It started with the best of intentions. When evidence emerged that monarch butterflies were losing the milkweed they depend on due to the. The butterfly that traveled to Mexico's mountains flew to the southern US in the There is a symbiotic relationship between the native milkweed plants and the monarch. Monarch caterpillar on swamp milkweed in Altona Forest . Topics. Topics. Select Category, Along the Trails (27), Creatures of Altona. In many cases, the milkweed plants (and caterpillar food source) may be . ask the appropriate questions, build a relationship with producers you trust, and.
Still these few small areas of central Mexico are the only places they travel to. When you see a monarch arrive in your garden, stop and realize that it has taken generations to get here.
They slowly began to make their way across the US and stopped to have another generation. If all goes well, the second or third generation will make it to your back yard.
Many starve if they cannot find sufficient wildflower nectar in farmlands to sustain them, and rainstorms, windstorms, and pesticides are often fatal to them. There is a symbiotic relationship between the native milkweed plants and the monarch.
The monarch butterflies enjoy the nectar from the flowers and help pollinate the plants. Unfortunately, there are no substitutes for where monarchs can lay their eggs. Swamp milkweed in Altona Forest damp growing conditions Monarch on common milkweed dry growing conditions Milkweed is a broad-leafed native plant that is used by monarchs as their only nursery.
Monarchs lay eggs on the undersides of the leaves and their larvae become striped caterpillars and feed on the leaves as they develop.
Monarchs and Milkweed – The Precarious Cycle | My Altona Forest
Without the milkweed, the caterpillars would die — but Ontario put milkweed on the noxious weeds list which forced its eradication. The monarch caterpillars are not affected by the mildly toxic nature of this plant and become toxic themselves which makes them less attractive prey creating their defense mechanism.
Monarchs feed and breed in Ontario summers. Come colder weather, they make that astounding migration south. The south-traveling generation are by far the longest-lived of the 4 generations. Once the caterpillar hatches, it must contend with a bed of dense hairs that are a barrier to consumption of the leaf. But monarchs are patient and have coevolved with the milkweed.
So, their first strategy is to shave that bed of hairs such that the caterpillar has access to the leaves that lie beneath.
Nature News: Monarch butterflies depend on the milkweed
When the caterpillar chews into that milkweed leaf it encounters a sticky toxic latex that does, in fact, kill a number of monarch caterpillars. The survivors are able to deal with the latex and take the toxin a cardiac glycoside into their bodies and hold onto it to use as a defense from predators. This seems like a somewhat one-sided relationship with the monarchs getting all the benefit, but, they in turn pollinate milkweed flowers, thus ensuring future generations of milkweed.
Other insects also pollinate milkweed, so while the monarch absolutely depends upon the milkweed for reproduction, the milkweed does not need the monarch. Monarchs generally lay just one egg per milkweed plant, and milkweed generally grows in large, robust stands, so it is unlikely monarch caterpillars could devastate a stand of milkweed.
Susan Pike, a researcher and an environmental sciences and biology teacher at St. Thomas Aquinas High School, welcomes your ideas for future column topics. She may be reached at spike gmail.
Read more of her Nature News columns online. Never miss a story Choose the plan that's right for you.