Leaf-footed bugs are members of the order, Hemiptera, and in the true bug family, Coreidae. Leaf-footed bugs get their name from the leaf-like shape of the hind legs.
There are probably fewer than 5 leaf-footed bug species in Singapore. The most commonly encountered species has a tiny head relative to its narrow brown body with pale markings across the wings. They can grow up to 3 cm long.
Leaf-footed bugs are primarily plant-feeding insects by sucking the juice from the leaves, seeds, fruits, etc. When it matures, the male will look for a female to mate.
After mating, the female usually deposits up to 20 eggs and are laid end-to-end in a single low along a stem or on a leave. When first laid, the 1.2 mm barrel-shaped eggs are dark brownish in colour. The eggs hatch after about 5-7 days. The freshly born babies are less than 10 mm and red in colour.
They will change into black colour within a hour or so.
They will soon abandon their eggshells and start feeding. When they are small and weak at this stage, they often stay close together to scare away any potential predator. Sometimes, as a cluster which makes them look bigger:
Sometimes, in a straight line that makes them look longer:
When the juveniles grow and become bigger in size, they will move on and feed in smaller group. Here is a gang of four:
Here is a group of three:
And a twin:
There are five nymph stages called instars and every leaf-footed bug has to go through five moults before becoming an adult. The nymphs moult as they grow, looking more like an adult each time. They often vary in coloration between their 5 moults. Based on my observation, the colour of the freshly moulted individual tends to be a mixture of yellow and orange during the earlier stage of moulting. This following moulting image is most likely into its 2nd instar stage.
However, the colour is more towards pink in the later stage of the moulting:
Regardless of which moulting stage they are in, the freshly moulted individual will change colour from their brightly yellow or pink to somewhat purplish in colour and eventually into a darker tone of grey within a hour or two.
The moulting process is not always successful. In fact, leaf-footed bugs are most vulnerable during their actual moulting which usually takes about 15 to 30 minutes. Here is a failed moulting disrupted by a predator, the lynx spider.
It takes approximately 4 to 5 weeks between hatching and adult emergence. Thereafter, adults mate and the life cycle of leaf-footed bugs continues.