Hatton's Garden.org.uk                                         Rearing  Caterpillars

If you have decided to rear caterpillars into adult moths, you should remember to look after them properly. Like pets they need cleaning out and feeding regularly, otherwise they are likely to perish. If the food plant is not available close to where you live, or you are not sure what they need, then it's best not to try. Usually the plant you found it on is a reasonable clue, though some caterpillars hide from predators during the day, and may not be on the plant upon which they feed.

If you are can successfully rear your caterpillar/s, the benefit is that you will see what kind of moth, or butterfly they become. You may wish to rear several species at once. If so it is a good idea to label your larval receptacles. This is a good idea if you plan on photographing them at different at different stages of heir development. Also you will know for certain what larva/e turned into what species of adult moth, or butterfly.

The breeding cages illustrated to the right, are ideal giving light well, and aired conditions.               continued below ....

If you use glass jars it is a good idea to use muslin secured with a rubber band, This is better than putting holes in the lid, as it will allow the larva/e to breathe more easily. Excessive moisture can form in jars, so put about half to three quarters of an inch of clean moist soil, or potting compost inside the jars. Provided that the soil is moist and not soggy, it will help to absorb excessive moisture. The jar and/or the soil, or compost may need changing periodically, if it becomes to moist. Excessive condensation can cause bacteria and result in disease, and fatalities.

Temperature is also important, not to hot, or to cool. The temperature should be as close to natural conditions as is possible. Sometimes an outhouse, or garage may give the required conditions. Light is needed but do not leave caterpillars in direct sunlight for even short periods of time.

Caterpillars on occasion will die anyway, they can become infected by parasites before you found them. To help avoid parasites, larva/e should be captured as soon after hatching as possible. Having obtained moth, or butterfly eggs is even better, you have the control over parasitic infections. Care should be taken over the food plant supply, be sure its not got parasites, or predators present. It can be gently rinsed, and must be gently patted dry with some kitchen towel, or excess moisture will be introduced. The most important point, is the welfare of your captive/s.

Then the branches are tapped sharply with a suitable stick, and the caterpillars are dislodged, falling into the outstretched tray.

 The beating stick should not be to light in weight, as it will not do the job properly. Also it is a good idea to pad the stick with a thin layer of foam sheeting, securely taped into place. The taping should completely encase the foam, otherwise the foam will be soon shredded by the beating actions. The padding will assist in minimising damage to tree branches.

Taps with the stick should be firm, and sharp, not heavy enough to severely damage the tree. Taps need to sharp enough however to dislodge the larva, they have a very firm grip. This method is less effective in windy weather, as the caterpillars are gripping more firmly than usual, to avoid the wind dislodging them. Beating the same area over, and over again in the same year should be avoided, try different places.

Beating trays can be purchased at entomological suppliers, or if you are handy at DIY you could make one. If you are on a tight budget, an old white, or light coloured sheet can be spread on the ground. This will catch the insects, and caterpillars that fall from the branches quite well. Whichever you use look carefully, on occasion some of the pieces of twigs and leaves on the sheet, after a few minutes may start crawling around. Insects are good at disguise, and may well surprise you.