The Traitor Aphid That Robs Potatoes 



Strange Story of the Part that Roses Played in Helping Along Last Year's Trouble 



EDITH M. PATCH 



Maine State Entomologist 



WHEN the slogan, Food Will Win the 

 War, went ringing through the 

 land, in the spring of 1917, Mac- 

 rosiphum solanifolii was innocently 

 sipping Rose sap, and if she had continued 

 that occupation, matters would have been 

 worse for our posies but better for our pota- 

 toes. And in spite of her foreign sounding 

 name, she isn't an alien enemy, either. So 

 she must be traitorous, as she is purely Ameri- 

 can so far as entomological records go, since 

 she was first introduced from Jacksonville, 

 Florida, in May, 1882. At that time she was 

 engaged in feeding on Pepper Vine. 



After that, little if any attention was paid 

 to her until about twelve years later, when 

 entomologists "up in Canada" and "down 

 in Maine" began to look about for a name to 

 apply to a beautiful big aphid, sometimes 

 pink, though usually green, that was playing 

 havoc with the potato crop. 



To settle doubts, a trip was made from 

 Maine to our National Capital, to see the 

 gentleman who was sponsor for Macrosiphum 

 solanifolii. The desired specimen was "prob- 

 ably knocking around the museum somewhere 

 in a vial, dried past recognition," but the 

 informant continued. "If you have a large 

 Mac. on Solanum, — that's solanifolii all 

 right." 



The entomologist returned to Maine and 

 the Aroostook potato fields, the stalks of 

 which looked like the accompanying picture, 

 only mussier and sticky. 



Where did the aphid come from? It was 

 evidently migratory, as the potato vines were 

 clean all the spring and the insects took flight 

 from them in the late summer, long before 

 egg-laying time. The second problem was: 

 What are the practical means of killing the 

 pest? 



Perhaps the gardener will think these two 

 problems should have been reversed in se- 

 quence; and perhaps they should. 



Fates favored the farmer. While he waited, 

 minute winged parasites and fungous disease 

 cleared his field of the pink and green insects 

 and so scarce they became that there was not 

 enough material left in Aroostook County for 

 the life-history studies planned. 



Incidentally, a few aphid specimens picked off 

 Japanese Rose one Spring, on the Campus of 

 the University of Maine, settled the question 



whence came the aphids to the potato and 

 whither they flew. The Rose bush, it chanced 

 was the favorite over-wintering host-plant, 

 in that locality. But after its sensational 

 appearance in Canada and Maine for a few 

 seasons, Macrosiphum solanifolii waited until 

 1917 to get the public really excited. 



To be sure, she brought in considerable 

 revenue to Uncle Sam in postage stamps 

 placed over innumerable inquiries such as, 

 "What species is this, as per example in box, 

 that is wilting potato vines to the ground and 

 weakening whole fields in this region? 



"This region," in reality stretched all the' 

 way from the Massachusetts coast to the 

 Mississippi and how much farther can prob- 

 ably be ascertained from the government 

 reports a bit later. 



But food at present weighs heavier on the 



Last season's potato fields from the Mississippi to the 

 Atlantic coast were badly attacked by a robber aphid. 

 Whence came it? The accompanying article tells you how 

 to guard this year's crop 



mind than postage stamps and that is why 

 it seems just to term the pink and green 

 potato aphid a traitor of 1917. In fact in 

 Ohio this insect was named "Kaiser bug," 

 which is significant enough. 



Of course a State recognizing the pest by 

 such a name could not do other patriotically, 

 than fight it; and thus it is from the Ohio 

 Agricultural Experiment Station (Bulletin 

 317) that we learn: 



Final Recommendations 



Based upon our observations and findings, confirmed by the 

 general results of the field demonstration spraying campaign, 

 we believe: 



Nicotine sulphate, i^ to 2 teaspoonfuls to a gallon of water, 

 or about I to 500, with enough soap added to form a suds, is 

 the most satisfactory spraying material for the control of this 

 species. 



Two applications or more may be necessary to control the 

 scourge, and these applications under conditions such as pre- 

 vailed this season should not be more than 3 days apart. 



Thoroughness of application is essential to success. Many 

 failures to control are due to insufficient or improper spraying. 



Because of the wide range of hosts, clean culture is an import- 

 ant adjunct to other control measures. 



Spraying in the early stages of an outbreak is essential to a 

 successful control. 



With proper equipment, proper materials and thorough 

 work, the green and pink potato aphid may be effectively and 

 economically controlled. 



Although this insect is to be classed with 

 the migratory aphids because it accepts one 

 type of food plant (i.e. the Rose) for over win- 

 tering host and another type (by perference 

 the potato) for the summer months it differs 

 from many such aphids in not being exclus- 

 ively confined to two food plants or their close 

 relatives. On the contrary, the pink and 

 green potato aphid has been collected in dif- 

 ferent parts of the country from members 

 of sixteen families of plants: certainly a broad 

 and catholic taste as is shown by the following 

 list: 



Corn, Iris, Gladiolus, Canna, buckwheat, 

 Curly Dock, Smartweed, Lamb's quarters or 

 Goosefoot, Redroot Pigweed, Pokeberry, 

 Turnip, Shepherd's purse, Apple, Rose, 

 Hollyhock, Plantain, Bean, garden Pea, 

 Pepper, Jimson weed, Matrimony vine, 

 Tomato, Ground Cherry, Eggplant, Pepper 

 Vine, Potato, Sweet potato, Ragweed, Aster, 

 Cineraria, Sunflower, Lettuce, and Sow- 

 thistle. 



As to the suggested remedies let it be 

 recognized that the special proprietary aphid 

 sprays and tobacco extracts on the market 

 are convenient vehicles for nicotine sulphate 

 on which they are all based. 



Hitting the High Cost of Fertilizers h. f. button s °^ c fe& is bnd 



Applying New Ideas in Soil Fertility so That the Gardener Can Get High Value at Lower Cost — Means at Hand to 



Supply Needed Potash and Phosphates 



TIME was, when whatever was, was 

 right; but the American gardeners of 

 to-day are so far from the ways of 

 their conservative forefathers that 

 they are like the Athenians, mentioned in the 

 scripture, who stood about in the public 

 places and talked of any new thing which 

 might be told by travelers or philosophers. 

 • There is so much to know about soil fertility 

 that, the beginner feels about it as Mark 

 Twain did about learning to be a pilot; that 

 no one could ever learn that amount, or if he 

 did learn it, his head would burst from the 

 excess of knowledge. But like the great 

 Mississippi pilot, we do learn it and then 



stand around waiting for a chance to learn 

 about some other new thing. 



Put Sulphur to Work! 



W/"E ALL know that sulphur is a necessary 

 * * element, yet somehow the books say but 

 little about it or its value in fertility. Careful 

 readers will remember the small scientific 

 flurry when some Wisconsin chemist discov- 

 ered a few years ago that existing methods 

 of analysis had missed a large share of the 

 sulphur. Even after this we heard but little 

 of sulphur until some recent studies were 

 made as to the effect of the raw product on 

 the soil and it was found that when finely di- 



145 



vided sulphur was mixed with soil, it disap- 

 peared in a few days leaving the soil sour. 

 In other words the bacteria had changed sul- 

 phur to sulphuric acid. As sulphuric acid is the 

 most important factor in making phosphate 

 rock soluble, it was a natural suggestion that 

 the gardener might be able to make his own acid 

 phosphate. In compost piles, where bac- 

 teria were sure to be active, rock phosphate 

 and flowers of sulphur were mixed and after 

 a few weeks of fermentation it was shown 

 both by growing crops and by chemical 

 analysis that the phosphate had become 

 soluble. Now rock phosphate contains twice 

 as much of phosphorus as does acid phosphate 



