Manual of the apiary

by Albert John Cook

The true stomach ([Fig. 9, b]) is very muscular, and often a gizzard, as in the crickets, where its interior is lined with teeth. The interior of the stomach is glandular, for secreting the gastric juice which is to liquify the food, that it may be absorbed, or pass through the walls of the canal into the blood. Attached to the lower portion of the stomach are numerous urinary tubes ([Fig. 9, c]) though Cuvier, and even Kirby, call these bile tubes. Siebold thinks some of the mucous glands secrete bile, and others act as a pancreas.

The intestine when short, as in larvæ and most carnivora, is straight and but little if any longer than the abdomen, while in most plant eaters it is long and thus zig-zag in its course. Strange as it may seem, the fecal pellets of some insects are beautiful in form, and of others pleasant to the taste. In some caterpillars they are barrel-shaped, artistically fluted, of brilliant hue, and if fossilized, would be greatly admired, as have been the coprolites—fossil feces of quadrupeds—if set as gems in jewelry. As it is, they would form no mean parlor ornament. In other insects, as the Aphides or plant-lice, the excrement, as well as the fluid that escapes in some species from special tubes called the nectaries, is very sweet, and in absence of floral nectar, will often be appropriated by bees and conveyed to the hives. Imagination would make this a bitter draught, so here, as elsewhere in life, the bitter and sweet are mingled. In those insects that suck their food, as bees, butterflies, moths, two-wing flies and bugs, the feces are watery or liquid, while in case of solid food the excrement is solid.

SECRETORY ORGANS OF INSECTS.

I have already spoken of the salivary glands, which Kirby gives as distinct from the true silk-secreting tubes, though Newport gives them as one and the same. . In many insects these seem absent. I have also spoken of the mucous glands, the urinary tubules, etc. Besides these, there are other secretions which serve for purposes of defense: In the queen and workers of bees, and in ants and wasps, the poison intruded with the sting is an example. This is secreted by glands at the posterior of the abdomen, stored in sacks ([Fig, 25, c]), and extruded through the sting, as occasion requires. I know of no insects that poison while they bite, except it be mosquitoes, gnats, etc., and in these cases no special secreting organ has been discovered. Perhaps the beak itself secretes an irritating substance. A few exceedingly beautiful caterpillars are covered with branching spines, which sting about like a nettle. We have two such species. They are green, and of rare attraction, so that to capture them is worth the slight inconvenience arising from their irritating punctures. Some insects, like bugs, secrete a disgusting fluid or gas which affords protection, as by its stench it renders these filthy bugs so offensive that even a hungry bird or half-famished insect passes them by on the other side. Some insects secrete a gas which is stored in a sack at the posterior end of the body, and shot forth with an explosion in case that danger threatens thus by noise and smoke it startles its enemy, which beats a retreat. I have heard the little bombardier beetle at such times, even at considerable distances. The frightful reports about the terrible horn of the tomato-worm larva are mere nonsense. A more harmless animal does not exist. My little boy of four years, and girl of only two, used to bring them to me last summer, and fondle them as admiringly as would their father upon receiving them from the delighted children.

If we except bees and wasps, there are no true insects that need be feared; nor need we except them, for with fair usage even they, are seldom provoked to use their cruel weapon.

SEX ORGANS OF INSECTS.

The male organs consist first of the testes ([Fig, 10, a]) which are double organs. There may be from one, as in the drone bee, to several, as in some beetles, on each side the abdominal cavity. In these vesicles grow the sperm cells or spermatozoa, which, when liberated, pass through a long convoluted tube, the vas-deferens ([Fig. 10, b, b]), into the seminal sack ([Fig. 10, c, c]), where, in connection with mucous, they are stored. In most insects there are glandular sacks ([Fig. 10, d]) joined to these seminal receptacles, which in the male bee or drone are very large. The sperm cells mingled with these viscid secretions, as they appear in the seminal receptacle, ready for use, form the seminal fluid. Extending from these seminal receptacles is the ejaculatory duct ([Fig. 10, e, f, g]), which in copulation carries the male fluid to the penis ([Fig. 10, d]), through which it passes to the spermatheca of the female. Beside this latter organ are the sheath, the claspers when present, and in the male bee those large yellow sacks ([Fig. 10, i]), which are often seen to dart forth as the drone is held in the warm hand.

Fig. 10.

a—Testes. b, b—Vasa deferentia. c, c—Seminal sacks. d—Glandular sacks.

e—Common duct. f, g—Ejaculatory sack. h—Penis. i—Yellow saccules.