Peponapis- squash bees (family Apidae)
Genus summary: Peponapis is a small genus with about 13 species in the New World, mostly in the deserts of Mexico and the southwestern U.S. (Michener 2000). There is a single species native to New York State (Danforth & Magnacca 2002) and another native to the northwestern portions of the U.S. and Canada.
Floral relationships: Peponapis are all specialists foragers on the family Cucurbitaceae (the squash family), which includes pumpkins, watermelons, squashes and gourds. Peponapis relies on Cucurbitaceae for different parts of its life cycle. Mating occurs inside Cucurbit flowers, males take shelter overnight in them, and females provide their young with nectar and pollen strictly from Cucurbits (Hurd et al. 1971). Peponapis forage most actively during the hours of early morning sunlight (Stephen et al. 1969); If you live where these bees are abundant, you can often find males asleep in closed squash flowers around midday.
Nesting habits: Peponapis are solitary ground nesting bees. They line their brood cells with a waxlike material that they secrete, as do closely related genera such as Melissodes and Svastra (Michener 2000).
Diagnostic characteristics: Peponapis is a genus with a diversity of form and structure among species. They are medium sized, fairly robust bees from 0.4 to 0.6 inches long (Michener 2000). They usually have brown hair, and only weak to no hair bands on the abdomen . Male antennae are somewhat shorter than in most Eucerini (Michener 1994), and males have a small yellow patch on their face (Michener 2000). The lower front part of their face sticks out a lot (like a “big nose”) (Michener 2000).
Similar taxa: Peponapis are similar to other genera in the tribe Eucerini (Melissodes, Svastra), but Peponapis males have shorter antennae and both males and females are typically seen around Cucurbit flowers.
Known conservation concerns: On a bee-per-bee basis, Peponapis have been shown to be more effective pollinators of cucurbits than the honey bee, Apis mellifera (Tepedino 1981). Recent research found that Peponapis are abundant and perhaps the dominant pollinator of Cucurbit crops throughout much of their range (Cane 2005). Considering the valuable role they could play in pollinating squash crops, it is important to learn more about the biology and nesting requirements of Peponapis spp. in order to provide habitat or manage squash fields to sustain populations of these important crop pollinators (Canto-Aguila 2000).
Interesting facts: Some species are expanding their ranges as humans have expanded the natural range of squashes, most of which originate from the southwestern United States (Cane 2005).
Additional resources: Canto-Aguilar (2000), Shuler et al (2005) - No till native bees and squash.pdf, Cane (2005) http://www.ars.usda.gov/Research/docs.htm?docid=12041