Beekeeping
The queen is the only sexually mature female in the hive and all of the female worker bees and male drones are her offspring. The queen may live for up to three years or more and may be capable of laying half a million eggs or more in her lifetime. At the peak of the breeding season, late spring to summer, a good queen may be capable of laying 3,000 eggs in one day, more than her own body weight. This would be exceptional however; a prolific queen might peak at 2,000 eggs a day, but a more average queen might lay just 1,500 eggs per day. The queen is raised from a normal worker egg, but is fed a larger amount of royal jelly than a normal worker bee, resulting in a radically different growth and metamorphosis. The queen influences the colony by the production and dissemination of a variety of pheromones or "queen substances". One of these chemicals suppresses the development of ovaries in all the female worker bees in the hive and prevents them from laying eggs.
Bombus pensylvanicus
Bumble bees are generally host to a diversity of parasitoids in which the larvae grow inside the living host. The majority of parasitoids for bumble bees are flies and about 30 percent or more bees within the area can be infected. The process of parasitism consists of the fly attaching to the bee in flight and inserting her oviposits between the terga of the bee. The larval fly hatches within the bee host and develops by feeding on the host’s tissues. The bee lives for about two weeks before dying. The fly then pupates and spends the winter inside the bee, fully developed, before it emerges the following year. "Bombus pensylvanicus" is host to one "cuckoo" bumble bee species, "B. variabilis". Hibernating queen bumble bees are parasitized by a nematode worm, "Sphaerularia bombi". This parasite does not reduce life span, but instead causes the sterilization of the queen. It has been observed that affected queens forage two to three weeks later than those that are unaffected. Parasitic microorganisms also use bees as their host. Parasitic microorganisms’ effects may be lethal or sublethal. Pathogens may be transmitted within a colony or the bee may be infected at flowers. Tracheal mites ("Locustacarus buchneri") leads to reduced foraging efficiency by living in the bee’s alveoli. Certain protozoans and fungi consume the host tissue or gut substances of the bumble bee’s digestive tract, decreasing foraging efficiency, life span, and thus the colony fitness. Bees may contain symbiotic bacteria that offer some immunity to pathogens. Further exposure to habitat loss as well as pesticide exposure may lead to bee predisposition, thus promoting the species’ decay.