About the only practicable remedy is to pick these insects by hand

About the only practicable remedy is to pick these insects by hand

Treatment. About the only practicable remedy is to pick these insects by hand. We can, however, protect our young plants by small nettings and thus tide them over the most dangerous period of their lives. These bugs greatly prefer the squash as food. You can therefore diminish their attack on your melons, cucumbers, etc. by planting among the melons an occasional squash plant as a "trap plant." Hand picking will be easier on a few trap plants than over the whole field. A small board or large leaf laid beside the young plant often furnishes night shelter for the bugs. The bugs collected under the board may easily be killed every morning.

Fig. 168. Flea-Beetle and Larva
a, larva; b, adult.
Lines on sides show
real length of insects

Source: Agriculture for Beginners