The name squash bee, also squash and gourd bee, is applied to two related genera of

bee Bees are winged insects closely related to wasps and ants, known for their roles in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyletic lineage within the superfamil ...

s in the tribe

Eucerini The Eucerini (often called longhorn bees or long-horned bees) are the most diverse tribe in the family Apidae, with over 32 genera worldwide that were previously classified as members of the family Anthophoridae. All species are solitary, though ...

; ''

Peponapis ''Peponapis'' is a genus of bees belonging to the family Apidae. They are Squash bees, specialized pollinators of squashes and related plants. The species of this genus are found in North America. Species: *'' Peponapis apiculata'' *'' Pepon ...

'' and ''

Xenoglossa ''Xenoglossa'' is a genus of large squash bees in the family Apidae Apidae is the largest family within the superfamily Apoidea, containing at least 5700 species of bees. The family includes some of the most commonly seen bees, including bum ...

''. Both genera are oligoleges (pollen specialists) on the plant genus ''

Cucurbita is a genus of herbaceous fruits in the gourd family, Cucurbitaceae (also known as ''cucurbits'' or ''cucurbi''), native to the Andes and Mesoamerica. Five edible species are grown and consumed for their flesh and seeds. They are variously know ...

'' and closely related plants, although they usually do not visit watermelon, cucumber, and melon plants. They are small genera, containing only 13 and 7 described species, respectively, and their combined range is nearly identical to the range of ''Cucurbita'' in the New World, from

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

. Their range has become somewhat expanded along with the movement of cucurbits into other areas (as crop plants). Species such as ''

Peponapis pruinosa ''Peponapis pruinosa'' is a species of solitary bee in the tribe Eucerini, the long-horned bees. Its common name is the eastern cucurbit bee. It may be called the squash bee, but this name can also apply to other species in its genus, as well as ...

'' have been in decline due to several reasons, probably at least in part to

pesticide Pesticides are substances that are used to control pests. They include herbicides, insecticides, nematicides, fungicides, and many others (see table). The most common of these are herbicides, which account for approximately 50% of all p ...

sensitivity.

Description

These bees are of moderate size, equal to various

bumblebee A bumblebee (or bumble bee, bumble-bee, or humble-bee) is any of over 250 species in the genus ''Bombus'', part of Apidae, one of the bee families. This genus is the only Extant taxon, extant group in the tribe Bombini, though a few extinct r ...

s. Compared to honeybees, squash bees are larger and bulkier, with longer antennae and rounder faces. The pollen-carrying hairs on their legs (the

scopa (; ) is an Italian card game, and one of the three major national card games in Italy, the others being and . It is also popular in Argentina and Brazil, brought in by Italian diaspora, Italian immigrants, mostly in the variation. is also p ...

) are unbranched or nearly so, to accommodate the exceptionally large, coarse pollen of the host plants. These hairs may be sparse, however among ''Peponapis'', the hind legs are fuzzy and brushlike. Males lack these hairs, as they do not carry pollen. Squash bees have also evolved a

matinal Matutinal, matinal (in entomological writings), and matutine are terms used in the life sciences to indicate something of, relating to, or occurring in the early morning. The term may describe the morning activities of crepuscular animals that a ...

daily activity cycle, flying before sunrise. Some ''Xenoglossa'' species have become morphologically specialized to fly while it is still dark, with greatly enlarged

ocelli A simple eye or ocellus (sometimes called a pigment pit) is a form of eye or an optical arrangement which has a single lens without the sort of elaborate retina that occurs in most vertebrates. These eyes are called "simple" to distinguish the ...

to allow them to fly in near-darkness. The two genera are sometimes thought to be

sister taxa In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

, but enough differences occur between them to suggest the similarities may be due to

convergent evolution Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last comm ...

, based on their adaptation to use the same host plants.

Life cycle

Squash bees build ground-based nests; they are solitary and do not live in colonies, but are sometimes gregarious. Each pollen-gathering female digs her own nest, which consists of a vertical tunnel terminated by a loose grouping of individual nest cells.

As pollinators

Studies have been carried out to compare ''Peponapis'' and honey bees regarding their effectiveness in pollinating cucurbits. The findings point to the squash bees being more effective and suggest the current practice of renting colonies of honey bees to perform this task may be unnecessary. Squash yield is fully dependent on insect pollinators. Plants pollinated by squash bees include summer squash,

winter squash Winter squash is an annual fruit representing several squash species within the genus '' Cucurbita''. Late-growing, less symmetrical, odd-shaped, rough or warty varieties, small to medium in size, but with long-keeping qualities and hard rinds, ...

, zucchini, pumpkins, and many

gourds Gourds include the fruits of some flowering plant species in the family Cucurbitaceae, particularly ''Cucurbita'' and ''Lagenaria''. The term refers to a number of species and subspecies, many with hard shells, and some without. Many gourds have ...

excepting cucumbers.

References

{{DEFAULTSORT:Squash Bee Apinae Insect common names