The meter worm is an organism that belongs to the Geometridae family. They owe their name to the peculiar way in which they move. They do this by stretching their body to its full length, to then collect the back of their body and join it to the previous one. This way is similar to when measuring a distance using the hand and the “by hand” method.
They were first described in 1815 by the English zoologist William Leach. Since then they have been widely studied, so there are very few aspects of them that remain to be elucidated.
These animals are very widespread throughout the world geography and prefer dry habitats, of average temperature (not very cold, not very hot) for their eggs that are deposited on the surfaces of the leaves of certain plants.
Members of the Geometridae family have cells that internally have a nuclear membrane, which delimits a space known as the cell nucleus, where the packed DNA is found, forming chromosomes. It is a characteristic that they share with the rest of the members of the Eukarya domain.
Likewise, they are multicellular because they are made up of several types of cells, each one specialized in a specific function.
As members of the phylum Arthropoda, measuring worms are triblastic, that is, they present during their embryonic development the three germ layers called mesoderm, endoderm and ectoderm. They are also protostomados and coelomados.
By drawing an imaginary line along the longitudinal axis, two exactly equal halves are obtained, so it is correct to say that these animals have bilateral symmetry. As for food, they are heterotrophic and herbivorous animals, since, not being able to synthesize their own nutrients, they feed mainly on plants, flowers and fruits.
They are animals that reproduce in a sexual way, with internal fertilization and oviparous . They also have an indirect development, since larvae hatch from the eggs that later transform into caterpillars, which build a cocoon in which they enter and undergo a metamorphosis, until they become adult butterflies.
The taxonomic classification of the meter worm is as follows:
– Phylum: Arthropoda
The measuring worm has a small, cylindrical body, with a length not exceeding 5 cm and a thin thickness. They present different colors, which range from bright green to almost black, through shades of brown and gray.
Some have very particular design patterns on their surface such as stripes or bands, mainly dark in color.
As with most arthropods, its body is divided into segments. In segments 10 and 6 they present structures known as false legs, which help them to have the distinctive displacement shape they have.
When they reach adulthood, they leave the worm shape behind and turn into a beautiful butterfly, usually dull colors like gray or brown. Many of them are able to blend in with the environment almost perfectly, thus managing to escape from potential predators.
Members of this family reproduce sexually. It is important to remember that this type of reproduction involves the exchange of genetic material and the fusion of a male sex cell with a female sex cell.
Now, it is important to mention that the reproduction process of these animals occurs when they are already adults, that is, when they are already converted into beautiful butterflies.
The reproduction process of the members of the Geometridae family is somewhat complex, since, in addition to fertilization itself, it includes a prerequisite that is made up of mating rituals in which both females and males display all their charms to ensure the successful mating.
The animals of this family, which includes a large number of butterflies, have certain rituals, such as the release of a chemical known as pheromones or the unfolding of wings by the male, who moves his wings quite quickly. With this they spread particles that fall on the female butterfly and that also contain pheromones.
This spreading of pheromones stimulates both individuals, preparing them for the next step in the reproductive process: fertilization.
In the members of this family, fertilization is internal, since it occurs inside the body of the female. The male deposits the sperm there.
For this to happen, it is necessary that there be physical contact between the female and the male. Both unite by bringing their abdomens together. When they come into contact, the male’s copulatory organ protrudes from his body and enters a small sac in the female’s abdomen in order to deposit the sperm there.
By depositing the sperm in that sac, it meets the female reproductive cells and fertilization occurs, thus forming the zygote that will eventually become a new individual.
Once all the eggs have been fertilized, the laying process begins. The female begins to lay the eggs on different plants, placing them on various leaves.
However, since there is no protection mechanism for these eggs, which prevents them from suffering any damage, the vast majority are exposed to adverse environmental conditions and possible predators. This results in many dying and only a small percentage surviving.
From these surviving eggs, the following stages of the animal develop.
When appropriate, the eggs hatch and from these a larva, a kind of caterpillar, emerges, which is the meter worm itself. It feeds on the leaves of the plant on which it lives and begins to grow satisfactorily.
Later, the caterpillar creates a kind of cocoon, where it hides. Inside that cocoon, the caterpillar undergoes a process of metamorphosis, through which it finally transforms into a butterfly, which emerges from the cocoon and begins to move to find a mate and start the reproduction process again.
In general, it can be said that the meter worm is a herbivorous animal, which means that it feeds mainly on plants. When the larva hatches from the eggs and becomes a caterpillar, it feeds on everything in its path, since it needs energy for its subsequent transformation into a cocoon and finally into a butterfly.
Depending on the plant in which the eggs have been deposited, the measuring worm can feed on leaves, roots, stems and fruits. From an ecological point of view, the presence of these worms in some crops is viewed negatively, as they can become terrible pests.
Many species tunnel into the plants on which they feed, greatly damaging crops. Likewise, there are also a few species that can be considered carnivorous, because they feed on small insects.
When they are adults, they begin to use their sophisticated and specialized oral apparatus and then they feed on the nectar of some flowers or some other liquid that is present there.
Arnett, R. (2000). American insects. 2nd edition. CRC Press, Boca Raton.