LONOMIA: CHARACTERISTICS, SPECIES, NUTRITION, REPRODUCTION - BIOLOGY - 2025

Lonomia is a genus of Lepidoptera native to South America. The species that comprise it are known because some of their caterpillars are highly poisonous, especially those of Lonomia obliqua and Lonomia achelous.

The larvae, called taturanas, hatch from the eggs that were deposited on the leaves of the trees. These are characterized by their numerous dorsal spines, at the end of which they have glands that secrete a very powerful poison. Just touch them so that this toxic substance is released.

Lonomia obliqua Source: Santa Catarina Toxicological Information Center

Butterflies are brown in color and when they spread their wings they look like dry leaves. They have a longevity of approximately seven days, being able to spawn up to 122 eggs in that time.

Accidents occur when people handle logs, branches or foliage, where the taturanas are found. In this way, the poison enters the bloodstream and can cause damage to the body.

Small amounts of this could cause inflammation in the affected area, hives and burns to the skin. However, in large proportions it could cause serious damage, such as hemolysis, internal bleeding and kidney failure, even death.

characteristics

Larvae

The larvae of this genus are between 6 and 7 centimeters in length. Its color is brown, with greenish and ocher hues. Longitudinally they have dark brown striations. In addition, in the dorsal area of ​​the third segment of the thorax they have a small white spot.

Their habits are gregarious. During the night they usually feed, consuming the leaves of the plants where it lives. During the day, they form groups, usually on tree trunks. When they move, they do it en bloc.

Thorns

The larvae have pointed and branched, brownish-green spines, which are present in the different larval stages. Said bristles are hard outgrowths of the cuticle that are distributed dorsally along the body, in a symmetrical manner.

At the tip of these is a special gland, which produces the poison that characterizes the genus Lonomia. Research confirms that once the poison is produced, it is stored at the end of the spines.

It only takes a little rub for the tip to break off and the toxic substance is released. However, not all sows have poison. Some possess and release hemolymph, which is a greenish fluid responsible for transporting nutrients through the animal's body.

Adult butterflies

Males are smaller than females and have quadripectinate antennae. In relation to the wings, the dorsal face is yellow, with dark transverse lines. In contrast, the underside is light yellow, with a few dark ones.

On the other hand, the wings of the females have a grayish brown dorsal face, delimited by dark stripes. The ventral part is yellowish brown, with light ash-colored spots. The antennae of the females are filamentous.

The poison

This substance is composed of toxins, such as the activators of clotting factors II, prothrombin and factor X. In addition, it has fibrogenases, serpin and hyaluronidases. In the species L. achelous, toxic substances such as lonomin, types II, III, IV, V, VI, VII are present.

Distribution and habitat

Species of the genus Lonomia are found throughout South America, Central America and in Mexico.

Lonomia achelous is found mainly in French Guyana and Venezuela, although there are reports that report its presence in Peru, Paraguay, Colombia and Ecuador.

In relation to the Lonomia obliqua, it lives in Paraguay, Uruguay, Argentina and southern Brazil, in the states of Paraná, Rio Grande do Sul and Santa Catalina.

In Colombia, in the departments of Amazonia and Casanare, there are clinical cases attributed to L. descimoni. Likewise, the Lonomia occidentalis is found in the Colombian departments of Antioquia and Caldas and the Lonomia inexpectata, in Villavicencio and Cundinamarca.

Habitat

Fire caterpillars, as those of this genus are called, develop at temperatures around 13 and 24ºC, and in areas with high humidity, between 64 and 92%.

Lonomia larvae live in various trees, such as cedar, fig, ipe and avocado. Also in the banana and the gomero, among others.

Other host plants are wild trees, such as aroeira and arctium. In addition, it lives in fruit trees such as pear, peach, plum and avocado.

Habitat expansion

Some of the species of this genus, especially the Lonomia obiqua, have spread to other regions, different from those that naturally develops.

They generally inhabit forests, forming communities in tall trees. However, in recent years accidents have been reported in various urban areas, where even some patients have died.

One of the factors that could be triggering this territorial expansion is deforestation. Vast areas of the forest were cut down to be used for plantations and for building cities.

When the natural habitat of the Lonomia changed, due to the disappearance of some of its fundamental foods, such as aroeira and cedar, this insect moved towards the fruit trees of the houses.

Species

Lonomia descimoni

Nutrition

The larvae of the taturana live mainly in fruit trees, whose leaves become their food. Larger caterpillars eat leaves at their edges, leaving thicker veins. In contrast, small larvae make small holes in the blade, thus leaving the skeleton intact.

The nymphs feed on plants, among which are avocado, guava, mango, peach, coffee and some citrus fruits. During the feeding phase, they store energy in their body.

This is because, from the pupal stage, the species of the genus Lonomia do not feed. The way to obtain the nutrients to live is through that accumulated fat.

The same situation occurs in adult butterflies, since their mouthparts are reduced, being unable to feed themselves in this way. For this reason, the life span of this insect is short, between 7 and 10 days. However, the energy allows the butterfly to mate and lay eggs.

Reproduction

Lonomia is an oviparous lepidopteran, with a complete metamorphosis. For this reason, its development occurs in several stages, morphologically differentiated. Development time may vary for each species.

However, there are factors, such as the availability of food and the temperature of the environment, that can influence this process. The life cycle comprises 4 phases: egg, larva, chrysalis or pupa, and butterfly.

Egg

The adult females deposit the eggs, generally in groups of up to 70 of these, on the leaves of the host plant, which will later serve as food for the nymphs. The eggs are elliptical in shape and hatch at approximately 17 days.

Larvae

They live in a group and remain in this phase for 3 to 6 months. This wide range is due to the characteristics of each species and the influence of environmental variables, such as humidity and temperature.

When they hatch, they devour the shell of their eggs, which contains important elements for their development. Later, they feed on leaves, consuming them at night.

During this stage they make about six molts, to later transform into pupae. When that time approaches, they are usually located at the base of the trunk, close to the ground. In addition, they build a cocoon that protects the chrysalis.

Pupa

The pupa can measure about 3 centimeters and is dark brown, with longitudinal dorsal stripes. When the larvae become chrysalis, they do so on the ground, on the leaves. These remain dormant until they transform into butterflies.

Butterfly

At the end of the pupal stage, the animal pumps hemolymph to all the extremities, in order to expand the body and break the chrysalis. After this, its body is soft and the wings are wrinkled. Later, your skin hardens.

References

1. Carrijo-Carvalho LC, Chudzinski-Tavassi AM. (2007). The venom of the Lonomia caterpillar: an overview. Recovered from ncbi.nlm.nih.gov.
2. Beatriz Camargo. (2003). Research identifies reasons for the population expansion of Obliquity Lonomia. Recovered from saopaulo.sp.gov.br
3. Hudson Barreto Abella, Joâo Batista Torres, Maria da Graça Boucinha Marques, Alaour Candida Duarte, Elvino Barros (2005). Manual of Diagnosis and Treatment of Poisonings by Lonomia. Recovered from sertox.com.ar.
4. SIB (2019).Lonomia obliqua. Recovered from sib.gob.ar
5. Canter, HM, Santos, MF, Moraes, RHP, Kelen, EMA, Cardoso, JLC, Paula, MA, Perez Junior, JA (2008). Taturanas. Recovered from infobibos.com.
6. Lisete Maria LoriniI, Gisele Sana RebelatoII, Juliano Bonatti (2004). Reproductive parameters of Lonomia obliqua Walker, 1855 (Lepidoptera: Saturniidae) in laboratory. Scielo. Recovered from scielo.br.
7. City of São Paulo (2018) Taturanas. Recovered from prefeitura.sp.gov.br
8. Albert Alejandro Ávila, Atilio Moreno, Andrés Garzón,
9. Álvaro Andrés Gómez (2013). Lonomic accident
10. Scielo. Recovered from scielo.org.co.
11. Gómez JP. (2014) Lepidopterism and erucism in Colombia. Biosalud Magazine. Recovered from scielo.org.co.
12. Rodrigo de Oliveira Andrade (2017). Spines filled with poison. Recovered from revistapesquisa.fapesp.br.