Bumblebees!

Bumble bee, Bombus
I. Introduction:

The scientific classification:
Kingdom- Animalia
Phylum-Arthropoda
Class- Insecta
Order-Hymenoptera
Family-Apidae
Genus-Bombus

There are over 250 known species of Bumblebees! They are primarily found in the Northern Hemisphere and live in colonies with 50 to 400 members. They are called Bumblebees because of their lazy buzz sound and bumbling flight. They are hairy little guys, normally with yellow and black stripes but occasionally they can be all black or orange.

II. Anatomy

Similar to all insects, the Bumblebee has an exoskeleton composed of chitin. It has a head with eyes, mouthparts, and antennae. The thorax contains the wings, wing muscles, and legs. The abdomen holds the digestive and reproductive organs as well as the sting. Bumblebees have four chitonous wings, two rear wings connected to the front wings by hooks called hamuli. They have the ability to ‘warm-up’ their flight muscles when it is cold out. They do this by shivering, similar to what humans do. They have three pairs of legs which are specialized for gathering pollen. Bumblebees have two compound eyes and three primitive eyes called ocelli. They are able to breathe through spiracles which are attached to the trachea.

Figure 1 Figure 2

Figure 3

III. Form & Function:

The Bumblebee has a long tongue with hairs at the end which help to absorb nectar. The tongue is only extended while feeding and is folded under the head and body during flight. The tongue and mouthparts also help with taste and smell. The hairs on the mouthpart and tongue have pores on them which allow molecules to pass through and travel to receptor sites on sensory cells.

Bumblebees use Malpighian tubules to produce their waste. They cannot lose water and these organs help with water conservation. Waste materials, like potassium, are collected by tubules which drain fluid “urine” into the intestine. The rectum reabsorbs the water, which results in a dry mixture of urine and feces. Besides uric acid, empty pollen grains are also passed just before spinning the cocoon.

In almost all species of Bumblebees, the male’s only job is to mate with the female. Female bees usually mate with several males in midair, gathering all the sperm she will ever need in her life time. Males usually die after mating because they leave their endophallus in the female’s body. After mating, the female returns to her nest to lay her eggs. Ovaries are activated when the queen lays her eggs. The eggs pass along the oviduct to the vagina. In the vagina there is a container called the spermatheca, this is where the female stores the sperm from her mating. She will decide if she wants to use the sperm to fertilize the eggs. Non-fertilized eggs will grow into males and only fertilized eggs will become females. The hormones that stimulate the development of ovaries are suppressed in other female worker bees while the queens remain dominant.

Queen and worker bumblebees can sting! Unlike honey bee’s, a bumblebees stinger lacks barbs, which means they can sting more than once. They are not normally aggressive, but they will sting to defend their nest or if they are harmed. One female species, the Cuckoo bumblebee, will aggressively attack the Queen but avoid all other animals and humans.

IV. Impact on the World & Humanity:

Bumble bees are EXTREMELY helpful to humans! They are becoming increasingly popular in cultured agriculture because they can pollinate species of plants by using buzz pollination. This is a method that other pollinators cannot achieve.

V. Journal Article and Review:

http://www.naturalnews.com/024814_bees_bumblebees_infection.html

This article is about commercially bred bees used to pollinate greenhouse crops possibly spreading diseases to the wild bee population. This comes as a great concern to scientists and the food industry because of the impact of pollination. Scientists captured a random sample of bumblebees from around a greenhouse and did a series of tests for pathogens. They found an intestinal parasite that matched the high infection rates predicted by a predicted mathematical model. 50% of wild bumblebees near the greenhouse were infected with the parasite Crithidia bombi.

Sources:

The bumblebee. (1997). Retrieved from

http://www.bumblebee.org/body.htm

(Used for information and Figures 1-3)

Bumble bee. (2011). Wikipedia. Retrieved May 1, 2011, from http://en.wikipedia.org/wiki/Bumble_bee

Wilson, T. (n.d.). How bees work. Retrieved from http://animals.howstuffworks.com/insects/bee5.htm