In this article on our site, we want to present you with information about the biological cycle of the processionary caterpillar, which corresponds to one of the Life stages of a type of moth known as pine processionary (Thaumetopoea pityocampa). This animal is an insect that belongs to the Lepidoptera order, which it shares with butterflies, and is also part of the Notodontidae family, a fairly diverse group that has a wide distribution.
This caterpillar has certain particularities, since it can be very irritating to people and animals, it can cause significant forest damage and it has a typical form of group movement. Whether you are interested in knowing more details about this animal or if you want to protect your dog from the effects that contact with it has on him, read on and discover the season of the processionary caterpillar, its stages of development and much more.
Pine processionary caterpillar season
The processionary moth is distributed throughout Africa, the Middle East and Europe, generally having an annual life cycle. However, it has been found that, in certain high- altitude regions, it can last up to two years. However, in general, adult moths lay their eggs on pine trees during the month of July. After 30-40 days, the larvae of this species emerge, so that the pine processionary caterpillar season begins between August and September.
Subsequently, the larvae remain grouped during the following months, both when they are at rest and when they feed on the trees where they develop. After three or four months, winter begins and the caterpillars proceed to nestbuildingof a white silk, which provide them with the necessary protection to withstand low temperatures. From that moment and until February-April, a series of phases take place in the caterpillars and finally they begin to descend from the treesto move in the typical way that the species does: in the form of a procession, one after another, which has given rise to its common name. The larvae burrow into the soil to give way to the next stage of the life cycle, the chrysalis.
To point out, then, we have that the pine processionary caterpillar season begins in August-September, which is when the larvae hatch. However, they do not come down from the trees until February, so if what we want to know is the season of the processionary caterpillar that we are most concerned about, that is, when they can harm our fellow animals, then it occurs from February and until April, approximately.
Phases of the processionary caterpillar
Let's learn about the complete life cycle of the processionary caterpillar below:
- Egg: The first stage of the species is the egg stage. After being fertilized inside the mother, they are placed in the trees and stay there for 30 to 40 days before hatching. A curious aspect is that the female generates some species of scales that cover the eggs and simulate the pine shoots where they are deposited. As we said, the laying of eggs occurs in July, so they hatch between August and September.
- Oruga: this stage is also known as larva and is the longest lasting in the species, since it remains in this Been at least 6 months. During this time, the caterpillar goes through a series of external changes in color and size. This is the phase of the processionary that most often worries dog and cat guardians because it is when their hair can cause serious injuries in these animals. Normally, it is from February when they come down from the pines.
- Pupa: in moths and butterflies it is common to refer to this stage of the life cycle as " chrysalis ". In it, the greatest changes in the individual occur through the metamorphosis from larva to adult. This is raised in the ground and lasts about 2 or 3 months.
- Adult: corresponds to the shortest phase, since it only lasts two days maximum, so basically it is a stage to fulfill with reproduction and start the processionary caterpillar cycle.
Nest of the processionary caterpillar
As we mentioned in the previous section, the processionary caterpillar builds nests while it remains in this phase of the life cycle, which corresponds to the larval stage. The construction of these nests begins before the arrival of winter to offer thermal protection and thus guarantee the survival of the species. The nest is distinctive and very peculiar, since it simulates a kind of tent made of white silk. In the adult phase no nests are built.
How does the processionary moth reproduce?
The adults of this species only live one or two days at most, then having their longest life span in the other phases of the life cycle. When the adults emerge from the ground, they seek to reproduce as soon as possible due to their short lifespan. Once the internal fertilization occurs, the female, which has less flight capacity than the male, moves to look for the tree where thewill take place. laying of eggs , specifically in needle-like leaves of pine trees
It has been reported that, on average, female moths travel 1.7 km to lay eggs, which consists of the typical mass of eggs produced by these insects, which in this case can be up to approximately 220 eggs. A curious aspect is that the female generates some species of scales that cover the eggs and simulate pine shoots, thus she keeps them protected.
The species known as moths are animals that usually reproduce at night, so communication between males and females is mainly of chemical type through pheromones. Hours after reproduction and egg laying, the adults die.
How is the processionary caterpillar born?
The egg masses measure between 4 and 5 cm and, after the process of embryonic development within it, which as we have mentioned lasts from 30 to 40 days, they hatch processionary larvae or caterpillars After they hatch from the egg, they go through a series of phases or changes that consist of changes in appearance and size that the caterpillar undergoes. Thus, at birth, it is an opaque apple green color to later finish the process with some reddish spots on the back. On average, an adult caterpillar measures about 40 mm.
On the other hand, these caterpillars are covered with some hairs that are arranged on each of the segments of the body and are arranged in pair form. One particular aspect is that these hairs are highly stinging because they constitute a defense mechanism for the caterpillar, so that if they come into contact with the skin or mucous membranes of people or animals can cause severe allergic reactions, so they should never be touched. In case your dog has been in contact with a caterpillar, go immediately to the clinic. Also, don't miss this post: "The processionary and the dogs".
Metamorphosis of the processionary caterpillar
Metamorphosis is a transformation process suffered by certain groups of animals, after which there are absolute changes in both their anatomy and physiology, as well as in their way of life. The processionary caterpillar, as occurs in general in butterflies and moths, goes through this dynamic.
From February to April, the adult caterpillars come down from the trees forming striking and long processions, where one goes after another to bury themselves in the ground In the underground stage, the formation of the pupa or chrysalis occurs inside a cocoon that builds the caterpillar, the which is about 20 mm long and initially white-brown or yellowish in color, later changing to dark reddish. Within this cocoon the greatest transformation of the individual occurs, since this is where the processionary caterpillar becomes an adult, at which point it is already capable of flight. An adult has a wingspan of between 36 and 49 mm for females and 31 to 39 mm for males.
Although annually it is common for adults to emerge from the ground, in some cases a percentage of them do not, since they remain in a state where development is suppressed, known as diapause. In the case of this species, it can remain for several years in this phase of inactivity and emerge as an adult when it has undergone metamorphosis. Although it all depends on the environmental conditions, in general, the chrysalis stage lasts 2-3 months
How long does the processionary caterpillar live?
The processionary caterpillar has a long lifespan in this phase of its life cycle, if we compare it with other stages of its development, such as the adult, which does not exceed two days. In this sense, the caterpillar lives for at least 6 months from when it hatches until it buries itself to undergo metamorphosis.
