. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. 24 PEELIMINAEY BEPOET OK ALFALFA of the season, however, during August, when the temperature is higher, the pupal period averages only 3 days, the cocoon being spun only about 36 hours before the larva pupated. The adult leaves the cocoon about a day after transformation, and unlike others of this genus does not devour the cocoon. Although the insect has passed through its transformation from egg to adult the injury it causes is by no means ended. The beetles them- selves not only feed upon the young gro
. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. 24 PEELIMINAEY BEPOET OK ALFALFA of the season, however, during August, when the temperature is higher, the pupal period averages only 3 days, the cocoon being spun only about 36 hours before the larva pupated. The adult leaves the cocoon about a day after transformation, and unlike others of this genus does not devour the cocoon. Although the insect has passed through its transformation from egg to adult the injury it causes is by no means ended. The beetles them- selves not only feed upon the young growth (fig. 8), but gnaw off the bark of the stems, and, together with the larvae still in the fields, in this way prevent the alfalfa from springing up for weeks after the first crop of hay has been removed. Two of such fields are shown in Plate V, figure 3, and Plate VI, figure 3, the ground being almost as bare of growing plants as in figure 1, Plate VIII, where the ground has been fig. 7.—The alfalfa ^orn Up with a spring-tooth harrow. The beetles some- Muc°h l cniargxi' times cluster in great numbers upon a single plant, as (Author's mus- illustrated in figure 8. tration.) FOOD PLANTS. In a series of experiments carried out by Mr. P. H. Hertzog, larvae of Phytonomus 'posticus were placed in cages on various food plants, both alone and with alfalfa, and it was found that they fed freely upon the following plants, in combination with alfalfa: Sweet pea, Laihyrus odoraius; Utah milk vetch, Astragalus utahensis; string bean, Phaseolus vulgaris; obtuse-leaved vetch, Vicia sp.; narrow-leaved vetch, Vicia sp.; white clover, Trifolium repens; red clover, T. pratensc; alsike clover, T. hybridum; yellow sweet clover, Mcliloiusindica(?); whitesweetclover, ; Mrdicago lupulina; M. echinus; M. hispida nijra; M. hispida confinis; M. hispida terebellum; M. muricata; M. orbicularis; M. scutellata; black locust, Robinia pseudacacia; fenugreek, Trigonellafcenumgrxcum. The following is
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