Giant Grasshoppers - The largest grasshopper
Valanga irregularis, Family Acrididae
This page contains pictures and information about the Giant Grasshoppers that we found in the Brisbane area, Queensland, Australia.
- Giant Grasshoppers male and female
- The Giant Grasshoppers are the largest grasshoppers in Australia. They also commonly known as Giant Valanga and Hedge Grasshoppers. The Giant Grasshoppers are native to Australia. The adult size vary from 60-90mm. They are very common in Brisbane. We can find these grasshoppers easily on every board leaf plants in our back yard. They eat almost all kinds of leaves. In the early morning, we can find them sun bathing on the trees. At that time they are easy to catch. After they have been warmed up, they can jump very high and fly away quickly. Notice the spines on their hind legs, if they are caught by birds or by spider web, they will attack their predators by their hind legs.
- Female, 90mm
- This colour pattern can be found in our backyard in Eight Mile Plains
- The colour patterns are also vary within the species. Usually the adults are greyish green and brown in colour with black dots pattern on forewings. The colours resemble the plant stem where they usually hide.
- Female, 80mm
- This colour pattern is found in Wishart in the bush along Bulimba Creek. Its size is about the same as the grasshopper in the above picture, 80mm in length.
- Male, 60mm
- Male Giant Grasshoppers look similar to the female, except they are smaller in size.
- The adults insects have four wings, the front wings, knows as tegmina, is tough and narrow when compare with the hind wings. At rest, the hind wings folded like a fans, covered and protected by the tegmina. Their hind wings is usually dray grey in colour, although some are colourless or light green. The fright is mainly achieved by the broadly opened membranous hind wings and the tegmina will give only little help.
The young grasshopper, or the nymph, are usually in flash green colour, so that they are not easily seen when they are feeding on the young leaves.
The nymph in the first picture, feeding on the red leaf plants, is very easily noticed by its predators, such as birds. However, after moulting, some of the grasshopper nymphs' body colour will charge to very close to their background environment.
The young grasshoppers look similar to the adults except they have no wings. Their size is 5mm for the first instar to 80mm for the last instar. The nymph are also vary in colour, some brown or grey colour can be found although not as common as the flash green colour. Notice that the young nymph has the two dark marks on the top of the hind femura. The dark marks become lighter in colour in the later instar stages.
- Green last instar found in March, later summer, 80mm.
- Yellow last instar found in August, late winter, 80mm.
- There are seven instar stages from hatch to mature adult. Each time they moult and then become the larger next instar stage. The last instars have wing buds but still cannot fly. Otherwise, look exactly as the adults. For both adults and nymph, their hind legs are highly developed, much stronger and larger than the other four legs. They are very good in jumping.
- They have large compound eyes and will see you meters away. If you approach near to them, they try to hide behind the leaf or branches, but will still peep at you by either one of their large eyes.
Let's get familiar with the the grasshopper's face. Actually the insect face is not much different from us. The insect face, like our face, is what "goes forward" to meet the environment. For most insects, like this grasshopper, it is equipped with all types of sensory organs. There are eyes to see , antennae to touch, smell and taste, mouthparts to taste. The face is responsible for much of the sensory input into an insect. Let's now look at the each parts on the grasshopper's face.
Antenna - A pair of jointed appendages located on the head of an insect above the mouthparts. Antenna is something like our nose but sense more information than our nose. It perceives odours, touch, humidity, vibration, wind velocity and direction.
Ocelli - Also known as simple Eyes. Those eyes can only detect light intensity and not actually see anything. It is believed that they help to find the sea-level or horizontal during flying. I think we still not exactly sure their functions..
Compound Eye - There are usually two compound eyes, located on each side of the head. Each eye composes of a number of individual units called ommatidia , which is marked by a hexagonal facet. Compound eyes can see shape, colour, movement, and tell the distance.
Mouthparts - Mouthparts have evolved for special needs for different insects. They can chew, suck, pierce, lap, and sponge-up their food. Grasshopper has the most primitive type of mouthparts for chewing. Basically all other types of mouthparts are evolved from the chewing type. The labrum is suspended from the clypeus and form the upper lip. Their function is to help keep food in the mouth. The mandibles are transverse jaws for cutting and grinding. Behind the mandibles there is the maxillae. The maxillae also function as a set of jaws for food manipulation. The labium functions as a lower lip. Maxillary palpus and labial palpus are used for touching, tasting, and sensing temperature.
For more information on insect body parts, please see the Insect Scientific Page.
- The Giant Grasshoppers can do large damage to plantation. The first picture show a big hole on a leaf that the Giant Grasshopper consumed within a morning. The second shows the grasshopper eating the flowers. They will feed on most kind of flash plant materials.
- They have strong mouth parts to cut the leaves from the edge. They are mostly solitary, but if condition is favour, such as in nurseries, they can be very large in number. They can be pest of shrubs and trees in gardens in Brisbane. Their close relative, within the same family, the Locust Chortoicetes terminifera is the famous plague which can build up in number, do big damages and migrate widely over Australia.
- If you approach near to them, they hide behind the leaf or branches and hardly can be seen.
- Last instar Giant Grasshopper nymph
- Body length 60mm
They have a single generation per year. Eggs are 5 mm in length and are laid in pods up to 90 mm deep in moist soil during early summer. The nymphs go through seven instars stages over a three months period. They become adults in late summer and autumn. We have taken some pictures to record their grow in one season. Notice that those pictures are taken in our back yard during the summer, they are not necessary the same grasshopper. Although they grew in about the same rate and about the same size.
-
- 8mm 22/01/2001 15mm 09/02/2001
- 30mm 18/02/2001 60mm 21/03/2001
- 80mm 22/03/2001
- The two pictures show the empty skin and the grasshopper just come out from its last moulting. The grasshopper is hanging on the plant and waiting for its wings to expand and dry. Notice the body colour is still pale in colour.
- 80mm 27/03/2001
- After a few days, most part of the body changed to greyish green, the colour of an adult.
- The adults grasshoppers hibernate during the winter (Australia mid-winter in July). Actually they are still active in winter, but not as active as in summer. They still feed on plants and come out for sun bathing during day time. But spend most of the time in hiding.
- 19/08/2001 24/08/2001
- Early spring - mating season.
- Then the female will lay eggs in the soil. The young grasshoppers usually hatch with mid-summer rains, and than start the next generation.
- 8mm, 08/12/2001, the young Giant Grasshopper and its first meal.
- On early summer 2001, we start to see the young Giant Grasshopper appear on the plants in our backyard. On a 1 meter high plant, we can easily find over 20 of them feeding on leaves. However, we also find a praying mantid and three Lynx Spiders hunting against them.
