Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A typical life cycle involves flightless females giving live birth to female nymphs—who may also be already pregnant, an adaptation scientists call telescoping generations—without the involvement of males. Maturing rapidly, females breed profusely so that the number of these insects multiplies quickly. Winged females may develop later in the season, allowing the insects to colonize new plants. In temperate regions, a phase of sexual reproduction occurs in the autumn, with the insects often overwintering as eggs.
Galls or cecidia are a kind of swelling growth on the external tissues of plants, fungi, or animals. Plant galls are abnormal outgrowths of plant tissues, similar to benign tumors or warts in animals. They can be caused by various parasites, from viruses, fungi and bacteria, to other plants, insects and mites. Plant galls are often highly organized structures so that the cause of the gall can often be determined without the actual agent being identified. This applies particularly to some insect and mite plant galls. The study of plant galls is known as cecidology.
Woolly aphids are sap-sucking insects that produce a filamentous waxy white covering which resembles cotton or wool. The adults are winged and move to new locations where they lay egg masses. The nymphs often form large cottony masses on twigs, for protection from predators.
The gall adelgid is an adelgid species that produces galls in spruce trees. They infect the new buds of native spruce trees in the foothills of the Rocky Mountains in the spring. They also attack blue spruce to a lesser degree. The insects complete two generations within the year. They require two different trees for its life cycle, the second being the Rocky Mountain Douglas-fir. They may also attack Sitka, Engelmann, or white spruce. The many different species of adelgids produce different galls on different spruce species.
The beech blight aphid is a small insect in the order Hemiptera that feed primarily on the sap of American beech trees. The aphids form dense colonies on small branches and the undersides of leaves. A secondary host, based on their geographic location, is the roots of the bald cypress (Taxodium distichum), where some aphids alternate between hosts and others remain with Taxodium distichum year-round.
Myzus persicae, known as the green peach aphid, greenfly, or the peach-potato aphid, is a small green aphid belonging to the order Hemiptera. It is the most significant aphid pest of peach trees, causing decreased growth, shrivelling of the leaves and the death of various tissues. It also acts as a vector for the transport of plant viruses such as cucumber mosaic virus (CMV), potato virus Y (PVY) and tobacco etch virus (TEV). Potato virus Y and potato leafroll virus can be passed to members of the nightshade/potato family (Solanaceae), and various mosaic viruses to many other food crops.
Cinara cupressi, the cypress aphid, is a brownish soft-bodied aphid. It sucks sap from twigs of conifers, and can cause damage to the tree, ranging from discoloring of the affected twig to the death of the tree. This insect appears to have originated in the Middle East and has been increasing its range and is considered to be an invasive species in Africa and Europe. It has been included in the List of the world's 100 worst invasive species.
Aphelinus mali is a parasitoid wasp that exploits the woolly apple aphid, a pest of apple trees. It is native to the northeastern United States but has been introduced to other parts of the world as a biological pest control agent.
Aphis gossypii is a tiny insect, an aphid ("greenfly") in the superfamily Aphidoidea in the order Hemiptera. It is a true bug and sucks sap from plants. It is a widely distributed pest of a variety of agricultural crops in the families Cucurbitaceae, Rutaceae and Malvaceae. Common names include cotton aphid, melon aphid and melon and cotton aphid.
The black bean aphid is a small black insect in the genus Aphis, with a broad, soft body, a member of the order Hemiptera. Other common names include blackfly, bean aphid, and beet leaf aphid. In the warmer months of the year, it is found in large numbers on the undersides of leaves and on the growing tips of host plants, including various agricultural crops and many wild and ornamental plants. Both winged and wingless forms exist, and at this time of year, they are all females. They suck sap from stems and leaves and cause distortion of the shoots, stunted plants, reduced yield, and spoiled crops. This aphid also acts as a vector for viruses that cause plant disease, and the honeydew it secretes may encourage the growth of sooty mould. It breeds profusely by live birth, but its numbers are kept in check, especially in the later part of the summer, by various predatory and parasitic insects. Ants feed on the honeydew it produces, and take active steps to remove predators. It is a widely distributed pest of agricultural crops and can be controlled by chemical or biological means. In the autumn, winged forms move to different host plants, where both males and females are produced. These mate and the females lay eggs which overwinter.
Euceraphis betulae, the birch aphid or silver birch aphid, is a species of aphid in the order Hemiptera. It is a tiny green insect with a soft body and wings. It is found living on the European silver birch tree where it feeds and multiplies on the buds and leaves by sucking sap.
Euceraphis punctipennis, the downy birch aphid or European birch aphid, is a species of aphid in the order Hemiptera. These aphids are tiny green insects with soft bodies and membranous wings. They are found living on downy birch trees where they feed and multiply on the buds and leaves by sucking sap.
Aphis craccivora, variously known as the cowpea aphid, groundnut aphid or black legume aphid, is a true bug in the family Aphididae. Originally of probable Palearctic origin, it is now an invasive species of cosmopolitan distribution.
Cinara confinis, the black stem aphid, is a species of aphid in the genus Cinara, found feeding on the twigs of various species of fir (Abies) and on several other species of coniferous trees. This aphid has a Holarctic distribution and is known from Europe, Asia, North America and Argentina.
Aphis pomi, commonly known as the apple aphid, or the green apple aphid, is a true bug in the family Aphididae. It is found on young growth of apple trees and on other members of the rose family where it feeds by sucking sap. Reproduction is mainly by parthenogenesis, in which unmated females give birth to live young.
Colophina clematis is a species of aphid in the woolly aphid subfamily, Eriosomatinae, native to Japan. This woolly aphid has the distinction of being the first species of aphid to have been identified as having a "soldier" caste. First instar nymphs of this type are able to protect the aphid colony, killing the larvae of predatory ladybirds, hoverflies and the flower bug Anthocoris nemoralis.
Phyllaphis fagi, the woolly beech aphid, is a species of aphid in the family Aphididae.
Tetraneura ulmi, the elm sack gall aphid and also known as a fig gall, is a species of aphid in the family Aphididae. It was described by Carl Linnaeus and named in his Systema Naturae, published in 1758. The mite is found in Asia, Europe and North America, causing abnormal plant growths, known as galls on their primary host, elm trees (Ulmus species). They feed on a secondary host, the roots of various grasses.
The woolly elm aphid is an aphid native to North America, found where Saskatoon and American elm trees are established.
Eriosoma ulmi, the elm-currant aphid, is a species of aphid in the family Aphididae found in Asia and Europe. It is a true bug and sucks sap from plants. It was described by Carl Linnaeus in his Systema Naturae, published in 1758. The mite causes abnormal plant growths, known as galls on their primary host, elm trees (Ulmus species). To complete there life-cycle they feed on a secondary host, the roots of currant bushes.
