96 



THE AMERICAN ENTOMOLOGIST. 



of this insecticide. 



the essence of Pyre- 

 in water ; and I think, 



the States east of the Rocky Mountains, are 

 grown in California only as a matter of curiosity, 

 or for table use at home. Their cultivation 

 leaves open a wide field of future possibilities 

 in var3'ing and modifying the wine product of 

 California, whose climate seems wonderfully 

 adapted to the assimilation of the most varied 

 cultures. ^_^ 



NOTES ON PYRETHRUM. 



In the pamphlet above alluded to, Prof. 

 Hilgard, after showing the importance of 

 freshness in the use 

 remarks : 



Like all volatile oils, 

 thrum is slightly soluble 

 from my experiments, that the tea or infusion, 

 prepared f7-om the flowers (which need not be 

 ground up for the purpose) is the most con- 

 venient and efficacious form of using this insecti- 

 cide in the, open air ; provided that it is used at 

 times when the water will not evaporate too rapidly, 

 and that it is applied, not b}' pouring over in a 

 stream, or even in drops, but in the for»i of a 

 spray from a syringe with flne holes in its rose. 

 In this case, the fluid will reach the insect de- 

 spite of its water-shedding surfaces, hairs, etc., 

 and stay long enough to kill. Thus applied, I 

 have found it to be efficient even against the 

 armored scale-bug of the orange and lemon, 

 which falls off in the course of two or three days 

 after the application, while the young brood is 

 almost instantly destroyed. As the flower tea, 

 unlike whale soap and other washes, leaves the 

 leaves perfectly clean, and does not injure even 

 the most tender growth, it is preferable on that 

 score alone ; and in the future it can hardly fail 

 also to be the cheaper of the two. This is the more 

 likely, as the tea made of the leaves and stems 

 has similar, although considerably weaker, ef- 

 fects ; and if the farmer or fruit grower were to 

 grow the plants, he would save all the expense 

 of harvesting and grinding the flower-heads, 

 by simply using the header, curing the upper 

 stems, leaves, and flower-heads all together, as 

 he would hops, making the tea of this material 

 by the hogshead, and distributing it from a 

 cart through a syringe. It should be diligently 

 kept in mind, that the least amount of boiling 

 will seriously injure the strength of this tea, 

 which should be madew'xlh briskly boiling water, 

 but then simplj'^ covered over closely, so as 

 to allow of as little evaporation as possible. 

 The details of its most economical and effectual 

 use on the large scale remains, of course, to 

 be worked out by practice. But I have little 

 doubt that its cultivation will prove an im- 

 portant acquisition to California, exposed as she 

 is to the importation of the insect pests of the 

 whole world. 



Some observations reported to me seem to 

 render it probable that the cultivation of the 

 Pyrethritm between the rows of other plants will, 

 in a great measure, protect these from the attacks 

 of insects ; as, of course the plants themselves 

 are let severely alone b}' them. It might even 

 seem worth while to try this plan against the 

 Phylloxera, in so far as the winged insect could 

 scarcely escape the deadly effects of the Pyre- 

 thrum, thus preventing its spread. It has been 

 reported that a certain kind of sumac has thus 

 served to save many of the vineyards of the Isle 

 of Cyprus, 



BIRDS vs. INSECTS. 



EDOUARD FERRIS. 



{Concluded from p. 69.] 



[The remainder of this paper (excepting the 

 parts in quotation-marks) has been freely trans- 

 l.Ttcd and very much condensed. A discussion 

 of the parasitism of insects has been wholly 

 omitted. 



While recognizing the fact that the considera- 

 tions brought forward by the author are essential 

 to a fair and complete idea of the services of birds, 

 the translator does not wish further to commit 

 himself to the views of Mr. Perris. — S. A. F.] 



Taking up the orders of insects seriatim 

 and referring first to the cockchafers, whose 

 larvae, known as white grubs, live on the 

 roots of plants, the author calls attention 

 to the fact that the mature insects, being 

 nocturnal, are subject to destruction only 

 by owls and goat-suckers. If we suppose 

 all these birds to live exclusively upon 

 cockchafers during their season, the num- 

 ber destroyed would amount to nothing 

 practically, since the birds are so few and 

 the insects so very numerous. 



The larvae, being subterranean, can be 

 reached only by birds which dig up the 

 ground, viz.: ravens, magpies, starlings and 

 woodpeckers. Magpies and woodpeckers 

 are too few and scattering to do any ap- 

 preciable good. The ravens and starlings, 

 however, gather in flocks in early autumn, 

 and pass the winter in France and more 

 southerly countries. Long observation of 

 their food habits shows that they live at 

 first on acorns, and on corn (maize) pilfered 

 from the fields. At seed-time they forage 

 the fields of barley and rye, probably pick-. 

 ing up a few insects as they dig for grain. 

 Later they scatter everywhere and live as 

 they can. They resort especially to pas- 

 tures and meadows where they pick to 

 pieces the droppings of stock for fragments 

 of grain and coprophagous larvae. They 

 also pick up grain, earthworms and hiber- 

 nating insects, frequently di^iging into the 

 ground a depth of 2 to 6 decimeters, but 

 not by any means deep enough to reach 

 tlie white grubs. These, in cold weather 

 especially, retreat far beyond the reach of 

 birds. 



" I believe, then, that it is demonstrated 

 that birds and cockchafers can live very 



