The Springdale news., 1919-01-03

during a hot season t will mutlpiy much more rapdly and more brood worms" can develop
 Let us compare the records of this season with those made by employees of this Bureau in 1908. at Sloan Springs. During that season there wers two full "broods" and 8 partial third. During the present season there were three full "broods" and 8 partial fourth Since these are the only records agailable for comparison we eaa Hat sy which IS nearer the norrnal number of broods" but # IS probable tt4; thg present season Is well above t}ae average. h addition t5 the fact that a hot season produces more "broods~ than 8 cooler one, each
 5road" n a given season is usually several times larger than the pre- ceding one Let Us suppose that the second generation or brood" is only four times larger than the first at this rate Of increase the third brood ' would be 16 times larger, and the fourth 6+ times larger Four times is probably a smaller rate of increase than actually occurs n orchards and is certainly very much smaller than ne rate af reproduction n cages. As for instance records on f76 female moths showed that they deposited on an average a fraction more than 52 eegs during the few days of their lives. Under orchard conditions the rate af reproduction Is somewhat re- duced by natural cheeks which how ever are not very effective in summer.
 These natural checks do destroy many overwintering worms, so that the first brood in the spring is com paratively small, unless an unusually large number went into winter quar- ters the preceding year
 For season with such rapid devei- opment of codling moth infestation spray applications were not eontin- ued late enough in the season, There were a number of orchards under the writers observation, in which the spraying had been thorough and time ly and in which as late as August lst, or two or three weeks after the last application had been made which ap peare8 to be practically free from worms. Late in the season they be- came 9ulte heavily infested The indications are that had ore or two mere applications been made the loss to codlins moth might have been pre- vented altogether.
 Harvest counts ea Ben Davis trees i4 the experimental orchard. IF which fruit n the easprayea check vas over 73 per cent 'wormy.' showed about 10 per cent infestation in plats that received the highest number ef applications Practically al of these worms attacked the fruit during ne last month after the effects of spray ing had passed. One or possibly t0o more applications would have gisen nearly perfect results
 So serious an outbreak that af the present season can not be 0La.iE chareeable to weather N n ss how favorable weather conditions may haye beae the tafeststion could not haze been = heavy unless there had been an aecuiamation of worms . from the proceeding season which furnished abundant breeding stock" to start with Practically all Of the orchard in which heavy infestations were observed by the writers had at least fair infes,ation, or were ad- jaeeEf to source of infestation the proceeding season Those orchards in which tbe iafestations were light this year were practically free last year Yoa have al probably obsery- ed how ufestation are heavier ia parts of orchards adjacent to evapor= ators. or ln part of an orchard n which cull pile remained late in the season, than in other parts of the same orchard On the other hand. you have observed how an orchard which lost a crop due t8 an early freeze CT any other reason so that no worms" could develop that season is apt ta be practically free from worms the following season. These observations illustrate the danger from an accumulation of 5nfestation as weA as the advantage of having a crop free from worms the pre- yl8us season.
 The cause of this accumulation of codling moths may have been due to extent to the fact that Is impor- tanee has not been recognized. or has been oveTshadoWed in the previous seasons by the fungus diseases of the apple Bat probably the most i'm portan, factor la the Bentoayilie yi- einity at least. Was the series of hail storms earlv in 1sl7. which cat ua the fralt sa ba3ig that many of the growers became discouraged with the