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Show ' ENTOMOLOGY Edited by Prof. E. G. TitmivState Agricultural Collect. THE ALFALFA-LEAF WEEVIL. Written for the Dcscrct Farmer. About five years ago an alfalfa field east of Salt Lake City was rather seriously injured in the early spring by what the owner thought was frost. His "second crop was almost totally destroyed and considerable inroads niade upon adjoining fields. It was then found that the injury was caused "by -a sriiall green worm. Whether this was 'the first appearance in numbers of this new alfalfa pest is not at present pres-ent known, but it is the earliest yet located. Every year since then litis seen a constantly increasing zone of injured fields until now the insect causing the -injury is known to occur from the hills northeast of- Salt Lake City to some distance south of Sandy and from the foothills westward. Tlu west line in most of the infested territory ter-ritory i6 the railroad, but in some places the pest has crossed this barrier; bar-rier; notably having spread to field $ wqst of the Fair Grounds during the past two seasons. Efforts to check its further spread should be made at once or the injury will, in a few years, cover a much larger alfalfa growing region. The insect causing this serious injury in-jury is very closely related to the destructive de-structive clover-leaf weevil of the East, an insect supposed to have been imported front Europe some time in the , '70s. So .far as we at present know nothing has heretofore been reported re-ported about the life history of the species injuring alfalfa. The full grown insect, the weevil as it is known, belongs to a group of beetles that with one scarcely well-proven well-proven exception, arc all injurious to plants. To this group belong the cot-tonJboll cot-tonJboll weevil, the strawberry weevil, the plum-curculio and many other injurious in-jurious insects all possessing one character An common, a beak more or less well developed which contains the jaws. The' alfalfa-leaf weevil is about a quarter of an incfr long, the male Usually Us-ually being a little shorter and more slender than the female and often darker in color. The beetle is oval in form, brown or grayish brown in color and when freshly emerged from the cocoon shows several pale markings mark-ings on the wing covers; it also is more or less covered with fine, short hairs and small tufts of scales. These arc rubbed off to some extent in a few days by the weevil wandering around in search of food in the grass and on the ground. While on the Continued on page 15.) THE ALFALFA-LEAF WEEVlT Prof. E. G. Titus. (Continued from page 3.) ground the weevil is almost indistin-guishablc indistin-guishablc from tljc ground upon' which it travels. The eggs arc oval in -shape, rather minute in. size, pale yellow, darkening before listening to a greenish yellow. They arc laid in several places about the alfalfa plant, but present obscr- vatfbns seem to show fthat the most arc" laid near the growing tips. The egg-laying period lasts for several weeks as the weevils do not all come 'from hibernation, at the, same time. The young larvae arc pale green, changing' "after their, first feeding to an alfalfa-leaf green. The color is so deceptive that it takes some considerable consider-able searching to locate the young larvae unless they arc quite numerous. When two-thirds or 'more grown they arc more easily seen, usually with the tip of the tailcnd curled around a part of the leaf or bud while they move the rest of the ibody to and fro along the leaf they are' eating. At this age they are easily disturbed and often fall to the ground before the plant' is touched. The length of time between the hatching of the egg and the spanning span-ning of the cocoon by the full grown larvae seems to range from three, to four weeks, although some instances have been noted where it was appar-" appar-" ently considerable shorter. All -stages of the larvae and the cocoons with fully developed beetle will be found , in June, July and August. Larvae, not yet half grown, have been .found as late as the middle of September; whether these are belated larvae from 1 tlic spring or a second brood lias not been established. " -U:s When the larvae arc-lull grown they drop to the grpund( and atiipng the fallen leases or at the base "b? the alfalfa al-falfa stems spin a cocoon that re sembles a' fine net-work of white M threads. In this the larva changes to M a pupa and after, some days this stage H changes into a soft, dirty white weevil M that gradually hardcnsrup and' later 1 cuts its . way frowifcthe- cocoon, craVls M up a stem and begins to feed. The H (beetle cannot fly though having well M developed wing covers (outer wings) M the under or wings used in flight arc M small and undeveloped. This fact H limits the spreading of the weevil to walking or being carried. Unfortu- H natcly they arc good walkers 'and 1 . man provides them with 4'everal M means of carriage. Recently unload- fl cd hayracks have been seen upon H which in June the green larvae layn H handfuls, and in August hundredsjof H weevils occupied" "tSe same place. H Numbers of the weevils dropped to the' ground in the fields and along the H roadway, and many of these arc now safely hidden away awaiting the awak- cning of the alfalfa next spring. Irri- gation ditches afford another casv 1 means .for them to reach new pas- H turcs. :Wccvils fall into the water and H arc swept along until lodged by their 1 own efforts' or owing to the water 1 spcading out over a fijejjjgljgr are not easily drowned and when once '1 they reach .solid footing arc steady, 1 untiring walkers. I have found them , scattered all over a forty-acre piece of uncultivated dry land all moving in one direction away from an alfalfa afield that was already seriously in- ' fested. In this instance many of them ' eventually reached a fine alfalfa field , on the farther side and the following year first and second crops were ,H short, the second practically wiped out. lH Almost anyplace", from a hay-stack to dead leaves along the ditch bank, afford them a winter protection. The hibcrnaiing weevil comes out early in the spring and soon commences feed- ing on the young and tender leavc3 Severely injured 'fields appear whir ened and from a distance liave the appearance of having been scorched. The first crop on many placas this past year was almost a total failure H and where the insec4- was numerous, if an attempt was adc to cut this H crop rather late, tlie second crop had almost no chance oficominl on for H several weeks, sihe-fhyoung larvae H 3,kept every sign of greenleaf cut H dpwni Wlcn a niajority of these H 'ldrvae spun cocoons the alfalfa again grew. 'M |