Illegal logging in Mexico and a lack of milkweed in the Midwest United States for the butterflies to lay their eggs in has also taken a toll on the Monarchs' population.
メキシコでの違法伐採と、米国中西部での蝶が産卵するためのトウワタの欠如も、モナークの個体数に大きな打撃を与えた。