An Orangevale man pleaded not guilty Wednesday after he was arrested last week on suspicion of detonating an improvised explosive device and planting several others across El Dorado and Sacramento counties. Benjamin Cunha, 41, was arrested last Friday after an investigation by the FBI, California Highway Patrol and El Dorado County Sheriff’s Office, the CHP and Sheriff’s Office said in statements. Cunha was arraigned on several felony charges including possessing and exploding an explosive device with the “intent to injure, intimidate, and terrify a person, and to wrongfully injure and destroy…