The others which attack them are more properly positive enemies than parasites, for they prey upon the bees themselves, or, as in the case of the remarkable genus _Stylops_, render the bee abortive by consuming its viscera and ovaries. I have spoken of these insects in the chapter upon parasites, to which I must refer, but I may here add that the female is apterous, and never quits the body of the bee. Much mystery attaches to their history in which their impregnation is involved, for the male, immediately upon undergoing its change into the imago, escapes through the dorsal plates of the abdomen of the bee wherein it was bred and takes flight. In localities where they occur they may be usually taken on the wing in the month of May. The female would seem to be viviparous, and produces extraordinary multitudes at one birth, extending to hundreds. Being born as larvæ within the body of the bee they seek to escape from their confinement, and find the opportunity in the suture which separates the mesothorax from the metathorax. Their extreme minuteness admits of their passing through the very constricted tube which connects the abdomen with the thorax. Having now escaped into the air they alight upon the flowers which the bee frequents, and thence they affix themselves to other bees which may visit these plants, and thus perpetuate the activity of the function it is their instinct to fulfil. That many may be lost there can be no question; but Nature is very prodigal of life, for by life it endows life, and thus its activity is enlarged to a wider circle. Although the matured _Stylops_ has preyed upon all the internal organs of the bee its attack is not immediately fatal, although the life of the creature may be thus considerably abridged, but it seems to live sufficiently long afterwards to disseminate the distribution of the _Stylops_. A small blackish _Pediculus_, which Mr. Kirby called _Pediculus Melittæ_, is found also both upon the flowers the bees frequent and also upon the bees themselves, especially the pubescent ones; but this insect is not limited to the genus _Andrena_, as I shall have occasion to notice. The flower I have chiefly found them upon is the Dandelion (_Leontodon_). Their peculiar economy and connection with the bees is unknown; it may be merely an accidental and temporary attachment, but they even accompany them to their burrows.