Lepidoptera

The word Lepidoptera is derived from the Latin term lepido-, which means scales, and the ancient Greek terms lepis and pteron, which imply wings and scales, respectively. As a result, Lepidoptera meaning refers to insects with scaly wings. It is the second-largest, most diversified, globally distributed, and well-known insect order in the phylum Arthropoda's class Insecta. It is divided into three classes by botanist Linnaeus: 1. butterflies, 2. skippers, and 3. micro-moths and macro-moths. There are 126 families and 46 superfamilies in this group. On the basis of morphological, anatomical, behavioural, and ecological traits, they can be distinguished.

In addition, there are 500,250 Lepidopteran pests species worldwide, including 70,820 butterfly species and 3700 skipper species. Moreover, around 165,000 species of moths, including micro-moths and macro-moths, have been discovered to date. Lepidoptera is regarded as a symbol of beauty and grace in nature. They are stunningly gorgeous natural creatures.

[Image will be Uploaded Soon]

Lepidoptera Examples

The Lepidoptera order is the second largest in the Insecta class. Butterflies, moths, and skippers are among the species. The group has no common name; ordinary people refer to them as butterflies and moths. A Lepidopterist is someone who collects or studies this order.

There are over 180,000 species in the order, divided into 128 families and 47 superfamilies. They account for 10% of all living organisms that have been identified. Only the order Coleoptera (beetles) contains more species than the others.

Here are Some of the Examples of Lepidopteran Pests:

• Owlet moths (family Noctuidae)

• Worm moths (family Geometridae)

• Moths (family Pyralidae)

• Brush-footed butterflies (family Nymphalidae)

• Skippers (family Hesperiidae)

• American false tiger moths (family Notodonidae) 

• Ctenuchid moths (family Arctiidae)

• Pine moth (Rhyacionia)

[Image will be Uploaded Soon]

Lepidoptera Classification

• Kingdom: Animalia

• Division: Bilateria

• Class: Insecta

• Infraclass: Neoptera

• Subclass: Pterygota

• Superorder: Endopterygota

• Unranked: Amphiesmenoptera

• Unranked: Holometabola

• Order: Lepidoptera Linnaeus

Lepidoptera Physical Features

Head

The feeding and sensory centre of a Lepidoptera insect's head capsule. It sclerotizes organisation and is tiny, spherical, or elliptical. The frons is the upper-middle section of the head; below it is the clypeus, and beneath it is the labrum, to both sides of which the mandibles' edges with varied features of the maxillary palps may spread beyond and/or underneath, even when viewed from the front. The overall form and size of the head capsule, as well as the colour patterns and position of hairs on the head, are helpful in distinguishing caterpillar species using a microscope.

Mouth

The imago has mouthparts that are similar to those used for syphoning. They are changed into a long, flexible hollow structure in which the suctorial proboscis is produced around a fluid-tight food tube. Lepidoptera feeds on nectar, and their proboscis can grow up to 100 times their original length. When they are not in use, they usually coil under the head with the help of little muscles located there. The basic structure of mouthparts in all Lepidoptera is the same, with each labium, labrum, hypopharynx, or tongue having pairs of mandibles and maxillae. 

[Image will be Uploaded Soon]

Antennae

Antennae differ greatly in shape, size, structure, and other traits between species and even between sexes. The basic structure of Lepidoptera antennae is filiform, which is transformed into capitates, which are club-shaped antennae with a long shaft and a bulb at the end. The majority of the antennae tips in skippers are replaced with a slender hook-like protrusion. The antennae of a moth are either feathery or saw-edged. They serve as a balancing organ as well. Antennae forms aid in the identification of Lepidoptera species.

Thorax

The thorax is the second section of the body and is made up of three jointed segments: the prothorax, mesothorax, and metathorax, all of which are descended from a primitive segment. They have tergites on the dorsal side, sternites on the ventral side, and pleurites on the side (chitinous plates). Identification of caterpillar and imago species is aided by characteristics such as the presence or lack of sclerotized plates, the placement of primary setae, and the location, colour, and form of the prothoracic spiracle.

Legs

Lepidoptera has three pairs of well-developed jointed legs. They are located in each segment of the thorax and covered with scales. Each leg consists of nine segments, that is, coxa, trochanter, femur, tibia; five tarsal segments with a pretarsus; and a pair of articulated curved claws on the fifth segment. Morphology of the legs also aids in identifying caterpillar and imago species. The aroliar pad (a pad extending between the tarsal claws) and pulvillus (plural: pulvilli, pads beneath each tarsal claw) are short or absent in some families. The tibia of each leg contains a subgenual organ, which detects and amplifies small vibrations.

Scales

The presence of scales gives this order its name, Lepidoptera. The head, thorax, abdomen, wings, and legs are coated in minute scales that are lamellar or blade-like and joined by a pedicel, while other forms may have hair-like or specialised sexual traits. They give colour either by colour pigments or structural colouration using mechanisms such as photonic crystals and diffraction grating. They help with gliding flight, insulation, pheromone production, and thermoregulation, among other things. The most important feature is the wide variety of their bright or indistinguishable pattern, which helps the creatures protect themselves from rivals and possible mates through camouflage or mimicry.

Lepidoptera Characteristics and Behavior

Diet

The diet habits of Lepidoptera vary greatly, depending on the species or group's adaptations to climate, environment, kind of food plant, feeding method, and a variety of other characteristics. Conifers and flowering plants make up the vast majority of food plants, although primitive plants like mosses, liverworts, and ferns, as well as some lichens, are eaten by a few groups. Various caterpillars with particular adaptations devour nearly every part of the plant.

[Image will be Uploaded Soon]

Many larvae, notably plume moths (family Pterophoridae), devour flowers, while nectar is taken by many adults. Others, such as yucca moths (family Incurvariidae), leaf roller moths (family Tortricidae), and various owlet moths, devour the cones and fruits, as well as their seeds. The flour moth (genus Ephestia) has become a household pest, preying on stored grains and cereals. Members of numerous families pierce into buds or soft, succulent stalks. Several Lepidopteran species, such as the pine moth (Rhyacionia), specialise in conifer terminal shoots.

Grass and sedge turf is consumed by a variety of species. Carpenter, ghost, and clearwing moths (families Cossidae, Hepialidae, and Sesiidae) burrow into woody stems and rootstocks. Carpenter moths, in particular, burrow into hardwoods for a long time. Fungus moths (family Tineidae), scavenger moths (family Blastobasidae), and snout moths (family Pyralidae) are among the many Lepidopterans that feed on dead and decaying plant waste, particularly mouldy detritus. In comparison to other insect orders, Lepidoptera rarely resides in plant galls or ingesting animal stuff. 

Reproduction

A pair of testes, vas deferens, accessory glands, ejaculatory duct, and aedeagus are all parts of the adult male Lepidoptera reproductive tract. During the third and fourth larval instars, sperm develop in the testes. During the larval and pupal stages, these divisions occur. Spermiogenesis is the process of maturing sperm. All butterflies and moths generate two types of sperm: eupyrene sperm, which have a nucleus and can fertilise eggs, and apyrene sperm, which do not have a nucleus but help eupyrene sperm fertilise eggs. A spermatophore, a protein-rich ejaculate, is used to transport mature sperm. It develops in the male's aedeagus and is transmitted into the female's bursa copulatrix with sperm towards the very end of copulation, which can take up to 16 hours.

The bursa copulatrix, sperm duct, spermatheca, ovaries with ovarioles, and common oviduct comprise the adult female Lepidoptera reproductive tract. The germarium is where oocytes are formed from the original germ cells at the end of the ovarioles. This begins in the larval stage and continues in the imago stage. Chorion, which occurs in the last stages of oogenesis, covers oocytes. Male genitals, on the other hand, have a vulva, which is usually big and utilised to hold the female during mating. There are three fundamental patterns of apertures for copulation, fertilisation, and egg-laying in female genitalia.

Hepialidae and kindred groups have an exoporian external aperture that transports sperm from the copulatory entrance of the gonopore to the ovipore. Second, primitive monotrysian groups have a single genital hole towards the end of the abdomen via which both copulation and egg-laying occur. Finally, all of the remaining ditrysian groupings have an internal duct that transports sperm and has two different openings for copulation and egg-laying (98 percent).

Few sperm are discharged from the spermatheca as the egg travels through the common oviduct. Fertilization takes place soon before an egg is deposited. In adult butterflies, high amounts of JH cause eggs to mature in females and the male reproductive tract to develop. JH levels in the hemolymph of Diapause Lepidoptera, which reach sexual maturity after the overwintering period, are low.

Lepidoptera Life Cycle

Lepidopterans have four phases in their life cycle: egg, larva (caterpillar), pupa (chrysalis), and adult (imago). The larvae do the majority of the eating, with the majority of species devouring stems, roots, fruits, or flowers.

[Image will be Uploaded Soon]

Egg

The number of eggs laid varies widely between species, ranging from a few hundred to over a thousand. Almost always, the eggs are placed in a specified manner, usually on or in an appropriate feeding plant. Many species lay their eggs singly and widely spread, while others lay them in masses that are sometimes covered by a hardened fluid from the female's abdomen glands. The female's terminal segments are substantially extended and bladelike in a few groups, and the eggs are placed in soft plant tissues or narrow slits or crevices.

Larva

The embryo's development and the emergence of the young larva are frequently controlled by a physiologically induced inactivity (diapause) mechanism, which has the effect of timing the larva's emergence to coincide with favourable weather and the growth of the food plant. The larva is the life cycle's most important, and often only, feeding stage. Its sole purpose is to convert enormous amounts of plant matter into the animal matter while remaining alive in the process. As they mature, most larvae moult four or five times, losing their exoskeleton in a process known as ecdysis. The majority of larvae spin silk threads that stick to the surfaces they dwell on, giving them an almost unbreakable grip. Silk is also used to make numerous nests, cases, and shelters for the larvae to protect them from the outdoors and predators. 

Pupa

The larval stage is followed by the pupa, a resting stage during which the caterpillar rebuilds its body tissues in preparation to emerge as an adult. Many moth species pupate on the earth with little or no cocoon, while others create cocoons in the soil, leaf litter, or under loose bark. Some cocoons are coiled in leaves or tied to twigs or trees. Leaf miners' cocoons are frequently developed in or near the "mine." Cocoons are usually made of silk, although they can also contain larval hairs, fluids, or waste products, as well as chewed wood pulp, rubbish, or leaves.

Adult

The adult may remain dormant within the pupal case for a long time, even if it is completely grown until the conditions are favourable for its emergence. Cocoon-cutting structures, such as the moveable mandibles of some primitive moths, the saw-toothed structures on the skull of blotch leaf miners, and the bladelike appendages on the wing bases of giant silkworm moths, help pupae escape the cocoon. The cocoon is largely destroyed by alkaline secretions in puss moths (Cerura) and others.

When the adult emerges from the cocoon, it creeps upward to a point where it can hang with its head up and back down. By compressing its abdomen and pumping blood into the unexpanded wing pads, the insect drives its bodily fluids into the thorax, forcing them to take on the size and shape of adult wings. The adult may be able to fly in a matter of minutes or may have to wait several hours for its wings to stiffen enough to fly.

Polymorphism

Polymorphism is the existence of morphologically distinct individuals in the life cycle of the same species. In the families Pieridae, Nymphalidae, Papilionidae, and Psychidae, sexual dimorphism is highly widespread, with male and female structures being structurally distinct. Geographical, seasonal, genetic, and environmental polymorphism are the other categories. In some animals, polymorphism is only found in one sex, usually the female.

[Image will be Uploaded Soon]

Lepidoptera’s Impact on Humans

Hundreds of species of Lepidoptera harm plants that are valuable to people, including food, textiles, fodder, and lumber. The bulk of the harmful species are moths, and the larva is always the most dangerous life stage. Unlike other insect orders, however, Lepidopterans do not carry plant illnesses, and none of them is parasitic or harmful to humans. Some species, on the other hand, eat open wounds or bodily secretions from wild or domesticated animals.

[Image will be Uploaded Soon]

Many grains, sugar beets and sugarcane, cotton, tobacco, several root and leaf crops, many fruits, and timber and shade trees are among the valued plants susceptible to Lepidopteran damage. The leaves, stems, roots, or fruit may be affected. In beehives, the larger wax moth causes significant damage.

Humans benefit from a few Lepidoptera species. Almost all silk is produced by the domesticated silkworm (Bombyx mori), which originated in China.

Many Lepidopterans are useful in biological studies, such as ecology, biogeography, systematics, genetics, and physiology. The silkworm moth and its relatives have provided most of the current knowledge of endocrine regulation of insect development.

Did You Know?

1. The first living organisms to be launched into space were fruit flies.

2. The wings of a bee beat at 190 times per second, or 11,400 times per minute.

3. Caterpillars have a total of 12 eyes.

4. In South Korea, people consume Beondegi (silkworm pupae) after boiling and seasoning them. 

5. Butterflies use their feet to taste things.

6. By eating poisonous plants, the red postman butterfly creates its own poison!

[Image will be Uploaded Soon]

Conclusion

This is one of the most well-known and easily recognised insect orders in Australia, with over 21 000 species. We are already aware now that the order Lepidoptera, which means scaly wings, includes both moths and butterflies. You must know that some people have an immense fear of lepidopteran pests irrespective of how beautiful a few insects are. And it has a name. According to science, the fear of butterflies or moths is known as lepidopterophobia. While some people have a modest phobia of these insects, a phobia occurs when you have an excessive and unreasonable dread that affects your daily life.