WORK IN THE APIARY

New Zealand Herald, Volume LXXII, Issue 22144, 25 June 1935, Page 16

WORK IN THE APIARY

WAX MOTH DEPREDATION MEASURES FOR CONTROL BY F.J.L. The damage to combs and beeswax wrought by the larvae of the wax moth is causing much anxiety to beekeepers. There are two species of this moth, both of which are of oriental origin and have been present in New Zealand for a number of years. Fortunately for beekeepers these pests are not usually so rampant as they have been this season. Galleria mellonella, the larger of these night flying moths, whose caterpillar grows to nearly one inch in length, is not so well known, but is more destructive than the caterpillar of the smaller moth, Achroea Grisella. The habits of both moths are similar, the eggs being laid on exposed wax or in handy crevices where they hatch out and commence to bore through the combs, spinning a protective silk-cov-ered tunnel as they proceed, thus preventing their most formidable natural enemies, the bees themselves, from readily attacking them. Immediate Attention

Stored combs infested with these pests will quickly be reduced to a powdered mass of web if measures are not immediately taken to eradicate caterpillars and eggs, and to prevent the laying of subsequent batches of eggs. Weak hives, especially of black bees, will sometimes be infected on the outer combs which are not occupied by the cluster of bees, in which case the weak hives should be united after the infected combs have been removed for treatment.

The careful storing of comb foundation, appliances which have wax on them, or scraps of wax before they are rendered, will help to prevent the breeding of the moths. To ensure this the wax or appliances should be kept in moth-proof containers. Empty supers or appliances which are too large to be so enclosed may be sprayed with a solution of formalin. Fumigation of Combs Thorough fumigation of the combs with cynogas or carbon bisulphide, or by burning sulphur, will destroy any moths or grubs, while by repeating the process in eight days' time the grubs which have since hatched from eggs will be destroyed. If a sufficiently airtight shed is not available in which to fumigate the combs, the super may be tiered over a fumigating box, if cynogas is used, all cracks being made airtight by pasting strips of paper over them. Owing to the deadly nature of its fumes, great care should be taken in the handling and use of cynogas. Carbon bisulphide is used by placing a small quantity of the liquid in a container, such as a tobacco tin, on top of the frames on the top of the tier of supers, an empty super with a cover being placed over the container. The liquid evaporates, forming a heavier than air gas which descends through the frames. This gas is very highly inflammable as well as poisonous. If sulphur is to be used, a few glowcoals are placed in an old iron pot or other suitable receptacle, the sulphur being spread on the coals. The method of fumigating is the same as for carbon bisulphide The sulphur fumes will be likely to corrode the wire in the frames, but well-drawn combs especially those which have had brood in them, should be strong enough even if the wire should be eaten away. Subsequent Protection After the second fumigation the combs may be stored, but since the moths are usually more in evidence in the spring than at this time of year, it is necessary to prevent the possibility of fresh eggs being laid in them. Close-fitting and well-covered tiers of supers help to keep the motiis out, although it is worth the extra labour to place sheets of newspaper between each super in the stacks. By doing this the few moths which may gain access to a super are confined to the one which they have entered, as are any grubs which may hatch. Mothballs may be placed in each super as an added precaution to the use of paper, in which case the frames require to be well aired before being placed on hives. The wax moth is by no means uncontrollable, although its presence calls for prompt and thorough action as well as future vigilance if the beekeeper would save the destruction of combs.