Africanized honey bees are an introduced species of honey bees to Southern California and the United States. This bee species was the creation of Brazilian researchers in the 1950s. These researchers attempted to hybridize European honey bees and African honey bees. Since that time, Africanized honey bees have migrated northward to North America. Africanized honey bees are more aggressive when defending their hives than their European and bumblebee relatives. When threatened, these bees attack invaders in large groups and will not relent until they has driven the threat far away from the hive. In Southern California, San Luis Obispo and Riverside Counties have reported Africanized honey bee sightings.
Another introduced bee species to the United States are the European honey bees. As their name implies, European honey bees are native to Europe. They arrived in the New World during the 17th and 18th centuries. These bees are more docile in nature than their Africanized counterparts. Also, most beekeepers in Southern California use European honey bees for honey production; European honey bees are known for storing nectar during the winter. European honey bees are larger than Africanized honey bees. These bees usually attack hive invaders alone, rather than call on the entire colony for defense.
One of the largest bee species in Southern California is the bumblebee. Two different species of bumblebees live in Southern California, the bumblebee (Bombus genus) and cuckoo bumblebee (Psithyrus). (see Reference 3; page 9) Both types of bumblebee grow to 1 to 2 inches long. Bumblebees differ from honey bees since they do not have barbed stingers; this means their stingers do not detach when they sting, so they are able to sting multiple times. Bombus bumblebees are social bees with a caste system of workers, drones and queens. Cuckoo bumblebees are parasitic and lay their eggs in the hives of other bumblebees.
Although they are hornets by name, bald-faced hornets are actually a species of yellowjacket wasps. You can identify this insect by the white markings on its face. The bald-faced hornet's abdomen, legs and thorax also possess white markings. Like other yellowjacket species, the queen bald-faced hornet is the largest specimen in a colony; queen bald-faced hornets grow up to .75 inches in length. Each colony has up to 300 to 400 workers. Bald-faced hornets nest in bushes and trees throughout Southern California.