Synonyms and other taxonomic changes
Taxonomy on BG follows (1)
When submitting images of aphids, more angles increase chances for an ID. Taking pictures of different morphs also helps. Alate forms can be easier to ID than apterous. Immature aphids generally cannot be reliably identified beyond family. Species identification is usually easier if host plant is known, but similar aphid species may colonize the same host. An attempt to organize aphid images by host plant
identification resources: (4) Aphid identification
[European and cosmopolitan taxa]
keys by host plants on (5)
worldwide, more diverse in temperate regions than in the tropics (unusual pattern among insects)
Different species have what are called seasonal peak flights. Males usually seen in the fall, and different morphs can also be present at specific times.
Aphids are phloem feeders, they use their sucking piercing mouthparts to suck plant juices. Some are restricted to a single host species or a group of related hosts. Others may alternate between two entirely unrelated host plants as a necessary part of their life cycle (e.g. Dysaphis plantaginea
begins the year on apple, then migrates to narrow-leaved plantain for several generations before winged adults return to apple trees where they produce eggs that will overwinter). Aphids that do alternate host plants are called heteroecious, and those that do not host alternate are known as monoecious. Aphids that feed on multiple species of plant are known as polyphagous, a few plants (usually related) is oligophagous, and if they only utilize one species of plant they are monophagous.
Aphids may need up to 4 hours to find and tap suitable phloem but once they hit an adequate sieve they may tap it continuously for several days.(6)
Two types of life cycle exist, holocyclic and anholocyclic. Holocyclic species alternate between sexual and asexual (parthenogenetic
) reproduction. Over-wintering eggs produced by sexual reproduction hatch in the spring. The aphids that hatch from those eggs are wingless parthenogenetic females known as fundatrices. The fundatrices give live birth to more females. The second generation of asexual females are known as viviparae, because they hold embryos in their bodies to give birth to live young. As the colony grows winged viviparous females known as alatae may be produced, although they are unknown in some species. In autumn as the photoperiod shortens and temperature decreases, male forms and egg-laying females called oviparae are produced. After mating, the oviparae lay fertilized eggs which overwinter until the spring. In anholocyclic species there is no sexual reproduction, only parthenogenetic reproduction. This is especially common in warm climates where overwintering is unnecessary. There are some anholocyclic species, such as Aphis nerii
, where males have never been observed in the wild.
Feeding aphids excrete a sugar-rich liquid known as honeydew, often consumed by ants who tend aphid colonies and protect them from predators in exchange. Ants may be herding aphids and "milk" them by stroking the aphids with their antennae, hence the common name Ant Cows. Some ant species move aphids from one plant to another when the food supply is insufficient, or even take aphid eggs into their nests to help them overwinter.
Predators of aphids include (left to right, below) lacewing larvae, coccinellids (adults & larvae), harvester butterfly caterpillars, and syrphid fly larvae.
Aphids are also attacked by parasitic wasps, which lay eggs inside them. Parasitized aphids swell, change color, and are eventually killed by the developing wasp inside. These are referred to as "aphid mummies."
Food quality is an important factor influencing wing formation. Also stimuli from crowded conditions stimulate wing development of offspring of apterous females.(6)
Hottes F.C., Frison T.H. (1931) The plant lice, or Aphididae, of Illinois. INHS Bull. 19: 121‒447. (Full text
Blackman R.L., Eastop V.F. (2000) Aphids on the World’s crops: An identification and information guide (2nd Ed.) John Wiley & Sons. 466 pp.
Blackman R.L., Eastop V.F. (2007) Aphids on the World’s herbaceous plants and shrubs. 2 vols. John Wiley & Sons. 1456 pp.
Quednau F.W. (1999) Atlas of the Drepanosiphine Aphids of the World Pt. I: Panaphidini Oestlund, 1922 – Myzocallidina Börner, 1942 (1930) (Hemiptera: Aphididae: Calaphidinae). The American Entomological Institute. 281 pp.
Quednau F.W. (2003) Atlas of the Drepanosiphine Aphids of the World Pt. II: Panaphidini Oestlund, 1923 – Panaphidinae Oestlund, 1923 (Hemiptera: Aphididae: Calaphidinae). The American Entomological Institute. 301 pp.
Quednau F.W. (2010) Atlas of the Drepanosiphine Aphids of the World Pt. III: Mindarinae Tullgren, 1909; Neophyllaphidinae Takahashi 1921; Lizeriinae E.E. Blanchard, 1923; Pterasteheniinae Remaudière & Quednau, 1988; Macropodaphidinae Zachvatkin & Aizenberg, 1960; Taiwanaphidinae Quesdnau & Remaudière, 1994; Spicaphidinae Essig, 1953; Phyllaphidinae Herrich-Schaeffer in Koch, 1857; Israelaphidinae Ilharco, 1961; Saltusaphidinae Baker, 1920 (Hemiptera: Sternorrhyncha, Aphididae). The American Entomological Institute. 361 pp.