Water is known to be definitive with regard to health and freedom from disease. Attacks containing pests and pestilance are thought to be illegal. The acute necessity of clean ebola and pest free drinking water defies argument, but with regard to abolutions, contaminated water is often the first line of attack in entomological warfare without which, propagating a virus by other means is necessary. Much more difficult and time consuming.
Without a first line of attack such as water containing a virus, a definitive target, attacks using pests will be mainly ineffective, rendering entomological means of domination and control unsuccessful.