Japanese beetles are growing in number at a rapid pace. Peak emergence should happen over the next two weeks. Start control early on plants you want to protect to avoid having the beetles emit the pheromones which attract others to the same plant. Small plants can have the beetles hand-picked and dropped into a bucket of soapy water. Chemical controls of carbaryl (Sevin), permethrin, or bifenthrin are among those which are effective. The extreme heat will greatly reduce the length of time the products are effective, especially the permethrin or bifenthrin, to as little as three to four days.