"Why do bumblebees suck your blood?" was the difficult question posed to a friend by a little girl returning from summer camp. It seems some boys had trapped a "bee" (it was probably a yellow jacket, because it was hovering around their lunch) under a paper cup. Sliding a piece of paper under the cup, they picked it up, shook it up real well (something only a boy would do) but then it escaped.
Bumblebees, of course, do not suck human blood. In fact, they are a gardener's best friend. As Southern California becomes more and more urbanized, the traditional pollinator of flowers, vegetables and fruit--the honey bee--is becoming ever more scarce.
Because honey bees live in large colonies, they need a good-size space--an attic, shed, large tree or other such place--to build their hives. These places are getting harder to find and, more often than not, the bees are forcibly evicted by the owners or others hired by them.
Bumblebees, on the other hand, live in small colonies, usually in the ground, and seem to be on the increase because suitable lodging is easier to find in urban areas.
Not only do bumblebees not suck human blood, it is difficult to provoke them to sting, unlike the common honey bee. I have never met anyone who has been stung by a bumblebee, although I have heard it is painful when one does sting. My oldest son used to pet bumblebees, stroking their downy fuzz, without provoking them. And I, while bumbling about myself in the garden, often have disturbed them without upsetting them.
Bumblebees have a close look-alike in the carpenter bee, though they are not related. While bumblebees are banded with yellow, the larger carpenter bees are pure, jet black. They get the name from their wood-burrowing habits, carving perfect dime-size tunnels in old wood. These tunnels are quite deep and hold a number of baby bees, packed in one on top of the other like Pringles potato chips in a can. (The first to hatch must wait until the last does before it can exit.)
Only one bee could be considered a pest. The leaf-cutter bee is the one that is cutting those neat circles out of your rose leaves, but each seldom takes more than a few chunks to line its nest.
Most wasps also are friends of the gardener, though they look very fierce and most unfriendly. The large, thread-waisted wasps that build homes of mud or paper are great hunters. While weeding, I have seen them cruising low in the plants to occasionally dive and come up with a larva of some kind, often cutworms unearthed as I work.
The most common big wasp is the golden polistes, which builds the small umbrella-like paper nests occasionally found on eaves of the house or in trees. These wasps are striped and colored like a yellow jacket, but with a long, narrow waist. They can be provoked and will sting.
The even larger mud dauber is mostly black with thin yellow bands. She builds the mud houses found in attics and garages and is not easily provoked and seldom stings. I have found this type of wasp to be a nice companion while working in the garden.
Even the yellow jacket does his share of hunting for garden pests, but he is the one to watch out for. Yellow jackets seem to enjoy stinging, and I've read that if you squash one, it releases an odor that brings more wasps and incites them to riot.
Yellow jackets usually are very yellow in color and are shorter and squatter than the other wasps in the garden. They are the ones that land on your hamburgers just as you are ready to take a bite, that like fruit almost as much as meat and that land on your lip during outdoor meals. They have no table manners at all.
In my own garden, they are not welcome, though I have yet to find a way to get rid of them. There are some high-tech traps available, but these didn't seem to work when I tried them briefly.
Yellow jackets also live in the ground, in colonies that get quite large by the end of summer (as many as 15,000 individuals according to "The Insects of the Los Angeles Basin" by Charles L. Hogue), and heaven help anyone who comes too near. Just walking nearby sends temblors through the ground that bring them out in droves.
One other wasp occasionally is seen in gardens and scares gardeners to death. The tarantula hawk stalks those big spiders and is easily recognized because it is a striking blue-black with red wings--and one of the biggest wasps in the world.
I used to go to a pile of gritty soil dumped by the road to get the makings of potting soil. One day I found a dead tarantula lying on top of the mound. A few days later, I realized I must have been digging in a mound that contained tarantula hawk nests. Sure enough, on my return I found them--cruising low over the ground and alighting near little tunnels in my dirt mound, which I promptly abandoned.
Because I had been doing most of my pillaging in winter, they were not active, but the weather had warmed up and with it came the hawks.
Wasps and bumblebees are most plentiful now at the tail end of summer because the colony starts anew each year, dying out in winter. In the case of bumblebees, the queen alone survives and she must begin a new colony all by herself in spring. Queens often are seen gathering pollen at the time fruit trees flower, pollinating them as they go.
As pollinators, all of the bees are important. They could make the difference between having a crop of fruit or not. And wasps are an important part of pest control (though I think yellow jackets aren't worth the aggravation). As gardeners, we should let them be.