Antherina suraka, the Madagascan savior of the rainforests

Antherina suraka (Boisduval, 1833), the Madagascan silk moth, is an endemic species to Madagascar and the Comoros islands.

Morphology of Antherina suraka

The Madagascan silk moth is a very colorful species, it shows a typical aposematic coloration, both in larvae and adults.

Larvae are initially blackish with orange dots; growing, they show a wide variability of colors. Last instar caterpillars are usually greenish with black and red markings. Adults present 1 large eye spots per each hind wing and have the ability to move them independently, resembling a sort of owl.

Distribution and biology of Antherina suraka

Antherina suraka is a silk moth species that belongs to the Saturniidae family, it’s the only species of the monotypic genus Antherina. Antherina suraka is widely distributed in Madagascar and in the Comoros Archipelago, located off the southeast coast of mainland Africa. The Madagascan bullseye moth shows a wide intraspecific morphology variation, probably due to adaptations to different habitats that occur in Madagascar, such as

–Evergreen humid forests: present throughout the eastern coast of Madagascar, from Sambava (North) to Taolagnaro (South). 

–The subhumid zone: that occurs in the mountainous central area dominated by sclerophyllous and rupicolous vegetation and grassland.

–The dry zone: that occurs in the western dry deciduous forests and plains from Vohemar (North) to Maromandia (South). 

–The subarid zone: located in the South Madagascar, characterized by dry deciduous forests and deserts.

–The mountain zone: that occurs in the mainland mountain zone of the island with an altitude exceeding 1.800 m.

Antherina suraka is widely distributed and it’s found in all bioclimatic zones and vegetation domains of Madagascar with different forms and subspecies. The typical form of Antherina suraka (A.suraka suraka) is found in the humid and subhumid zones and it’s characterized by very little variation in size and coloration pattern. The dwarf form australis occurs in the subarid and dry zones restricted to the western part of the island where deciduous forests occur, this form is very similar to the typical form but it’s just smaller in size. Antherina suraka comorana is a subspecies recorded in all four islands of the Comoros Archipelago in degraded forests and urban areas, it has a larger wingspan (125-130mm) than the typical form A.suraka suraka (105mm).

Why is this species so important?

Antherina suraka rearing as protection of the Madagascar’s rainforest

Three distinctive Antherina suraka populations resident in three different habitats show the importance of protecting forests in this incredible biodiversity hotspot, Madagascar.

Madagascar and the Comoros Archipelago are located off the southeast coast of mainland Africa and they’re part of a biodiversity hotspot in the western part if the Indian Ocean, presenting several plants and animals species found nowhere else in the world (Myers et al. 2000). This richness is highly threatened by deforestation and human exploitations.

Rates of deforestation are extremely high, they’re accelerating due to human population growth and global warming, which cause an increase in fires, drought and floods.

Agriculture is one of the main overexploitation of natural resources (Harper et al. 2007 , Malik 2013 , Vieilledent et al. 2013a). Nevertheless, different strategies have been designed to preserve what is left of this unique ecosystem. A valid approach consists in integrating local people with conservation strategies, teaching the importance of preserving the environment surrounding them.

Antherina suraka provides a valuable example of conservation strategies: the easily reared larvae spin gold-brown cocoons that are used by locals to craft silk products. The usage of A. suraka for sericulture, together with other unconventional silk moth species, is a component of community-based conservation. This strategy is offering alternative incomes to local communities, which rely on forest resources. For example, in Maroantsetra the last remaining large evergreen humid forest in Madagascar is found. In this area, the sericulture of A. suraka is an established activity for local people. The broad distribution of A. suraka in Madagascar and the use of different local host plants to raise them (Randrianandrasana et al. 2014) suggest that sericulture can be an effective way to preserve native forests in Madagascar.

Despite importing Antherina suraka from Madagascar can sound as a non-ethic action, selling them is pushing forward the local market. This way local breeders are able to directly sell to EU consumers without passing through an intermediary. Local breeding of this species for silk production or for other uses (human consumption or exporting cocoons) provides an ecologically compatible alternative to forest destruction and raise awareness of the rural communities in conserving their natural heritage.

Breeding and rearing Antherina suraka

Antherina suraka is a very easy species to rear as it feeds on a big variety of plants (including the most common hedges in Europe like Ligustrum, Prunus and Acer), it’s also very easy to pair too.

Eggs can be incubated in the classic Petri dish at room temperature, they will hatch in 1-2 weeks depending on temperature. During the first hours of its larval life, the caterpillars eats the eggshell, which consists in the first ingestion of proteins and other nutrients. In the early days of the caterpillars’ life, you can use an atomizer to spray a fine mist on top of them. The following day, when the larvae have drunk some water and eaten most of their eggshells, they can be moved in a rearing box.

The classic rearing method by using our rearing cage is perfect for that species. Here you can find an article that better explains how to rear Saturniidae in general. Don’t worry as A. suraka is fairly easy to rear and breed in captivity, thus is recommended for beginners.

The cocoon is spun among foliage, adults emerge in about 1-2 months. In some cases, they can remain quiescent for almost one year. This phenomenon is called dispersions over the time and serves to keep gene flow open between different generations over time. Spraying cocoons is not required, but it can help in synchronizing emergence.

Antherina suraka host plants

Antherina suraka is a polyphagus species that can feed up on 23 plant families. In captivity, the best host plants are: Ligustrum*, Prunus laurocerasus* and Nerium oleander*. Madagascan bullseye moth caterpillars will also accept Salix, Prunus ecc. Here is the full list.

*evergreen species

Antherina suraka eggs for sale

Antherina suraka eggs, the madagascan bullseye moth, are now available for sale in our shop, don’t miss them!

Sources:

Antherina suraka (Lepidoptera: Saturniidae): Ecology, systematics, and potential economic uses to promote conservation in Madagascar. Randrianandrasana, Maminirina. University of Illinois at Urbana-Champaign. ProQuest Dissertations Publishing, 2014. 3710947.