The African Migratory Locust.
Locusta migratoria migratorioides.

Last update: 17 August, 2002

Locusts are one of the most important animals cultured for the purpose of feeding the many species of insectivorous animals being maintained in captivity today. They can be obtained in all sizes from very small hoppers (suitable for medium sized frogs and lizards), to adults, which are very good eating for all of the larger carnivorous reptiles end amphibia. For the average person, however, they are not, unfortunately, very easy to breed and rear in worthwhile quantities.  They are mentioned here while space permits purely for the sake of completeness.

However, it cannot be denied that, for those Dendrobatid keepers concerned about their animals' monotonous diets, newly hatched hoppers are, indeed, of a suitable size to be of use to some of the larger and/or more ravenous frogs.  I would consider them well worth a try at least.

Being large insects (some three times bigger than the smaller Dendrobatids!), they require quite a lot of space if they are to be bred on a continuous basis.  They withstand crowded conditions very well, provided there are plenty of twigs to act as perches. Indeed, they do much better when kept in such conditions, and insects kept in low densities often will not breed.

In their reproductive behaviour, they are fairly typical grasshoppers, the males calling to the females, which lay their eggs in long 'pods' in sandy soil. The pods contain from between 30 to 100 eggs each, and each female will lay up to six pods with an interval of six days between each pod. At 32°C, eggs will take approximately 11 days to hatch.


Development of locust hoppers


Egg pod


Newly laid pod (left)
Mature egg pod (right)


1st instar hopper


2nd instar hopper


3rd instar hopper


4th instar hopper


5th instar hopper


Hatching hoppers

Being grasshoppers that grow by gradual metamorphosis, the eggs hatch into nymphs. These wriggle out of the soil protected in a nymphal skin or sac, which is shed immediately on reaching the surface. From then on the nymph looks unmistakably like a baby grasshopper, and will moult five times before becoming adult, with wings and the ability to reproduce. The charts give some idea of the growth patterns at various temperatures.

Merely rearing the insects from one stage (or 'instar') to another is not difficult if one has bought a supply of small hoppers. If they are fed on fresh grass, kept warm, dry and very clean, they will grow quite quickly. Attempting to breed them is slightly more difficult, however, especially during the winter. I have found that it is not only important to supply them with fresh grass on a continual basis, but that it is important to feed them with fresh, growing grass. Reasoning this out, growing tips must provide them with various hormones that are apparently important for their well being from the point of view of fertility. Unless one is prepared to grow wheat or grass seedlings constantly, it is, therefore, very difficult to provide them with an adequate diet during our winter months. Books indicate that they will accept a 'dry' diet of bran etc., but although they may survive for quite a time on this, they will not be fit enough for egg production, at least in my experience. During the summer, though, they present few difficulties as long as one has enough space available.

The ideal cage is a purpose built locust breeding cage as designed by the Anti-Locust Research Centre. These are made of aluminium sheeting, and currently (1988) cost in the region of 160! They are, however, very good and success is almost guaranteed. Ideally, you would need at least two of these for continuous culture, although hoppers can be reared in the cylindrical type of cage made of acetate sheeting. These can be stood in a circle around, say, a 100W light bulb for heating purposes. The cages have holes cut into the floor to allow access by the locusts to glass or metal tubes filled with damp sand, for the purposes of egg laying. The tubes are then removed on a regular basis for incubation, and replaced with fresh tubes. Heating is invariably with light bulbs, the exact wattage of these depending upon the ambient temperature of the room in which they are to be housed.

 

A temperature of around 3235°C should be aimed for, in all aspects of their husbandry. Conditions should be dry at all times, and the cages should be disinfected at regular intervals. Only enough grass should be supplied which will be totally consumed within twelve hours. The cages should be full of perches. These are important especially to hoppers, which must have a secure base from which to hang during skin shedding.

Incubation of egg pods is a simple matter. As the egg tubes are removed from the cage, they are covered with cooking foil or cling film, and incubated at 32°C for around nine days, after which they should be inspected at regular intervals for signs of hatching. I have had some success in removing the pods from the sand and incubating them on damp paper towelling inside flat Petri dishes.

The newly hatched hoppers should be transferred to a clean, sterilised cage for rearing. They are best kept in rather dense populations, say around 1,000 per cage, and later thinned out so that there are between 50 - 100 adults once maturity is reached. They should be fed on fresh, growing grass, and this need be their only food. Only enough grass should be placed in the cage to last the day, and all should be consumed within the 24 hours. If the grass is bundled tightly together (perhaps tied in a knot), it will stay fresh for longer while it is being consumed, than if it were simply scattered loosely about the cage.


Fourth to fifth instar moult


Final moult to adult.
Note wings.

As hoppers grow they shed their skin, and for this purpose hang upside-down from a suitable perch. For this reason, the cage needs to be supplied with masses of twigs or plastic mesh, to give each hopper enough space for moulting, as mentioned above. The locusts are adult once they obtain wings, and shortly after this will mature, and will be seen mating frequently. Now is the time to make suitable damp compost available to them, say in jam jars, for the purpose of egg laying.

This account deals primarily with Migratory locusts but an oft-supplied alternative is Schistocerca gregaria. This is a larger and more colourful species, and fares better on 'dry' diets during the winter, but the males may not mature in low-density populations. Migratory locusts, on the other hand, have a shorter life cycle (26 days at 2832°C vs. 36 days) and have a reputed higher resistance to disease. The two species are, however, maintained in more or less identical conditions.

Locust photographs: Anti-Locust Research Centre

Supply:
Insect cage YSK-200-Y 15.24
Locust cage YSK-522-E 156.37
Glass tubes x6 YSK-524-020J 17.60
Prices as at 1988

Griffin and George,
Bishop Meadow Road,
Loughborough
Leicestershire,
LEII ORG.
Tel. (01509) 233344

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