Show APHIS IS destructive insect Is generally distributed over the united states one of moat most prolific of all plant lice und and Is injurious to va rlou rious leguminous crop crops notably clovers Ct over by J DA DAVIS VIS the periodic occurrence of the pea aphis in unusual abundance on varl ous leguminous crops more especially red and crimson clovers cl overe vetches detches vet ches field and garden peas and sweet peas has placed it among the important anju rious insects of the world tor for it Is al most cosmopolitan and more or lees less injurious wherever found in europe it has been the subject of numerous numerals treatises both from cram tho the systematic and economic viewpoint and its identity haa has been much confused cn fused with other closely related species epo cloa in america it larva of a specie species of fly which preys upon the pea aphis seema seems to bavo have mado made its first appear ance in destructive destruct ire and noticeable in 1899 although it la Is known to have been present here at least two decades previous and each year since 1899 this aphis has been recorded as injurious in one or more localities in the united states records of at injuries by this insect have been reported by various author ittes in different parts of this country showing that for a good many years tho the pea aphis has been present in serious numbers num bere dr J W folsom reports injury to red clover in the following words in 1903 the louse killed an Im immense mentle amount of red rod clover and weakened much more in do kalb county 11 I 1 found on ono one farm 80 acres a 0 acil d clover roots la in ono one field not ono root in a thousand showed any signs of ot life and on tho the ground were thousands of at cast skins of tho the aphid at cutting time the lie bad had been such a nuisance that the men objected to handling the crop after cutting tho the der never revived in neighboring fields there were many bare spots where the aphids bad had killed the clover locally and in the growing clover were many centers of new now in fest ution duo doubtless to migrant winged females all of the clover in that part of the country was more or less injured not only old clover but also the first year growth returning turning Ile to the same region the following sum mer to ace see the consequences of the injury I 1 did not stay long ong for it was hard to find a field of clover anywhere the farmers reported that the clover had been winter killed to their surprise since the winter had not been a severe ono one and the clover often eur sur aved worse kwintera win tera mr 11 morrison Morr lson discussing the tle abundance of thia this insect in indiana in 1910 says I 1 it val wa so common in many fields that the clover remained on the ground for more than a w after cutting without showing signs of curing the clover stems acle cre so plastered with honeydew that the moisture could not evaporate train them wo we havo have seen clover fields in in clana clans so baal badir anfe i d that the plante plants would be covered with the so honeydew a sticky sweetish fluid ejected by the aphis walking through such an infested field onoe ones trousers appear green so thirld would mauld they be covered by the plant lice and ruined by the boney honeydew dew which cov cred ered tho the plants while it la Is seldom that at fields are killed outright as described by doctor folsom there can bo be no doubt that the heavy infestations loleata tlona which are eo so common have a decided weakening effect on the plant and much of the winter killing ct tf clover can be traced back to the depredations of the pea aphis most lhost probably much damage to clover has been overlooked or attributed to other causes for or while a crop may be injured on large largo held field crops such an clever clover tho the injury will be overlooked tho the field la Is almost killed outright and subsequent effects such as via the weakening ening of tha the vitality of the plants is a too often a tributes tri buted to winter killing as doctor folsom baa has pointed out especially may this insect be a very dangerous clover pest pent if the weather conditions are favorable favor ablo to the aphis and a long dry spell retards the growth ot of the clover the aphis prefers the young bendot leaves and atoms stems of its host but eventually it covers the entire plant garden and sweet peas being succulent plants aro are seriously attached and readily succumb to the depredations of the insects clover claver particularly rod red clover on tho the other hand 1 ablo able to witha withstand tand considerable injury but as has bean noted oven even this plant la to not tree free from serious damage in fact entire fields of clover are sometimes destroyed wo we have no definite reports of injury to cattle by feeding clover hay bay which has been heavily infested with the aphids indeed we have been beau in formed by cattle feeders that such clover which has a slightly sweetish taste because of at the honeydew covering it Is to rather relished by cattle in 1911 it was reported that feeding cattle with alth infested vines was supposed by farmer to bo be tho the cause of the death of of his cattle but there seema to he no proof and tho the conclusions were probably incorrect the pea aphis commonly feeds r clover red and crimson clovers garden grass canadian field and sweet peas vetch and not infrequently quent ly on alfalfa the thu pea aphis ie in rno one of tho the most prolific of plant lice A female can give birth to as many as 24 young in a period of 14 consecutive hours tho A adult pea aehle average number of young per female for all individuals where records were kept in 1912 and 1913 was 37 per day but this Is the average for the entire productive period of each female tondra the latter doya days of this insects life the birth rate greatly diminishes aften cot not averaging cne ene young a day it if to doubtful if it any species of plant lice is more harassed by enemies than Is tho the pea aphis the common aphis fungus Is to tho the moet mott important natural enemy ibis fungus thrives under moist conditions specially especially when accompanied com ranted by warmth thia hia fungus Is contagious and spreads with wonderful rapidity heavy rains destroy great numbers nun bers of ilant lice and vory very hot dry wf weather eather seems to hinder excessive multiplication so that weather conditions aro are a great factor in the natural control of this pest |