Seven Backyards - Noel McFarland

There are always at least a FEW diurnal (day-flying) moths in every locality, and a small percentage of these may fly both day and night (Ctenucha venosa, for example, is pictured at the left). Strictly diurnal moths are easily assessed (as to local abundance) simply by looking for them wherever they tend to congregate, exactly as one would do for most butterflies, which can be found visiting their favored flowers, or coming to mud and seepages, etc., etc.. Those (few) moths that don't feed or drink as adults, but are nevertheless strictly diurnal in their activity, are a little more challenging to obtain (males of Gloveria spp., for example)! Some of these diurnally active males are also rapid and very erratic fliers (again, Gloveria males) almost impossible to chase down with a net. And they don't (or rarely) come to lights after dark! The best collecting technique for such moths is to place a freshly-emerged living female (inside a screen cage) out in the habitat. Her pheromones will often attract the flying diurnal males sometimes in large numbers. They are then quite easily captured, as they flutter around the cage trying to reach the unmated female.

In quite a number of unrelated moths (various families), there may be a very noticeable difference seen in the numbers of one sex versus the other coming to lights. In some of these species, the males arrive in large numbers, but females are rarely seen and, vice versa. In this locality, females of a common summer arctiid, (Hemihyalea labecula), come readily to my uv. lights, but males are almost never seen! Yet, in two other closely-related arctiids here (H. edwardsi & H. splendens), both sexes regularly come to light in about equal numbers. In the more usual situation, with the vast majority of nocturnal moths that are attracted to lights, it is typical that more males will show up, OR that both sexes will be about equally represented. The most unusual of these various examples would be that of H. labecula at this location, where it is the males that are rarely seen at light. Typically, if there is any noticeable difference in numbers coming to light, it will be the females that are rarely seen — NOT the males!