ENTOMOLOGICAL.

Otago Witness, Issue 1920, 4 December 1890, Page 5

ENTOMOLOGICAL.

By Entomologist.

SPIDER ENEMIES.

Although the is Buoh a formidable enemy to the flies that have the misfortune to become^entangled in its net, it is in its own turn subject to Beveral terrible enemies. Some of these attaok it openly and others by a more insidiouß process. One large fly of the wasp kind pounceß upon it and carries it off bodily when it appears in sight and when it is lying in .wait 'hidden in its den. He will pretend to be entangled in the web, and when the spider rushes out will easily disengage himself, and carry her off in his powerful jaws. Other flies, too, allied to the ichneumonidae depoßit their eggs on the nidus of the spider, into whioh the larvae penetrate and devour the eggs and young spiders. But the most singular of all the spider's enemies iB a small fly of the genus polyspbineta. This insect has the temerity to approach the spider and deposit an egg upon the baok or upper surface of the abdomen, and to bind it in its position by means of a silken thread. It certainly seems a wonderful instinct that teaches this delicate little insect to place its egg in suoh an extraordinary position, where the larvae when hatched oan feed upon the life juices of the spider. It must be endowed with a wonderful amount of courage to venture into such proximity to an animal which could instantly seize and destroy it had it not adroitness to keep beyond reach of its death-dealing fangs. The larvae, too, must be in a peouliar position perched on tbe back of a spider, barely beyond the reach of the monster, and living upon the blood of its most deadly enemy, These spider parasites have very long been known to science, but it has been reserved for Mr\ E. Ernest Green, of Pundiloya, Ceylon, to discovers moat singular peculiarity in the action of this fly — viz., that it invariably selects the female spider to deposit its egg upon and never tbe male. From this we would imagine tbat the fly must be aware that the male always falls a prey to the female. It cannot be that the male is less easily approached, because he is the less ferocious of the two, but it does seem impossible to believe that the fly can know anything about spiders' ' matrimonial arrangements. Still, such being the faot, it follows that the natural instinct of the little insects, or else its habit of observation, must teach it to select the female spider. If we reject either of these theories we must fall baok on the belief that insects have the means of imparting intelligence to eaoh other ; but it is aftei all one of those mysteries of Nature which we are unable to understand.