Pachymeta contraria

Pachymeta contraria is a great species of lappet moth found in Cameroon, Congo, Kenya, Nigeria, Tanzania and Uganda.  “Great” in this context is not subjective: with a wingspan up to 150mm, it is one of the biggest Lasiocampidae. The moths appear to be uniformly  (light) brown but upon closer insect they have a few very subtle white and grey patches. The most unique feature is the striped abdomen; the abdomens are white with black (female) or brown (male) stripes. This is most likely a warning pattern that scares away predators. When the moths are disturbed, they lift their wings to reveal the abdomen as a threat. While the moths are actually harmless, this tricks certain enemies into thinking they are potentially harmful creatures.

Males are less than half the size of the females, which is normal for many Lasiocampidae species. Before this captive rearing experiment, nothing was known about the life history of Pachymeta contraria at all, and it’s ecology remains quite obscure and unknown. In captivity the caterpillars were not very picky and ate a variety of food including bramble (Rubus), oak (Quercus), firetorn (Pyracantha) and more plants; mainly those from the Fagaceae and Rosaceae families. Quite interesting was their long development time – raising this species from young caterpillars to cocoons took 4.5 to 5 months.


Pachymeta contraria


Pachymeta contraria

  • Difficulty rating: Moderate – Larvae test your patience by growing very slowly [3 to 6 months!] depending on food plant and temperature.  
  • Rearing difficulty: 6.5/10 (From egg to pupa)
  • Pairing difficulty: 6.5/10 (Archieving copulations)
  • Host plants:  Quercus (oak), Fagus (beech), Rubus (bramble), Pyracantha (firethorn) in captivity. What they prefer in the wild is not well-known but they are perhaps similar plants, from atleast the families Rosaceae and Fagaceae. 
  •  Natural range:  Cameroon, Congo, Kenya, Nigeria, Tanzania and Uganda
  • Polyphagous:   Yes  
  • Generations: Multivoltine (continuously brooded)
  • Family: Lasiocampidae (eggar moths)
  • Pupation:  Cocoon (silk encasing)
  • Prefered climate:  The average(!) temperature where the eggs were collected for breeding is  23.7 °C – it is constantly warm, but the humidity and environment varies since they experience dry and wet seasons. 
  • Special notes:  Spends a very long time as larvae, in captivity potentially 3 tot 6 months depending on food plant and temperature. In the first instar the caterpillars are more picky, mine only accepted firethorn (Pyracantha) as hatchlings and nothing else, but the larvae grew to be more open minded and polyphagous as they became older and more mature. 
  • Wingspan: 60mm-150mm
  • Binomial name: Pachymeta contraria (Walker, 1855)

The females of Pachymeta contraria lay about 50 to 200 eggs depending on the size and the vitality of the female. The eggs are pale white, almost completely round, and have a visible black micropyle. Multiple weeks after laying them, the eggs hatch and small black and white striped larvae appear from them. After wandering around for some time, these larvae eventually settle down on their food plants in order to start eating. It seems that the first life stages prefer different food plants than the mature caterpillars; they did not accept other plants than Pyracantha (firetorn) and Crataegus (hawthorn), while the mature larvae fed on a wide range of plants including Quercus sp. (oak), Prunus sp.(cherry), and Rubus (blackthorn). While this statement is speculative, they seem to be fond of Fagaceae and Rosaceae and potentially feed on these plant families in the wild. However, it’s ecology and life cycle in the wild remains largely obscure and unknown.

Pachymeta contraria female with eggs

From the eggs, small white larvae with black stripes and large grey tufts hatch in a few weeks. The larvae are solitary and will wander a lot before settling down in the vegetation to start feeding on their host plants. The small caterpillars can be raised in airtight plastic containers.

Pachymeta contraria  L1

Pachymeta contraria L1

After eating a lot, the caterpillars will shed their skins in a few days time and change their appearance; they now become fluorescent green, with a blue/grey head capsule and bright red marking on their thorarical segments, behind the head capsule.

Pachymeta contraria L2

The third instar is very similar to the second instar and shows the same red markings (although reduced), blue head capsule. However, the third instar seems to be more polyphagous: they accepted Quercus (oak) and Rubus (bramble) while the first and second instar did not. Perhaps, as they mature, they become more ‘open minded’ and exihibit a higher degree of polyphagy. The first three instars can be raised in plastic boxes without much problems, they seem relatively tolerant of less ventilation and higher humidity.

Pachymeta contraria L3

Pachymeta contraria L3

The fourth instar looks completely different. It has a creamy white body covered in grey stripes and hair, giving it an overall grey appearance; it also has large tufts next to its head capsule that it can direct forward in order to obscure its head and blend in with the surroudings.

Pachymeta contraria L4

Pachymeta contraria L4

The fifth instar looks like an elarged version of the fourth instar. By now they are covered by sharp spines that will cause skin irritation if touched; the caterpillars are quite agressive too when startled because if they are stressed they will attempt to attack the source of irritation and ram their head and bodies into the source of irritation, embedding the sharp spines into their potential attacker.  From the fifth instar and beyond they should recieve a little bit more ventilation and free space to roam; such as a cage or box with the lid removed.

Pachymeta contraria L5

Pachymeta contraria L5

The sixth instar is very large with larvae reaching a size of about 14cm. While it looks similar to the previous instars, it is quite impressive to see how long these large, elongate larvae can become. The caterpillars that develop into males are also clearly smaller than the female larvae in this stage, for the female larvae outsize them by a few centimetres. In the sixth and final instar, the sharp spines on their bodies are very painful and may cause skin irritations, autoimmune responses and mild inflammation. I recall accidently grabbing one that was hidden on a branch of oak tree for it was so well camouflaged that I did not notice it; my hand actively hurt for a full week. Despite that, they are relatively harmless if they are not handled and by no means do they need to be touched or handled. If seriously disturbed, the caterpillars will also let go of the surface they are sitting on and fall to the floor while rolling around.  To see this behaviour click here (link to a video).

Pachymeta contraria L6

Pachymeta contraria L6

Pachymeta contraria L6

The total rearing of Pachymeta contraria takes a lot of time and patience, for larvae seem to start cocooning after being 3 to 5 months old. The development time is also affected by warmth and food plant quality; in colder conditions, it may take the larvae even a longer time to grow, potentially up to half a year (6 months). If kept warm, they can perhaps be raised in about 3 months time.

Pachymeta contraria cocoons

When finished, they will spin an elongated, oval cocoon make of papery thick silk with and orange/yellowish sandy colour. Interestingly the cocoons seem to have an ‘opening’ on one side that allows the moths to escape the cocoon more easily. While the opening is still sealed from the inside by a layer of silk and the cocoon is fully closed, the silk at the top of the cocoon is very thin. While the silk of the entire cocoons is overall very thick and though, this thin layer allows the moths an easier enclosure, much like an escape hatch.

Pachymeta contraria cocoons

Inside the cocoon, wine red pupae can be found. The female pupa is visibly bigger than the male with thinner antennae. While the pupae are normally never exposed, they were removed from their cocoons by me for photography and documentation purposes.

Pachymeta contraria male (top) and female (bottom) pupa

Video:

After about 1.5 to 2 months time, the moths will hatch from these cocoons if kept properly warm and humid. It is unknown if cocoons can diapause through the dry season, but in captivity it appears to be continuously brooded.

The adults are nocturnal. The females will rarely move unless disturbed, but males will be very active at night and seek out the females by smell (pheromone). They can be paired in net cages (aerariums) in warm breezy conditions. Females will become more active and restless after pairing and start laying a lot of eggs. Adult moths of neither sex are able to feed and have a lifespan of about 6 to 14 days.

The females are gigantic with a 15cm+ wingspan in some cases. They are nearly uniformly chocolate brown although upon closer inspection, some obscure grey lines and white/grey patches on their wings can be seen. She is very heavy with a large, hairy abdomen – females have white abdomens with black stripes, and if they feel threatened they can lift their wings to reveal the abdomen, which could function as a warning mechanism that discourages predators.

Pachymeta contraria female

Pachymeta contraria female

Pachymeta contraria female

Males are half the size of females and have a wingspan of about 75mm. They have very large and noticeable antennae. They are brown like the females but are a slightly darker shade of brown. The males have striped abdomens (with brown instead of black stripes) that they use as warning signal; sometimes, when disturbed, the males will lift up their hindwings in order to show off the striped abdomen. If further molested they can also drop themselves to the floor and flop around.

Pachymeta contraria male

Pachymeta contraria male

Pachymeta contraria male

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