16 



PRELIMINARY REPORT ON ALFALFA WEEVIL. 



The beetles pass the winter hidden away among matted grass or 

 other similar vegetation, including alfalfa, and, indeed, among most 

 kinds of rubbish anywhere, wherever they will be protected from the 

 weather. The beetles have also been found in early spring under 

 clods and about the crowns of alfalfa plants where the ground had 

 been roughly cultivated the previous autumn. The overgrown mar- 

 gins of fields and irrigation canals and ditches afford excellent places 

 for hibernation, some of which are shown in Plate II, figures 1, 2, 

 and 3. 



With the first warm weather in spring the beetles become active 

 and diffuse themselves over the alfalfa fields, feeding upon any living 



part of the plants that 

 have escaped the win- 

 ter or, as soon as it 

 commences to push 

 forth, on the fresh 

 growth, both leaf and 

 stem. During some 

 years the beetles are 

 abroad in the fields in 

 Utah early in March; 

 in other and colder 

 springs it may be April 

 before they bestir 

 themselves. Latitude 

 and elevation, with 

 the consequent modi- 

 fications of tempera- 

 ture, will have much 

 to do in deciding the 

 time of emergence 

 from winter quarters 



Fig. 2.— The clover-leaf weevil (Hypcra punctata): a, Egg; 6,6,6,6, inspiring. Tlievalsoto 

 larvae feeding;/ cocoon; ^beetle; fc same dorsal view (6,/, /.Natural extent hibernate 



size; k, enlarged; a, greatly enlarged.) (From Riley.) 



in the alfalfa fields. 

 As soon as the beetles have spread from their winter quarters out 

 over the fields they pair, and the females are ready to deposit their 

 eggs (figs. 3, 4). As a matter of fact, however, pairing has been 

 observed in the fall, and females taken while hibernating are ob- 

 served to lay 75 per cent of fertile eggs. According to the notes of 

 Mr. Fiske, made in Italy, they may place their eggs in the old, dead, 

 overwintered stems or even in the dead stems of plants other than 

 those of alfalfa, but in Utah the beetles refused to oviposit in dead 

 stems in the laboratory cages. According to Dr. Giovanni Martelli, 1 

 at Portici in 1909 the first adults which he obtained appeared toward 



1 First contribution to the biology of Phytonomus variabilis Herbft. Bollettino del Laboratoria di Zoo* 

 logia Generale e Agraria della R. Scuola Superiore d'Agricoltura in Portici, vol. 5, March, 1911. 



