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Dangers to the monarch butterfly and how to grow milkweed plants as food for monarch butterfly caterpillars
Monarch butterfly caterpillar
Bad news for the Monarch Butterflies
Monarch butterflies are experiencing terrible problems in America and the numbers arriving in Mexico to overwinter have been at a record low. This news has been reported by the mainstream media, including National Geographic.
But good people who are concerned about the survival of these amazing and much-loved butterflies are doing what they can to help them. This is happening throughout North America and elsewhere in the world. A lot of people want to help the monarchs survive. Growing milkweed for the caterpillars is one of the best ways.
Monarch butterfly poll
Would you like to help Monarch Butterflies?
Threats to Monarch Butterflies
Known threats the monarchs include the use of pesticides and herbicides, habitat destruction and Climate Change.
One serious problem they are facing is lack of the food-plants for the caterpillars. They are able to eat any species of .and under normal conditions, as they once were, these plants were commonly found all the way up from the southern States up as far as Canada. milkweed (Asclepias)
Different species in the milkweed genus are able to grow in the different climatic zones. Sadly large areas devoted to farming now grow Roundup Ready genetically engineered crops that are sprayed with the herbicide Roundup. This has killed off vast amounts of milkweed that used to grow in the fields where they crops, such as maize and soya, are planted.
If that wasn’t bad enough, it is said, that airborne pollen from these crops that lands on milkweed that has survived and that has caterpillars on, will kill them because of the toxins genetically engineered into it to be resistant to herbicides. This has not been adequately studied though.
However, it is definitely agreed that there are far fewer milkweed plants about now. So the supply of food for the larvae has been drastically reduced. It is estimated that this reduction is as much as 58%.
Another problem is that forests that they used to roost in in Mexico have been cut down.
Extreme weather conditions have taken a heavy toll as well.
Why fewer monarch butterflies are surviving their winter migration
Monarch distribution elsewhere in the world
Monarch butterflies at this stage are not regarded as an endangered species because they are found in many countries around the world besides America,
However, what is currently is endangered is their spectacular migration route from Canada and the States in the most northerly parts of the US down to Mexico for the winter and then back up the country again the flowing year.
This fantastic migration has been recognised as one of the real wonders of nature and has made the monarch butterfly world-famous for its ability to do this.
Pen for growing Milkweed for Monarch Butterflies
Pens with Milkweed plants
Closeup of corner of a pen for monarch caterpillars and milkweed
What can be done to help Monarch Butterflies?
People in America have been helping the monarchs by planting more milkweed. are readily available from Internet suppliers and on Amazon and eBay. There are species that will grow in the different climate zones too. The seeds
A big problem that people who cultivate milkweed for the monarch caterpillars is that the larvae will eat so much food that they will strip the plants of leaves, flowers and seed-pods. If insufficient plants are grown to feed a growing army of these large and striped larvae then many of them will starve to death.
So all people who grow milkweed must grow as much as possible and find ways of helping the plants regenerate, which they will do in a short space of time if not subjected to another attack by hungry caterpillars.
The answer to this is quite simple and Lawrence Chapman from Tenerife in the Canary Islands where the butterflies also live and breed has come up with a brilliant idea. He has created pens that can be placed over a garden plot on which milkweed plants have been growing.
The pens stop more female monarchs getting access to the plants to lay their eggs. This means that plants that have already been stripped of leaves by caterpillars can be covered by a pen and allowed to grow back again. The pens are made with a wooden frame and covered with gauze mesh making them easy to make and lightweight so they can be easily moved.
To make a monarch food-plant pen you need: straight lengths of wood 2 cm by 1 and half cm, small brackets from a hardware store (about 1 inch ones) and a pack of plastic netting as well as a staple gun. You can make them to fit with the room you have. A good size for the average garden is 1 m long 80 cm high and 90 cm wide. This can be easily lifte and moved around.
After eating enough leaves the caterpillars spin a small pad of silk either on stems of the plant or on a fence, wall or under garden furniture. They hang head downwards and change into a mint-green chrysalis after changing their skin for the last time as larvae.
The butterflies emerge 10-days to two weeks later depending on temperature.
It is a marvellous experience to watch the transformation from egg to butterfly and to know you have played a role in helping the survival of this beautiful butterfly.
Monarch butterfly chrysalis
© 2014 Steve Andrews