may be hoed out or the injured plants pulled and destroyed, together with the younger maggots.

Most of the methods mentioned above have been used with success against onion maggots and other root-feeding species, and are all that are required in many cases of ordinary infestation of vegetable

roots.

Other remedies have been tested; mostly, however, without avail.

CUTWORMS.

Onions are subject to serious attacks by certain cutworms. These appear sometimes in great numbers in spring and early summer and frequently do severe injury before their ravages are noticed. Their method of attack is to cut off young plants at about the surface of the ground, and as cutworms are voracious feeders, they may destroy many plants in a single night, frequently more than they can devour. During the past two years these insects, working generally throughout the United States, destroyed hundreds of thousands of dollars worth of crops. By the timely application of remedies in some of the principal trucking regions, e. g., in southern Texas, in the vicinity of Rocky Ford, Colo., in California in the vicinity of Sacramento, in Stark County, Ind., and in some other regions, these insects were readily controlled, large areas being successfully treated.

Of the cutworms which were most injurious in Stark County, Ind., the most abundant in 1911 was Euxoa punctigera Walk. Of other species, Euxoa tessellata Harr. and Euxoa messoria Harr. occurred in about equal numbers but were not so numerous as the one first mentioned. The last is called the dark-sided cutworm, and has been an important onion pest, to our knowledge, since 1885. Another very injurious species in some years is the variegated cutworm (Peridroma margaritosa Haw.). No very careful attention has been paid to the principal species injurious to onions in other regions. There is perhaps a slight difference in the habits of all of these species in regard to the time of attack. The adult, or moth, of Euxoa punctigera is -shown in Plate XXXI, above, and the adult of Euxoa tessellata in the same plate, below.

The usual method of control is by the use of poisoned baits. To a bushel of bran 1 pound of arsenic or Paris green is added and mixed thoroughly into a mash with 8 gallons of water, in which has been stirred half a gallon of sorghum or other cheap molasses. After the mash has stood several hours it should be scattered in lumps of about the size of a marble over the fields where injury is beginning to appear and about the bases of the plants set out. It should be applied late in the day, so as to place the poison about the plants over night, which is the time when the cutworms are activc. The application should be repeated if necessary.

When cutworms occur in unusual abundance, which happens locally, and sometimes generally in some seasons, they exhaust their food supply and are driven to migrate to other fields. This they do, literally in armies, assuming what is called the army-worm habit. At such times it is necessary to treat them as army worms. While the methods which have been advised are valuable in many cases, they may be too slow to destroy advancing hordes of cutworms, and other methods must then be employed. These include trenching, ditching, the plowing of deep furrows in advance of the traveling cutworms to trap them, and the dragging of logs or brush through the furrows. If the trenches can be filled with water, the addition of a small quantity of kerosene, so as to form a thin scum on the surface, will prove fatal. In extreme cases barriers of fence boards are erected and the tops smeared with tar or other sticky substance to stop the cutworms as they attempt to crawl over.

Clean cultural methods and rotation of crops are advisable, as also fall plowing and disking. Many cutworms can be destroyed where it is possible to overflow the fields. This is particularly applicable where irrigation is practiced.

Cutworms caused considerable damage to onions in northern Indiana in 1911 and 1912 just after the plants had emerged from the soil. In the sections where injury was greatest the growers were no more familiar with the cutworm problem than with the culture of onions— this being their first year in growing this crop for market. In the regions where onions were grown previously the cutworms were prevalent also, but were controlled by the use of the bran-mash bait that was used so successfully last year in the same fields. About 1,000 acres were treated for cutworms by the use of the bran mash, the formula being as before, 1 pound white arsenic, 1 bushel bran, and fromto 1 gallon corn sirup with enough water for moistening. Some used Paris green instead of the white arsenic and obtained excellent results. Some growers suffered a loss of from one-third to one-half of their crops from cutworm ravages alone. This could have been averted by the use of the bran mash in time.

WIREWORMS.

The term "wireworm" is applied to numerous forms of elongate wirelike creatures, the larvæ of snapping beetles or "snap bugs," 1 and is given them because of their firm texture, so different from that of many insect larvæ.

There are many species of these insects and quite a number of them have shown some preference for onions. More often, however, they do their greatest damage to truck crops following land which has

1 Coleoptera, family Elaterida; genera Drasterius, Melanotus, Cardiophorus, et al.

been in grass or meadowland. One of these species, known as the wheat wireworm (Agriotes mancus Say), has been found very injurious to onions in Stark County, Ind. It is shown in figure 10 about four times natural size. The life histories of the different genera have not been thoroughly worked out. Wireworms

(See

injure plants by the destruction of the roots and are very difficult to treat satisfactorily. Among direct applications some forms of salts and even brine, not too strong, have been used successfully in some regions. Salty fertilizers, such as kainit and nitrate of soda, are of value. p. 331 for discussion.) Clean cultivation, crop rotation, and poison baits, the latter discussed on page 332, are always to be recommended, as for cutworms. According to recent observations made by Mr. J. E. Graf on the sugar-beet wireworm in California, clean culture against the adults, compelling them to seek shelter elsewhere and exposing them to the attacks of their natural enemies such as birds, appears to be for that c, anal segment of larva in profile. species the most practicable remedy, the efficiency of which may be in

α

FIG. 10.-The wheat wireworm (Agriotes mancus): a, Beetle; b, larva;

About four times natural size. (Author's illustration.)

creased by fall plowing and early planting.

In Plate XXXII an injured onion plant is illustrated to show so-called "pathological conditions," found afterwards to be due to wireworms at the roots.

OTHER INSECTS.

Onions at present are little injured by insects other than those which have been mentioned in the foregoing columns. We might add such common pests, however, as the tarnished plant-bug, some forms of true bugs, and the strawberry thrips. The last-mentioned has, however, been frequently misquoted in mistake for the onion thrips, the two species being quite different.

CONDENSED AND DESICCATED MILK.

By LEVI WELLS,

Dairy Inspector, Dairy Division, Bureau of Animal Industry.

INTRODUCTION.

Milk is a bulky product, expensive to transport, and very susceptible to contamination, which in a short time renders it unpalatable. In its natural state it contains about 87 per cent of water, which is a comparatively worthless constituent.

Efforts to reduce the water content of milk, leaving the solids in a more concentrated form without destroying their food value, and at the same time improving the keeping qualities, have resulted in developing the manufacture of both condensed milk and desiccated milk or milk flour. The condensing processes now used reduce the volume of milk to one-half or one-fifth its original bulk, and if the product is carefully sterilized or preserved with cane sugar and sealed in air-tight containers it becomes easily transportable and keeps for long periods in any climate.

The desiccating processes now perfected remove practically all the water in milk, leaving a dry powder soluble in water. In the manufacture of this product whole milk is reduced to about one-eighth, and skimmed milk to about one-eleventh the original volume. By this means the volume is reduced to a minimum, and the keeping quality, particularly of dried skim milk, is superior.

CONDENSED MILK.

Removing a portion of the water from milk, leaving a product of good keeping quality which may be restored to its normal consistency without injuring its natural flavor, is a problem that has been studied for many years. It is claimed that during the first half of the last century foreign inventors evaporated a part of the water from milk, and, with the addition of cane sugar, made what was then known as condensed milk (see Scientific American, export edition, July, 1905). The early patents of De Heine (1810), Newton (1835), and Grimwade (1847) show that much attention was given to the subject before the present generation was born. The successful manufacture of condensed milk on a commercial basis, however, dates from 1856,

when Gail Borden, who has been called the father of the condensedmilk industry, built the first milk-condensing factory at Wolcottville, Conn.

During the last 25 years great strides have been made toward perfecting various processes for successfully producing condensed and evaporated milks. The industry is no longer in its experimental stage, but has reached a point where, with proper equipment and skilled operators, there is no uncertainty about obtaining a satisfactory product. During this time the industry has attained vast proportions, and there are now in this country over 300 milk-condensing plants, located in 24 States, and representing an investment of over $15,000,000 in buildings and equipment. These plants have a capacity of over 15,000,000 pounds of milk daily. Census reports show that the value of condensed milk made in the United States during the year 1909 was $33,563,129, and that during the period from 1880 to 1905 the production of condensed milk increased 1,202 per cent.

The term "condensed milk" is generally applied to milk from which a portion of the water has been removed, thus reducing its bulk and weight, and increasing its density and percentage of solids. It is made from whole milk or from partially or wholly skimmed milk, according to the use for which it is intended. In trade circles, however, the term "condensed milk" is applied to milk that is concentrated and preserved with cane sugar. The term "plain condensed milk" is applied to milk that is concentrated and sold in bulk without being sterilized or preserved with sugar, and the term evaporated milk" is applied to milk concentrated and preserved in cans by sterilization. Evaporated milk contains nothing but normal milk reduced to about one-half of its original bulk, while the sweetened condensed milk contains fully one-third cane sugar. Evaporated milk has, to a large extent, taken the place of sweetened condensed milk.

Before the pure-food laws prohibiting misbranding were in force, unsweetened concentrated milk was frequently labeled “Evaporated cream," but as the product was made from milk and sometimes from skim milk, it was plainly a violation of such laws, and the practice was finally discontinued.

Besides evaporated milk put up in cans, large quantities of plain condensed milk made from skimmed or partially skimmed milk are manufactured. The keeping qualities of this class of goods are about equal to those of pasteurized milk or cream and range from a few days to a week or two, depending on the temperature at which it is held. This product is usually shipped in 40-quart milk cans and is used largely by confectioners and ice-cream manufacturers.

To produce a condensed milk of good flavor and keeping quality the milk to be treated must be of a superior grade. This is so