Have you ever seen a morning glory bee? If you live in eastern North America and like to look at morning glory blooms at dawn, you have a better chance! Eucera (Cemolobus) ipomoeae is a specialist bee that is rarely seen. This large, long-horned bee is also referred to as the morning glory bee!

Why is it called the morning glory bee? This bee uses several species in the morning glory genus Ipomoea as its source of food (particularly pollen). These bees have evolved a specialized relationship with this group of plants. When morning glory flowers begin to bloom in the summer, adult morning glory bees emerge from the ground and begin foraging for pollen and nectar.

Eucera (Cemolobus) ipomoeae (Robertson, 1891), male, side. Photo Credit: USGS Bee Inventory and Monitoring Lab / CC PDM 1.0

Where can you find it? It is distributed from Illinois east to North Carolina and south to Georgia. However, in 2018, researchers at the University of Colorado collected six female bees when conducting bee surveys (Carper et al., 2018). In the López-Uribe Lab collection, we have 2 specimens that were collected by Dr. Dave Biddinger in Pennsylvania between 2012 and 2015.

Taxonomy. Eucera (Cemolobus) ipomoeae is in the family Apidae, and the tribe Eucerini. It is closely related to the subgenera Peponapis and Xenoglossa that are commonly known as squash bees.

Morning Glory bees can be identified by a section of their face called the clypeus. Their clypeus has a wide central rectangular projecting lobe with one large triangular tooth on either side.


Life History. This species is solitary, meaning that there is only one female in each nest. In the summer, individuals of Eucera (Cemolobus) ipomoeae emerge from the ground, where the females from the previous year had their nests. After emergence, males and females will mate. Then, females will begin collecting pollen and nectar from morning glories and carrying it back to their nesting place. After creating a pollen provision  (mixture of pollen, nectar, and secretions from the mandibular glands), they lay their eggs on top of the provision. Over time, the eggs hatch and turn into larvae that eat the pollen, build cocoons, and overwinter underground until next summer when they emerge and the cycle begins all over again.

In the months of June, July, and August when morning glory flowers are blooming, Eucera (Cemolobus) ipomoeae is active but is rarely seen or reported most likely because these bees are active at dawn and not seen away from the blooms of their host plants. These bees are large; females are 12.5 to 14.5 mm and males are 13 to 14.5 mm. This is roughly 1.5 times larger than the European Honey Bee (Apis mellifera).

Cemolobus ipomoeae, Keng-Lou James Hung / CC BY-NC 4.0
Morning Glory Flower with distributed pollen. Photo Credit: Isabella Petitta.

Plant use. Eucera (Cemolobus) ipomoeae is known to be monolectic meaning that it only collects pollen from a single plant genus, Ipomoea (Cane and Sipes, 2006). The species Ipomoea pandurata, also called man-of-the-earth or wild sweet potato, was thought to be the only species that was foraged on. While this plant is used, others in the genus Ipomoea such as bush morning glory have been found along with Cemolobus bees. It is also suggested that false bindweed (Calystegia R. Br.) is a source of food (Fowler and Droege, 2020). Sweet potatoes—that are commonly found in grocery stores—come from the tuberous root of Ipomoea batatas and are not fruits. Therefore, sweet potato pollination does not produce sweet potatoes, but pollination is needed for the plant to produce seed and breed sexually. Pollinators carry pollen between sweet potato plants and maintain genetic diversity in sweet potato populations.

Natural Enemies. Bee species can be impacted by a range of predators, parasites, and parasitoids that can kill bees. Little is known about the enemies of Cemolobus since they have not been widely documented or studied.

Relationship with Humans. Morning glory bees are rare, so humans do not interact with them normally. Humans can impact wild bee populations by increasing pesticide use and disrupting wild bee habitat as these factors have been found to be harmful to wild bees. More research is needed to understand how humans are impacting Cemolobus bees.

References

Cane J, Sipes S (2006) Floral specialization by bees: analytical methodologies and a revised lexicon for oligolecty. pp. 99-122 In Plant-Pollinator Interactions: From Specialization to Generalization. N. Waser and J. Ollerton, (eds.), Univ. Chicago Press.

Carper A, Schwantes C, Jamieson, M (2018) A New State Record of the Rare Bee, Cemolobus ipomoeae (Hymenoptera, Apidae), from Colorado, USA. Journal of the Kansas Entomological Society, 91(2):171-175. https://doi.org/10.2317/0022-8567-91.2.171

Fowler J, Droege S (2020). Pollen Specialist Bees of the Eastern United States. https://jarrodfowler.com/specialist_bees.html

 

Contributed by
Isabella Petitta
Pennsylvania State University

Updated 30 September 2021