In North America, the decline of
the monarch butterfly (Danaus plexippus), this migrating orange
butterfly with black veins that winters in Mexico and California to
travel to Canada in the summer, is widely publicized. Its population has
been decreasing for at least 50 years and, from 2008, the population
fell in a particularly drastic way, from 1 billion butterflies to 93
million.
Several authorities attribute much of the responsibility for this decline to modern agriculture, since routine use of herbicides on a large scale creates large areas where nothing other than the crop is grown (maize, soy, etc.). The fact is that monarchs cannot live in these environments which do not provide the plants they need to feed themselves.
In addition, several years of climatic disruption in Texas, the US state through which all butterflies from eastern America must pass, have exacerbated the situation. Not to mention the cutting of forests in Mexico where monarchs spend several months dormant each winter and the indiscriminate use of insecticides almost everywhere along their route.
In recent years, various associations that promote the safeguarding of the monarch have put forward the idea of asking amateur gardeners to lend a hand to these butterflies by creating an oasis for monarchs on their land: a flat -band at home where monarch butterflies would not only be tolerated but where their presence would even be encouraged. If enough people created flower beds all over the road that butterflies travel from Mexico to southern Canada, maybe we could help the monarch population to recover!
Many people have understood at least one element of this strategy: that more milkweeds (Asclepias spp.) Need to be planted. Indeed, the larvae (caterpillars) of monarchs can only feed on milkweed (and plants of the related African genus Gomphocarpus): they are their only source of food. They die if they are offered anything else.
The idea that saving the butterfly goes through the cultivation of milkweeds has become so popular that the sale of milkweeds has skyrocketed in Canada and the United States: it looks like everyone is planting it ... and that's well so. Many associations seem to be stopping at the idea that the planting of milkweeds is the solution to the problem, but it is a little more complicated than that.
Just as important as planting milkweed to feed the larvae is planting and maintaining nectar plants for adults, and especially plants that bloom in late summer and fall. Adult monarchs, in fact, are not at all limited to milkweed flowers, but feed on a wide range of native and imported nectar-bearing flowers. They need it throughout the summer.
The idea that saving the butterfly goes through the cultivation of milkweeds has become so popular that the sale of milkweeds has skyrocketed in Canada and the United States: it looks like everyone is planting it ... and that's well so. Many associations seem to be stopping at the idea that the planting of milkweeds is the solution to the problem, but it is a little more complicated than that.
Just as important as planting milkweed to feed the larvae is planting and maintaining nectar plants for adults, and especially plants that bloom in late summer and fall. Adult monarchs, in fact, are not at all limited to milkweed flowers, but feed on a wide range of native and imported nectar-bearing flowers. They need it throughout the summer.
Where the problem is most acute is in late summer and fall. It is that, if in the spring the migration of the monarchs takes place in several generations, that is to say, that the butterflies "stop" on the way to lay eggs and produce new butterflies which will continue the road towards the North, and therefore that milkweed is essential to feed the caterpillars of the rising generation, the return from North to South is done in a single generation. The same butterfly born in mid-summer on a milkweed in Lac-Saint-Jean in Quebec, at the extreme north of the monarch's area, must then fly to central Mexico, at a distance of 4800 kilometers. Along this route, it needs nectar-bearing flowers.
During its flight to the South, the butterfly no longer specifically needs milkweeds, because the female will not lay many eggs and there will be no caterpillars that must feed on milkweed leaves. On the other hand, it will not be until March or April, 5 to 7 months later, when the monarch butterflies wake up from their winter dormancy, that the search for milkweed will start again.
Besides, some scientists consider that, in the effort to try to restore the population of monarchs, planting late-flowering nectar plants is even more important than planting milkweed! (See the study by Dr. Anurag Agrawal of Cornell University: Linking the continental migratory cycle of the monarch butterfly to understand its population decline.)
Besides, some scientists consider that, in the effort to try to restore the population of monarchs, planting late-flowering nectar plants is even more important than planting milkweed! (See the study by Dr. Anurag Agrawal of Cornell University: Linking the continental migratory cycle of the monarch butterfly to understand its population decline.)
If you want to create an oasis for monarchs at home, here are some considerations:
It will ideally be in full sun in a place protected from the wind.
It will contain milkweed to feed the caterpillars and a good variety of nectar-bearing flowers to feed the adults.
The larger the flowerbed, the more it will be used (do you really need this sea of grass that surrounds most houses and is the equivalent of a desert for butterflies?).
Learn to accept that certain leaves are chewed. (You have to feed the caterpillars!)
Avoid treating your oasis with products that are toxic to butterflies, such as insecticides, preferring gentle treatments if you have to intervene: water jet, manual harvest, etc.
Plants that feed monarchs
To feed monarch larvae, it is clear that milkweed is absolutely necessary.
It will ideally be in full sun in a place protected from the wind.
It will contain milkweed to feed the caterpillars and a good variety of nectar-bearing flowers to feed the adults.
The larger the flowerbed, the more it will be used (do you really need this sea of grass that surrounds most houses and is the equivalent of a desert for butterflies?).
Learn to accept that certain leaves are chewed. (You have to feed the caterpillars!)
Avoid treating your oasis with products that are toxic to butterflies, such as insecticides, preferring gentle treatments if you have to intervene: water jet, manual harvest, etc.
Plants that feed monarchs
To feed monarch larvae, it is clear that milkweed is absolutely necessary.
The tuberous milkweed (A. tuberosa), zone 4, with orange or yellow flowers, and the milkweed incarnate, also called milkweed (A. incarnata), zone 3, with pink or white flowers, are the easiest to find in a nursery. The first prefers very well-drained, even dry soils, the second, rich soils and at least a little wet.
In eastern North America, milkweed (A. syriaca), also known as small pigs, is already widespread in the wild, but not widely available commercially. In addition, it can be a little intrusive for a flower bed.
Usually plants of interest to butterflies produce inflorescences of grouped flowers such as Asteraceae, Apiaceae and Verbenaceae. Butterflies usually leave pollination of individual flowers to bees. The brightly colored flowers attract a lot of attention from monarchs, but they are relatively indifferent to scents (except for the milkweed fragrance which they can detect from a distance). Beware of double flowers: often, the multiplicity of petioles makes the nectar inaccessible to monarchs.
The belief that we should limit ourselves to native flowers is wrong: more recent studies indicate that it is a mixture of native and imported flowers that attracts and feeds the most butterflies.
In eastern North America, milkweed (A. syriaca), also known as small pigs, is already widespread in the wild, but not widely available commercially. In addition, it can be a little intrusive for a flower bed.
Usually plants of interest to butterflies produce inflorescences of grouped flowers such as Asteraceae, Apiaceae and Verbenaceae. Butterflies usually leave pollination of individual flowers to bees. The brightly colored flowers attract a lot of attention from monarchs, but they are relatively indifferent to scents (except for the milkweed fragrance which they can detect from a distance). Beware of double flowers: often, the multiplicity of petioles makes the nectar inaccessible to monarchs.
The belief that we should limit ourselves to native flowers is wrong: more recent studies indicate that it is a mixture of native and imported flowers that attracts and feeds the most butterflies.
At the end of summer, monarchs must drink a lot of nectar to accumulate a good supply of lipids, not only to feed the long flight ahead, but also to ensure their survival during the months when they are dormant, set on trees in Mexico. Thus, they will frequent the gardens even more this season, not only by preparing their flight, but during the journey. This is why it is doubly important to offer them an abundance of flowers that bloom in late summer and fall, like the following:
Scrofular leaf agastache (Agastache scrophulariifolia) - zones 4-7
Agerate (Ageratum spp.) - annual
Scented alyssum (Lobularia × hybridum) - annual or zones 9-11
Milkweed (Asclepias spp.) - zones 3-10
Aster (Aster spp., Symphyotrichum spp. And several other genera) - zones 2-9
Button wood (Cephalanthus occidentalis) - zones 4-10
Boltonia (Boltonia spp.) Zones 3-8
Buddleia or butterfly tree (Buddleia spp.) - zones 6-9
Callistemon (Callistemon spp.) - zones 9-11
Caryoptera (Caryopteris spp.) - zones 5-9
Celosia (Celosia spp.) - annual or zones 10-11
Garlic chives (Allium tuberosum) - zone 3-8
Coroépsis (Coreopsis spp.) - zones 3-9
Cosmos (Cosmos spp) - annual
Dahlia (Dahlia × hortensis) - annual
Duranta or Cayenne vanilla (Duranta spp.) - zones 9-11
Echinacea (Echinacea spp) - zones 3 to 9
Eupatory (Eupatorium spp., Conoclinium spp. And Eutrochium spp.) - zones 3-9
Gaillard (Gaillardia spp.) - annual or zones 3-10
Gomphocarpus or family jewelry (Gomphocarpus spp.) - annual or zones 10-11
Gomphrena (Gomphrena spp.) - annual
Lantana (Lantana spp.) - annual or zones 9-11
Liatride (Liatris spp.) - zones 3-8
Mountain mint (Pycnanthemum spp.) - zones 4-8
Mikanie scandente (Mikania scandens) - zones 6-9
Monarda fistuleuse (Monarda fistulosa) - zones 3–9
Nepeta (Nepeta spp.) - zones 3–9
Pentas (Pentas spp.) - annual or zones 9-11
Garden phlox (Phlox paniculata) - zones 3–8
Rose (Rosa spp., Single flowering varieties) - zones 3–10
Rudbeckia (Rudbeckia spp.) - zones 3-9
Sage (Salvia spp.) - annual or zones 5-11
Russian sage (Perovskia spp.) - zones 4b-9
Sedum (Sedum spp. And Hylotelephium spp.) - zones 3-9
Ragwort (Pseudogynoxys chenopodioides, syn. Senecio confusus) - annual or zones 10-11
Silphium (Silphium spp.) - zones 4-8
Mexican Sun (Tithonia rotundifolia) - annual
Spirea (Spiraea spp.) - zones 3-8
Marigold or marigold (Tagetes spp.) - annual
Sunflower (Helianthus annua) - annual
Verbesina (Verbesina spp.) - zones 4-8
Goldenrod (Solidago spp.) - zones 3–9
Vernonia (Vernonia spp.) - zones 4-9
Veronicaster (Veronicastrum spp.) - zones 3-9
Blue verbena (Stachytarpheta jamaicensis) - annual or zones 9-11
Good-for-nothing verbena (Verbena bonariensis) - annual or zones 7-9
Canadian Verbena (Glandularia canadensis) - annual or zones 6-9
Verbena hybrid (Verbena x hybrida) - annual or zones 9-10
Zinnia (Zinnia spp.) - annual
monarch,butterfly,garden
0 تعليقات