Philanthus bicinctus

(Mickel, 1916)

Bumble Bee Wolf, Bumblebee Wolf

Philanthus bicinctus, commonly known as the Bumblebee Wolf, is a of beewolf to the American Rockies. This solitary wasp is notable for its specialized on bumblebees, which it paralyzes to provision underground nests for its larvae. Research conducted at Yellowstone National Park has documented large of this species and its significant potential to influence dynamics and insect-flower interactions. Males exhibit strong territorial , defending hilltops and elevated areas to secure mating opportunities.

Pronunciation

How to pronounce Philanthus bicinctus: /fɪˈlænθəs baɪˈsɪŋktəs/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from other Philanthus by specific morphological features; males lack the tarsal rake (digging spines on forelegs) present in females. The species can be confused with other beewolf and cuckoo bees in the Nomada, but differs in having emarginated (notched) inner margins. Females have spines on the front legs adapted for digging burrows in sandy soils.

Habitat

to the American Rockies; forms large nesting in sandy soils. Males establish territories on hilltops, ridges, and other elevated areas. Documented from Yellowstone National Park where research aggregations occur.

Distribution

to the American Rockies; North America.

Seasonality

Active during summer months; research conducted in summer 2003 at Yellowstone. Male territorial observed during breeding season.

Diet

Preys almost exclusively on bumblebees. Females paralyze bumblebees with a sting between the front legs, disabling a nerve center, then transport prey beneath the body using middle legs. Multiple bumblebees are required to provision each larval .

Life Cycle

Females excavate burrows 15-24 cm deep (up to 1 meter in expanded nests) in bare, coarse sand, sandy-clay, or sandy loam soil. Burrows contain individual at ends of short tunnels radiating from the main shaft. Each cell is provisioned with multiple paralyzed bumblebees; a single is laid on the first prey item. Larvae feed on the cached bees before pupating. Some evidence of burrow sharing by sibling females and multi-generational nest expansion.

Behavior

Females actively stalk bumblebees at flowers, attacking when bees are distracted while foraging. Males are highly territorial, perching on elevated sites to intercept females and chase competing males; larger males tend to hold superior territories. Males scent-mark vegetation using abdominal hair brushes to signal territory ownership. Males may aggregate in female burrows overnight and during inclement weather, returning repeatedly to the same burrow.

Ecological Role

that can dramatically influence insect-flower interactions and dynamics. As a predator of bumblebees, may impact pollination services and plant reproductive success in areas where occur.

Similar Taxa

Philanthus gibbosusMost common North American beewolf; differs in prey breadth ( vs. on bumblebees) and geographic range (transcontinental vs. Rocky Mountain ).
Nomada spp.Cuckoo bees frequently mistaken for beewolves; lack predatory and have different wing venation and body hair patterns.
Aphilanthops spp.Related philanthine that prey on queens rather than bees; differ in straight inner margins and prey type.