The Lygaeidae are a family in the Hemiptera

Hemiptera

Hemiptera is an order of insects most often known as the true bugs , comprising around 50,000–80,000 species of cicadas, aphids, planthoppers, leafhoppers, shield bugs, and others...

 (true bugs), with some 60 genera

Genera

Genera is a commercial operating system and development environment for Lisp machines developed by Symbolics. It is essentially a fork of an earlier operating system originating on the MIT AI Lab's Lisp machines which Symbolics had used in common with LMI and Texas Instruments...

 in six subfamilies. The family includes the insects commonly known as milkweed bugs, and also some of those known as seed bugs. The family used to be vastly larger, as numerous former subfamilies have been removed and given independent family status, including Artheneidae, Blissidae, Cryptorhamphidae, Cymidae, Geocoridae, Heterogastridae

Heterogastridae

Heterogastridae is a family of lygaeoid bugs consisting of 23 genera and 97 species.The group has been considered a subfamily, tribe and subtribe, but most recently has been restored to family status....

, Ninidae, Oxycarenidae, Pachygronthidae, and Rhyparochromidae

Rhyparochromidae

The Rhyparochromidae are a large family of true bugs , many of which are commonly referred to as seed bugs. The family includes two subfamilies, 368 genera, and over 1,800 species....

, which together constituted well over half of the former family. Many of the species feed on seeds, although some feed on sap (mucivory), and a few, such as the wekiu

Wekiu bug

The wēkiu bug is a species of seed bug, endemic to Hawaii island.-Description:The wēkiu bug is flightless and inhabits the summit area of Mauna Kea, over ....

 bug, feed on insects.
The bizarre and mysterious beetle

Beetle

Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...

-like Psamminae were formerly often placed in the Piesmatidae

Piesmatidae

Piesmatidae is a small family of true bugs, commonly called ash-grey leaf bugs. It contains a mere three living genera with over 40 described species altogether. The Piesmatidae are distributed mostly in the temperate Northern Hemisphere, with some occurring in Africa, Australia and South America...

, but this is almost certainly quite incorrect. Their true affiliations, however, are not entirely resolved to satisfaction.

List of Genera

Subfamily Bledionotinae

• Austropamphantus
• Bledionotus
• Pamphantus

Subfamily Henestarinae

• Engistus
• Henestaris

Subfamily Ischnorhynchinae (this subfamily is occasionally treated at the family level)

• Acanthocrompus
• Cerocrompus
• Crompus
• Kleidocerys
• Koscocrompus
• Neokleidocerys
• Pylorgus

Subfamily Lygaeinae (list incomplete; at least 30 included genera)

• Lygaeus
• Lygaeospilus
• Melanocoryphus
• Melanopleurus
• Neacoryphus
• Ochrimnus
• Oncopeltus

Subfamily Orsillinae (this subfamily is occasionally treated at the family level)

• Austronysius
• Belonochilus
• Eurynysius
• Hyalonysius
• Lepionysius
• Neortholomus
• Neseis
• Nithecus
• Nysius
  Nysius
  The genus Nysius in the insect family Lygaeidae, contains approximately 106 species throughout the world.Like other seed bugs, there are some species in the genus that have proven to be crop pests of wheat and other grains , as well as many vegetables...
  
  
• Oceanides
• Orsillus
• Ortholomus
• Reticulatonysius
• Xyonysius

Subfamily Psamminae

• Psammium
• Saxicoris
• Sympeplus