Threats to monarchs

Monarch butterflies have many threats to their survival, some of the main ones are:

• Loss of Milkweed Plant

Monarchs often lay their eggs on certain milkweed plants, but milkweed are often seen as unwanted weeds. Farmers, property owners and landscape managers have have taken out native milkweed and have replaced them with other plants. Over 3.1 billion milkweed stems have been lost over the past 20 years.

• Loss of winter habitat

Butterflies winter habit is shrinking at a fast pace, due to deforestation, harsh weather, development, and other disruptions.

• Climate Change

The climate has changed to unexpected storms, severe temperatures increases, and drought. The combination of wet and cold has resulted in deaths of hundreds of million of butterflies. In California, the drought has led to extensive habitat damage due to wildfires. Also, a recent study indicated that hotter temperatures caused by global warming can cause tropical milkweed to overproduce a toxic chemical called cardenolides. While monarch butterflies can normally handle cardenolides in milkweeds, too much can actually poison monarch butterflies.

• Parasitic Diseases

These diseases can be passed down from their parents or passed from another butterfly, or from the food they've eaten. The biggest parasitic threat currently is ophryocystis elektroscirrha ("OE"). About 30% of Western Monarch Butterflies are infected with OE.

• Agricultural Insecticides and Pesticides

Agricultural insecticides are chemical substances that are used to kill insects and pests from eating or damaging crops. Such chemicals are also toxic to monarch butterflies.

• Planting Non-Native Species of Milkweed