During the summer I love being outside, even if it’s for only a couple of minutes in the garden. This past summer I paid close attention to the insects I saw. The insects that attracted my attention the most were the bees and the butterflies. Because 2012 is the year of the bee, I thought it would be nice to dedicate a post on these insects, with a description of which bee species were buzzing around in my garden. However, while trying to determine which species they were, I came across another biological phenomenon: mimicry, were a species looks a lot like another species. Therefore, in this post I’ll focus on bees and their look-alikes, the hoverflies.
Bees can be divided in two groups, those that are social and those that live solitary. Social bees generally create colonies in which one female (the queen) is fertile and thus capable of producing offspring. Other female bees are worker bees and are not fertile. Their tasks include feeding of the queen and offspring, collecting food and maintaining the neststructure. Male bees are only present during certain stages of the cycle as their only job is to fertilize the queen. After their task is completed, they die. Social bees are the ones that produce wax and honey. The most common example of a social bee is the honeybee.
Solitary bees are called that way because all females are fertile and make their own, small nests in hollow twigs or tunnels in the ground. They don’t produce honey or wax. They feed on nectar and pollen instead of going through all the trouble to make honey. Although bees are generally thought to be social, there are actually more solitary bee species than social ones. Some species have living arrangements in between social and solitary. They do share nests, but each female arranges their own provision and egglaying.
A distinct type of bee is the bumblebee. These are larger, furry bees and are social in that they have a queen which lays the eggs. Eggs that are not fertilized will produce males, while fertilized eggs produce females, of which some will become the next queen bee. Their nests are usually found in tunnels in the ground made by other animals.
Bees have the special ability to defend themselves and their nests by stinging anyone who provokes them. There is a category of insects who mimic bees (and wasps) to trick their enemies into thinking that they are also bees or wasps. These are the hoverflies. Hoverflies themselves are harmless; they cannot sting. However, their markings and body types resemble their stingy body-doubles so much that it is sometimes very hard to see the difference. There are some visible differences between a bee and a hoverfly: differences in flight (a hoverfly can ‘stand’ perfectly still in the air), caused by the amount of wings (bees have 4 wings, hoverflies 2) and the lenght of their antennae (hoverflies have short ones). Although these three differences should make it easier to determine if it is a bee or a hoverfly, some species look so much alike that even insect experts (of which I’m not one of!) have a hard time knowing which species it is.
Take a look at my pictures and the links below if you think you can determine whether the insects I saw are bees or hoverflies!
http://www.tuin-thijs.com/zweefvliegen2.htm (In Dutch)
http://en.wikipedia.org/wiki/Helophilus_pendulus (about a wasp look-alike)
http://en.wikipedia.org/wiki/Eristalis_tenax (about the drone fly)
http://entomology.ifas.ufl.edu/creatures/livestock/rat-tailed_maggot.htm (detailed info about the drone fly)
http://en.wikipedia.org/wiki/Bombus_terrestris (about a bumblebee)