Butterflies and moths belong to the order Lepidoptera, one of the most numerous groups of insects, with about 160,000-180,000 described species worldwide.
Traditionally, Lepidoptera have been divided into butterflies and moths. Butterflies usually fly during the day, rest with their wings folded upwards and have club-shaped antennae. Moths, on the other hand, are generally nocturnal or crepuscular, rest with their wings spread horizontally and have feathery or filiform antennae. However, this classification is not biologically precise, as there is no rule that completely differentiates butterflies and moths. Therefore, they will be referred to hereafter simply as Lepidoptera.
Characteristics of Lepidoptera
Lepidoptera can be distinguished from other insects by two main features, their scales and proboscis. The scales are made up of modified, flattened hairs that cover the body and wings, arranged in the form of shingles and giving rise to the characteristic colours and patterns of each species. In fact, the name Lepidoptera comes from Ancient Greek, lepismeaning "scale", and pteron,"wing". The proboscis is the tubular mouthpart used by most adults to feed on liquids. However, some species have functional mandibles instead of a proboscis.
Regarding their life cycle, Lepidoptera go through a complete metamorphosis. They are born as larvae, known as caterpillars,which have a hardened head with mandibles and several pairs of pseudolegs behind the three pairs of true legs. When they are about to enter the pupa stage,i.e. the transformation phase between caterpillar and adult, many species secrete a silk cocoon for protection. Other species pupate buried, or in the open air, with a hardened, green or brown surface and spiny structures or grooves to help camouflage them.
Where do they live?
Lepidoptera have adapted to life in a wide variety of habitats, from the tropics, where the greatest diversity of species is found, to the Arctic. In the high mountains and in the polar areas,some species have dark fur to absorb more heat and make short flights to avoid being blown away by the wind. In addition, they hibernate going into a state of dormancy during cold periods with low availability of food plants. This mechanism is also used by Lepidoptera that live in the meadows and the forest clearings of temperate zones.
In the tropical forests,the warm climate and abundance of rain and vegetation allows many species to be active all year round, although some species also hibernate in the dry season.
What do they eat?
Most caterpillars feed on living plant tissue: leaves, flowers, fruits, stems and roots. Some species feed from outside the tissue, while others develop inside, such as leafminers and seed and root borers.
On the other hand, there are also caterpillars which consume fungal spores, fungi that grow in decaying wood, animal and plant remains as dry leaves or wool (such as the clothes moth Tineola bisselliella), and species that prey on mealybugs, homopterans, ants and flies.
Adults usually feed on flower nectar.However, some species consume sap and honeydew from aphids and other homopterans or, in the case of those with mandibles, pollen and spores from ferns. There are even species that do not feed in its adult phase.
Ecological importance
The main role of Lepidoptera in ecosystems is that of primary consumers of plants, serving as a food source for parasites and predators such as flies, wasps, spiders, ants and birds. Likewise, species that feed on animal and plant remains, such as noctuids, act as decomposers of organic matter, contributing to the formation of humus. Finally, it is also remarkable its function as pollinators,and in plant biological control. For example, the cactus moth (Cactoblastis cactorum) was introduced in Australia to control the invasive cactus species Opuntia stricta.
If you are eager to learn more about the butterfly species of the Iberian Peninsula, here we have compiled a series of free resources to help you identify them.
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