272 INJURIOUS LND BENEFICIAL [NSECTS Of C LLlJH >R\ I \ . 



with finely sculptured surface and about 1-40 inch long. 186 The larvae 

 are white or pale-yellow with brown head and the tip of tail gray. 

 When full-grown they are from 1 to H inches long. The pupae are 

 first white, becoming- dark as they mature. 



Life History. — in general the life history of this species is the same 

 as that of D. soror. The adults hibernate, emerge in the spring and 

 begin egg-laying in March, April and May. The eggs are deposited in 

 small masses about the bases of the food plants, 

 just under the surface of the soil, and hatch 

 within a week or ten days. The larvae feed upon 

 roots, boring tunnels into them, and become full- 

 grown in about one month. The pupal cells are 

 made near the surface of the ground and within 

 about two w^eeks the adults emerge. There are 

 at least two broods a year, with an indication of 

 a third. 



Nature of Work. — The adults feed upon foli- 

 age, buds and flowers of many plants, riddling 

 them with holes and producing sickly, ragged 

 and unsightly plants. As the larvae tunnel into 

 the roots or bases of plants under the ground, 

 the injuries are less easy to locate. 



Food Plants.— While this beetle is an omniv- 

 orous feeder, certain plants are apparently pre- 

 ferred and the damage becomes almost certain 

 ive- y ear a fter year. In the Southern States the 

 spotted cucumber beetle, larva? do much damage to corn crops and there 

 on". ' Adult" greatly en- the insect is known as the Southern corn root- 

 larged. (Original) worm. They also work similarly upon the roots 



of Johnson grass, wheat, rye, millet, oat, Budbeckia, bulrush, pigweed 

 and jimpson weed. In the Northern States many other plants, like 

 alfalfa, beans, muskmelon, watermelon, cucumber, squash, pumpkins, 

 umbrella plant, etc., are more seriously injured. Nearly all vegetables, 

 forage crops and weeds are also attacked, while many kinds of fruit 

 and wild trees are not exempt. 



Distribution. — This species is generally distributed throughout the 

 United States, but is replaced in California by the Western forms, 

 Diabrotica soror Leconte and Diabrotica 12-punctata tenella (Leconte). 

 Control. — Poisoned sprays as recommended for D. soror should also 

 be used for this species. Where special crops, like corn, cucumbers and 

 beans, are regularly attacked it may be advisable to plant as a rotation 

 a crop less subject to the ravages of the beetle. Thorough cultivation 

 is said to be helpful in reducing or preventing heavy infestations, as it 

 destroys many of the pupae and larvae. 



185 Sanderson, E. D., Ins. Pests of Farm, Garden and Orchard, p. 160, 1912. 



