Lonomia electra — “assasin caterpillar”

“Assassin caterpillar” or, in Spanish, “taturana”—these are the names appointed to caterpillars of the genus Lonomia. It’s a name rightfully deserved: Species of the South American genus Lonomia are of medical significance due to their larval forms that may cause severe envenomation and even death to humans. Lonomia is often considered to be the most venomous genus of Lepidoptera, in particular L. obliqua, of which the hemotoxin is known to inflict severe envenomation and cause disseminated intravascular coagulation and haemorrhagic disease in victims.

Lonomia electra: amazing polymorphism showing a diversity in leaf camouflage

  • Difficulty rating:  Very easy (Easiest Saturniidae I bred in my life, I produced 28 adults from just 30 eggs, which I paired up and them kept breeding the same bloodline for over 1.5 years, producing over 300 individuals from that line over time. )
  • Rearing difficulty: 2/10 (From egg to pupa)
  • Pairing difficulty: 3/10 (Archieving copulations)
  • Host plants: Ligustrum, Prunus, Fagus
  •  Natural range:  Central America (Mexico, Costa Rica)
  • Polyphagous:   Yes 
  • Generations: Multivoltine (continuously brooded)
  • Family: Saturniidae (silkmoths)
  • Pupation:  Just lies on the floor and pupates right there, no silk spinning involved. Barely tries to burrow, but will try to hide under objects if they can
  • Special notes: Some Lonomia species are so toxic, touching them can result in death (L. obliqua / achelous)
  • Wingspan: 75 – 115 mm
  • Binomial name: Lonomia electra (Druce, 1886)
  • Health warning: Yes (Caterpillars have venomous spines that urticate. While the sting of Lonomia electra seems to be painful and otherwise harmless, some Lonomia species are recorded to be deadly upon skin contact – such as Lonomia obliqua and Lonomia achelous from Brazil and Peru. For that reason alone extreme care should be taken when handling any Lonomia, even the harmless species. You never know.)

Lonomia electra is the first species I have reared from this genus, and I fell in love with them. After studying their life cycle for 1.5 years and publishing this data, I now have extensive knowledge of this species. For those interested, here is some background reading and my publication: Up close and personal with venomous moths (AES) or for the .pdf file of the scientific publication: Click here for science!

These Lonomia from Costa Rica seemed to do quite well on Ligustrum ovalifolium in captivity. A lot of patience is needed to rear them as they larvae have an extremely slow development rate for a Saturniidae (I recorded over 100 days). Eggs seem to take a month to hatch aswell.

A larval congegration of Lonomia electra on my hand

Lonomia seems gregarious up until the final instar – this means they exihibit social behaviour for the entirety of them being caterpillars. They seem to tolerate being reared in plastic boxes with no ventilation at all quite well and withstand the highest degree of humidity. The rearing takes quite a lot of patience, however it seems that the pupae hatch quite fast (in a month). Pupae should be sprayed frequently as this species seems to prefer a higher degree of humidity and pupae dessicate rather fast. The larvae do not spin a cocoon before pupating; in fact they will lazily lie down on the floor and pupate on the spot. They do not even seem to attempt to burrow that much – I theorise that in their natural habitat the larvae pupate between the leaf litter covering the forest floor, giving them the opportunity to just lie down somewhere on the ground and pupate.

The adults seem to exihibit nice polymorhism. The females are always grey (though significantly larger than the males) while the males have two different colour forms: one orange/brownish rusty colour, and one lighter yellow form.

In the picture: one larger, greyish female (botton left) and three males (top) – showing both colour forms the males can have, the orange and yellow form.

Breeding Lonomia on Ligustrum was worthwhile, but in captivity they should eat Prunus and many other Rosaceae too, and perhaps  a wider range of host plants too since they are reported to be quite polyphagous. More experimenting will be needed to confirm other host plants. Pairings seems to last very short and unnoticable;  despite breeding these in very large numbers for three generations over a span of 1.5 years, never have I observed the actual pairing. Rearing this species in captivity should be easy even for beginners as long as they remember to keep the caterpillars together in one large group (the more the better, these thrive in bigger groups not small ones). They even seem to tolerate a bit of neglect and mold in their containers. From my experience it  was a very easy and hardy species to breed in captivity.


Picture: pupae of Lonomia electra

Final instar Lonomia larvae eating Ligustrum

Contact urticaria from touching Lonomia larvae. DO NOT TRY THIS AT HOME, SOME LONOMIA SPECIES CAN BE *DEADLY*. 

Dear reader – thank you very much for visiting! Your readership is appreciated. Are you perhaps….. 

Was this information helpful to you? Then please consider contributing here (click!) to keep this information free and support the future of this website. This website is completely free to use, and crowdfunded. Contributions can be made via paypal, patreon, and several other ways. 

The aim of this website is to provide information about many species of moths and butterflies around the world, with a slight focus on rearing them in captivity.

%d bloggers like this: