56 MANUAL OF VEGETABLE-GARDEN INSECTS 



armed with a series of six strong spines and a pair of prominent 

 toothed plates which point backward. These structures are 

 apparently of use to the larva in making its way through the 

 pod and in entering the pea. It also possesses three pairs of 

 small slender legs. Soon after entering the pea, the grub 

 molts and the spiny structures on the prothorax are lost. The 

 larva becomes proportionately shorter and thicker and lies 

 normally in a curved position. It soon works its way to the 

 center of the pea and there eats out a large cavity. When 

 full-grown, it is about j inch in length, white in color, with 

 brownish mouth-parts. The short stumpy legs are easily 

 overlooked. In Italy the larva reaches maturity about forty 

 days after hatching. It then cuts out a smooth round hole to 

 the surface of the pea, leaving only the outer hull as a cover- 

 ing. It lines the cavity w^ith a paste-like substance, thus ex- 

 cluding all excrement from its pupal chamber. The pupa is 

 dirty white in color. The insect remains in this stage from 

 nine to seventeen days. Only one weevil is found in a pea. 

 In the warmer parts of its range, many of the beetles emerge 

 from the seeds soon after transformation but in the North a 

 large proportion remain in the seeds until the following spring 

 and are often planted with the seed peas. Weevils that emerge 

 in the field hibernate in dry sheltered places and fly back to the 

 pea fields the following spring. There is only one generation 

 annually. 



In the case of small peas, the weevil destroys about one half 

 of the contents, in larger peas about one third. Infested peas 

 are not suitable for planting. Experiments in Kansas have 

 shown that in a germination test only about 25 per cent of the 

 infested peas will sprout. In a field experiment in which thir- 

 teen varieties of peas were used, only 4.4 per cent came up 

 and only 8.8 per cent produced fair sized plants. At the same 

 time, 64 per cent of uninfested peas of the same varieties gave 

 a good stand of strong plants. Experiments in Canada have 



