Master Gardeners of Northern Virginia

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Fothergilla gardenii Witch Alder
Fothergilla gardenii (Witch Alder). Photo © Mary Free

Morphology of Butterflies & Moths

Pollinator Week June 20-26, 2022

About Butterflies and Moths – Part 2

By Mary Free, Extension Master Gardener 

Pollinator Week Challenge: Read the paragraphs below and fill in the blanks. Then search for those words in the puzzle to the right. (Click on the puzzle and save it to a PDF on which you can highlight the letters on your computer or print it out if you prefer.) Words appear horizontally, vertically, and on both diagonals. (Hint: there are four diagonal words.) Answers will post tonight. Good luck! 

Like most adult ____, butterflies and moths have three main body parts: a head with a pair of compound eyes and a pair of ____; a ____ that bears ____ pairs of legs and carries two pairs of ____; and an abdomen.

Like adult lepidopterans, caterpillars have three main body parts but there are striking differences. A caterpillar head has six pairs of simple ____ that detect light and ____; a pair of usually short antennae; ____ for chewing food; and spinnerets that may produce ____. The segmented thorax bears three pairs of true legs that enable it to crawl and manipulate its food and on its first thoracic segment, ____ pair of spiracles, small holes that allow the exchange of gases (____ and carbon dioxide). Eight more pairs of spiracles line either side of the segmented ____, which, depending on the species, is supported by two to seven pairs of short, fleshy pro____ with hook-like suction cups, which allow it to grasp on to leaves, stems, and silk.

Verbena with Eastern Tiger Swallowtail (Male) from Creating Inviting Habitats
Ventral view of male eastern tiger swallowtail.
Dorsal and ventral views of adult tobacco hornworm (Manduca sexta
A tobacco hornworm caterpillar (Manduca sexta) on Datura innoxia in September.

Clockwise from left to right: Eastern tiger swallowtail butterfly adults dorsal and ventral views and caterpillar and tobacco hornworm and the adult Carolina sphinx moth dorsal and ventral views.

One way to differentiate adult moths from butterflies is by their antennae. Moth antennae are thread-like (female) or ____like (male) and are more pronounced in some families like the Saturniidae. In moths, these differences are related to sexual selection–the male antennae are attuned to sex pheromones released by females, which aid in finding a mate over long distances. One study showed that “younger females attracted males with longer antennae” (Johnson et al. 2017). Moths also use their antennae to sniff out food and to find ____ plants for oviposition. Butterflies have long, thin antennae with club-like or knobbed tips. These tips can measure ambient temperature. Chemoreceptors covering the antennae are highly attuned to odors and nectar producing plants. Although olfactory receptor genes in butterfly antennae are similar to those of moths, both numerically and qualitatively (Carlsson et el. 2013), it is unclear whether butterflies use their antennae for foraging, feeding, and reproduction to the same extent as moths do.

Male moths, like Actias luna, have featherlike antennae.
Female moths, like Actias luna, have thread-like antennae.
Monarch on gomphrena with close-up of antennae.
The antennae tips of skipper butterflies, like silver-spotted skipper (Epargyreus clarus), are pointed and hooked.
The black and white striped antennae of pearl crescent butterflies (Phyciodes tharos) are black-tipped for males and orange-tipped for females.

Clockwise left to right: Antennae of male and female luna moths and of pearl crescent, silver-spotted skipper, and monarch butterflies,
.

Lepidopteran wings (____wings and ____wings) are covered with modified hairs called scales. In fact, Lepidoptera is derived from Greek lepido- “scale” and pteron “wing.” The wing scales of each species have unique arrangement, pigmentation, and reflective qualities. Scent scales, like the black dot on a male monarch’s hindwing, help disperse pheromones. 

Luna moth (Actias luna) scales.
Scent scales (black dots) distinguish this male monarch (Danaus plexippus) on gomphrena.

Left to right: Luna moth and citrus swallowtail butterfly wing scales; male monarch scent scales.

Moths usually have a thicker coating of scales that makes them appear furry as well as subdued coloring that makes them less conspicuous as they rest during the day. Not all moths are strictly ____ (active at night) though. White-lined sphinx moth (Hyles lineata) flies at night but it is also crepuscular (active at ____ or dusk) and sometimes can be seen during daylight hours. Pandora sphinx moth (Eumorpha pandorus) prefers to fly at dusk. Ailanthus webworm (Atteva aurea), hummingbird clearwing (Hemaris thysbe), and orange mint (Pyrausta orphisalis) moths fly during the day,

Orange mint moth (Pyrausta_orphisalis) on Pycnanthemum muticum (short-toothed mountain mint) on a sunny June day.
Sphinx Moth at Simpson Garden
Nocturnal large lace-border (Scopula limboundata) spends the daytime resting on a shady leaf.
Nocturnal tulip-tree beauty moth rests on the trunk of a juniper tree in May.
Nocturnal polyphemus moth (Antheraea polyphemus) with prominent hindwing eyespots.

Left to right: Diurnal orange mint moth; crespular Pandora sphinx moth; nocturnal large lace-border and tulip-tree beauty moths and polyphemus moth with prominent hindwing eyespots.

Butterflies that are ____ (active during the day) often sport wings more vibrantly colored and patterned. Prominent wing eye ____ have proven, under certain circumstances, to be effective in intimidating or deflecting predators and some postulate they may play a role in signaling during courtship and selecting a mate.

Broad, bright orange-red bands adorn the forewings and the margins of the hindwing of red admiral (Vanessa atalanta) butterfly.
Contrasting yellow and black wings with pronounced orange cells and iridescent blue scales of the female eastern tiger swallowtail (Papilio glaucus)
The brown-black and orange checkered pattern of the variegated fritillary (Euptoieta claudia) in late October.
The white-m hairstreak deflects predators with its hindwings' "false-head" pattern–eyespots in the margins and thread like tails, which move to imitate antennae.
Common buckeye butterfly perches in the Scented Garden in August 2019.

Left to right: Red admiral, Eastern tiger swallowtail, variegated fritillary, and white-m hairstreak butterflies; common buckeye butterfly with prominent wing eyespots.

Lepidopterans are “cold-blooded,” which means that their body ____ varies according to the environment. Butterflies need the radiant energy of direct ____ to warm their flight muscles in order to ____, which is why they are often seen ____ on sunny leaves or rocks. When conditions are unfavorable–clouds, wind, rain, nightfall–butterflies retreat to protective cover, often within or under plant foliage, called roosts. Most moths cannot take advantage of the sun, so they heat up their flight ____ by vibrating their wings or shivering.

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References