Malayan Jungle Nymph (Heteropteryx Dilatata)

The Malayan Jungle Nymph (Heteropteryx dilatata) is a spectacular and distinctive phasmid species native to Malaysia. This stick insect has gained popularity among enthusiasts due to its striking colours and unique appearance. Furthermore, the adult female is the heaviest known phasmid and the species has a longer lifespan compared to other phasmids.

Nymphs: Newly hatched nymphs are already considerable in size, measuring about 25mm in length. Nymphs range from beige to tan to dark brown in colouration. They display an amazing variety of patterns throughout their early stages, including white stripes, orange adornments, and darker markings.

Females and males can be sexed from a young age: females are typically beige or brown, while males are dark brown with beige segments in a regular pattern. A few moults before maturity, females change from beige to bright green or yellow. In total, nymphs undergo about 6 moults before reaching maturity.

Females: This species exhibits extreme sexual dimorphism. Adult females are wide-bodied and come in beautiful shades of lime green and occasionally bright yellow. They are large phasmids, reaching ~150-180mm in length. Their bodies are covered in small, sharp spines, which are particularly prominent on the underside of the legs and are reddish in colour. Females can weigh up to 50g, making them the heaviest phasmid in the world and far too heavy for flight. Nevertheless, they have two pairs of rudimentary wings covered with small spikes, which lie flat along their back.

Males: Adult males are significantly smaller and narrower than females, reaching 90-100mm in length. They are brown in colour with developed, long wings that extend down each side of the body to the abdomen. Males are lighter than females and capable of flight. The hindwings of both sexes are an amazing magenta or pink colour, with males also displaying black patterning. Both sexes have long, dark-banded antennae.

The lifespan of this species is approximately 16 to 24 months. Males mature faster than females and typically have a lifespan that is a few months shorter.

The Malayan Jungle Nymph is a nocturnal species, remaining docile during the day and becoming active at night for feeding, egg-laying, and movement. This species is naturally aggressive, especially as adults, and possesses a range of defence mechanisms when threatened.

When feeling endangered, they first place their head close to the ground and raise their hind legs. The spines on their legs can clamp onto skin when touched and potentially draw blood, so caution is essential when handling this species. It is advisable to wear gardening gloves for protection. Males have an additional defence tactic: they can throw themselves on their back while vigorously fluttering their wings. Females, on the other hand, can produce a hissing-like rustling sound with their wings.

While males can fly, their flight is limited to short glides, as they are not strong flyers.

Nymphs and juveniles are very agile, lively, and more adept at climbing compared to their adult counterparts. When sensing danger, young Malayan Jungle Nymphs will drop to the ground and remain motionless, mimicking a twig.

Malayan Jungle Nymphs primarily feed on bramble, raspberry, rose, oak, and eucalyptus species. When selecting food plants, ensure they are free from insecticides or other harmful chemicals.

Before offering food to your phasmid, it's advisable to wash the cuttings with water.

To maximise plant longevity and minimise maintenance, consider keeping the food plant in a pot of water within the enclosure. However, take care to cover or reduce the size of the pot's opening to prevent the phasmids from accidentally falling in and drowning.

Always provide a fresh source of food. On average, clean out the enclosure once a week, replacing old food with fresh offerings and adding new substrate to remove waste. This weekly maintenance is also an ideal time to collect any eggs that have been laid.

The Malayan Jungle Nymph thrives in a spacious and warm environment.

Temperature: Maintain temperatures between 24°C to 28°C during the day, allowing them to cool to 20°C - 22°C at night. However, this species can usually be kept at room temperature without issues. The warmer they are kept, the quicker they develop.

Humidity: This species appreciates high humidity levels of approximately 70-80%. To achieve this, spray the enclosure once or twice daily, focusing on the food plants. Proper moisture is essential for successful moulting, the process by which the phasmid grows and develops. When misting, use non-chlorinated water to avoid potential harm. To maintain high humidity, consider using paper towels or coir (coconut fibre) as a substrate.

The Malayan Jungle Nymph enjoys drinking occasionally, so providing water droplets through regular misting is beneficial.

Lighting: Mimic natural day/night cycles using either natural or artificial lighting.

When housing the Malayan Jungle Nymph, a minimum enclosure size of 40cm x 40cm x 45cm (width x length x height) is recommended. As this is a large species, their living space should reflect their size. Additional height is beneficial, as it provides ample space for the insects to hang vertically during moulting.

It's important to implement secure, strong branches throughout the enclosure due to the species' significant weight. These branches help support the phasmids weight and allow them to climb effectively.

Proper ventilation is equally important as maintaining high humidity. Ensure ample airflow to prevent stagnant conditions and mould developing. At a minimum, a mesh or netted roof is recommended. Netted material also provides easier grip for the insects, which is especially beneficial during moulting when they often hang from the ceiling.

Breeding Malayan Jungle Nymphs is relatively straightforward, as they readily reproduce under suitable conditions once they reach maturity. You may observe males "piggy-backing" on females during mating.

Unlike some other phasmid species, the Malayan Jungle Nymph cannot reproduce via parthenogenesis, so sexual reproduction is necessary for viable eggs to be produced.

Although this species is largely arboreal, females will descend to the ground to lay their eggs. They prefer to lay in soft substrate, so providing a small container with damp substrate, such as sand mixed with coir, is recommended. This container should have a depth of at least 50mm and can be placed anywhere on the enclosure floor - the female is clever enough to find it. This method allows for easy relocation of the eggs for incubation.

Females lay their eggs using the ovipositor at the end of their abdomen and their hind legs. They typically lay in batches every few days, with each female producing approximately 100-150 eggs over her laying life.

The eggs are fairly delicate. They are oval-shaped, resembling seeds, and measure about 10mm in length. When damp, they appear brown or dark grey; when dry, they are pale slate-grey with a smooth texture.

Incubation for this species is notoriously long, requiring patience as it can take 12-18 months until hatching. Maintain the eggs at temperatures similar to those for juveniles and adults, ranging from 24°C to 28°C. Lower temperatures will extend the incubation period. To prevent dehydration, keep the eggs moist. Ensure they receive daily light exposure and regularly check for mould growth.

If you notice mould on an egg, carefully remove it from the container. You can attempt to gently wipe off the mould using a clean paper towel or soft brush. However, if the mould growth is extensive, it's best to discard the egg to protect the health of the others. If mould has developed, thoroughly clean the container housing the eggs. Pay particular attention to the substrate, especially if using paper towels. Vermiculite or coconut fibre substrates are less prone to mould growth.

The hatch rate for this species is relatively low at approximately 40-60%, but after hatching, they have low mortality rates.