This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
DR. Hull, of Alton, Ills., is probably the most successful fruit grower of the West. From 1,930 trees this year, he captured not less than 153,000 curculios, and he tells the Alton Horticultural Society how he did it: "Early in the season I commenced a series of experiments to determine, if possible, at what particular period of the day curculios were at rest. On three different days I dropped a number of curculios in flour, and near sundown of each day put them in the forks of the trees and watched them until they crawled into some place of concealment which was usually in the crevices of the rough bark, and into depressed parts made by cutting off limbs of trees. Out of 30 insects thus watched to places of rest all concealed themselves as stated, except one, which went to the ground and crawled under a clod of earth. Out of 30 insects thus watched, all but one were found early the following mornings just where they Went to rest at night.
Again, I made other tests with marked insects by placing them on the trees in the morning. This experiment was repeated on three successive days, employing 30 insects each day. Near sunset the trees were, thoroughly jarred over a curculio catcher. This experiment resulted in the capture of 27 of the 90 insects on the trees on which they were put, and at different times since in other parts of the orchard 49 of these marked insects have been jarred down, leaving 16 yet at large.
From these tests I infer curculios, as a rule, rest at night and fly freely by day. They make clear what every practical man when jarring trees must have observed, viz., that these insects fall near the center of the catcher, because places of concealment are most numerous near the trunks of the trees, and for this reason, also, a small curculio catcher is nearly as good as a large one, provided the trees are jarred during the colder part of the day."