American bumblebee
Bombus pensylvanicus, the American bumblebee, is a threatened species of bumblebee native to North America. It occurs in eastern Canada, throughout much of the Eastern United States, and much of Mexico.
Once the most prevalent bumblebee in the southern United States, populations of Bombus pensylvanicus have decreased significantly in recent years, including in its scientific namesake state of Pennsylvania, where its numbers are considered critically low. Overall the population has dropped nearly 90% in just the last 20 years.
Bombus pensylvanicus tends to live and nest in open farmland and fields. It feeds on several food plants, favoring sunflowers and clovers, and functions as a pollinator.
Te
TerrestrialTerrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
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OviparousOviparous animals are female animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive...
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Not a migrantAnimals that do not make seasonal movements and stay in their native home ranges all year round are called not migrants or residents.
B
starts withBombus pensylvanicus is a widespread species, characterized as long-tongued. In comparison to its similar species B. sonorus, B. pensylvanicus has a darker color pattern and is located in the eastern United States. Characteristics of B. pensylvanicus include: a yellow thoracic dorsum, a black posterior, 3 initial alternating black and white tergal segments, a long and lanky malar space, and short hair. These characteristics resemble those of B. fervidus and B. auricomus, leading to confusion among species. B. pensylvanicus is similar in color and range to Bombus fervidus. In terms of characteristics within the hive, a larger queen measures 22–26 mm compared with a worker at 13–19 mm. Males have an outward penis valve head with a broad banana shape and often have extensive yellow on the thoracic dorsum posteriorly.
Whilst bees normally forage close to their nests, it has been observed that individuals can return from up to 1.5 miles away, though there is likely individual variation in homing ability and the time it takes a bee to find its way back to the nest. The method utilized by the bees is most likely trial and error, not a sixth sense or homing instinct, because the time taken to return to the nest varies. Males become more common in late summer.
Bombus pensylvanicus ranges from the Eastern Great Plains to eastern and central US and southern Canada, and Mexico. The species has become rarer, declining in number mainly in northern parts of its range. B. pensylvanicus generally nests in fields of long grass, but may sometimes nest underground. The species utilizes bundles of hay or long grass to create sheltered nests above ground. Some nest in established crevices and burrows, such as old bird nests, rodent burrows and cinder blocks. This species has even been noted to nest in human-made objects such as buckets and barns.
Current research states that Bombus pensylvanicus is uncommon and declining quickly. As stated in previous sections, the northern range of B. pensylvanicus has significantly decreased. Once the most abundant species throughout the southern United States, B. pensylvanicus is now a rare species that has been extirpated in certain areas and has suffered declines in others. Conservation efforts are encouraged in order to maintain the species, including in agriculture with wildlife-friendly techniques including hedgerows and pest management.
