 25, 000 372, 229 372, 229 The estimates for 1937 request the same amount as available for the fiscal year 1936. In comparison with appropriations there is, however, an apparent increase of $25,000, as the Second Deficiency Appropriation Act, 1935, continued available and made a part of this item $25,000 of the unexpended balance of the appropriation for "Grasshopper control" to provide for cooperative surveys on grasshoppers. There was available for 1936 the sum of $347,229 provided by the regular appropriation act and $25,000 referred to above, making a total of $372,229, the amount requested for 1937, which includes provision for continuation of the grasshopper surveys. WORK DONE UNDER THIS APPROPRIATION General.-Investigations under this item are concerned with the development of effective and economical means of controlling insects affecting cereal and forage crops, including sugarcane and rice. The production of cereal and forage crops is the most important agricultural activity over a large part of the United States. The insects attacking these crops annually cause immense losses, and in some areas crops may be completely destroyed by these pests. Investigations on the European corn borer are also included under this item. Cereal and forage-insect investigations.-The activities under this project are concerned with investigations to develop effective and economical means of controlling insects affecting corn, small grains (except rice), and forage |