Aphid

“ All these phenomena may occur in the case of a single species, though in a very variable extent.
The simple form of Aphid life may be described as follows:—eggs are laid in the autumn, and hatch in the spring, giving rise to females of an imperfect character having no wings; these produce living young parthenogenetically, and this process may be repeated for a few or for many generations, and there may be in these generations a greater or less number of winged individuals, and perhaps a few males. ”

“ There are not many of them, for each female lays only from one to a dozen; but it is these eggs that are to remain on the trees through the winter to produce the stem mothers of next spring, who will start another cycle of aphid lire repeating the his- tory of that just closed. The production of sexual forms in the fall in temperate climates seems to have some immediate connection with the lowered temperature, for in the tropics, it is said, the aphid succession continues indefinitely through par- thenogenetic females, and in most tropical" species sexual
[ I67]
INSECTS Fig. ”

“ At springtide, when the leaves begin to sprout from the opening buds the aphid eggs are hatched, and the young insects after a series of moults, through which hardly any change of form is apparent, all grow into wingless 'stem-mothers' much larger than the egg-laying females of the autumn. ”

“ The small, bright orange, slug-like larvae inject a toxin into aphids' leg joints to paralyze them and then suck out the aphid body contents through a hole bitten in the thorax. Larvae can consume aphids much larger than themselves and may kill many more aphids than they eat when aphid populations are high. A single larva kills 4-65 aphids per day. ”

“ When one of these miniature monsters becomes full-grown, it ceases its depredations on the aphid flocks, enters a period of quietude, and fixes the rear end of its body to a leaf by exuding a glue from the extremity of its abdomen. Then it sheds its skin, which shrinks down over the body and forms a spiny mat ad- hering to the leaf and supporting the former occupant by only the tip of the body (Fig. 132 E) . With the shedding of the skin, the insect has changed from a larva to a pupa, and after a short rime it will transform into a perfect lady-beetle like its father or mother. ”

“ Galls.—Like Phylloxera, many species of Aphidae live partially, others wholly, in galls that are produced by plants as the result of one or more Aphids interfering with a delicate part of the plant when it is in a young and growing state. The usual position of Aphid galls is on a leaf or leaf-stalk. But in the case of the genus Chermes, {588}a bud or some growing part of the spruce-fir is affected in such a way that it gives rise to an object having externally the appearance of a little fir-cone, while inside it consists of chambers in which the Aphids reside. ”

“ An English naturalist has figured out that a single-stem mother of the common aphis, or 'greenfly' of the rose, would give origin, at its regular rate of multiplication and provided each individual born lived out its natural life, which is only a few days at best, to over thirty-three quintrillions of rose aphids in a single season, equal in weight to more than a billion and a half of men. Of course such a thing never happens, because so many of the young aphids get eaten by lady-bird beetles and flower-fly larvæ and other enemies before they come to be old enough to produce young. ”

“ Many species of aphid migrate from one plant to another at certain stages in their life-cycle when their numbers have very largely increased, and F.M. Webster has observed ants, foreseeing this emigration, to carry aphids from apple trees to grasses. It has been shown by M. Büsgen that the sweet secretion (honey-dew) of the aphids is not derived, as generally believed, from the paired cornicles on the fifth abdominal segment, but from the intestine, whence it exudes in drops and is swallowed by the ants. ”

“ The Aphids need the Eco Tree and the ants; the Eco Tree depends on the Aphid Eater birds to ensure that the Aphids do not become too populous, and it depends on the ants to give it the right soil conditions ”

“ The little ants may be seen sometimes turning the eggs over and over and carefully licking them as if to clean them of dust-particles.
"In the late spring the aphid eggs hatch, and the young must have sap to drink right away. Their little beaks are thirsty for the plant-juices that are their only food. But there are no tender corn-roots ready for them in the fields because the corn has not yet been planted. What, then, shall the hungering baby aphids and their foster-mothers, the little brown ants, do? ”

“ In order to breed, they need an abundance of aphids; These insects have a diverse diet so they can survive when aphids are scarce, including honeydew, nectar, pollen, or even petals and other soft parts of plants; Once aphids leave a crop, beetles will also. To retain active beetles, maintain cover crops. ”

“ Experiments which bring about changes in the life-cycle, and also those which produce parthenogenesis in insects which are normally sexual, can not be considered surprising. As to changes in the lifecycle, the case of the rose aphid is a good illustration. This insect produces parthenogenetically female offspring during the summer months, and normally on the appearance of winter begins to produce both males and females. This winter condition may be indefinitely postponed if the animals are kept in a suitable environment with plenty of food and water. ”

“ An American Aphid of the genus Pemphigus produces black, ragged, leathery and cut-shaped excrescences on the young branches of the hickory.
The Chinese galls of commerce (Woo-pei-tsze) are stated to be produced by Aphis Chinensis, Bell, on Rhus semialata, Murr. (R. Bucki-amela, Roxb.) , an Anacardiaceous tree indigenous to N. India, China and Japan. They are hollow, brittle, irregularly pyriform, tuberculated or branched vesicles, with thin walls, covered externally with a grey down, and internally with a white chalk-like matter, and insect-remains (see fig. 2) . ”

“ In many cases the ants have been observed to stroke the aphids with their antennae in a way which seems to induce the aphid to give out a drop of the sweet liquid for the ant to lap up. In a similar way these ants seem sometimes to stroke these little caterpillars with their antennae and thus to induce them to turn their little pockets inside out with the drop of liquid at the tip. ”

“ The aphids are all sizes and ages, though as to age the difference is probably but a few days. With a glass, the process of "milking" may be observed, the ants merely stroking the aphids with their antennæ. Two small tubes, like sap quills, protrude from the back of the aphid, and from time to time minute glistening drops are seen to exude from these tubes and are removed by the ants in attendance. Surely, to the ant here is the land of milk and honey. They move constantly to and fro among the aphids, now and then stopping to stroke one. ”

“ The aphides are always with us. Where is the lover of the rose-garden who is not painfully familiar with the pests, their pale green swarms completely encircling the tender shoots, and shedding their sticky, shining "honey-dew" everywhere like a varnish upon the leaves and flowers beneath. Hardly a plant or tree escapes their parasitic attacks in one form or another, where, with their beaks imbedded in the tender bark, [127] they suck the sap, and literally overflow with the bounty which they thus absorb and convert into "honey-dew." ”

“ The leaf-infesting stages of the insect cause pocket-like galls to form, which open on the upper surface of the leaf by a narrow aperture concealed under a tuft of delicate hairs (Fig. 9, 5) . In each gall the aphid matures and deposits several hundreds of eggs, from which wingless females hatch; these wander to other leaves, and each insect forms a new gall for itself. Several generations develop thus, but later many of the offspring migrate underground and join the root-infesting colonies. ”

“ PART III ANIMAL ECOLOGY CHAPTER XXIX THE STRUGGLE FOR EXISTENCE, ADAPTATION, AND SPECIES-FORMING
Technical Note.—Multiplication, or increase by geometric ratio, among animals can be illustrated by noting the many eggs laid by a single female moth or beetle or fly or mosquito or any other common insect (or almost any other non-mammalian animal) . The production of many live young by each female rose aphid can be readily seen; the number of young in a litter of kittens or pups or rabbits is a good illustration. ”

“ The woolly aphis is more common on the roots of apple trees, being especially a pest of nursery stock, but it migrates to both the twigs and the roots of the apple from the elm, which is the home of its winter eggs. An underground aphid of particular interest is one that lives on the roots of corn. We have seen that all aphids are much sought after by ants because ol c the honey dew they excrete, a substance greatly relished and prized by the ants. It is said that some ants protect groups of aphids on twigs by building earthen sheds over them ”

“ The mother is but little concerned with the birth of her child, and she usually continues to feed dt?ring its delivery, though she may be somewhat annoved by its kicking. The average summer female gives birth to two or three young aphids every day. The succession of forms in the familles is one of the most interesting phases of aphid lire. ”

“ But this state of affairs in no wise hinders the multiplication of the species, for these re- markable females are able of themselves to produce off- spring (a faculty known as parthenogenesis) , and further- more, they do not lay eggs, but give birth to active young. Since they are destined to give rise to a long line of sure- mer generations, they are known as the stem mothers. One of the three aphid species of the apple buds is known as the green apple aphis (Fig. 95 B) . ”

“ Aphids parasitized by a parasite that makes a cocoon beneath the body of the aphis, where it changes to a pupa and, when adult, emerges through a door cut in the side of the cocoon
worst enemies that insects have to contend against; but really they do not contend against them in most cases, except in the way characteristic of insects, which is to insure themselves against extermination by the number of their offspring. The aphid colonies are often, how- ever, greatly depleted during a season favorable to the predacious and parasitic insects that attack them ”

“ During the summer only the females exist and they are so astonishingly fertile that one such aphid and her progeny, supposing none dies, will produce one hundred million in the course of five generations. ”

“ This aphid is usually controlled with nicotine sulfate (40 percent nicotine) , 3/8 pint plus summer oil emulsion, 2 quarts per 100 gallons of spray. Parathion and benzene hexachloride have given good results in experimental work but are not yet generally recommended.
~Pecan phylloxera.~ The pecan phylloxera [16] is related to aphids. It attacks principally the vegetative parts of the tree such as the leaves, petioles, and shoots on which galls (Fig. 6) are produced. Pecans, hickories, and other species of nuts are subject to infestation. ”

“ Their food is the sap of the growing corn-plants which they suck from the roots. Although each corn-root aphid is only about one-twentieth of an inch long and one-twenty-fifth of an inch wide and has a sucking-beak simply microscopic in size, yet there are so many millions of these little insects all with their microscopic little beaks stuck into the corn-roots and all the time drinking, drinking the sap which is the life-blood of the corn-plants that they do a great deal of injury to the corn-fields of Illinois and cause a great loss in money to the farmers. ”

“ The aphids attack the opening buds, the young fruits, the growing shoots, and the leaves, sucking the plant juices from the succulent parts by means of long, very slender, tube-like beaks, which they thrust through the skins of the affected organs into the soft tissues beneath. ”

“ In some species the workers serve as herdsmen, caring for the ant-cattle or aphids, from which they receive minute drops of a sweet juice for food. The aphids are tended on the leaves of various plants during the summer, and are carefully reared and stabled and fed below ground during the winter months. In other species seeds are procured and stored in underground granaries. ”

“ PLANT ENEMIES Aphis. Aphis or green plant louse is the most commonly encountered of all the insect pests. It used to be dreaded, but with modern methods it may be readily and effectively exterminated. There are several forms and colors of these pests. If you have attempted plant-growing you are undoubtedly familiar with them. In the house, shaded places, crowded plants, poor ventilation, dry plants, all furnish environment favorable to the development of aphids. ”

“ When the larvae encounter prey, they generally bite a hole in the body and suck out the contents. The non-flying larvae consume about 50 aphids or similar prey per day. Some species of adults also prefer to east aphids, however most eat other soft bodied insects. ”

“ The leaves of plants are for the most part the objects of attack, but many aphids and scale-insects pierce stems, and some go underground and feed on roots. The enormous rate at which aphids multiply under favourable conditions makes them of the greatest economic importance, since the growth of immense numbers of the same kind of plant in close proximity—as in ordinary farm-crops—is especially advantageous to the insects that feed on them. ”

“ Aphids (primary) Plus other soft-bodied insects:
thrips, mealybugs, bean beetles, immature whiteflies, scale, moth eggs, very small caterpillars, spider mites Lacewing (Chrysopidae and Hemerobiidae families) Description. Adults are light green or brown with long slender antennae, golden eyes and long delicately veined wings. Adults fly, larvae do not.
Life Cycle. Complete metamorphosis. Females lay eggs in groups on slender stalks which keep young larvae from eating each other after they hatch. Larvae grow through three stages for 2 to 3 weeks before each spins a white silken cocoon. ”