Butterflies of Formosa - Get to Know Butterflies

That is a butterfly
Many people enthralled by butterflies as flying flowers or jewels. Most people assume butterflies are generally active in the daytime and are more colorful and more attractive than most moths. Butterflies also have large and beautifully scaled wings, siphoning mouthparts, large compound eyes, and a complete metamorphosis life cycle.

In taxonomy, butterflies and moths belong to the phylum Arthropoda, class Insecta, and order Lepidoptera. ‘Lepido’, a prefix derived from Greek ‘lepis’, means wings with scales. There are about 20,000 documented butterfly species in the world. Butterflies account for only 15% of all insect species from the order Lepidoptera. The remaining 85% are moths.


Origin of Butterflies
The oldest Lepidoptera fossil came from Europe and Central Asia in the Jurassic. The oldest butterfly fossil, a butterfly from the family Hesperiidae, came from Denmark in the late Paleocene (about 52 million years ago). Some scientists estimated that butterflies originated from the late Cretaceous or early Paleocene when flowering plants were already established in large numbers. A recent study suggests the family Nymphalidae may have originated in the Cretaceous, 90 million years ago (Wahlberg et al. 2009).

Butterfly or Moth?
Based on current classification practice, scientists classify butterflies into Papilionoidea, Hespenoidea, and Hedyloidea under subsection Bombycina in Lepidoptera. This classification suggests butterflies are actually a kind of moth. In French, butterfly and moth do not have separate names. They are both called ’Papillon’. Some scientists only consider species from the superfamily Papilionoidea as true butterflies and that species from superfamilies Hesperioidea and Hedyloidea are not.

Early classification systems emphasized apparent morphological characteristics to conveniently classify taxa. Modem practice, however, tries to adjust classification systems to more accurately reflect phylogenetic relationships among taxa.

In the past, scientists used characteristics of antennae to classify butterflies and moths into suborders Rhopalocera and Heterocera, respectively. Since this classification did not reflect phylogeny, it is not commonly used.

Superfamily Papilionoidea
Some scientists consider only members from the superfamily Papilionoidea as true butterflies. Compared to species from superfamnilles Hesperioidea and Hedyloidea, Papilionoidea butterflies have obvious clavate antennae, larger wings, slimmer abdomens, and generally brighter colors.

Families in the superfamily Papilionoidea are Papilionidae, Nymphalidae, Pieridae, Lycaenidae, and Riodinidae.

Family Papilionidae
Papilionidae butterflies are quite large. Usually radius vein in each forewing has five branches. The posterior edge of each hindwing has one or several tails.

Family Pieridae
Pieridae butterflies are medium to small in size. They are usually white or yellow with black patterns on the wing edges. They have normal front legs. Each leg has a pair of claws. Pupae are long and narrow in shape. This family has many common species with large populations, which occasionally migrate in large flocks.

Family Nymphalidae
The name, Nymphalidae, indicates degenerated front legs and lack of claws. Nymphalidae species walk on the remaining middle and hind legs. This family has many species, which are mostly very common.

Family Lycaenidae
Small in size and quick at flying, lycaenid butterflies usually have metallic patterns on their wings. Males have short, clawless front legs. Females have six normal legs with claws. Larvae usually look like flat slugs. The surface of pupae is smooth.

Family Riodinidae
Riodinidae and Lycaenidae are closely related. Sometimes Riodinidae are placed under Lycaenidae as a subfamily. Adult riodinids have the degenerated front legs like adult nymphalids. Larvae and pupae, however, are most similar to lycaenids.

Superfamily Hesperioidea
Because species from the superfamily Hesperioidea resemble moths, sometimes they are not considered butterflies. Analyses combining morphological and molecular characters indicate Hespenoidea are more closely related to Papilionoidea than to the other lepidopteran superfamilies. Hespenidae are the only family under Heaperloidea. These insects are called skippers because of their swift flying behavior.

Moth-butterfly-Moth? Butterfly?
American Moth-butterflies (Hedylidae) are distributed in Central and South America. They used to be considered as moths. They are the best example of difficulty in distinguishing between butterflies and moths.

Adults of American Moth-butterflies have filiform antennae. They are nocturnal, attracted to light, and have wing shapes and colors similar to geometer moths (Geometridae). American Moth-butterflies were long classified as members of family Geornetndae. In 1986, Malcolm J. Scoble found that the internal and external morphology of American Moth-butterflies are more closely related to butterflies. Their immature stages also support the idea. Their eggs are similar to pierid eggs. Their larvae are similar to nymphalid larvae. Their contigua pupae are similar to papilionid pupae.

Unlike ordinary butterflies, American Moth-butterflies have hearing sensors on their wings and can use them to hear like many moths do.

Life Stages
Butterfly species with complete metamorphosis have four life stages:
egg, larva, pupa, and adult. Each stage is enormously morphologically different.

Larvae just emerging from eggs are 1st instar larvae. They increase one instar after each molt. Generally by the end of 5th instar, the larvae will have chosen a suitable location to pupate. They use the spinneret on their mouthparts to spin a silk pad for their tails’ attachment. Then, they wiggle their bodies to get rid of the old cuticle and become pupae.
The appearance of a pupa roughly reveals characteristics of an adult. Tissues inside the pupa begin to collapse as they transform into adult organs. Through this unique tissue destruction and reconstruction, pupae finally turn into beautiful butterflies.

Female butterflies must choose proper locations on host plants for laying eggs. Larvae would starve to death on inappropriate host plants. Eggs laid on visible places can attract predators or parasitoids. Once they hatch, larvae usually eat the chorion for nutrition and to eliminate signs of hatching.

Butterfly Kingdom – Diversity of Taiwan Butterflies
With an area of about 36000 square kilometers, Taiwan is home to about 400 butterfly species- Over 50 are endemic to Taiwan. This gives Taiwan an unusually high number of species and endemic species. This rich butterfly diversity is a result of interactions of Taiwan complex landscape, unique geographic location, abundant flora, and the effect of repeated glacial and interglacial cycles.

Taiwan Island is 144 km wide and 395 km in length. Two-thirds of Taiwan is mountainous, including the Shueshan range, Central range, Yushan range, Alishan range, and Coastal range. These ranges cover most of island, running from north to south. Taiwan Island has over 200 mountain peaks taller than 3,000 meters. Many rivers flow east-west, cutting the mountains into many deep gorges. Western Taiwan is an alluvial plain connected to the Eurasian continental shelf. Although Taiwan Island is only 36,000 square kilometers, it has an extremely complex terrain that provides great diversity of habitats.

Interchange of Butterfly Species
Butterflies in Taiwan Island largely originated from continental East Asia. With the end of the last glacial epoch, Taiwan became an island again and the east-west flow of species was reduced. North-south flowing air and ocean currents became important mechanisms for increasing Taiwan butterfly species diversity by bringing temperate butterflies from Japan, subtropical butterflies from the Ryukyu Islands, and tropical butterflies from the Philippines.

Currently, Taiwan has temperate butterfly species living in its high mountain grasslands, including species widely distributed in East Asia and around the globe. Taiwan also has tropical butterfly species in Hengchun Peninsula and southeastern islands, glacial relic butterfly species restricted to its high mountains, and species recently introduced from the west and the south, either naturally or by human activities.


National Museum of Natural Science