Table 4. Pecan Spittle Bug and Nut Development Anna, Illinois, 1952
——————————————————————————————— Insect Date Tree ——————————————————————————————— Egg stage Apr. 24 Catkins 1/2 to 3/4 inch First nymphs May 5 Catkins 1 to 1-1/2 inch Many nymphs and spittle May 12 Catkins 2 to 3 inches Fruit buds Peak hatch May 20 Female flowers Spittle drying June 2 Nuts developing 1st. 2nd brood June 27 Hatch mostly over July 7 Spittle drying July 26 ———————————————————————————————
Another phase of life history which is of practical importance is the increase of second brood over first. Records were made both at Anna and at Eldred in unsprayed blocks at approximately the peaks of occurrence of nymphs and spittle, and are tabulated in Table 5.
Table 5. Pecan Spittle Bug Infestation, first and second broods, 1952
Number of spittle masses per 100 terminals
========================================================== First brood, June Second brood, July ————————————————————————————— Anna 41 62 Eldred 23 50 —————————————————————————————
This table shows an increase of approximately 50% at Anna and 100% at Eldred. It is thought that a 3 inch flash flood which occurred at Anna might have reduced the first brood infestation somewhat after the counts were made and been responsible for no greater increase and possibly that the heat and drought in both places might have resulted in a reduction. Be that as it may the total infestation was not as severe in 1952 as in 1951.
4. Control.
First Brood Sprays
It was originally planned to spray in both places but at Anna the owner sprayed all but the 1951 check block with parathion early and the infestation was reduced to the point where later hatch did not build up to a sufficient point that good results could be observed so no spraying was done at Anna till the second brood. At Eldred two materials only were available, Lindane and Dieldrin.
At Eldred we had two difficulties in spraying. One was the type of machine with which I was not familiar and the other the inaccessibility of some of the trees. The machine is probably more fitted for field crop work than for large trees. It is called a Mechanical Aresol Generator, manufactured by the Hessian Microsol Corporation of Darien, Conn. The engine is a Wisconsin Air cooled motor made in Milwaukee, Wisconsin. The machine was mounted on a platform and transported in the orchard on a truck. Two fifty gallon barrels constitute the tank. Due to the nature of the machine and to lack of agitation only liquid materials can be used in it. It uses a much smaller amount of material than I had been accustomed to, and my first job was to learn to what extent the materials must be concentrated to compensate for the small output and how to get a comparison with the amounts used in regular orchard sprayer. In concentrate tests on fruit trees we arrive at this by judging the number of gallons which a tree would normally receive with a standard sprayer. There was little background to go on with nut trees and the problem was further complicated by the arrangement of trees which were not planted but grafted in their original positions in the woods. A clump of trees which could not be approached individually might have to receive not much more material than one tree which could be hit from both sides. Sizes of trees also varied. It was decided to use only 25 gallon lots of material and even this small amount sprayed from 55 to 65 trees of varying sizes. It was soon seen that the tops of the moderate and large sized trees were not covered very well. For the first brood sprays at Eldred about six times as much material per 100 gallons was used as had been successful at Anna the previous season. The results are shown in Table 6.