Name

Butterflies (Rhopalocera)

Class

Insects

Order

Lepidoptera (name derived from the Greek words “lepi” for scale and “pteron” for wings. Wings covered with scales)

Taxonomy

We traditionally distinguish between diurnal butterflies (Rhopalocera) and moths (moths or Heterocera).
Rhopalocera are not a natural group having taxonomic value; they only represent useful classification, a designation still utilized by entomologists and naturalists.

According to one of the most recent denominations, the Hesperioidea superfamily are ascribed to this group, including the Hesperiidae family , and the Papilionoidea superfamily including Papilionidae, Pieridae, Lycaenidae and Nymphalidae families.

Anatomy

The body of butterflies, like all insects, is divided into three parts: head, thorax and abdomen.
The head, relatively small, has two large compound eyes and each one is made of thousands of facets.
In Rhopalocera, the antennas positioned between the eyes have a club-shaped pinnacle and are the site for sensory organs.

The mouthparts have the shape of a sucking tube, called the proboscis, which is carried coiled up under the head, when not in use.
The thorax consists of three segments: the prothorax, mesothorax and metathorax; each part carries a pair of legs.

The prothorax hasn’t got wings and is very small. The mesothorax is well developed, provided laterally with tegulae (movable components covering the insertion of the front wings). The other smaller pair of wings is inserted into the metathorax. The wings are subtriangular and show considerable surface when compared to the rest of the body.

On each side the pair of wings is united and during the flight operates as a single entity. The wings are constituted by a double membrane crossed by tubular thickenings and the nervations, which give rigidity to the ensemble and also serve as hemolymphatic conduits.

The nervation morphology takes the name of venation and it is important to characterize the various lepidopteran families. The magnificent colors of butterfly wings are dependent on the pigments in scales (chemical colors) such as melanin, proteins, flavones, carotenoids and ommochromes, or on the optical phenomena of interference, diffraction and scattering of sunlight on the deep surface microstructures of the scales (physical colors).

The abdomen, larger in females, is fusiform and limbless, and contains the organs of generation. It is made up of 10 segments, and in each of them there is a couple of stigmas (tiny openings that allow air to enter the respiratory system).

The last two segments are generally the external genitalia. The structural diversity reproductive system present in rhopalocerians have the fundamental purpose of not allowing the cross between different species. The butterflies feed on liquids, mainly nectar, which is drawn through the proboscis.

Biology

Butterflies are holometabolous insects (they have a state of quiescence called pupa) and that’s why the body morphology radically changes during development, in a complete metamorphic cycle which consists of four stages: an egg, a caterpillar or larva, a pupa or chrysalis and an imago or adult.

Eggs are very variable in shape and egg-laying is performed in many different ways (individually or in small groups or in countless masses). After egg deposition and embryonic development, eggs hatch into larvae that represent the first phase of feeding and growth.

The inextensibility of external cuticle of the larva (or caterpillar) causes its change through the ecdysis phenomenon which is repeated 3 to 5 times in the larval life. After the last molting, the caterpillar stops eating and starts looking for a place suitable for transformation into a chrysalis.

At this stage the caterpillar secretes a silk thread with which attaches itself to the chosen shrub. After a very variable period (less than a week, or more than one year), the chrysalis matures, being marked on the outside by a progressive integument darkening.

Wing flicker is the next step and consists in the hatching from its chrysalis; the process is regulated by a hormone, ecdysone, and occurs due to increased pressure of the organic liquids, causing the integument rupture.

Daytime Butterflies in Madonie Park

In the territory of the Madonie there have been found 90 Lepidoptera types of the 100 surveyed in Sicily. These varieties belong to five families::

• Hesperiidae (14 species);
• Swallowtail Butterflies/ Papilionidae (5 species);
• Pieridae (11 species);
• Lycaenidae (19 species);
• Nymphalidae (41 species).

The interest in Madonie Lepidoptera is not only limited to the rich biodiversity, but also to the peculiarity of its characteristic endemic elements. Among the endemic species, we may mention: Hesperia comma hemipallida, Parnassius apollo siciliae, Lycaena alciphron bellieri, Eumedonia eumedon nebrodensis, Polyommartus daphnis pallidecolor.