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.

  Moth Pollination

Moths visit more plant species than bees and other insects.
Moth sipping nectar.

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.

  Why Is Moth Pollination Important?

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.

  Protecting Moths

Moth with its 4-inch proboscis retracted into a coil.
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.

  Attracting Moths To Your Garden

Moth Pollination 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.

  Feeding Moths

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.

  Selecting Plants for Moths

Black and white moth on a flower. 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.

  Moth Life Cycle

Graphic of moth life cycle.

Egg - Embryonic Stage

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.

Caterpillar - Larval Stage

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.

Cocoon - Pupal Stage

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.

Adult - Imaginal Stage

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.

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