OCR Text |
Show SERIOUS DAMAGE BY CLOVER WORM Alfalfa Crop Suffers Much Injury in Eastern Part of the United States. BEST MEASURES OF CONTROL When Outbreaks Are Particularly Severe Use of Hopperdozer Is Advisable Caterpillar Feeds on Different Plants. (Prepared by the United States Department Depart-ment of Agriculture.) Serious damage to alfalfa by the green clover worm lias been reported to the United States department of agriculture from several parts of the eastern half of the United States, where (his pest Is distributed generally. general-ly. Although for many years it has been known to occur commonly on clover and has received its popular name from this fact, its injury to this crop has rarely been sufficiently serious seri-ous to justify control measures. It usually confines Its attacks to leguminous legum-inous crops, such as alfalfa, clover, soy beans, cowpeas. and vetch, but sometimes feeds on strawberries and blackberry plants and some common weeds. Best Control Measures. The best control measure consists in timely cutting of the alfalfa crop, so as to remove the food supply when the caterpillars of this insect are most abundant. Clean culture is also rec- i ...... ' T .. it S1 , f f X ,j ft' , A i vy I I - i'VlV I ' 1 ! ; f 4 i i Alfalfa Is Highly Regarded as a Forage Crop. ommended, and when outbreaks are particularly bad the use of the hopper- i dozer is advisable. t There are three or four generations j of the green clover worm a season, ac- j cordjng to the bulletin, which allows ample time for the insect tg increase greatly in a summer. The caterpillars are killed in considerable numbers by natural insect enemies, but this method of control can not be relied upon for protection of the alfalfa i crop. The alfalfa should be mowed when the insect is in the caterpillar or worm stage from ten days to three weeks after the time of the appearance ap-pearance of the moths in great abundance. abun-dance. To insure success the field should be left an clean and bare as t possible In order" to remove flie food supply and any shelter protecting them from the direct rays of the sun. which hastens their destruction. j Clear Fields of Insects. If these measures can not be carried i out without injury to the alfalfa, I either from premature cutting or too prolonged delay, wait until the alfalfa is ready for another cutting. It ought j to be possible, however, before the summer is passed, to clear the fields of this insect in this manner. In the eastern states premature cutting cut-ting often results in permanent injury to alfalfa, especially while it Is young, and for this reason the cutting of this crop much in advance of the normal peilod is not recommended. As the caterpillar feeds on many different plants, ditch banks and fence rows should be kept free from weeds. The caterpillars have been caught . readily by dragging a field with a hop- ! perdozer, such as is used for grasshopper grass-hopper outbreaks. It does not hurt the 1 alfalfa when not used to excess, and irill catch many injurious insects. . |