Art. XVI.—On “Sugaring” for Lepidoptera in Southland.
[Read before the Wellington Philosophical Society, 15th January, 1901.]
During the spring and summer months moths are always more or less plentiful, and can generally be taken at various blossoms or netted in the evening, so that “sugaring” at this period is not an important means of obtaining specimens. But when the days grow shorter, and there are no attractive flowers in bloom, then “sugar” may be used with advantage. Even in midwinter many fine species may be secured, especially if the rigours of the season be broken by a few mild days. During June and July I have taken Melanchra mutans, plena, and stipata, Bityla defigurata, Declana floccosa, Hydriomena gobiata, Xanthorhoe rosearia, Elvia glaucata, Selidosema dejectaria and panagrata, and Ctenopseustis obliquana. In August several of the early spring moths are out, such as utistriga and vitiosa, beata, semifissata, and suavis, and these come eagerly to the alluring sweets. I think that midsummer is the poorest season to use “sugar”; there are then so many attractive flowers in bloom that artificial sweets seem to be despised.
It is of little use laying “sugar” in native bush, even if good tracks can be followed. The best situation is a few good trees surrounded by cultivation. I remember once travelling some distance to what I thought would be a splendid place for “sugaring.” It was a little open space, almost surrounded by native bush, and with native herbage growing luxuriantly amongst the scattered tree-trunks. The night was warm and dark, an ideal night for moths; but after two hours’ work I had taken but a dozen specimens. Before setting out, however, I had laid some “sugar” on a few Pinus insignis which shelter my orchard and garden, and on my return I found these trees absolutely swarming with months.
The “sugaring” mixture should be placed on the sheltered side of the trees, and should be well rubbed in with the brush; if only laid on lightly much of it will trickle down on to the ground, where it is inconvenient to bottle the moths.
I prepare my “sugaring” mixture by adding a wine-glass each of beer and rum to a pound of black treacle and stirring thoroughly. I have tried port wine instead of beer and rum, and found it answer very well; but I do not think its effects
are so lasting. If not in too exposed a situation the beer-and-rum mixture will attract very well for a week, without fresh material being laid. I have also tried condensed milk as a base instead of treacle, but, though apparently equally attractive, it is much too sticky to be recommended.
It is best to have two or three killing-bottles. One often has to take more than one specimen from the same tree, and if but one bottle is used it is probable that the first moth will escape while the second is being secured. It is well also to have a bottle or box to place the dead moths in, as they are liable to be knocked about by the freshly taken specimens.
The present season has, so far, been a poor one for “sugaring.” Though the weather has been for the most part delightfully fine, chill easterly breezes have prevailed, a condition of things fatal to the success of “sugaring” operations.