White Spotted Assassin Bug Care Guide (Platymeris biguttatus)

An extract from the posterior venom gland of this species kills a wax moth larva at 20.4 micrograms per gram of body weight, and the corpse is liquefied inside ten minutes. That figure comes from Gao and colleagues in 2022, and it is worth leading with because almost everything else written about this animal in the hobby is borrowed from a different species.

The short version

• A large African reduviid, Platymeris biguttatus (Linnaeus, 1767), matt black with two white forewing spots and banded legs.
• Five nymphal instars, from around 7mm to around 28mm, then the adult moult.
• Warm and mostly dry, heavily furnished with bark, fed on live insects. Straightforward to keep.
• Never handled. The risk is real but it is specific, and the popular version of it is wrong.

What you are actually keeping

A true bug with no jaws. The rostrum folds back under the head and carries fine stylets that go through an insect's cuticle, deliver saliva that dissolves the tissue, and draw the result back out. Everything about the animal is built around that one method.

Chłond, Bugaj-Nawrocka and Junkiert described the immature stages in 2015 and give five instars with measured body lengths: 7.2 to 7.5mm, 10.8 to 11.5mm, 13.7 to 14.8mm, 19.4 to 20.5mm, and 26.5 to 28.2mm. Knowing those numbers is more useful than it sounds, because it lets you tell a late nymph from a small adult by size and wing development instead of guessing.

Their museum material also settles the range, and it is wider than the hobby usually states. Specimens are recorded from Senegal, Gambia, Guinea, Mali, Ivory Coast, Togo, Benin, Niger, Nigeria, Chad, Sudan, Ethiopia, Somalia, the Democratic Republic of Congo, Uganda, Kenya, Tanzania, Zambia, Zimbabwe and Mozambique. That is West, Central, East and southern Africa, not a West African endemic.

The venom, and the number everyone repeats

You will read on almost every page selling this animal that it spits venom up to 30 centimetres and can blind a person. Both halves of that deserve unpicking.

Where the 30cm comes from

The measurement traces to Edwards, writing in 1961 about Platymeris rhadamanthus, the red-spotted species, and it was repeated by Walker and colleagues in 2019 who quote his account of jets propelled from the proboscis up to 30cm. Both of those papers studied rhadamanthus. Neither studied biguttatus.

That does not mean the white-spotted species cannot do it. Gao's team collected defensive venom from biguttatus by harassing the animals, so a defensive discharge plainly exists. It means the distance was measured in a relative and has been attached to this one ever since, and I will not print a number I cannot stand behind.

What is documented about the effects

Walker and colleagues applied sprayed venom to mammals. On intact skin it did nothing. Applied to eyes or mucous membranes it produced behaviour consistent with strong pain, and in cell work the venom caused calcium influx by lysing membranes of mammalian neurons. Human effects were not tested in that study, and the widely repeated blindness claim traces to an uncited line, not to any published case.

So the honest position is narrower than the scary version and more useful. Skin contact is not the hazard. Eyes and mouth are.

Two glands doing different jobs

Gao and colleagues separated the anterior and posterior chambers of the venom gland in this species and tested them independently. The anterior extract killed nothing and did not even slow the test larvae down, and it is dominated by hemolysin-like proteins, a venom protein family and serpins. The posterior chamber is where the lethality sits, running to serine proteases at over 40 per cent of its protein content, and it is the fraction that produces the ten-minute liquefaction.

Edwards had already described the endpoint in the red-spotted species in 1961: nerve and muscle excitability abolished quickly, then a general breakdown that spares only cuticle and collagen. A cricket does not so much die as get taken apart.

Safety, stated precisely

This is a no-handling animal, and the reason is not that it is aggressive. It is that the one genuinely risky exposure, venom reaching an eye, is exactly the exposure you invite by putting your face over an open enclosure.

• Open the lid at arm's length and work from the side, never leaning directly over the opening.
• Move animals on bark or with tongs. Never with fingers.
• Wash hands afterwards, and do not rub your eyes first.
• Venom in an eye or the mouth: irrigate at once with plenty of clean running water, then ring 111. No published human case exists to tell you how it will go, so do not wait and watch.
• Adults only in a house with young children.

An alarmed bug will usually warn you before anything else happens. They produce an audible rasping sound, and a 2025 study describes the stridulation apparatus across several Platymeris species and how it develops from nymph to adult. Take the noise as the signal to close the lid and come back later.

Housing

Airflow and hiding places decide whether this works, and the listing already covers the basic build. Two things are worth adding. The substrate should stay dry over most of its area, with a single corner kept faintly moist for eggs. And bark wants stacking upright, because a bug that feels exposed will climb the walls instead of tucking itself away.

Mine are held between 22 and 26°C from a thermostatted mat fixed to a side wall. Heating from below removes the cool floor the animals retreat to, which defeats the whole purpose of running a gradient.

They climb glass, they are quick, and a badly seated lid is the only realistic route out for an adult.

Feeding

Live insects, and they are not fussy. Roaches make the best staple because you can size them up in step with the nymphs; crickets, locusts and soldier fly larvae all get eaten. Keep prey no longer than the bug offering it.

Anything still walking about the following morning should come out. A loose cricket will chew on a bug that is mid-moult, and that kills more captive assassin bugs than anything else.

Twice a week suits an adult. Nymphs want feeding more often and put on size accordingly. One that has stopped eating and gone still is about to moult and needs leaving completely alone until the new cuticle has hardened.

Breeding

They will breed readily in a well-run enclosure and the hard part is keeping the young alive, not getting eggs. Females drop eggs into the substrate, which is the reason for keeping one corner slightly damp, and first instars are around 7mm and cannibalistic if crowded and underfed.

Rear them with more cover than you think necessary and more frequent small feeds than the adults get. Published rearing data for this species is thin, and figures you see quoted for egg-to-adult timing are mostly uncited, so treat any single number you read, including mine, as a starting point rather than a schedule.

Common questions

Can it hurt a person?

The defensive bite is reported as more painful than a bee sting. Venom on unbroken skin does nothing measurable. The exposure that matters is an eye or the mouth, and that is what the handling rules above are built around.

Does it really spit venom 30cm?

That distance was recorded for the red-spotted Platymeris rhadamanthus, not for this species. A defensive discharge is documented in the white-spotted bug, but nobody has published a distance for it.

Can I keep more than one together?

Adults are usually kept in groups without much trouble, given enough bark and enough food. Cannibalism is a function of crowding and hunger, and it shows up most in small nymphs.

Do I need a licence?

No. Nothing in UK law restricts this species and no permit applies. What does apply is the duty not to let a non-native animal get out, which for a climbing predator comes down to the lid and to checking it every time.

Is this a beginner animal?

It is easy to keep and it is unforgiving of casual handling, which is a different question. If you already run a feeder roach colony and you are comfortable working in an enclosure without putting your hands in it, yes. Ours are listed as white spotted assassin bugs.