[19] Phylloxera (Daktulosphaira vitifoliae) are insects which caused the Great French Wine Blight that devastated European viticulture in the 19th century. Aphids brush against the microscopic spores. [90], Aphids are often infected by bacteria, viruses, and fungi. Aphids avoid this fate by osmoregulating through several processes. Control is complex; some aphids alternate during their life-cycles between genetic control (polymorphism) and environmental control (polyphenism) of production of winged or wingless forms. [53] The live young are produced by pseudoplacental viviparity, which is the development of eggs, deficient in the yolk, the embryos fed by a tissue acting as a placenta. [20] Aphids have a tail-like protrusion called a cauda above their rectal apertures. Peter Marren and Richard Mabey record that Gilbert White described an invading "army" of black aphids that arrived in his village of Selborne, Hampshire, England, in August 1774 in "great clouds", covering every plant, while in the unusually hot summer of 1783, White found that honeydew was so abundant as to "deface and destroy the beauties of my garden", though he thought the aphids were consuming rather than producing it. [20] Sexual females and males mate, and females lay eggs that develop outside the mother. Some species feed on only one type of plant, while others are generalists, colonizing many plant groups. [126], For small backyard infestations, spraying plants thoroughly with a strong water jet every few days may be sufficient protection. Some species produce winged progeny in response to low food quality or quantity. The stylus is inserted and saliva secreted, the sap is sampled, the xylem may be tasted and finally, the phloem is tested. Aphids have antennae with two short, broad basal segments and up to four slender terminal segments. This occurs in, for example, the life cycle of the rose aphid (Macrosiphum rosae), which may be considered typical of the family. [22], The phylogenetic tree, based on Papasotiropoulos 2013 and Kim 2011, with additions from Ortiz-Rivas and Martinez-Torres 2009, shows the internal phylogeny of the Aphididae. In this respect, the probing behavior of an aphid tasting a host is more damaging than lengthy aphid feeding and reproduction by stay-put individuals. Winged aphids may also rise up in the day as high as 600 m where they are transported by strong winds. This assumption is well supported by the evidence, and several phylogenetic relationships have been suggested on the basis of endosymbiont studies. They have a pair of compound eyes, with an ocular tubercle behind and above each eye, made up of three lenses (called triommatidia). [116][117] Honeydew produced by aphids has been observed to reduce the effectiveness of fungicides as well. [112], Plants mount local and systemic defenses against aphid attack. Aphids of the round morph cause the ants to farm them, as with many other aphids.

[26][27][28], Aphidina (Aphis spp, e.g.

As fall approaches, the soybean plants begin to senesce from the bottom upwards. The eggs survive the winter and hatch into winged (alate) or wingless females the following spring. This is a mutualistic relationship, with these dairying ants milking the aphids by stroking them with their antennae. [88], Aphids are eaten by many bird and insect predators.

Winged females may develop later in the season, allowing the insects to colonize new plants. [8] They probably fed on plants like Cordaitales or Cycadophyta. The results depend on the assumption that the symbionts are strictly transmitted vertically through the generations.

they are born pregnant). [31] The wild potato, Solanum berthaultii, produces an aphid alarm pheromone, (E)--farnesene, as an allomone, a pheromone to ward off attack; it effectively repels the aphid Myzus persicae at a range of up to 3 millimetres. [b][67] Although mutualistic, the feeding behaviour of aphids is altered by ant attendance. [11][30], When host plant quality becomes poor or conditions become crowded, some aphid species produce winged offspring (alates) that can disperse to other food sources. [101], Although aphids cannot fly for most of their life cycle, they can escape predators and accidental ingestion by herbivores by dropping off the plant onto the ground. [100] Aphids that form closed galls use the plant's vascular system for their plumbing: the inner surfaces of the galls are highly absorbent and wastes are absorbed and carried away by the plant. On the University of Florida / Institute of Food and Agricultural Sciences Featured Creatures website: This article is about the insect.

Thus, one female hatched in spring can theoretically produce billions of descendants, were they all to survive. The removal of sap creates a lack of vigor in the plant, and aphid saliva is toxic to plants. The eggs are laid in batches, each female laying several hundred.

[11] They feed on sap using sucking mouthparts called stylets, enclosed in a sheath called a rostrum, which is formed from modifications of the mandible and maxilla of the insect mouthparts. Some species interact with plant tissues forming a gall, an abnormal swelling of plant tissue. In a nitrogen-poor environment, this could provide an advantage to an infested plant over an uninfested plant.

[123] They are major pests of greenhouse crops and species often encountered in greenhouses include: green peach aphid (Myzus persicae), cotton or melon aphid (Aphis gossypii), potato aphid (Macrosiphum euphorbiae), foxglove aphid (Aulacorthum solani) and chrysanthemum aphid (Macrosiphoniella sanborni) and others, which cause leaf yellowing, distorted leaves, and plant stunting; the excreted honeydew is a growing medium for a number of fungal pathogens including black sooty molds from the genera Capnodium, Fumago, and Scorias which then infect leaves and inhibit growth by reducing photosynthesis. Here they mate and overwinter as eggs. The aphids are forced upwards and start to produce winged forms, first females and later males, which fly off to the primary host, buckthorn. They overwinter on primary hosts on trees or bushes; in summer, they migrate to their secondary host on a herbaceous plant, often a crop, then the gynoparae return to the tree in autumn. Aphids are among the most destructive insect pests on cultivated plants in temperate regions. Once a phloem vessel is punctured, the sap, which is under pressure, is forced into the aphid's food canal.

The soldier morphs are mostly first and second instars with the third instar being involved in Eriosoma moriokense and only in Smythurodes betae are adult soldiers known. [74] The original association may is estimated to have occurred in a common ancestor 280to160 million years ago and enabled aphids to exploit a new ecological niche, feeding on phloem-sap of vascular plants. [89] Insects that attack aphids include the adults and larvae of predatory ladybirds, hoverfly larvae, parasitic wasps, aphid midge larvae, "aphid lions" (the larvae of green lacewings), and arachnids such as spiders. At this point, the ants attack the butterflies, but the butterflies have a sticky wool-like substance on their wings that disables the ants' jaws, allowing the butterflies to fly away without being harmed. [103] Peptides produced by aphids, Thaumatins, are thought to provide them with resistance to some fungi. The Aphidoidea includes a single large family Aphididae that includes all the ~5000[2] extant species. A typical life cycle involves flightless females giving live birth to female nymphswho may also be already pregnant, an adaptation scientists call telescoping generationswithout the involvement of males. [70], Another ant-mimicking gall aphid, Paracletus cimiciformis (Eriosomatinae), has evolved a complex double strategy involving two morphs of the same clone and Tetramorium ants. An integrated pest management strategy using biological pest control can work, but is difficult to achieve except in enclosed environments such as greenhouses. [20], Many aphid species are monophagous (that is, they feed on only one plant species). [31], Aphids usually feed passively on sap of phloem vessels in plants, as do many of other hemipterans such as scale insects and cicadas. Queens leaving to start a new colony take an aphid egg to found a new herd of underground aphids in the new colony. Around 400 of these are found on food and fiber crops, and many are serious pests of agriculture and forestry, as well as an annoyance for gardeners. [46] They are the only animals other than two-spotted spider mites and the oriental hornet with this capability. [43] These symbionts recycle glutamate, a metabolic waste of their host, into essential amino acids. [29] The cabbage aphid, Brevicoryne brassicae, sequesters secondary metabolites from its host, stores them and releases chemicals that produce a violent chemical reaction and strong mustard oil smell to repel predators. [11] It has been hypothesized that the ancestors of the Adelgidae lived on conifers while those of the Aphididae fed on the sap of Podocarpaceae or Araucariaceae that survived extinctions in the late Cretaceous. [52], When a typical sophisticated reproductive strategy is used, only females are present in the population at the beginning of the seasonal cycle (although a few species of aphids have been found to have both male and female sexes at this time). [47] Using their carotenoids, aphids may well be able to absorb solar energy and convert it to a form that their cells can use, ATP. [16] Early 21st-century reclassifications substantially rearranged the families within Aphidoidea: some old families were reduced to subfamily rank (e.g., Eriosomatidae), and many old subfamilies were elevated to family rank.

Insecticides do not always produce reliable results, given resistance to several classes of insecticide and the fact that aphids often feed on the undersides of leaves. [15] Some authors use a single superfamily Aphidoidea within which the Phylloxeridae and Adelgidae are also included while others have Aphidoidea with a sister superfamily Phylloxeroidea within which the Adelgidae and Phylloxeridae are placed.

[48], The simplest reproductive strategy is for an aphid to have a single host all year round.