Another test is to dip the blade of a clean knife into the mixture. If a thin film of copper forms on it after holding it there a minute or so, more lime must be added. Use good materials and prepare the mixtures thoroughly. In making up the various mixtures, never use iron vessels, but use glass, wood or crockery receptacles instead. Strain all mixtures thoroughly into the spray pump to prevent clogging of the pump or nozzles. Spray thoroughly and in good season. _Be in time._ Do not use mixtures which have been leftover and allowed to stand for some time. FOOTNOTES: [L] Orton, W. A., proceedings second annual convention National Nut Growers' Association, 1903, p. 82. 1904. CHAPTER XV. INSECTS ATTACKING THE PECAN. Some time ago the statement was occasionally made that the pecan had no known enemies. This, to thinking and observing persons, was too good to be true, and fortunately the words, "no known," were inserted, for later investigations, particularly on the part of Profs. Gossard and Herrick, have revealed the fact that the pecan, in common with all other fruit trees, is subject to the attacks of insect and other enemies. But the outlook is hopeful, for we know of the abandonment of no fruit industry because of the attacks of insect pests, and the pecan industry is in no wise in danger of being abandoned because of their inroads. FEEDING HABITS OF INSECTS. If an insect is to be successfully controlled, the grower must know something of its life-history, and particularly of its feeding-habits. Careful observation of the insect, while at its work of destruction, will frequently give a clue to the method of control. Many insects, like the caterpillars of the pecan, bud-moth and case-worm, obtain their food by biting off pieces of the leaves or other parts of the tree and swallowing the solid particles. On the other hand, a number of insects, such as the scales and plant-lice, obtain their food by thrusting their small, bristle-like sucking tubes into the tissues of the leaves and sucking out the juices contained in the cells. [Illustration: PLATE VIII. The Pecan Bud Moth (Proteopteryx deludana). 1. Winter stage on bud, enlarged. 2. Tube made in leaf. 3. Work of bud destruction. 4. Caterpillar, enlarged about twice. 5. Cocoon, enlarged. 6. Chrysalis, reduced. 7. Moth, enlarged. 8. Moth, about natural size.]