Butterflies are the Lepidoptera order of insects, the second order in number of species with more than 165,000. The largest known butterflies are the Ornithoptera alexandrae (Queen Alexandra’s birdwing butterfly) which can measure up to 31 centimeters in length. long and lives in New Guinea, and the Attacus atlas (Atlas butterfly) that unfolded reaches more than 400 cm 2 in surface area and lives in the tropical areas of Southeast Asia. The butterflies that we know best are the diurnal ones but most of the species are nocturnal. All of them have similar morphological characteristics; Next we will see the characteristic parts that make up a butterfly.
The upper figure shows the most relevant parts that make up a butterfly. The first thing that catches our attention in a butterfly are its wings . The wings of a butterfly are composed of a pair of forewings, attached to the midsegment of the thorax (component A in the figure) and a pair of hindwings attached to the metathorax (the last segment of the thorax; component H in the figure).
The wings of butterflies have ribs whose design is characteristic and unique to each species. The wing surface is made up of scales that expose a large number of edges, sometimes separated by less than one micron between them, that is, one thousandth of a millimeter. This creates light reflection effects that produce the beautiful colors and iridescent hues seen in many species. According to some studies, butterflies could still fly without hind wings, but they need them to perform evasive flight. The forewings of males release pheromones to attract females of their species.
The butterfly’s head has a shape that approximates a sphere. In it we find structures associated with sensory functions such as its antennae; and others that are associated with their diet, such as the proboscis. The head also houses its brain, two compound eyes, and the pharynx, the first section of the digestive system. The proboscis (component D in the figure) is a proboscis or beak-shaped mouth apparatus used by butterflies to suck. It is made up of two hollow tubes that the butterfly can unfold when it needs to feed. The eyes of butterflies (component B in the figure) are composed of thousands of ommatidia, visual sensory units that have cells that detect light and in some cases can distinguish colors.
The antennae (component B in the figure) are two chemoreceptor sensory appendages that, when responding to chemical stimuli from the environment, have functions that resemble the senses of taste and smell. Butterflies also use their antennae to detect wind speed and direction, heat, and humidity. In addition, the antennas have a touch function. Butterflies’ antennae help them maintain balance and orient themselves.
The thorax of butterflies (component E in the figure) consists of three segments and a pair of legs emerges from each of them. The three segments are articulated through flexible joints that allow the butterfly to move. Like the wings, the thorax of butterflies is covered in scales that give it the same visual effects.
The six legs of the butterflies (component F in the figure) are articulated in six sections; the coxa, the femur, the trochanter, the tibia, the pretarsus and the tarsus. Tarsi have chemoreceptors with olfactory and taste functions; butterflies can locate their food sources using the chemoreceptors on their feet. Through their legs, the females can also identify a suitable place to deposit their eggs.
The abdomen of butterflies (component G in the figure) consists of ten segments. The last three to four segments are modified to form the external genitalia. At the end of the abdomen there are also accessory reproductive structures; in the male there are elements that allow him to cling to the female during mating; in the female, the abdomen contains a tube through which the eggs are deposited.
Sources
- Aguado Martín, LO The diurnal butterflies of Castilla y León (Lepidoptera ropaloceras) . Species, biology, distribution and conservation I. Valladolid, Junta de Castilla y León, Spain, 2007.
- de Viedma, MG, Baragaño, JR, Notario, A. Introduction to entomology. Ed. Alhambra, 1985.
- Jantzen, B., Eisner, T. Hindwings Are Unnecessary for Flight but Essential for Execution of Normal Evasive Flight in Lepidoptera. PNAS, National Academy of Sciences, USA, 2008.
- Smart, P. The Illustrated Encyclopedia of the Butterfly World . Chapter 2, Chartwell Books, 1977.
