Show THE ALFALFA weed SPREADING washington D C aug 1 7 the al falfa alta weevil is spreading in a way which makes it possible that sooner or it later every section of the country nil ill have to consider the problem of guarding against this pest during the twelve years since the weevil was wa s weevil introduced into america it ila lias bee been r 1 confined to the limits of the great basin of 0 the west but it has been found this year by the bureau of entomology tom at malta mccammon pocatello and blackfoot idaho all well within the snake river fiver drainage system and at Duclie sue utah in the colorado river system which like that of the snake slopes to the pacific within tile the great basin the weevil has spread as far south as richfield anto nto the alfalfa fields of central utah the insect in spreading across the continental divide department entomologists say is to be regarded merely as passing a convenient landmark rather than as aa surmounting a barrier for experience lias has not shown that it spreads faster along rivers than across mountain ranges nevertheless it is now many miles nearer to important alfalfa growing districts which have hitherto felt safe from its attack A description of the alfalfa weevil and methods of combating its ravages are contained in a new publication ot of the U S department of agriculture farmers bulletin the spread of 0 the pest has as a matter of fact been slower than at one time feared but its progress has been steady in utah and in small portions of idaho and wyoming where it now exists it has caused at times a loss of 50 per cent of the first cutting of alfalfa and a total loss of tile the second cutting in order that farmers in those sections in n which the weevil has not yet appeared may be able to recognize the pest and to protect their crops from it it the bulletin already mentioned contains details of its habits babits and of 0 its appearance in the various life stages the weevil is most easily discovered in the form of tile the full grown larva it is then a green wormlike worm like creature one fourth of an inch long with a black head and a taint faint white down the middle of the back it feeds upon the leaves of alfalfa mainly during late slay may june and early july and may be found by sweeping the tops of the plants with an insect net or by looking tor for the notches in the leaves where it has fed when the larvae are numerous they destroy most of the tender growth and cause the tops to appear white making the field look as it frost bitten when viewed from a distance the adult insect Is an oval brown beetle tb three ree six sixteenths teen of an inch long with a prominent snout its color frequently is nearly black this beetle is harder to discover than the larva but on the other hand it Is present in the field trie tae whole year around in winter it can be ba found by digging about the crowns and roots of alfalfa plants the alfalfa weevil does not hibernate definitely when the weather is cool tile the adults are quiet but with warmer temperature they quickly reume resume ume their activities egg laying he be begins in early spring and is usually ended by june 10 one efficacious method of 0 controlling con tolling the pest therefore is to destroy the eggs by pasturing the first crop up to that time A similar result may be obtained by cutting the alfalfa green and feeding it as a soiling crop I 1 it this is not done the larvae hatch batch in large numbers about the last week of may or ealler caller and eat the alfalfa leaves so rapidly that the plant is unable to outgrow the injury after the field is cut the larvae which have been feeding upon the first crop gather upon the buds of the stubble and frequently consume all of the second crop by that time most of the insects have completed their growing period and have gone into the or resting stage the later growth of the crop therefore does not suffer from them to protect the crop pasturing as has been said Is effective in the early part pan of the season the field should be divided into tac or three lots and each lot should be pastured alternately the animals being left in it until the alfalfa has been eaten down close to the ground the number and size of the lots should be proportioned to the producing power of the field and councel CoU nuel on an page three THE ALFALFA WEEVIL SPREADING continued irom from page five the number of animals to be pastured so that each lot may be grazed about once in two weeks pasturing should be continued until most of the weevil eggs have been laid which in practice means a little later than the usual cutting time of the first crop this method has the additional adian advantage tage of providing an economical method of fattening live stock combined with the proper feed of grain alfalfa pasture lure is excellent tor for putting on weight an and d it is said that many farms would probably be more profitable it their management centered about the pasturing of stock on alfalfa with the growing of enough other crops to provide grain and forage throughout the year it if the weevils are not killed early in the year they may be destroyed after the first crop has been removed by getting rid of 0 allo all the vegetation in the field crushing the clods and filling the cracks so as to expose the ent entire I 1 re surface to the sun this is best done by covering the field with a dust mulch tile the dust being an additional means of killing weevils we evils success obviously depends upon doing tile the work when the ground is dry and the weather warm warin and bright the second crop may also be protected by spraying the stubble spraying may also be resorted to in the spring from 50 to gallons per acre of a mixture of of zinc and water in the proportion of 4 pounds of powder in gallons gallon are used for this purpose the apparatus best suited for alfalfa spraying is described in detail in ane bulletin already mentioned still another recommendation made in this bulletin is the stimulation of the growth of the alfalfa by cultivating the held field in the spring this does not destroy the weevils but it serves to produce a larger arid and earlier yield when their attacks make early cutting necessary up to the present however morn more tanners farmers are concerned with preventing the alfalfa weevil reaching their fields than they are with controlling it in them no one knows exactly low liow the weevils spread but certain facts in regard to this matter have A been ascertained it is known diio wn for example that the insects are often found in green alfalfa fresh from the field and in second crop hay and among potatoes which have been in contact with it they are found also in cured alfalfa hay especially that of the second cutting catuns potatoes often are hauled in cars upon a bedding of green alfalfa hay and there is danger that the weevil may be transported in this way on the other hand however there is no evidence to show that the weevil w bevil spreads more rapidly along railroads than elsewhere |