THE AMERICAN ENTOMOLOGIST. 



the notes shows that here, too, a single 

 bird had eaten nothing else. Ants rise 

 suddenly from 2 per cent, in May, to 20 

 per cent, in June, taken by six of the 

 birds. Most of these, however, were of 

 the winged forms, and their number is evi- 

 dently due to the same cause which ren- 

 dered the Aphodii so abundant in April. 

 Three of the birds of June proved, to my 

 surprise, to have eaten raspberries, and 

 one gooseberries — these fruits amounting 

 to 8 per cent, of the food of the month. 

 No cut-worms were recognized in June, 

 but measuring worms {Phalccind(c) re- 

 placed them, composing 6 per cent, of the 

 food. While all the cut-worms found in 

 any month whose food was at all distin- 

 guishable had eaten nothing but grass — 

 or endogenous foliage, more accurately 

 speaking — several of these Phalcenid(B 

 had been feeding on netted-veined leaves. 

 T\\Q Hafpalince (6 percent.) mc\\\6.Q Evar- 

 thriis, sp., rterostichiis lucuhlandus and 

 Amsodactylus baltivwrcnsis. June beetles 

 [PhyllopJiagd) had been eaten by one bird, 

 a Mclanotus, a curculio, and a long-horn 

 beetle {Tetraopes tetraophthalmiis), each by 

 one. CydnidcB reach 5 per cent., chiefly 

 Hymenarcys nervosa, and Orthoptera fall 

 to 3 per cent. The excess of ants is there- 

 fore taken, like the excess of Aphodii, 

 from the caterpillars and grasshoppers. 



The averages of beneficial and injurious 

 species stand 30 per cent, to 26 per cent., 

 respectively. Regarding ants, I find such 

 conflict of opinion among good authorities, 

 that I am not aisle to give them a definite 

 place on either side the line. The injury 

 to fruits is probably too insignificant to be 

 taken into account, except as evidence that 

 the species is not strictly insectivorous, 

 even in midsummer. 



(To be continued.) 



SUPPLEMENTARY INSTRUCTIONS TO AGENTS 

 OF THE U. S. E. C. 



We draw the attention of our readers to 

 the following instructions to agents of the 

 U. S. E. C, sent out as supplementary to 

 the printed circular issued in June, in the 

 hope that others besides those employed by 



the Commission may be induced to make 

 such observations and experiments as the 

 instructions suggest : 



Office of the U. S. Entomological Commission, 

 1700 13th St., N. W., Washington, D. C, 



July 30th, 1880. 



In addition to instructions already transmitted 

 to )'Ou, I hereb}' call your attention to a few im- 

 portant points, which should have especial at- 

 tention. 



In the application of poisons already known 

 to be effectual, the great desideratum is to ascer- 

 tain the minimum quantity that can be used suc- 

 cessfully. It is my intention to perfect appli- 

 ances that will throw either an extremely fine 

 mist or an almost impalpable cloud of dust from 

 near the ground up among the plants and on the 

 under side of the leaves. 



Test, therefore, thoroughly, by a series of accu- 

 rate experiments, whether : 



1st. London Purple, Paris Green, or Arsenic 

 can be used without diluents, by forcing them 

 dry in minimum quantity on to the plants, and 

 ascertaining how much ground a pound of each 

 may be made to cover. 



2d. If they cannot be used without diluents, 

 the minimum quantit)' of such diluents necessary. 



3d. How far, b}' finer spraying and economy 

 in preventing wastage on the ground, the num- 

 ber of gallons of water to a pound of these ma- 

 terials may be reduced — the idea being in all 

 these desired experiments to reduce the bulk 

 and expense of the diluents by forcing the poi- 

 sons in finer and fewer particles up among the 

 plants (rather than down upon them) through 

 small perforations, or (what will prove prefer- 

 able) crescent-shaped slits of various dimensions 

 in nozzles that will bear great pressure from within. 



4th. Test how far, /. e., over how much ground, 

 on the above principles, a pound of Pyrethrum 

 maybe made to go and still prove effectual. 



5th. Ascertain, if possible, whether the moths 

 are not killed by sucking at the glands, where 

 the plant is poisoned from below. 



6th. Ascertain the effect of these different poi- 

 sons on the eggs. 



7th. Always note the difference in effect on the 

 very young and the full-grown worms. 



8th. Observe well in the woods and in the 

 neighborhood of infested fields if the Alelia larva 

 can be found feeding on an)' other plant, search- 

 ing particularly plants of the same family {Mal- 

 7'ace'tc), as that to which cotton belongs. 



Qth. Note and stud}' any mites found preying 

 on the eggs. 



loth. Send me a summary of the experiments 

 made with yeast ferment, or beer mash, as soon 

 as they are completed. 



nth. Study well the influence of ants in the 

 cotton field, and in how far they prove destruct- 

 ive to Aletia, especially to the eggs, or young 

 larvje. Respectfully, 



(Signed) C. V. Riley, 



Chief U. S. E. C. 



Mr. Herbert H. Smith, whose excellent 

 book on Brazil recently appeared, has 

 promised the Cornell University a set of 

 Brazilian Insects, including 1,000 species 

 chiefly beetles. 



