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, from a 2024 study using ultraconserved genetic elements, is shown in the cladogram:^[4]

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

The evolutionary position of several fossil taxa are unclear. A suggested phylogeny is:^[5][6]

	†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)