— 102 — 



the beetle and artificial applications, I will instance the orchard of Mr. 

 Packard, at Montecito, Santa Barbara County. During the last twelve 

 months this orchard has been thoroughly sprayed three times, with the 

 exception of some half dozen rows of trees through the center; these 

 were colonized with Rhizobiids in October, 1893. The condition of the 

 orchard to-day shows 500 per cent in favor of the parasites. This 

 proves two things: First, that the "free labor system" of the latter is 

 far preferable to the "forced rule" of using artificial means; secondly, 

 that the Rhizobiids will not work on trees frequently sprayed. You 

 might as well expect to find sound morality in a community or house- 

 hold where tobacco and whisky rule supreme. These parasites do. not 

 confine themselves to the black scale. Only last week, in inspecting an 

 apple orchard situated about seventy yards from the orange grove of 

 Charles Hails, above mentioned, large numbers of the Rhizobius ventralis 

 were found eating the San Jose scale with which the apples were infested. 

 I have found them in multitudes feeding on the walnut aphis, and also 

 devouring the red scale of the orange and the apricot scale. 



The rapid increase of the scales has caused many to think it impos- 

 sible for a minute beetle to be able to contend with and exterminate 

 such an army. Let us calculate a little. Professor Coquillett once 

 stated that he had counted 3,000 eggs beneath a single black scale. 

 Prof. A. J. Cook, of Claremont, told me in September that he had 

 counted 1,800. He also stated that he had found 189 black scales on 

 one olive leaf. If we take Professor Coquillett's estimate of 3,000; and 

 supposing that Professor Cook overlooked eleven scales (we will call it 

 200 scales to a leaf), we shall have 600,000 young scales to one leaf 

 when the eggs hatch. Multiply this by the 10,000 leaves upon each 

 tree and we have 6,000,000,000 on a single tree — a pretty strong force to 

 meet. 



We will now put a pair of Rhizobiids upon this tree in springtime, 

 and if the location is favorable we shall have from 50 to 200 eggs for the 

 first brood, and. there will be not less than six (possibly there will be 

 ten) generations during the season. Taking the lowest estimates 50 — 

 and six broods — we shall have 15,625,000,000 (or in round numbers 

 16,000,000,000) of beetles in one year. The life of a beetle from the egg 

 to its death is perhaps thirty days. Please divide the supplies among 

 them. Why, allowing that the birds, the toads, the lizards, and other 

 foes destroy fifteen sixteenths of the Rhizobiids, there will be but six 

 eggs (or scales) apiece for the one sixteenth to subsist upon for thirty 

 days. Just try for only one year (nay, for a single month) to live for 

 thirty days on a half dozen little eggs, and my word for it, you will 

 not be troubled with gout nor dyspepsia. But it is claimed that " the 

 shell of the scale is so hard that it is impregnable to the ladybird." 

 Whoever heard of an epicure calling for a five-year-old hen, or a ten- 

 year-old gobbler for his plate? No! It is spring chicken that he 

 wants; and these Rhizobiids have a taste for the good things of the sea- 

 son as well as their higher brothers. During the cold winter they sub- 

 sist by "hunting and fishing" for such game as they can find; living 

 on short rations; delving and prying for a few eggs that they are fort- 

 unate enough to find, and sleep away the tedious days, anticipating the 

 warm time coming when they can feast and fatten on the young scales 

 as they hatch. 



In estimating the cost of importing predaceous insects, I find that 



