Phyllium philippinicum

Females: From the L3 stage, and certainly by L4, female Phyllium philippinicum are quite easy to identify. Their abdomen is noticeably broader than that of males, and their antennae are shorter and stumpier. As adults, females develop into large, heavy-bodied insects, especially when carrying eggs. They reach lengths of ~80-90mm. Their bodies are broad and rounded, extending outward well past the last set of legs before tapering back towards the tip of the abdomen. The overall colour is a light to lime green, though individuals may display subtle yellowish or brown edging along the abdominal lobes and wing margins. Occasionally, yellow females appear, but this species is not known for much colour variation. With age, females often show increasing amounts of brown mottling.

The wings are large, lying flat across the back and covering most of the body – often around 80%. Despite their impressive appearance, these wings are non-functional, as females are incapable of flight. The surface of the wings displays a striking network of vein-like patterns. The legs are adorned with large, leafy lobes, especially on the forelegs. The head is relatively small compared to the bulk of the body, with short cylindrical antennae that are far smaller than the long antennae of males. Just behind the head, the narrow prothorax forms a distinct neck-like section before broadening into the thorax and abdomen.

Males: By the L3 or L4 stage, male Phyllium philippinicum are also straightforward to identify, with their slimmer abdomens and noticeably longer antennae. As adults they reach lengths of ~55-60mm and are slender and lightweight. Their abdomen is narrow and elongated, tapering smoothly to the tip, giving them a streamlined profile. The forewings are reduced, covering only part of the thorax, while the hindwings are long covering the entire body, transparent, and fully functional, enabling strong flight.

The legs of males are long and thin, with only small lobes on the femora and tibiae, far less developed than in females. Their colouration is usually a uniform lime or bright green, sometimes with yellowish highlights along the wings or legs, but without the mottling often seen in females. The head is proportionally larger than that of females and bears long, feather-like antennae.

Adults, by contrast, are calm and docile. Both males and females spend most of the day motionless on their food plants, blending seamlessly with the leaves around them. They become active at night, feeding and moving under the cover of darkness. If you listen closely at dusk, you can even hear the faint rustling of them feeding.

When it comes to handling, this species is excellent for beginners. Females in particular are very tolerant, often content to sit quietly on your hand and explore at their own pace. Males can also be handled, though they are more likely to take flight if startled, using their fully functional wings.

Phyllium philippinicum are not aggressive towards one another, and multiple males can be kept together without risk of fighting. The only minor damage that may occur is accidental as sometimes one insect mistakes another for a leaf and gives a small nibble at the abdomen or wings, a testament to just how convincing their camouflage is.

Overall, Phyllium philippinicum are strong feeders, reliable breeders, and display a range of behaviours that make them both fascinating and easy to keep in captivity.

Unlike some other leaf insect species, Phyllium philippinicum young nymphs have a strong feeding instinct. Some keepers encourage feeding by trimming the edges of leaves with scissors, though in my experience this has never been necessary. A gentle breeze or the use of a low-speed fan can also stimulate feeding at any life stage by mimicking natural airflow and encouraging activity.

To keep food plants fresh for longer and reduce maintenance, I recommend standing the cuttings in a pot of water inside the enclosure. Always cover or narrow the opening of the container to prevent the leaf insects from falling in and drowning. A fresh source of food plant should be provided at all times. On average, clean out the enclosure once a week, replacing old food with fresh cuttings and adding new substrate (I recommend paper towel) to remove frass. This weekly maintenance also provides a good opportunity to collect any eggs that may have been laid.

Temperature: Maintain temperatures anywhere between 18°C and 28°C during day and night. A slight cooling after dark is beneficial, as it mimics the natural drop they would experience in the wild. For most homes, normal room temperature is perfectly suitable.

Humidity: As with most phasmids originating from Asia humidity plays a huge role in the development of leaf insects. Aim for levels of at least 60%, with 70–80% being ideal. To achieve this, spray the enclosure once or twice daily, focusing on the food plant. Proper moisture is essential for successful moulting, a process by which the leaf insect grows and develops. It also seems to benefit adult males and younger nymphs, which will often drink directly from water droplets on the leaves. Therefore, when misting, use dechlorinated water to avoid potential harm. Keep in mind it is easier to maintain a higher humidity in a glass enclosure (such as an Exo Terra) rather than a netted enclosure.

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

For adults, a minimum enclosure size of 30 × 30 × 45 cm (width × length × height) is recommended and will comfortably house two to three adult pairs. Personally, I prefer using netted enclosures of 40 × 40 × 60 cm, as the extra space it provides is considerable.

For adults a minimum size of 30cm x 30cm x 45cm (width x length x height) is recommended for this species which can fit two to three adult pairs comfortably. I like to keep mine in 40cm x 40cm x 60cm netted enclosures for even more space. The more height available, the better, as this allows the leaf insect more room when hanging down during moulting. More vertical space is always beneficial, since leaf insects hang downwards during moults and need clearance to shed successfully.

Proper ventilation is equally important as maintaining high humidity. Ensure ample airflow to prevent stagnant conditions. 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.

Females typically lay ~3 eggs per day over a period of about three months, dropping them to the floor of the enclosure with a whip-like movement of their abdomen. The eggs of Phyllium philippinicum are mid-brown to dark brown in colour and have an irregular, wrinkled, seed-like appearance. Their surface is deeply ridged and grooved, giving them a textured, fibrous look rather than being smooth or lumpy. The overall shape is oval to kidney-like, with no obvious symmetry. A key feature of this species’ eggs is the presence of fine, hair-like frills along the surface. Under normal conditions these frills are often subtle, but with increased humidity they absorb moisture and swell outward, becoming more prominent and noticeable. This appearance makes them easy to identify compared to frass. The eggs measure ~4.4mm in length and ~2mm in width.

Incubation usually takes 4–5 months, though in cooler or drier conditions this may extend to 6–8 months. This is still relatively short compared to many other leaf insect species.

Maintain the eggs on a moist substrate such as paper towel, coconut fibre, or preferably vermiculite, at a stable temperature of 20°C–26°C. Avoid large fluctuations in temperature, as stability is important for development. Ensure the eggs receive daily light exposure and monitor regularly for mould. If mould appears 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, but if the mould is extensive, it's best to discard the egg to protect the others.

I personally incubate my Phyllium philippinicum eggs using the vermiculite bottle cap method. For detailed steps on this technique and more information on phasmid egg care, please refer to my article. To maintain high humidity levels of around 80%, I spritz the vermiculite base with dechlorinated water 2–3 times per week.

In the absence of males, female Phyllium philippinicum can reproduce via parthenogenesis. This process produces unfertilised eggs that hatch into genetic clones of the female. I also have an article on this process!