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 monophyly, monophyletic lineage within the ...

s in the tribe

Eucerini The Eucerini (often called 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 many nest in lar ...

; ''

Peponapis ''Peponapis'' is a genus of bees belonging to the family Apidae. The species of this genus are found in America. Species: *'' Peponapis apiculata'' *'' Peponapis atrata'' *'' Peponapis azteca'' *'' Peponapis citrullina'' *'' Peponapis cras ...

'' and ''

Xenoglossa ''Xenoglossa'' is a genus of large squash bees in the family Apidae. There are about 11 described species in ''Xenoglossa''. Species These 11 species belong to the genus ''Xenoglossa'': * ''Xenoglossa angustior'' Cockerell, 1899 * ''Xenoglossa d ...

''. Both genera are

oligolege The term oligolecty is used in pollination ecology to refer to bees that exhibit a narrow, specialized preference for pollen sources, typically to a single family or genus of flowering plants. The preference may occasionally extend broadly to mu ...

s (pollen specialists) on the plant genus ''

Cucurbita ''Cucurbita'' (Latin for gourd) 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 ...

'' 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 relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

. Their range has become somewhat expanded along with the movement of cucurbits into other areas (as crop plants). Species such as '' Peponapis pruinosa'' have been in decline due to several reasons, probably at least in part to

pesticide Pesticides are substances that are meant to control pests. This includes herbicide, insecticide, nematicide, molluscicide, piscicide, avicide, rodenticide, bactericide, insect repellent, animal repellent, microbicide, fungicide, and lampri ...

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 group in the tribe Bombini, though a few extinct related gener ...

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 ''Scopa'' (; literally "broom") is an Italian card game, and one of the three major national card games in Italy, the others being ''Briscola'' and ''Tresette''. It is also popular in Argentina and Brazil, brought in by Italian immigrants, mostly ...

) 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 crepuscular animals that are significantly active dur ...

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 (sometimes called a pigment pit) refers to a form of eye or an optical arrangement composed of a single lens and without an elaborate retina such as occurs in most vertebrates. In this sense "simple eye" is distinct from a multi-l ...

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 t ...

, 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 com ...

, 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 Summer squash are Cucurbita, squashes that are harvested when immature, while the rind is still tender and edible. Nearly all summer squashes are varieties of ''Cucurbita pepo'', although not all ''Cucurbita pepo'' are considered summer squashes ...

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, are ...

, 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. One of the earli ...

excepting cucumbers.

References

{{DEFAULTSORT:Squash Bee Apinae Insect common names