Leaf insects can be surprisingly expensive pets to buy due to their ongoing rarity in the hobby. They’re also quite short-lived, rarely living for more than a year between hatching and death.
This means that breeding leaf insects should be considered a vital part of keeping these stunning insects. Done properly, you will soon be able to expand your collection, ensuring that your colony never dies out, and helping other hobbyists to enter the wonderful world of leaf insect care.
Sexing Leaf Insects
Leaf insects are relatively easy to sex, as the males and females have entirely different body shapes from an early age. As adults these differences are even more obvious. Females are broad and considerably larger than the more delicate-looking males. The adult males, in contrast, are narrow and have long, fragile-looking wings.
Identifying adult pairs is therefore very easy itself; you’re just looking for fully-winged individuals, some of whom are broad (females) and some of whom are narrow (males).
One potential problem when breeding leaf insects is that males tend to mature faster than females. As they are smaller at adulthood, they also need fewer moults to achieve adult size. As they may only live for a few months after reaching maturity, it is not unheard of for the males of a colony to due of old age before the females actually mature.
If you plan to breed leaf insects it therefore makes sense to either (a) start with purchasing mature specimens of both sexes from a breeder, or (b) to start with a large number of eggs/youngsters. In this way you maximize your odds of having at least one adult of each sex maturing at the same time.
Rest assured, a single mated female can produce an astonishing numbers of eggs and guarantee the survival of your colony into the future.
The Breeding Cage
Breeding leaf insects is reasonably simple, as rarely do they need any encouragement. Simply having a number of adult pairs in a single cage will normally be enough to start the breeding process.
Leaf insects are not aggressive or possessive towards one another so a large cage can house dozens of adults. Typically you will start to observe matings soon enough, as the males climb on top of the females, and gently wrap their abdomen around to connect with the female’s.
Soon afterwards, eggs should start to be deposited.
While the process of getting your leaf insects to mate is unlikely to be problematic, collecting the eggs can become so. Eggs left in the cage rarely hatch as well as those that have been carefully collected and incubated properly.
As a result the following system starts to work well. It starts with a large mesh cage, which minimizes any problems with mould or bacteria. Cuttings of the chosen food plant (typically bramble) are placed densely into a old jam jar filled with water. This jar is then placed into the cage, and the leaf insects individually released onto the foliage.
In time the adult females will simply start to drop fertilized eggs out of their abdomens, which fall to the floor.
On a weekly basis the jam jar is removed, the water removed and the jar scrubbed. Fresh foodplants and water are added to it. The base of the mesh cage will then consist of just three things. Firstly, you’ll find tiny dry dots – the faeces of your leaf insects. Secondly you’ll find the eggs that your females have laid. And typically there’ll also be a few corners of leaves that have fallen off the food plants.
The eggs are easily picked out, therefore, as they’re so different to anything else in the cage. This is in contrast to some keepers who use a thick layer of substrate, where locating and identifying the eggs is not always easy.
The eggs are removed to be incubated, the remaining litter is disposed of and the cage is set up once again.
This process, carried out every week or so, as the food plants start to wilt, is all that is necessary of you to successfully breed these wonderfully cryptic insects.
In a good-sized colony you will be literally over-run with eggs. Some of my colonies have produced literally thousands of eggs in a single season, so be prepared for the forthcoming hatching!
The incubation process typically takes some three months or more, however. Generally speaking I find that the adults have mostly died of old age before their youngsters begin to hatch.
This brief period between the end of one colon and the start of another can be a good time to thoroughly clean your equipment, replace anything that is a little worn and to prepare for the excitement of new life in your collection.
Incubating the eggs involves three core principles:
- Keep the eggs warm (ideally 25’C works well)
- Keep the eggs humid (this helps with hatching)
- Prevent the eggs getting mouldy
Over the years I have tried a range of solutions and what follows is what I have found to be the simplest yet most effective solution.
It starts with scattering the eggs into a plastic tray of some form. An old cricket tub with the lid removed, for example. To reduce the build-up of mould the eggs shouldn’t be packed too tightly. Ideally a little air should be able to move between them.
This tray is then placed into a larger, sealed container such as an old fishtank with a lid. The floor of the fish tank is lined with kitchen towel, which is subsequently moistened with water. The cage is then placed onto a heat mat to warm it to the required temperature.
Ongoing maintenance involves removing the seed trays each week, replacing the paper towel from the fish tank, and adding more water. This will keep things hygienic, and ensure that your eggs have enough moisture in the air at all times.
Over time, as the eggs absorb moisture they will change in appearance. Starting off like smooth seeds, they will start to develop fringes and flanges. This is normal – and should be considered a good thing.
As many colonies will produce hundreds, if not thousands of eggs, it can also be a good idea to segregate the eggs being incubated into time periods. This way you will know when a specific tray in likely to hatch in relation to the others. As eggs may be incubated for three months or more before hatching it helps to know which eggs to focus your attention on.
You’ll want to keep an eye on the incubator regularly, just to see if any of the tiny brown ant-like babies have hatched. Despite having kept leaf insects for years I still get a thrill every year as the latest batch of babies starts to emerge – the wonder of nature happening right in your home.
When the youngsters hatch your mission has been completed and the colony can start life all over again.