. Bulletin. Les insectes ; les insectes nuisibles ; entomologie ; insectes ; les insectes nuisibles ; l'entomologie. 48 LA RACINE GEAPE-VER. ces cages variait de 1 à 2 pouces, et étaient d'une hauteur uniforme de 20 pouces. Les deux grands côtés était constitué de plaque de verre avec des volets en bois extérieur de chaque côté qui pourraient être enlevés pour l'examen du contenu. L'émergence de dossiers Tableau I, comme indiqué par la courbe de la figure 13, sont les résultats d'environ 15 expériences distinctes avec larvse transformer dans de grands pots en terre rempli de terre. Depuis le moment de l'émergence de la coléoptères et leur incidence relative a un di

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. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. 48 THE GEAPE ROOT-WORM. these cages varied from 1 to 2^ inches, and were of a uniform height of 20 inches. The two larger sides consisted of plate glass with outer wooden shutters on either side which could be removed for the exami- nation of the contents. The emergence records of Table I, as shown by curve in figure 13, are the results of about 15 separate experiments with larvse transforming in large earthen pots filled with soil. Since the time of emergence of the beetles and their relative occurrence has a direct bearing upon the time of application of poison sprays against this pest, special attention and care were exercised in preparing these experiments. In the early spring approximately 1, 000 larvae were collected in different vineyards in the vicinity of North East, Pa. In many instances soil from different localities, which varied from loose sandy soils to heavy clay, was trans- ferred with the larvae to the rearing pots (fig. 22). Pro- vision for the spring feeding of the larvae was made by planting young grapevines in the pots. Finally the pots were placed in the ground in the open field and were left undisturbed for the rest of the season. Before the beetles commenced to Fig. 22.—Earth en pot with wire-screen cover used in rear- appear wirC SCTCen COVCrS ing the grape root-worm. (Original.) ^^^^ placed OVCr Cach pot, SO that a complete daily record could be kept of the number of beetles emerging from each separate pot. By preserving the beetles from the above-mentioned experiments, rearing material of known source and age was obtained for further experiments. The daily catch of beetles throughout the emergence period was transferred to so-called ''stock jars, " from which insects were taken as needed for miscellaneous experiments. The "stock jars" shown in the rearing shelter (fig. 18) consisted of large-sized glass jars covered with thin cloth. A layer of

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