Lately it seems that every time I pick up a paper, watch the six o’clock news or catch-up on the latest world events via the web, Mother Nature seems to be taking it on the chin.
The latest of these ominous events is the sudden crash of the monarch butterfly population that overwinters in Mexico.
The populace is estimated by counting the space they occupy by the acre in the forests west of Mexico City, with the latest stats being 1.65 acres compared to 2.93 acres the year before.
But when these numbers are compared to the peak of 44.5 acres in 1995, the severe decline becomes evident.
These butterflies have been overwintering here for centuries and are celebrated as returning souls during Mexico’s Day of the Dead celebrations, Nov. 1.
Last year, the few that returned were late, causing alarm among celebrants and tourists who frequent the overwintering sites. Mexico has been doing its part to preserve the pine and fir forests that the monarchs use, but illegal logging is still taking its toll.
And there are other factors at play, including the extended drought in the southern United States, which has resulted in fewer nectar-producing wildflowers for the migrating butterflies.
That being said, the biggest threat to the monarch is the pervasive use of herbicide-resistant genetically modified crops such as corn and soybean. This butterfly only lays its eggs on milkweed (asclepias), as this is the only food source for the emerging larvae or caterpillars. The use of GMO herbicide-resistant crops has resulted in an estimated loss of 80 per cent of all of the milkweed in the central United States. In Iowa cornfields, that percentage moves up to 98 per cent.
So without its primary food source, much fewer monarch butterflies are being produced.
The demand for biofuel corn has also resulted in farmers cultivating every scrap of land, leaving few if any wildflowers for the monarchs to forage on.
Things are a little better for the western population of monarchs which overwinters in southern California, as their numbers have stabilized. They have adapted by overwintering on non-native eucalyptus trees and are less exposed to vast GMO-crop farms and the extensive herbicide sprays associated with them.
These are the butterflies that we see occasionally in the Fraser Valley, but only when we experience a long, extended summer – as we are at the northern tip of their range. Nevertheless, I have very fond childhood memories of our purple lilac hedge (syringa vulgaris) smothered in bright orange monarchs in our otherwise mundane Winnipeg garden.
While the tiger swallowtail butterfly is a common sight here, I have only ever seen one local monarch – a rather tattered fellow (it almost looked like he survived the grill of a car) who was foraging on our gloriosa daisies (rudbeckia hirta) at the garden center and is pictured above.
For those of you who would like to see a few more butterflies in your garden, there are many common shrubs and perennials that will draw them in – including the aforementioned milkweed (asclepias), French lilac (syringa vulgaris) and rudbeckia, as well as verbena bonariensis, asters, Joe-pye weed (eupatorium), butterfly bush (buddleia), fennel, purple coneflower (echinacea) and salvias.
If you would like to learn more about butterflies in general, I would encourage you to visit our Nature Day this Saturday and have a conversation with Hendrik Meekel, who will be displaying his world-class insect collection, including many butterflies.
Mike Lascelle is a local nursery manager and gardening author (firstname.lastname@example.org).