Giant Lime Green Stick Insect (Diapherodes Gigantea)

The giant lime green stick insect (Diapherodes gigantea), native to several Caribbean islands including Saint Vincent and Grenada, is one of the more popular phasmids in culture. Their popularity stems from their impressive size, striking lime green colouration, and relatively simple care requirements. In Germany, they are aptly nicknamed 'walking pea' due to this vibrant green.

Nymphs: Newly hatched nymphs measure ~30mm in length and display a light brown colouration with green heads and legs. Following their first moult, they already start to display the characteristic lime green colouration all over. Females reach maturity after ~6 months, while males mature slightly earlier at ~5 months.

Females: As their name suggests, giant lime green stick insects are among the larger phasmid species, with adult females reaching impressive lengths of ~150-160mm. They boast a stunning light green colouration that covers their entire body. This body is cylindrical and bulkier compared to other phasmid species. Their bodies and legs are adorned with small spines along the edges. Bright yellow eyes and yellow antennae, extending to ~70mm in length, further enhance their appearance. Their wings are small and vestigial, rendering them incapable of flight.

Males: This species exhibits fascinating sexual dimorphism. Male giant lime green stick insects are smaller and slenderer than their female counterparts, typically measuring ~110-120mm in length. Males display a predominantly brown colouration, accented with green spots and highlights. Their brown antennae are longer than those of females, reaching ~80mm in length. Both fore and hind wings are well-developed, featuring a distinctive brown colour with a white band along the outer edge. These wings are long, covering almost the entire abdomen. While functional, they are not suitable for sustained flight.

Females live for ~14-18 months.

Males live for ~11-12 months and mature faster than females.

Giant lime green stick insects are primarily nocturnal, exhibiting increased activity and feeding during night-time hours. As one might expect given their substantial size, they are a relatively slow-moving species and generally docile, making them easy for gentle handling.

These insects are known for their deliberate, measured movements and distinctive gait. While males possess fully developed wings, they rarely engage in true flight. Instead, when threatened, they may employ a combination of jumping and gliding to evade potential danger. In many phasmid species, nymphs tend to be more hyperactive and skittish. However, giant lime green stick insect nymphs are on the calmer side.

Giant lime green stick insects primarily feed on bramble, eucalyptus, and oak species. It's important to note that young hatchlings may exhibit a strong preference for eucalyptus, sometimes exclusively accepting this food source in their early stages. As they progress through later instars, their dietary flexibility increases, and they readily accept bramble leaves. 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.

Young nymphs can find it challenging to kick start feeding. To assist them, carefully cut the edges of leaves using scissors. This simple step can greatly improve nymph survival rates.

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 giant lime green stick insect is an easy-care phasmid and therefore great for beginners.  

Temperature: Maintain temperatures between 20°C to 27°C during the day and night. This species can be kept at room temperature without issues. The warmer they are kept, the quicker they develop.

Humidity: This species appreciates average humidity levels of approximately 60-70%. To maintain appropriate humidity, mist the enclosure once a day, focusing on the food plants. Adequate moisture is crucial for successful moulting, which is essential for the insect's growth and development. Use dechlorinated water for misting to prevent potential harm. A substrate of paper towels or coir (coconut fibre) can help maintain higher humidity levels.

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

Due to their substantial size, giant lime green stick insects require spacious enclosures. A minimum size of 60cm x 45cm x 45cm (width x length x height) is recommended. Additional height is beneficial, as it provides ample space for the insects to hang vertically during moulting. To accommodate their larger size, it's advisable to furnish the enclosure with substantial sticks or branches, offering secure gripping surfaces and support.

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 giant lime green stick insects is relatively straightforward, as they readily reproduce under suitable conditions once they reach maturity. During mating, you may observe males "piggy-backing" on females, a behaviour characteristic of many phasmid species.

This species reproduces sexually and asexually. can reproduce both sexually and asexually. In the absence of males, females can produce offspring through parthenogenesis, laying unfertilized eggs that develop into genetic clones of themselves.

Following successful mating, females typically begin laying eggs a few weeks later, depositing 1-2 eggs per day. Over their lifetime, they are prolific egg layers, producing hundreds of eggs. The eggs are distinctive: oval-shaped, approximately 5mm in length, dark brown in colour, with a slightly textured surface. Females deposit these eggs on the enclosure floor using a whip-like movement of their abdomen.

Incubation takes about 8-9 months at a humidity of ~60% and temperature between 20°C and 27°C. Lower temperatures will extend the incubation period. 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 high at approximately 75%, and after hatching, they have low mortality rates.