130 APPLIED ENTOMOLOGY 



often entering one bean. Feeding is completed by early August and the adults 

 are produced later in the fall. They generally winter in the beans but do not 

 breed in dried beans, there being therefore only one generation a year. 



Injuries. — The damage caused by the attacks of pea and bean weevils 

 is of two kinds: injury by consuming the bulk of the seed and leaving the 

 remainder unfit for food; and injury by so reducing the stored material 

 or the germ itself that the seed cannot germinate and grow. 



Control of Pea and Bean Weevils. — The original attacks of these in- 

 sects are upon growing plants out-of-doors. Here no. control seems pos- 

 sible. When the crop is gathered, however, treatment can easily be 

 given by shelling at once, placing the seed in gas-tight receptacles, and 

 fumigating it with carbon disulfid, using this at the rate of at least 8 or 

 10 lb. for every 1,000 cu. ft. of space in the container, and continuing the 

 treatment for at least 1 — better 2 — days. The disulfid may be poured di- 

 rectly onto the top of the seeds. For best results this should be done in a 

 place where the temperature is at least 75°F. Then the seed should be 

 packed in weevil-tight boxes, but it would be wise to examine it again 

 after a time and if living weevils are still present, give it another treat- 

 ment. Where the seed is not to be used for food, packing it in air-slaked 

 lime at the rate of 1 part by weight of lime to 2 or 3 parts by weight of 

 seed has proved satisfactory. Even where use as food is intended, this 

 method can be used if the seed is thoroughly washed before cooking. 

 Cold storage below 34°F. will prevent development of the insects. Heat 

 will destroy the weevils and if seed is raised to 131°F. and kept at that 

 temperature for an hour, this will kill all the weevils present. Appar- 

 ently, treatment in this way and for this length of time will not prevent 

 germination. None of these methods will prevent reinfestation if the 

 seeds are afterwards exposed to attack by insects from outside, where 

 the temperature is such that they are active. In general then, give the 

 first treatment immediately after gathering, and store in tight containers 

 and preferably in a cold place. 



The shorter seasons and cold winters of the North give the pea and 

 bean weevils less opportunity to increase through a number of generations 

 than in the South, and many of the adults are killed by the cold. North- 

 ern climates for these reasons are therefore better for the extensive pro- 

 duction of seeds of these plants. 



Family Cerambycidae (Round-headed Borers or Longicorn Beetles). — 

 The insects of this family are for the most part of fair size, a number being 

 several inches in length. Their antennae are usually long — sometimes 

 longer than the body — and the beetles are frequently bright-colored and 

 strikingly marked (Fig. 123). 



The larvae are chiefly wood-borers, living in burrows in the trunks or 

 roots of trees, or the pith of plant stems, and are termed round-headed 



