The state agriculture department is telling Marylanders not to use insecticides to try to kill emerging cicadas. Officials say doing so will not help control the bugs and may harm other beneficial insects including bees and butterflies. The cicadas are returning by the billions to Maryland, DC and Northern Virginia this spring after growing underground for 17 years. Experts say the cicadas do not bite or sting and are not harmful to most plants and pets, unless they consume more than just a few of the bugs.