Hunting for Monarch Eggs in Canada’s Gardens – Environment
When Canadian conservation enthusiasts go looking for monarch eggs, it’s always with a magnifying glass and notebook. These are volunteers who take part in a summer census of iconic endangered butterflies.
July and August are the best months, when the monarch is visible in Canada at all stages of its development: eggs, caterpillar, chrysalis and adult butterfly.
This is also the breeding season for the generation that will take off in a few weeks on a 4000 kilometer (2,500 mile) trek to Mexico.
But this is complicated research. “The monarch lays one egg per leaf. There are insects that can lay a dozen eggs in all while the monarch lays one. So we are looking for something very small, ”explains Jacques Kirouac, who is one of the hundreds of people who take part. in the Mission Monarch citizen science program.
The eggs of these creatures known for their striking orange and black colors are off-white or yellow and the size of a pinhead, with ridges that run from tip to base.
The dramatic situation of the species led to the creation five years ago of this program set up by the Montreal Insectarium to document the monarch’s breeding grounds. The data is used by researchers, in particular to determine the areas to be protected. There are similar programs in the United States.
The monarchs of the eastern part of the continent are in a difficult situation: their population has shrunk by more than 80% in two decades. Western monarchs – which hibernate in California – are even worse off: fewer than 2,000 were reported in the last census by Western Monarch Count, down 99.9% since the 1980s.
More generally, the disappearance of insects – less spectacular and less striking for the public than that of large mammals – is just as worrying, say scientists.
They are essential to ecosystems and economies because they pollinate plants, recycle nutrients, and serve as a staple food for other animals.
‘Not enough data’
“It’s a beautiful butterfly. It would be a real loss to lose it,” said Renald Saint-Onge, also a volunteer for the Monarch Mission.
This 73-year-old former carpenter and ornithologist feels compelled to “save this butterfly”. So he decided to grow as many milkweed plants as possible at home. Often regarded as a weed, this perennial is the only plant the monarch lays on. But we find it less and less.
“The natural fields where we had milkweeds and nectar-bearing plants are increasingly rare,” explains Alessandro Dieni, coordinator of the Mission Monarch program. And the plants are “of lower quality because we have fields with monocultures everywhere” and heavy use of pesticides in the country that killed them.
Logging has also devastated the forests of Mexico where monarchs spend the winter.
Faced with the catastrophic decline of this insect, the Canadian government has decided to get involved in helping the monarch by seeking to protect its breeding grounds. “However, there was not enough data in Canada to know where to go to protect the monarch,” says Dieni.
The decline of insects, which make up two-thirds of all terrestrial species, dates back to the beginning of the 20th century, and accelerated in the 1950s-60s to reach alarming proportions over the past 20 years.
“Thanks to the censuses, we can now do more precise research,” says Marian MacNair of McGill University.
“This allows us to better understand the routes taken, the conditions that the monarch particularly likes”, adds the biologist who is astonished at the capacity of this small emblematic butterfly to travel thousands of kilometers.
The monarch butterfly makes a good study for scientists because often “it is very difficult to observe the evolution” of insect populations. But the monarch’s territory is rather small, so it’s easy to do calculations and observations and document “the extent of the disaster,” MacNair says.