Supporting resident and migrating pollinators, including bees, not only aids a critical link in the natural ecosystem cycle, but a farm’s production can increase substantially with the presence of ample pollinators.
By giving pollinators safe shelter, water and a supplemental food supply in addition to nectar supplied by crops, their activity on the farm can increase. It’s helpful to remember that while pollinators include the more familiar honeybees and mason bees, they also include various other animals. The Fish and Wildlife Service reports that there are more than 100,000 different animal species (they say the numbers may be as many as 200,000) which play roles in pollinating the 250,000 kinds of flowering plants on the planet. The most common ones are the insects which include bees, wasps, moths, butterflies, flies and beetles. But they report that as many as 1,500 species of vertebrates, including birds and mammals such as hummingbirds and fruit and nectar-eating bats, also serve as pollinators.
Though butterflies and moths pollinate somewhat differently than honeybees, the more familiar pollinators, they’re still a vital link in nature’s overall pollination plan even though a few of their caterpillars can become pests to farmers growing certain crops.
Butterflies, in general, have very good vision and can also see the color red, which bees cannot, according to the USDA Forest Service. They’re also able to detect ultraviolet light which further helps them find nectar. Butterflies taste with their feet and prefer bright colored flowers that are open during the day and that have wide landing platforms whether the flowers are in close clusters or larger singles. While perching on the flowers, pollen collects on their legs and wings as they hunt around for nectar. Not as much pollen is touched and stuck to their long legs and wings as does pollen on bees, but their flight range is often further, allowing them to spread the pollen they do collect throughout a larger region.
Monarchs, specifically, are known to seek out milkweed to lay their eggs. Their caterpillars feed only on milkweed (meaning they leave farmed crops alone) and milkweed also offers nectar to other important pollinators. But as adults, monarch butterflies need a steady supply of other nectar plants. And with monarchs being migratory, the Monarch Joint Venture (MJV) points out that the timing of the blooming plants needs to correspond with the timing of the monarchs’ arrival. Therefore, even if a list of favored monarch nectar plants is planted and nurtured on the farm, climate change and other variables could mean those plants’ blossoms open too soon or too late to feed the butterflies when they are passing through. The MJV website, monarchjointventure.org, has articles and links for rural landowners interested in aiding both the western and eastern monarch populations.
Farmers can play an important role in creating monarch (larva and butterfly) feeding areas as well as helping to manage their migratory corridors. According to MJV, agricultural fields used to be an important source of milkweed for monarch caterpillars because historically, native milkweed grew alongside crop plants. The widespread use of herbicides and herbicide- tolerant crops diminished much of the milkweed growing on farmlands. Though milkweed can tolerate light tilling, it can’t survive herbicides. MJV suggests that farmers plant native flowers in fallow fields, hedgerows and farm field margins which combine early, middle and late blooming species with blossoming times that overlap. If possible, they suggest allowing native milkweed to either grow in unused portions of the farm, or to use either no-till or low-till farming techniques and allow more milkweed to grow alongside crops.
Though the cost of the initial native milkweed and flower planting, including the time itself to plant the pollinator habitat, can be an obstacle for some farmers, others may be able to synergize their monarch (or other butterfly and moth pollination projects) with agritourism to at least indirectly benefit the farm’s bottom line. CSA farmers, for example, can request help, donations and feedback from their members regarding the farm becoming a monarch or butterfly habitat. Farms that benefit financially from positive public exposure can use the project to attract media attention. The MJV also offers information on Citizen Science projects CSA members can take part in. Farmers involved in farm-to-school programs may be able to coordinate farm tours with area teachers and classrooms. The tours can be fee-based at cost-per-head, or can be used as a method to sell other on-farm products directly as a result of visitors coming to the farm to see the monarch habitat. And of course, a native nectar garden also feeds other pollinators which can directly enhance the production of many farm crops.
Various moth species contribute to butterflies’ pollination for daytime bloomers as well as for plants with flowers that open at night. In one extreme case, the crop cannot survive without its partnership with a specific moth. The yucca plant which is grown and sold far from its original native habitat depends on the yucca moth for survival. The adult yucca moth doesn’t seek nectar because its lifespan is so short. But after mating, the female moth carefully scrapes off pollen from yucca flowers, holds the pollen in a lump under her “chin,” then purposefully and carefully deposits pollen into the stamen of a flower.
Not only that, she makes sure the pollen is deposited in a different flower from the one she collected it from to ensure cross pollination. She eventually lays her eggs in the flower, and though some of her young will consume a few seeds, the number of yucca seeds eaten in general does not put a dent in the number of seeds that will be formed because of her pollination. She can even detect if a flower already has eggs laid in it and if so, she moves on to another flower, which makes sure no flower will have too many of its seeds eaten because of too many larvae. Though yucca plants are grown and sold far beyond their area of origin, even into Canada, the moths have managed to follow them and adapt to the newer climates.
This report appears in the July 2015 issue of Acres U.S.A.
RESOURCES
For those interested in adding habitats or gardens specifically for pollinators, the following sources offer free or low cost guides.
The U.S. Fish and Wildlife Service offers basic overviews for planting pollinator gardens and building bee nesting blocks. From there, it offers links to more in depth information and instructions; www.fws.gov/ pollinators/pollinatorpages/yourhelp.html.
The National Center for Appropriate Technology offers a low-cost publication on attracting native pollinators. It provides information and resources on how to plan for, protect and create habitat for native bees in agricultural settings. The full-color digital version is currently $4.95. The black and white print edition is currently $7.95; attra.ncat.org/ attra-pub/summaries/summary.php?pub=75.
When planting for pollinators, native plants are usually encouraged. Landowners can contact their local or state Native Plant Society for names of and resources for appropriate species.
The Pollinator Partnership of the NAPPC offers free eco-regional pollinator planting guides and resources for pollinator gardens and lists the types of blossoms the various pollinator species groups (bees, bats, etc.) prefer; www.pollinator.org.
USDA’s Natural Resources Conservation Service offers a number of documents and leaflets on conserving pollinators; plants.usda.gov/ pollinators/NRCSdocuments.html.
Some state’s cooperative extension services offer guidance on planting for local resident and migrating pollinators. To find extension services in any given state, visit the National Institute of Food and Agriculture’s extension page; www.extension.org.