While wandering (aimlessly) around the billionaire’s place yesterday, I stumbled upon a bumble bee hive. I mean I literally stumbled – they nest in the ground. Who knew? So like any good student I found an authoritative web site to plagiarize. Just kidding, the photo is mine (click on it to enlarge) but the following text is from the “Bee spotter” project at the University of Illinois at Urbana-Champaign. I assume that California bumble bees are just like Illinois bumble bees, after all they’re all American bumble bees – Bombus pensylvanicus. OK that’s wrong – Bombus yes, pensylvanicus no. They don’t come this far west. More likely they’re Bombus caliginosus, Bombus californicus or maybe Bombus vandykei or even Bombus terricola occidentalis.
Thanks to bumblebee.org
Bumble bees usually nest on the ground in the abandoned remnants of rodent nests or in patches of dried grass. The nests are usually lined with mammal fur or soft plant material. Bumble bees use wax secreted by their abdomens mixed with pollen to make oval cells in which nectar is stored or pollen is packed. In other cells, the queen lays eggs and then the growing larvae are fed honey and pollen by adult bees. There are usually several eggs per cell. Although both honey bees and bumble bees have nests consisting of various cells, the size and shape of bumble bee cells are much less regular than honey bee comb.
Like honey bees, most species of bumble bees are eusocial. However, there are several big differences in how bumble bee and honey bee colonies are organized. First, unlike honey bee colonies that can live for many years, bumble bee colonies are annual, meaning they begin new colonies from scratch every year. Also, their colonies are generally much smaller than those of honey bees; the number of bees per colony ranges widely among species (from fewer than 100 to over 400 females). Although bumble bees also have a division of labor with some worker bees specializing on foraging or nest work, a bumble bee’s age is not nearly as good a predictor of what her job is in the colony. Rather, there is size variation among workers and larger workers tend to spend more time foraging and smaller workers work more in the nest.
Unlike honey bees, queen and worker bumble bees usually look the same, although queens are normally quite a bit larger than workers. In some species, worker bumble bees will fight with each other and the queen and try to lay eggs. The queen is able to maintain her status as the prime egg-layer of the colony using a combination of aggressive attacks, eating worker eggs, and signaling via chemicals (called pheromones). At the end of the colony cycle, the queen, males, and most of the workers of the colony will die, leaving a few large females to survive the winter. The following spring, these females will set off on their own to start new colonies.