THE APIARY.

Otago Witness, Issue 3783, 14 September 1926, Page 11

THE APIARY.

By

J. A.

THE LARGE WAX MOTH. I have ne\*r seen this vnoth in Southland. It is, however, a plague in Nelson. On this account I have been advising beekeepers here to Italianise their apiaries, as -it is known that the Itulian bee will put up a much better fight against the moth than will the common black. This week I had occasion to examine several colonies of Italians in my orchard apiary, and was very pleased that I could not find any* trace of the moth. Strange to say, a black colony, also examined, was as clean as the Italians. It was a new and to me a very pleasant experience to spend an hour with the bees and not discover so much a 3 a trace of the scourge. Mr Robinson, the apiary instructor for Taranaki, in addressing the Hamilton Conference, ventured the opinion that the moth is as destructive as foulbrood. lie said it is justly thought by some to bo more deadly than foul-brood, as it completes its work of destruction in less time. My experience here would lead me to endorse this opinion. It is most repulsive, and very deadly, especially if the colony is not too strong. 1 do not know whether there is any climatic or other reason why this moth should not operate in southern apiaries, and it may be that it is there though unknown to me. There is a smaller moth which is often very destructive on stored combs, but otherwise does not cause the beekeeper much trouble.

For the benefit of beekeepers who do not know anything of the large moth I quote from Mr Robinson’3 address, as given in the Fruitgrower: “In length it i 3 about Jin. The wing colour is light ashen grey, the back third of each front wing is bronze, and the body is brown. The wing expanded is liin. The male is smaller than the‘female ; the length of the grub fully matured is about lin. . . . When first hatched the young worm i« only gin in length. After hatching the larvae are inert for a short period. They, however, soon become active, and may be observed hurrying over the combs trying to gain an entrance. Their first meal is soon taken. It consists of scales of wax, which they loosen from the combs in their attempts to enter them. They never enter the combs near the eggs from which they are hatched. The entrance is made at the top of the combs, between the walls of adjoining cells. it is during the short period of an hour or so after being hatched that they are at the mercy of the bees, but no doubt few, if any, are killed at this time. The entrance is extended by the larvae into tunnels towards the centre of the comb or the bottom of the cells. In constructing these tunnels the larvae push behind themselves bits of chewed wax These pieces contain strands of the web of the larvae, and it is evident that this web is secreted continually by the larva* During the period of reaching the centre of the comb the growth of the larvae i« very slow, and the tunnels extending tc* the bottom of the cell are increased in size to accommodate the growth of the larvae. The time taken in extending these tunnels is from four to eight days. When the centre of the empty comb i 3 reached the holes are cut through to the bottom of the cell walls, and the larvae leave their tunnels and wander along the midrib from cell to cell. At first only holes are eateu through the cell walls, but in a few days lines of web can be seen lining the passageway from cell to cell. At all times the larvae avoid light as much as possible. At various places through the comb false cocoons are spun that serve as a protection and resting-places. They feed but little during the day, carrying on their work of destruction during the night. In the same way dark comb is preferred by them to light. In a badly infected hive a distinct gnawing is audible at dark. The length of the larval period varies from 49 to 110 days.” I need not follow the description through the pupal stage. It is sufficient to say that for this purpose they seek any crevice that can be found about the inside of (he hive, and there spin (heir cocoon, lator to devlop into the moth. It is the wanderings of the larvae that form the greatest interest to the bee keeper. Not only do they tunnel the comb in all directions, 'but the bees in their efforts to destroy them cut away the ceds to get at them, and thus it is that an infested comb comes to have holes cut through it until it becomes useless. These tunnels sometimes run just under the brood cappings, and the heads of the young bee larvae are apparently eaten in the passing. The bees tear" the cappings off to get at them, but are hampered bv the. web secreted by the moth larvae, and seemingly used as a protection. When fully developed these larvae are very active, and present to the beekeeper a loathsome sight. In the first case I had I threw a few larvae to a rooster, who lijced them so well that on several subsequent occasions he watched out for more when the hive was being reexamined. I soon learned that to clean the hive was not possible, though every comb was thoroughly gone over and the hive itself as thoroughly cleaned. Attempts are made to control with fumigation, but it is hardly wise to waste time on them. One thing is certain, however, and that is that it pays to clean up all pieces of comb and to leave no wax about the apiary. The cure is to have strong colonies and to Italianise. So far this appears quite successful with me. I shah, however, watch very closely, as well a 3 anxiously, throughout this summer.