The Melectini are a tribe of medium- to large-sized apid

Apidae

The Apidae are a large family of bees, comprising the common honey bees, stingless bees , carpenter bees, orchid bees, cuckoo bees, bumblebees, and various other less well-known groups...

 bee

Bee

Bees are flying insects closely related to wasps and ants, and are known for their role in pollination and for producing honey and beeswax. Bees are a monophyletic lineage within the superfamily Apoidea, presently classified by the unranked taxon name Anthophila...

s found essentially worldwide. They are brood parasite

Brood parasite

Brood parasites are organisms that use the strategy of brood parasitism, a kind of kleptoparasitism found among birds, fish or insects, involving the manipulation and use of host individuals either of the same or different species to raise the young of the brood-parasite...

s of the related typical digger bees (Anthophorini

Anthophorini

The Anthophorini is a large tribe in the family Apidae, with over 750 species worldwide that were previously classified in the family Anthophoridae; the vast majority of species are in the genera Amegilla and Anthophora. All species are solitary, though many nest in large aggregations...

) and will occasionally visit flowers e.g. in prairie

Prairie

Prairies are considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and grasses, herbs, and shrubs, rather than trees, as the dominant vegetation type...

 landscapes of the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

.

As in other cuckoo bee

Cuckoo bee

The term cuckoo bee is used for a variety of different bee lineages which have evolved the kleptoparasitic habit of laying their eggs in the nests of other bees, reminiscent of the behavior of cuckoo birds. The name is technically best applied to the apid subfamily Nomadinae...

s, females can be easily distinguished from those of their hosts by the lack of scopae

Scopa (biology)

The term scopa is used to refer to any of a number of different modifications on the body of a non-parasitic bee that form a pollen-carrying apparatus. In most bees, the scopa is simply a particularly dense mass of elongated, often branched, hairs on the hind leg...

 and other pollen

Pollen

Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...

-collecting adaptation

Adaptation

An adaptation in biology is a trait with a current functional role in the life history of an organism that is maintained and evolved by means of natural selection. An adaptation refers to both the current state of being adapted and to the dynamic evolutionary process that leads to the adaptation....

s, as well as lacking prepygidial fimbria

Fimbria

A fimbria is a Latin word that literally means "fringe." It is commonly used in science and medicine, with its meaning depending on the field of study or the context...

 and basitibial plates. Their body hair is rather short and on the abdomen

Abdomen

In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...

 lies flat against the exoskeleton

Exoskeleton

An exoskeleton is the external skeleton that supports and protects an animal's body, in contrast to the internal skeleton of, for example, a human. In popular usage, some of the larger kinds of exoskeletons are known as "shells". Examples of exoskeleton animals include insects such as grasshoppers...

. They may therefore be difficult at first glance to distinguish from Nomadinae

Nomadinae

The subfamily Nomadinae is the largest and most diverse group of cleptoparasitic "cuckoo bees" with 31 genera in 10 tribes; they occur worldwide, and utilize many different types of bees as hosts. As parasites, they lack a pollen-carrying scopa, and are often extraordinarily wasp-like in appearance...

, but the details of their wing venation are characteristic: the marginal cell is shorter than the first two submarginal cells, and the second abscissa of vein M+Cu is extremely short, with the cells it connects being almost adjacent to each other. The jugal lobes are very small, less than half as long as the vannal lobes.

Genera

The following bee genera belong to the Melectini:

• Afromelecta Lieftinck 1972
• Brachymelecta Linsley 1939
• Melecta Latreille 1802 (= Bombomelecta, Symmorpha)
• Sinomelecta Baker 1997
• Tetralonioidella Strand 1914 (= Callomelecta, Protomelissa)
• Thyreomelecta Rightmyer & Engel 2003
• Thyreus
  Thyreus
  Thyreus is a genus of bees commonly known as cuckoo bees, which parasitise other species of bee. Some are brightly coloured - three species from the Sydney region, Thyreus nitidulus, T. lugubris, and T...
  
  Panzer 1806 (= Crocissa, Crocisa)
• Xeromelecta Linsley 1939
• Zacosmia Ashmead 1898 (= Micromelecta )

Several of these (Afromelecta, Melecta and Xenomelecta) have subgenera which some authors may consider independent genera.