Other Pollinators — Moths
Moths do the pollinator night shift – and they work harder than daytime insects.
Moths have long been seen as the annoying creatures that leave holes in your
clothes. But new research suggests that those pesky insects have been badly
misjudged.
You might only see them bobbing around street lights at night, but they actually
spend most of their time visiting flowers, pollinating them in the same way butterflies
do during the day, while drinking nectar with their long tongues.
Moths visit more plant species than bees and other insects.
Moths were known to pollinate flowers at night, but science has only recently begun to
uncover their efforts in detail. Most of what we know about
pollinators, and how to help them, comes from research on daytime species such as bees,
hoverflies and butterflies.
Nocturnal flowers with pale or white flowers with an open cup or tubular shape and
with a heavy fragrance and copious dilute nectar attract these pollinating moths.
Moths visit flowers to drink the flower’s sugary nectar. Upon walking around on the flower
to search for the nectar source, pollen is picked up on their legs by happenstance. Since
moths do not actually use the pollen for their own gain their bodies their own gain their
bodies are not designed for collecting pollen.
Moths transport pollen most frequently on the moth’s ventral thorax (chest), rather than
on the proboscis (tongue), allowing it to be easily transferred to other plants
Despite all odds, moths often brush up again some pollen and inadvertently carry it to
another flower. While they may not carry as much pollen as bees, they visit a high number
of flowers and can fly longer distances which makes up for the smaller amounts of pollen.
Do Moths Have Tongues?
Many moths have a single tongue-like projection known as a proboscis
located at the front of their faces which they use to feed.
When not feeding the proboscis is retracted either into the mouth or curled up like a
spring. However, many moth species do not feed and so do not have a proboscis.
Some species such as the Humming-bird Hawk-moth have an elongated tongue which it projects deep into
flowers to sip nectar.
Moths are especially important as pollinators because they are active in the evening or
overnight, which means flowers that do not open until later in the day or overnight have a
chance to be pollinated. Because there is a smaller pool of pollinators overnight,
night-blooming flowers are specialized in attracting pollinators.
Moth with its 4-inch proboscis
retracted into a coil.
Pollinators face many threats, including habitat loss, pesticide exposure, disease, and
invasive species. But one hazard unique to nocturnal pollinators is light pollution.
Artificial lights disorient moths, and research has found this can impair finding mates, evading
predators, and pollinating plants. Nocturnal visits to plants can be reduced by 62% in areas
with artificial illumination compared to dark areas.
Air pollution from the volatile compounds emitted by cars and industrial manufacturing can also
interfere with nocturnal pollinators’ scent-based communication. To help conserve moths and
other night-active pollinators, keep your garden and other outdoor areas free of unnecessary
lighting
Research also indicates that the best way to protect moths is to protect their habitat. We need to
reduce pesticide use where we can, and we must encourage a landscape with many different
types of plant species and many different types of habitats such as grassland, woodland, and
freshwater sources like ponds.
Few people take notice of moths, despite their close relationship with butterflies. Even fewer people intentionally
create gardens for them. The muted colors of many species, along with the reputation of a tiny fraction of them
as crop or wardrobe pests has done little to endear moths to the average gardener. But the truth is that moths
are a beautiful and interesting wildlife group that anyone can attract to a garden.
Though your moth gardening aspirations might be modest, with more than 11,000 moth species in North America,
you are assured of infinite opportunities for fascinating observation. Perhaps equally valuable to many gardeners
is the fact that moths are important sources of food for countless other animals such as bats, tree frogs, flying
squirrels, songbirds, and even small owls.
Just as when gardening for butterflies, the moth gardener should consider the life cycle of moths and what
they need to thrive. Fortunately, gardening for moths is not that dissimilar as gardening for butterflies, and
they share many of the same needs including food, water, and shelter. One notable exception being that moth
caterpillars feed on a somewhat more diverse range of foods than butterflies
Like butterflies, the vast majority of moths feed on a host plant during their caterpillar stage. Rather than limiting
themselves to leaves as most butterflies do, some moths also eat seeds or roots, or by boring into woody stems
or branches, eat the plant from the inside. It should be noted that less than 1% of moth species eat fabrics
such as wool.
A notable distinction between butterflies and moths in North America is the fact that some moths do not have
functional mouths or digestive tracts as adults. These moths, which include the wild silk moths, does all of their
feeding as caterpillars, then emerge later as non-feeding adults that live for only a few days before they mate
and die.
Common wisdom has it that moths visit night-blooming plants with flowers that are typically white or pale in
color such as sacred Datura (Datura wrightii), morning glory (Convolvulus spp.), and common evening
primrose (Oenothera biennis).
While there is certainly some truth in this, the relationship between moths and
plants is far more complex.
The flower preferences of nocturnal or crepuscular (active at dawn and dusk) moths are less well understood.
We know that these species are often extremely important pollinators of night-blooming plants since other
pollinators such as bees are generally inactive at night.
Once the female moth has mated, she will deposit her fertilized eggs, usually on plants
that will serve as food for her offspring. The length of time required for the egg to hatch
is dependent on the species, as well as environmental factors. Some species lay winter-hardy
eggs in the fall, which hatch the following spring or summer.
The newly hatched caterpillar is said to be in its first instar. Once it grows too big for its
cuticle, it must shed or molt. The caterpillar may take a break from eating as it
prepares to molt. Once it does, it has reached its second instar. Often, it will consume its old
cuticle, recycling the protein and other nutrients back into its body.
Caterpillars readying for pupation often wander from their host plants, in search of a safe
place for the next stage of their lives. Once a suitable site is found, the caterpillar forms a
pupal skin, which is thick and strong, and sheds its final larval cuticle.
During the pupal stage, the most dramatic transformation occurs. Traditionally, this stage has
been referred to as a resting stage, but the insect is far from at rest, in truth. The pupa does not
feed during this time, nor can it move, though a gentle touch from a finger may yield an occasional
wiggle from some species.
Within the pupal case, most of the caterpillar body breaks down through a process called histolysis.
Special groups of transformative cells, which remained hidden and inert during the larval stage,
now become the directors of the body's reconstruction. Once the metamorphosis within the pupal
case is completed, the butterfly or moth may remain at rest until the appropriate trigger signals the
time to emerge.
The adult, also called the imago, emerges from its pupal cuticle with a swollen abdomen and shriveled
wings. For the first few hours of its adult life, the butterfly or moth will pump hemolymph into the veins
in its wings to expand them. The waste products of metamorphosis, a reddish liquid called meconium,
will be discharged from the anus.
Once its wings are fully dried and expanded, the adult butterfly or moth can fly in search of a mate.
Mated females lay their fertilized eggs on appropriate host plants, beginning the life cycle anew.
Please Help Native Pollinators
Ask the Wisconsin Dept of Transportation to replace the planting of non-native grasses
with pollinator-friendly native plants along Wisconsin roadways. Provide a corridor for
Bees, Butterflies and Birds to move through the State and restore the natural beauty of
our roadways.
Find Out More