Arizona republican., 1908-04-30

on several species of amaranths and
 saltbushes growing in and about mel
 on patches The Wingless form of this
 plant louse was found on the flower
 ing stems of shepherds purse about
 Tucson during the present winter.
 From the above it is seen that the
 species feeds on a large number of
 our common plants in addition to the
 Cucurbits. and that at least under
 favorable conditions it can endure our
 winters.
 The life history of the species is in
 brief about as follows: Winged males
 and females are developed in the late
 fall. al which time the eggs are de-
 posted on weeds and other plants that
 will afford nourishment in the early
 spring.: with the return of warm days
 the eggs hatch. and the young, with
 those plant-lice which have wintered
 over. multiply rapidly; by means of
 winged forms which appear in abun-
 dance at this time. the species is
 transferred from the weed patches and
 other situations to the melon fields
 In the course of d few days these
 winged forms on the melon vines be- come surrounded with small colonies of winsless forms. their offspring.
 which, like their winged mother con
 tinue to multiply rapidly by bringing forth their young alive frequently sev- eral d day. In the meantime the wing ed insect has left for other parts of the patch to start more colonies.
 Unless the melon grower makes fre- quent examination of the condition of his vines, the first indication 10 him of the presence of this pest in his melon field is the characteristic wrinkling or curling of leaves. usually those at the center of the hill; this peculiarity re- suits from the melon-louse feeding from the lower surface of the leaf, thus eXhausting the sap as well as kill ing the cells in that portion. At this time also, or sometimes q little later, the eXcretion of enormous quantities of honey -dew-the ''manteca" of the Mex noticeable, the vines the ground. and even the fruits at times being covered over with the swedish, oil-like liquid. 1t is this sweet fluid-the honey dew-thar sol greatly attracts the flies and ants. and, generally speaking. the presence of ants running to and fro on the vines can be taken as an indication of the occurrence of the melon aphis somewhere in the immdiate vicinity.
 IL is common practice among Mex jeans and other melon growers to de- stroy, by burning or burying, the lousy hills wherever found. The uselessness Of this treatment is appar ent when We examine the melon hills adjacent to the ones badly for we find them well stocked with plantlice. Though they may show no signs of the leaf-curl or Gf the honey dew. they are, nevertheless, yer itable centers of infection. and are just as dangerous 10 the field as the hill the vines Of which are ready to die. From the points of infection the spread is rapid if conditions are favorable, and in the course of ten days or two weeks an entire field may be uniform Iy infested rom a few starting points As the attacked leaves become with cred winged forms are developed which make their way to neighboring hills and fields. These winged forms were observed last year early in June. and continued more or less during theI season.
 The lousy" hills referred 10 above can be treated effectively as will be de- scribed later, and with little extra care they may be made to outgrow the attack and bear melons.
 Since these melon aphids feed upon a large variety of plants. including many of our common weeds, in addition toI the CUcurbitous vines. clean cultiva tion is of prime importance. Clean cul- tivatiOn will do much to lessen their chances of rapid development in theI early spring. and it may do away with them entirely for the year Also, at the close of the season. all weeds, vines. and other trash in the field, to- gether with the weeds growing on waste lands in the vicinity Of melon patches. should be raked in piles and burned. If the land is covered with a growth of young plants in the fall, iti should be plowed deep before winter, so as to destroy all weeds and other plants that are likely to harbOr plant lice or their eggs.
 As soon as the young vines get four pr six leaves they should be carefully and frequently examined for plant-lice and at the first appearance of the winged forms they should be fumigat- 70 with carbon bisulphide. It has been shown here and elsewhere that carbon Disulphide will kill the melon-louse without injuring the vine. It is a matter Of great importance that these winged plant-lice be destroyed as they come in from the surrounding vege- tatiOn. before they have had time to 1 establish large colonies. Tn order to 1 combat this insect most successfully l ! mutual action k desirable one l negligent ncighbor may be as great ] . menace to a melon growing com 1 as q lousy" melon hill is to ! , thriving patch.
 The method of Immigration consists ! n covering the young vines with l tight boxes nr other covers twelve to 1 'ighteen inches in diameter, and in | reducing under each box vessel con | aiming one or two tcaspOonfulS of | ,arbon bisulphide. one teaspoonful | should be allowed for every cubic foot | ,f space under the cover. and this will | 'dsily kill all the plant-licc in three | Iuarters of an hour. though it will do | 10 harm to leave the cover in place i, or an hour. A cheap tin cup. d clam | hell, saucer. or other open dish will | answer to hold the carbon bisulphidc. | { is very desirable that the cover : mould fit SnuGly to the ground. either |