Evening Republican, Volume 18, Number 15, Rensselaer, Jasper County, 17 January 1914 — THE SAN JOSE SCALE PARASITE [ARTICLE]

THE SAN JOSE SCALE PARASITE

By James Troop,

Department of En-

tomology, Purdue University School of Agriculture, Purdue University Agricultural Extension.

Eastern papers have been making much noise recently over,the discovery that certain parasitic Insects have been at work in thq orchards of Pennsylvania cleaning up the San Jose and other scales. If these published reports are all true, it will soon be unnecessary for the eastern orchardists to use the spray pump any more in order to hold' the scale in check. As these arq native species, there should be no reason why they should not thrive in Indiana as well as In Pennsylvania; and so, in order to ascertain just how efficient they are going to be in cleaning up the San Jose scale in our Indiana orchards, I have procured some of them, and have introduced them to some of our Hoosier scales in different sections of the state. It is possible that the conditions here may not prove favorable for the propagation and dissemination of the parasite, but let us hope that it may prove ifsell equal to the occasion, and do what the farmers and fruit growers have not been able to do, viz., to clean up the scale to such an extent as to prevent further serious Injury. Let us too hopeful, however, and depend entirely upon this parasite to take care of our orchards. People are liable to get over enthusiastic sometimes. Even if we do succeed in getting it Introduced into our Indiana orchards, it will be some time before we pan safely discard the spray pump. There is one fact In this connection that should be borne In mind, and that la that there are quite a number of species of these parasites which have been known to work on the San- Jose scale for years, in fact, aver since the San Jose scale has been known in this country. In bulletin No. 62 of the division of entomology, department of agriculture, Washington, D. C., published in 1904, Marlatt names eight species found In this country, and a

number of other entomologists have described species as working on the scale, as far back as 1880, when Professor Comstock published his description of the San Jose scale. But Professor Surface of Pennsylvania states that some -of the species of parasites which he has bred are entirely new to science, but their effect on the scale, method of propagation, etcy. are the same as are those that are well known. The skeptic might inquire how long have these new species been in existence, and why have they not made themselves felt in the realm of scaledom before this? Well, conditions which operate to hold in check the undue increase of the various insect tribes are constantly changing, and it may be that some influence which we know not of has been at work during these past years to prevent them from multiplying in sufficient quantities to enable them to make an impression in the economic world. Hqwever, we shall watch them.' carefully, and give them every opportunity to get in their work, and if we find them measuring up to their op. portunities and our expectations, we shall distribute them all over the state at the earliest opportunity.