Sternorrhyncha

The Sternorrhyncha^[1][2][3] suborder of the Hemiptera contains the aphids, whiteflies, and scale insects, groups which were traditionally included in the now-obsolete order "Homoptera". The name "Sternorrhyncha" refers to the rearward position of the mouthparts relative to the head.

Sternorrhyncha Temporal range: Permian–Recent PreꞒ Ꞓ O S D C P T J K Pg N
An aphid.
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hemiptera
Suborder:	Sternorrhyncha
Superfamilies
Aleyrodoidea Aphidoidea Coccoidea Phylloxeroidea Psylloidea

Distributed worldwide, all members of this group are plant-feeders, many considered pests feeding on major crops and ornamental plants.

Many exhibit modified morphology and/or life cycles, including phenomena such as flightless morphs, parthenogenesis, sexual dimorphism, and eusociality.

Phylogeny

The phylogeny of the extant Sternorrhyncha, inferred from analysis of small subunit (18S) ribosomal RNA, is shown in the cladogram.^{[citation needed]}

Sternorrhyncha	Psylloidea (jumping plant lice, etc.) Aleyrodoidea (whiteflies) Coccoidea (scale insects) Aphidomorpha Phylloxeroidea (phylloxera bugs) Aphididae (aphids)

The evolutionary position of several fossil taxa are unclear. A suggested phylogeny is:^[4][5]

	†Pincombeomorpha Boreoscytidae Pincombeidae Simulaphididae Coccidomorpha †Naibiomorpha Dracaphididae Naibiidae Sinojuraphididae Aphidomorpha †Protopsyllidioidea †Dinglomorpha Aleyrodomorpha †Liadopsyllidae Psylloidea

Groups

Well-known groups in the Sternorrhyncha include:

• aphids – (Aphididae)
• woolly and gall-making aphids (Eriosomatinae)
• pine and spruce aphids (Adelgidae)
• phylloxerans (Phylloxeridae, including the vine phylloxera)
• whiteflies – (Aleyrodidae)
• jumping plant lice (Psyllidae and allied families)
• Superfamily Coccoidea (scale insects)
  • cottony cushion scales, giant coccids, and ground pearls (Margarodidae)
  • armoured scales (Diaspididae)
  • cochineal insects (Dactylopiidae)
  • lac scales (Kerriidae, Lacciferidae, Tachardinidae)
  • soft scales (Coccidae)
  • pit scales (Asterolecaniidae)
  • mealybugs (Pseudococcidae)
  • felted scales (Eriococcidae)