ONIVEBSITY OF CALIFORNIA FPBLICATIONS COLLEGE OF AGRICULTURE AGRICULTURAL EXPERIMENT STATION BERKELEY, CALIFORNIA CONTROL OF THE POCKET GOPHER IN CALIFORNIA I. Natural History of the Pocket Gopher; Various Methods of Control By JOSEPH DIXON Contribution from the Museum of Vertebrate Zoology University of California II. A Method of Poisoning Pocket Gophers By E. RALPH DE ONG Agricultural Experiment Station, University of California BULLETIN No. 281 JULY, 1917 UNIVERSITY OF CALIFORNIA PRESS BERKELEY 1917 Benjamin Ide Wheeler, President of the University. EXPERIMENT STATION STAFF HEADS or DIVISIONS Thomas Forsyth Hunt, Director. Edward J. Wickson, Horticulture (Emeritus). Herbert J. Webber, Director Citrus Experiment Station ; Plant Breeding. Hubert E. Van Norman, Vice-Director; Dairy Management. William A. Setchell, Botany. Myer E. Jaffa, Nutrition. *Robert H. Loughridge, Soil Chemistry and Physics (Emeritus). Charles W. Woodworth, Entomology. Ralph E. Smith, Plant Pathology. J. Eliot Coit, Citriculture. John W. Gilmore, Agronomy. Charles F. Shaw, Soil Technology. John W. Gregg, Landscape Gardening and Floriculture. Frederic T. Bioletti, Viticulture and Enology. Warren T. Clarke, Agricultural Extension. John S. Burd, Agricultural Chemistry. Charles B. Lipman, Soil Chemistry and Bacteriology. Clarence M. Haring, Veterinary Science and Bacteriology. Ernest B. Babcock, Genetics. Gordon H. True, Animal Husbandry. James T. Barrett, Plant Pathology. Fritz W. Woll, Animal Nutrition. Walter Mulford, Forestry. W. P. Kelley, Agricultural Chemistry. H. J. Quayle, Entomology. Elwood Mead, Rural Institutions. J. B. Davidson, Agricultural Engineering. H. S. Reed, Plant Physiology. D. T. Mason, Forestry. W. L. Howard, Pomology. William G. Hummel, Agricultural Education. John E. Dougherty, Poultry Husbandry. S. S. Rogers, Olericulture. fFRANK Adams, Irrigation Investigations. C. L. Roadhouse, Dairy Industry. David N. Morgan, Assistant to the Director. Mrs. D. L. Bunnell, Librarian. Division of Entomology C. W. Woodworth G. P. Gray W. B. Herms G. A. Coleman E. C. Van Dyke S. B. Freeborn J. C. Bradley H. H. Severin E. O. Essig E. R. deOng * Died July 1, 1917. t In co-operation with office of Public Roads and Rural Engineering, U. Department of Agriculture. I. NATURAL HISTORY OF THE POCKET GOPHER VARIOUS METHODS OF CONTROL By JOSEPH DIXON Contribution from the Museum of Vertebrate Zoology, University of California The damage done by the pocket gopher in the United States has been estimated at over twelve million dollars per year. 1 California is one of the chief losers. The depredations by the gopher are locally numerous, involve nearly the entire state, and go on all the year. The losses, taken one by one, may be trivial, but in the aggregate are considerable. These features all taken into account lead to the belief that more damage is done by the gopher in this state than by any other one animal, not excepting the ground squirrel or the coyote. NATURE OF THE POCKET GOPHER The pocket gopher is a small, chunky, short-legged, burrowing rodent, with large protruding front teeth, fur-lined cheek pouches, which are used to carry food, not dirt, and which open outside the mouth, small ears and eyes, and short tail, often naked at the tip. The gopher averages smaller than either the common house rat or the wood or "trade" rat, but there are often great differences in size, especially between the sexes. Because most of the gopher's work is done in the dark, either underground or at night, the disastrous results are better known to most people than is the animal itself. The Pocket Gopher Compared with Animals Sometimes Mistaken for it Tail Fur External cheek pouches Front teeth Gopher short, 2 to 3 in., often naked at tip harsh always present large, protruding Mole short, 1 to 1% in. velvety none small Meadow mouse short, 1 to 1% in. harsh none small Kangaroo rat long, 6 to 10 in. silky always present small The mistake most often made is that of confusing the work of the mole with that of the gopher. These two animals, however, are totally different. The mole is not a rodent (gnawer) at all. It lives on animal matter (worms, grubs, and insects) and not vegetable matter. A mole may occasionally be caught in a gopher run; but the gopher iU. S. Dept. Agric, Farmers Bulletin No. 335 (1908), p. 19. 4 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION is the real cause of such damage as eating potatoes and cutting off roots, which is sometimes attributed to the mole. The mole crowds along just beneath the surface in loose soil, leaving ridges in which numerous cracks are visible. The gopher digs tunnels, and the sides of these are left clean cut. During dry weather, especially, the mole often burrows deeply and throws up mounds, but these show no trace of an opening, while those of the gopher do. Many moles have been caught for museum specimens by setting Macabee gopher traps care- fully in the main runs of moles (see p. 9, Special Sets). BREEDING HABITS The data recorded with the 2100 specimens of gophers, collected throughout the state, which are now in the University of California Museum of Vertebrate Zoology, form the main basis for the following breeding notes. Gophers have from three to twelve young in a litter. The smallest number of embryos (unborn young) found in females were three and four, the greatest eleven and twelve, while the average in twenty-eight females from many parts of the state was 5.8. There is evidence to indicate that two litters are frequently raised in a season where food is plentiful, as in alfalfa fields. Out of eighteen female gophers taken near San Bernardino, November 7 and 8, 1916, four contained small embryos and all but two of the remainder were ready to breed. The breeding season can perhaps best be gauged by the period of growth of the alfilaria, or "filaree. " This and malva, among all our native plants, seem to be the gopher's favorite food. The alfilaria is one of the earliest plants to start after the first fall rains, and the resulting nutritious food supply seems to start the gophers breeding. The nest is underground, and usually placed beneath a stump, rock pile, brush pile, or some other such surface protection as will discourage badgers or coyotes from digging. The young remain in it for several weeks after birth and do not leave until they are nearly half grown, when they are able to forage for themselves. In plowing an abandoned field in San Diego County in the middle of January, 1911, the writer uncovered at the bottom of the furrow near a willow stump a nest containing a mother gopher and four hairless, helpless young, barely able to crawl. ' The following dates show the approximate time of year when the main crop of young begin leaving the nest, though young may also be found foraging for themselves much earlier or later than these dates: southern California, March 30: San Joaquin and Sacramento CONTROL OF THE POCKET GOPHER IN CALIFORNIA valleys, April 1; Owens Valley, April 15; foothills of Sierra Nevada, April 30; northwest coast region, May 15. WHEN TO TRAP AND POISON Obviously, the time to combat gophers most successfully is before the young make their appearance in the spring. Poisoning is very effective, but harder to carry on than trapping in the dry season, especially during August, September, and October, when the supply of green food is scarcest. Trapping is most easily carried on soon after the green vegetation starts in the early winter or spring, for the gophers are then most active. The wise old males which usually cause the trapper the most trouble, seem to lose their instinctive caution during the mating season and often blunder blindly into traps which they would never enter at other times. Every female caught at this time, before the young are born, means the destruction of from four to twelve gophers for the current season. METHODS OF DESTRUCTION The five most effective methods of destroying gophers are: (1) poisoning with strychnine; (2) trapping; (3) fumigation with carbon bisulphide; (4) flooding; (5) for permanent relief, encouragement and protection of the gopher's natural enemies, especially the barn owl and gopher snake. The solution of the gopher problem lies in a combination of two or more of the above methods, rather than in any one of them. Where a large acreage is to be treated, poisoning with strychnine will be found effective in reducing the pest. Traps are safe, can be used at any time, and are effective in the hands of a man who is not afraid to dig and who uses care in setting and in placing his traps. Traps are especially adapted to pasture, where there might be danger of poisoning stock, to gardens, to orchards and to banks of irrigation ditches. The use of carbon-bisulphide should be restricted to periods when the ground is wet. Both traps and carbon-bisulphide are good "follow-up" methods in getting the gophers which refuse to take poisoned bait. Land that can be successfully flooded, so as to drown out the gophers, has usually been graded for irrigated crops such as alfalfa. Flooding (irrigation) is therefore automatic, and I have yet to see anyone who was so stupid that he would not hunt and kill gophers which were being drowned out. A man that kills all the gopher snakes and barn owls on his place will have to fight gophers, nnd deservedly so. 6 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION 1. POISONING The four things necessary to poison gophers successfully are: (a) an effective poison such as strychnine; (6) a succulent bait that will be relished by the gopher; (c) bait large enough so that the gopher must eat it at once and not put it in his pocket and carry it away to his storehouse; and (d) placing of the bait in the main run where the gopher can readily find it and not cast it out with the dirt, as would often be the case were it placed in an open hole or in a lateral. In poisoning ground squirrels it has been found that strychnine is more readily absorbed through the membranous cheek pouches, which open inside the mouth, than through the stomach. However, the fur- lined pockets of the gopher which open outside the mouth do not readily absorb the strychnine. Hence poisoned bait, such as strych- nine-coated barley, which is effective on the ground squirrel, is not effective on the gopher. The gopher often puts the poisoned grain in its pockets and carries it away to the storehouse, where the poison soon loses strength. There are two methods of using strychnine. The first method, which is adapted to treating a large acreage, is given by Mr. de Ong in the second part of this bulletin. This method of placing the bait in the run through a hole made by a probe works well when the soil is damp. However, in cultivated fields when the ground is dry, a second method becomes necessary, as the dry surface soil will run in and promptly fill up the hole made by the probe. In this case it is best to dig down and place the poisoned bait well back in the main run of the gopher. Many times only a few poisoned baits are re- quired. These may be prepared quickly and used as follows : Carrots, parsnips, sugar beets or sweet potatoes, cut into one-inch cubes and poisoned by inserting a few sulphate of strychnine crystals into a slit made by the point of a knife, are good, especially in the dry season when green food is scarce. Carry the poisoned cubes in an old covered pail marked Poison. Find the main run in the same manner as when setting a trap, and with a slender pointed stick, so that you will not have to touch the bait, place one of the poisoned cubes a foot back in each hole, which should then be tightly closed. The hole may be opened forty-eight hours later and if it remains open the gopher may be considered dead. Poisoned alfalfa has been found effective in orange groves in southern California. The heads of a few tender stalks are bent back and tied with a string so that the tuft is formed at the end. A little strychnine mixed with orange juice is concealed inside the tuft, CONTROL OF THE POCKET GOPHER IN CALIFORNIA 7 which is then pushed well back in the run, and the hole then tightly covered. 2. TKAPPING Almost any kind of trap will catch gophers sometimes, a few will catch gophers most of the time, but we have yet to see the trap that will catch every gopher every time. There seems to be among experi- enced farmers throughout the state a decided preference for a gopher trap of the Macabee type (fig. 2a). After a practical test in the field, extending over several years, the "catching average" of this style of trap has been found to equal or surpass that of any other trap that the writer has been able to secure. Its cheapness, compactness, and reliability place it at the head of the list. Any form of explosive trap, or "gopher-gun," is not recommended because of the degree of danger which attends its use. Where to Set the Traps The most effective "set" for the Macabee trap is in the main runway (fig. la), and not in the lateral run (fig. lb) that leads to the surface mound. This necessitates the use of two traps per setting, one in each direction; but the results are so much more certain and quicker that the catch per trap per day is* greater than where but one trap is set in a lateral run, where it is often filled full of dirt by the gopher. A common stiff-handled twelve-inch iron spoon is of great assistance in finding the main run and in properly placing the trap. This spoon had better be supplemented by a light short- handled shovel, for the man that is afraid to dig will never get rid of his gophers. The freshest mound should be selected and the probable direction of the main run determined by noting the angle of the dirt-plugged hole. The mounds are usually situated one or two feet distant from, and nearly at right angles to, the main run. Now to business : Take the bowl of the iron spoon in your hand and push the other (handle) end of the spoon into the ground where you think the lateral, which leads from the mound to the main run, is. If the spoon strikes an open lateral you will feel the spoon handle drop through the opening. If the lateral is filled loosely with dirt the drop will be less noticeable but still plainly felt. If it is plugged tight you will have to use the shovel to dig down a little distance before probing again. If this fails, try a new mound. When the lateral is found, follow it down to the main run, which is always kept open by the gopher. Use the shovel until you have cleared a place where you can set a trap in each direction. Smooth out the hole with s UNIVERSITY OF CALIFORNIA EXPERIMENT STATION the spoon but do not disturb more than is necessary. Set the treadle, or pan, so that a slight touch will spring the trap, and place the trap well back within the hole. A little loose dirt should be left in the bottom of the hole, as it will cover the prongs and front end of the trap when the trap is pushed into place. When in place, press the trap down firmly so that it will not slide back if the gopher pushes against it. Then plug the burrow with a clod or a handful of grass or alfalfa and cover completely so that no light can get to the trap. A gopher's instinct prompts him to tightly close all open burrows to keep out his natural enemy, the gopher snake (nature's own gopher Fig. 1. — a. Best place to set traps or leave poisoned bait, in the main run which is always kept open by the gopher, b. Lateral run, usually partly plugged with dirt, leading to surface mound. trap). Therefore, if poisoned bait or a trap be placed in an open hole, or the hole be left open, the poisoned bait will often be thrown out, to become a menace to stock, or the trap sprung by the dirt which the gopher pushes ahead of him in plugging the open hole. Set the traps and place the poisoned bait well back in the main runs, which should then be tightly closed. The trap should have a wire or light chain attached to it and fastened to a chunk of stove-wood or, better still, an old worn-out stewpan which will rattle should you forget and run over the set trap with a harrow or cultivator. Coyotes and house-cats dislike the noise, also, and do not drag the trap so far when they rob it. In case only one trap is available when the main run is found, a careful watch will often, but not always, reveal one or more little flies emerging from the run where it is first opened. These flies seem to have a direct CONTROL OF THE POCKET GOPHER IN CALIFORNIA 9 relation to the gopher, as experiments have shown that the side that they come from is the one occupied at that time by the gopher and hence the place to set the trap. Traps should be visited morning and evening, or oftener. Special Sets Individual gophers will frequently be found that refuse to enter any sort of trap. These gophers are generally old males and are likely to be the ones that do most of the gnawing on fruit trees. When one of these old-timers repeatedly fills the trap with dirt, then special Fig. 2. — a. Eegular Macabee gopher trap. ~b. Reconstructed Macabee trap used to catch ' ' wise ' ' gophers, and moles. care becomes necessary to catch him. Moles may be captured in this way also. Take a Macabee trap (fig. 2a) and move the treadle forward about an inch and a half, placing the wire which carries the treadle below, instead of above the two longitudinal wires. Cut off the wire trigger to meet this change (fig. 2b). Then bend the treadle backwards at right angles to its former position (fig. 3a) so that it will lie parallel with the trap (fig. 3c), instead of sticking up at right angles and obstructing the runway (as in fig. 36). Set the trap so it will spring easily. Put a pinch of loose cotton under the treadle to keep the dirt out, and when the trap has been placed in 10 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION the run take a stick and cover the whole trap with a thin layer of loose dirt. Another method is to take a recently caught female and rub the reproductive parts on the face of the treadle of the regular Macabee trap. A few drops of urine may be squeezed out during the process, but this only adds to the efficacy of the decoy. If all else fails catch a gopher snake and turn him loose in the run. After you have put in poison or traps the tops of all the gopher mounds should be kicked off, so that when you make your next round the newly made mounds will tell you where gophers remain and where to put out more poison or traps. The reconstructed form of the Macabee trap above described will be furnished by the manufacturer if the demand warrants. .1 1 / o i=fl (L __. _ >w/_ ^ a be Fig. 3. — a, b. Vertical " treadle' ' or "pan" of regular trap; heavy dotted lines show places to bend vertical treadle to form horizontal treadle (e). 3. CAEBON BISULPHIDE Carbon bisulphide is volatile as well as inflammable and the gas from it is explosive, so that caution should attend its use. Its use is advisable only when the ground is damp or full of water, as the cracks in dry ground let the gas escape. It does not seem to be as effective on gophers as on ground squirrels, for the gopher burrows are much more extensive and the gopher is therefore harder to reach. It is more valuable as a "follow up" method than for general appli- cation. There are two methods of applying carbon bisulphide. The first is to pour about a tablespoonful on cotton waste, corncobs or other absorbent material, which is then quickly pushed down the hole and the opening promptly and tightly closed. The better way is by the CONTROL OF THE POCKET GOPHER IN CALIFORNIA 11 use of a special apparatus which forces the gas down the hole. This is accomplished by a hand bellows attached to the top of a tank that contains the carbon bisulphide. The air is forced through a pipe from the bellows to the tank, where it passes over the bisulphide and is carried out through a rubber hose which is pushed down the open hole and then tightly surrounded by dirt. Contrivances of this sort, such as the Eureka Squirrel Exterminator, are on the market. 4. FLOODING As has been pointed out above, flooding of fields often is an essen- tial part of agriculture in irrigated sections. The main point, then, is to see to it that the gophers which are drowned out and seek the higher borders, are promptly dispatched. A good dog will do this effectively until he gets tired, and then the farmer must be ready to give the gophers proper attention with the back of a shovel. 5. ENCOUEAGEMENT OF THE GOPHER'S NATURAL ENEMIES Comparatively few ranchers realize the true value of barn owls and gopher snakes as allies in their war on gophers. A pair of nesting barn owls were .found by the writer to catch from three to six gophers a day for their young. No one who has ever counted the number of rodents brought in by a pair of these owls during a single season would ever doubt their value as gopher destroyers. On May 13, 1914, near Mendota, Fresno County, California, Mr. John G. Tyler 2 found two pairs of barn owls nesting in an old tank house. "One nest was placed in the tank on the bones, fur, pellets, and refuse that had accumulated to a depth of several inches. One bird was perched on a beam overhead asleep, while his mate occupied the nest, which contained four very small birds and six eggs. Scat- tered about on the floor were five pocket gophers (Thomomys) , five kangaroo rats {Perodipus), one pocket mouse (Perognathus), and two white-footed mice (Peromyscus), all of which were in good condition and undoubtedly of the previous night's capture. Besides these, there were partly eaten remains and fresh skeletons of several more. ... If the thoughtless persons who so relentlessly destroy this owl on account of its supposed fondness for chickens and pigeons would take the trouble to keep watch of a nest-site through one season, the most ignorant among them could hardly fail to realize that they are working against their own best interests whenever they kill a barn owl." 2 Condor, XVII, January, 1915, p. 57. 12 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION The gopher or bull snake may steal eggs occasionally, but his main diet consists of small rodents, chiefty gophers. A wise man will there- fore protect the gopher snakes on his premises. Every gopher that the barn owl or gopher snake destroys means one less for yon to oatch. OTHER METHODS OF CONTROL Some other methods of controlling pocket gophers are: (1) pro- tecting trees with wire netting; (2) planting gopher repellant plants; (3) using rodent virus; (4) surrounding small plot by a trench; (5) protecting of ditches by cement. 1. PEOTECTING TREES WITH WIRE NETTING One-inch mesh galvanized wire netting in the form of a cylinder one foot in diameter and eighteen inches high may be placed about young trees when they are planted, to protect them from the attacks of gophers. The top of the netting should be put just below the surface of the ground, and the trunk of the tree above ground pro- tected in some other way so as not to interfere with cultivation, which the netting will certainly do if it sticks above ground. 2, 3. GOPHER REPELLANT PLANTS; RODENT VIRUS Plants which will drive gophers away, and a virus of a "gopher infectious" disease, have both been much exploited, but neither remedy seems to have "made good," and cannot therefore be recom- mended. 4. SURROUNDING SMALL PLOT BY A TRENCH Small plots of ground have been protected by being entirely sur- rounded by a trench eighteen inches wide and two feet deep, with open five-gallon cans buried flush with the bottom in the ditch at twenty-five foot intervals, to catch and hold the gophers which tumble into the ditch, and thence into the cans. 5. PROTECTION OF DITCHES BY CEMENT A power company which had much trouble with gophers in a large ditch dug a four-inch trench six feet deep straight down through the middle of the lower bank of the ditch. The dirt was loosened with an iron bar and removed with a narrow shovel, of the type used in digging telephone-pole holes. The trench was then filled with a "lean" mixture of cement and sand, which was carried on a barge that floated on the water in the ditch. The cement was conveyed to the bottom CONTROL OF THE POCKET GOPHER IN CALIFORNIA 13 of the trench by a galvanized iron chute which was built in sections so as to be readily adapted to any depth. This method was said to have been expensive, but satisfactory in the long run. A small irrigation ditch having a seven-foot "surface" has been protected from gophers, weeds and leakage by applying to the sides and bottom, first a %-inch coat of 7 to 1 cement and then a surface layer % inch thick of 3 to 1 cement. This proved satisfactory. All of these preventatives are costly and are advisable only in those situations where protection against gophers cannot be obtained by their destruction. 14 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION II. A METHOD OF POISONING POCKET GOPHERS By E. EALPH de ONG Agricultural Experiment Station, University of California One of the most satisfactory, and at the same time, one of the cheapest methods of controlling pocket gophers is through the use of poisoned baits, such as chopped vegetables, dried prunes, or raisins. The formula 3 which has proved very successful at the University Farm is as follows : Sweet potatoes, parsnips, or carrots 8 quarts Flour paste y 2 pint Strychnine alkaloid, powdered y 4 ounce Saccharine i/ 1( . ounce Chop the vegetables, or cut them with a knife, into one-half inch cubes. Make a thin paste of flour and water and boil for a few min- Fig. 4. — Tool for probing ground so as to locate underground burrows of pocket gophers. utes. Stir the strychnine and saccharine into one-half pint of the cooked paste and pour it over the chopped vegetables, stirring until each piece is coated. Two or three or these cubes are to be dropped in each runway. The alkaloid form of strychnine should be used in preference to the sulphate, as the former is but slightly soluble in water and remains largely on the outside of the bait, leaving the center sweet. The saccharine is used to disguise partially the bitter- ness of the strychnine. To locate the underground burrows, the method previously recom- mended will prove satisfactory, or a simple tool may be used, which can be made at any blacksmith shop. This is a shank of steel, three- quarters of an inch in diameter and about fifteen inches long, pointed 3 U. S. Dept. Agric, Farmers Bulletin No. 484, p. 39. CONTROL OF THE POCKET GOPHER IN CALIFORNIA 15 at the lower end. This is fitted into a wooden or iron handle, three feet long, one end tapered slightly, to be nsed in enlarging the open- ings made into the runway. To aid in sinking the probe into the ground, a foot-piece should be welded on to one side of the steel rod (fig. 4). To use this tool it is necessary for the ground to be wet down to the ordinary depth at which the gophers are working, usually from three to eight inches below the surface. Sink the probe into the ground, ten or fifteen inches from the gopher hill, continuing the work until the burrow is located, which will be recognized by a sudden dropping of the probe. If necessary, enlarge the opening into the runway with the blunt end of the handle, then drop in the bait, and close the hole with the foot. The operator will soon become expert in locating the runways so that, where gophers are abundant, one man may bait hundreds of runs in a single day. One piece, of seven acres of heavily infested alfalfa land, has been covered by one man in a day and a half. Poisoning is more successful from late summer, after green food has become scarce, until grass starts in the fall or winter, depending on rainfall and temperature. It should be delayed until the top layer of ground is thoroughly wet, not only to facilitate operations, but because, after the heavy rains begin, gophers have a tendency to migrate into fence rows or the uncultivated strip along driveways, which greatly reduces the amount of ground necessary to cover. One thorough application in such places should kill 90 per cent or more of the gophers. After another rain the ground can be gone over again and any fresh hills poisoned. Alfalfa is not as successfully treated as orchard or bare land, on account of the abundance of suc- culent food. STATION PUBLICATIONS AV AIL ABLE FOR FREE DISTRIBUTION REPORTS 1897. Resistant Vines, their Selection, Adaptation, and Grafting. Appendix to Viticultural Report for 1896. 1902. Report of the Agricultural Experiment Station for 1898-1901. 1903. Report of the Agricultural Experiment Station for 1901-03. 1904. Twentv-second Report of the Agricultural Experiment Station for 1903-04. 1914. Report of the College of Agriculture and the Agricultural Experiment Station, July, 1913-June, 1914. 1915. Report of the College of Agriculture and the Agricultural Experiment Station, July, 1914-June, 1915. 1916. Report of the College of Agriculture and the Agricultural Experiment Station, July, 1915-June, 1916. BULLETINS No. 207. 208. 212. 213^ 216. 2?5. 230. 241. 242. 244! 246. 248. 249. 250. 251. °m2. 253. °55. 257. No. 65. 69. 70. 107. 108. 109. 113. 114. 115. 117. 118. 121. 124. 126. 127. 128. 129. 130. 131. 132. 133. 134. 135. 136. 137. 138. 139. The Control of the Argentine Ant. The Late Blight of Celery. California White Wheats. The Principles of Wine-Making. A Progress Report Upon Soil and Cli- matic Factors Influencing the Com- position of Wheat. Tolerance of Encnl ptus for Alkali. Enological Investigations. Vine Pruning in California, Part I. Humus in California Soils. Utilization of Waste Oranges. Vine Pruning in California, Part II. The Economic Value of Pacific Coast Kelps. Stock-Poisoning Plants of California. The Loquat. Utilization of the Nitrogen and Organic Matter in Septic and Imhoff Tank Sludges. Deterioration of Lumber. Irrigation and So'l Conditions in the Sierra Nevada Foothills, California. The Citricola Scale. New Dosage Tables. No. 261. Melaxuma of the Walnut, "Juglans regia." 262. Citrus Diseases of Florida and Cuba Compared with Those of California. 263. Size Grade for Ripe Olives. 264. The Calibration of the Leakage Meter. 265. Cottonv Rot of Lemons in California. 266. A Spotting of Citrus Fruits Due to the Action of Oil Liberated from the Rind. 267. Experiments with Stocks for Citrus. 268. Growing and Grafting Olive Seedlings. 270. A Comparison of Annual Cropping, Bi- ennial Cropping, and Green Manures on the Yield of Wheat. 271. Feeding Dairv Calves in California. 272. Commercial Fertilizers. 273. Preliminary Report on Kearney Vine- yard Experimental Drain. 274. The Common Honev Bee as an Agent in Prune Pollination. 275. The Cultivation of Belladonna in Cali- fornia. 276. The Pomegranate. 277. Sudan Grass. 278. Grain Sorghums. 279. Irrigation of Rice in California. The California Insecticide Law. The Extermination of Morning-Glor<\ Observations on the Status of Corn Growing in California. Hot Room Callusing. The Common Ground Squirrels of California. Spraying Walnut Trees for Blight and Aphis Control. Grape Juice. Communit" or Local Extension Work bv the High School Agricultural De- partment. Correspondence Courses in Agriculture. Increasing the Dut- of Water. Grafting Vinifera Vine-ards. The Selection and Cost of a Small Pumping Plant. The County Farm Bureau. Some Things the Prospective Settler Should Know. Alfalfa Silage for Fattening Steers. S-nraving for the Grape Leaf Hopper. House Fumigation. Insecticide Formulas. The Control of Citrus Insects. Cabbage Growing in California. Spraving for Control of Walnut Aohis. When to Vaccinate against Hog Cholera, Countv Farm Adviser. Control of Raisin Insects. Official Tests of Dairy Cows. Melilot"s Tndica. Wood Decav in Orchard Trees. The Silo in California Agriculture The Generation of H-drocvanic Acid Gas in Fumigation bv Portable Ma- chines. CIRCULARS No. 140. The Practical Application of Imnroved Methods of Fermentation in Califor- nia Wineries during 1913 and 1914 141. Standard Insecticides and Fungicides versus Secret Preparations. 142. Practical and Inexpensive Poultry Ap pliances. 143. Control of Grasshoppers in Imperia Valley. 144. Oidium or Powderv Mildew of the Vine 145. Suggestions to Poultrymen concerning Chicken Pox. 146. Jellies and Marmalades from Citrus Fruits. 147. Tomato Growing in California. 148. "Lungworms." 150. Round Worms in Poultry. 151.. Feeding and Management of Hogs. 152. Some Observations on the Bulk Hand- ling of Grain in California. 153. Announcement of th° California State Dairv Cow Competition, 1916-18. 154. Irrigation Practice in Growing Small Fruits in California. 155. Bovine Tuberculosis. 156. How to Operate an Incubator. 157. Control of the Pear Scab. 158. Home and Farm Canning. 159. Agriculture in the Imperial Valley. 160. Lettuce Growing in California. 161. Potatoes in California. 162. White Diarrhoea and Coccidiosis of Chicks. 163. Fundamentals Affecting the Food Sup- plv of the United States. 164. Small Fruit Culture in California. 165. Fundamentals of Sugar Beet under California Conditions.