Bee Aware of Stingers

Understanding which insects can and will sting, along with their toxicity and pain thresholds, is the best defence for avoiding unpleasant and/or life threatening situations.  Also knowing the correct medical treatments, should the unfortunate happen, presents the best opportunity for minimizing the adverse effects of any encounter.

In Canada, we are fortunate to live in a region of the world where the native bees are predominately docile, non-aggressive and reluctant to sting.  The majority of the native bees found here have mild to weak venom, so that should a stinging occur it is generally not a serious issue.  This amiable environment should be viewed as a benefit, allowing the easy and productive use of native bees for agricultural, horticultural and environmental advantages.

Most species of Hymenoptera have stingers (a modified ovipositor) with which they use to inject venom.  The purpose of these stingers is primarily for self-defence, although a number of predatory wasps use it for procuring food.  In the case of the social insects (such as the ants, wasps, and bees that form large colonies) the main body of defence lies in the protection of the nest, more so than the individual insect.  This is evident in the behaviour of honey bees that die from physical trauma after delivering a sting to a thick-skinned animal when defending their hive.  Although any insect capable of stinging will do so if seriously threatened such as when swatted or sat upon.

Some exceptions exist within the Hymenoptera order of animals as seen in the numerous species of 'stingless' bees and docile ants that do not have stingers.  They do however defend themselves with biting and harassing techniques.

All stinging insects deliver an injection of venom through a hollow shaft (the sting) by means of a pumping muscle attached to the venom gland. They vary in size from 1/16" up to ¼" in length.  Each species has its own variety of venom, composed of acids (formic), melittin, histamines, biogenic amines and in some cases neurotoxins.

A honey bee sting will deliver from 5 to 50 micrograms of apitoxin along with an alarm pheromone.  This pheromone (which has an odour similar to banana) excites the surrounding bees into attacking the threat.

Only female bees have stingers. In the case of honey bees, the worker bee has a barbed stinger that causes it to become imbedded into the skin of an animal (including people).  The queen bee has a smooth stinger and although very reluctant to sting a non-bee, can do so without injury.

Two factors are important to be aware of when working with or in the area of stinging insects.  These two factors are related and should be considered together.  The first is aggression – how likely are they to sting, and with how much vigour. Secondly, what is the toxicity of the venom of that particular species?

Aggression will vary between species and even among the same species depending on the environmental conditions and time of year.  However, some hierarchy is notable and listed in the STINGING RISK scale posted with each species description on the native bees page.

A highly aggressive genus (scientific classification containing a set of species) is the vespid wasps, which include the paper wasp, the pepsis wasp and the Asian Giant wasp.

The venom toxicity is best classified in the SCHMIDT PAIN INDEX.

The scale runs from lowest of 0 to the highest of 4.


 

INSECT

INDEX

 

DESCRIPTION

 

Sweat bee, Leafcutter bee, Mason bee, Carpenter bee

1

 

STING:  Light, mild.
DURATION:  brief.

Bumblebee

2

 

STING:  Medium, slow hard pressure.
DURATION:  5 - 10 minutes.

Honey bee

 2.1

 

STING:  Medium, very hot.
DURATION:  4 - 10 minutes.

White-face hornet

2

 

STING:  Medium, noticeable pain.
DURATION:  3 - 4 minutes.

Yellow-jacket wasp

2

 

STING:  Hot.
DURATION:  4 - 10 minutes.

Paper wasp

3

 

STING:  Strong, caustic and burning.
DURATION:  5 - 15 minutes.

Asian Giant Wasp

4

 

STING:  Extreme.
DURATION:  hours.

Tarantula Hawk Wasp

4

 

STING:  Intense.
DURATION:  hours.

Some people have an allergy to insect venom that ranges from mild to severe.  In the severe cases a small amount of venom can cause anaphylactic shock with heavy swelling and breathing difficulties.  For people known to have and those that suspect they may have this condition, it is recommended to avoid all contact with insects that may cause this reaction.  Allergy testing and an emergency measures prescription are available from a physician.

For the majority of people who can tolerate insect stings the following medical treatment is advised.  (It should be noted that the majority of professional beekeepers tolerate stings on a regular basis and have developed conditioned immune system responses requiring little or no treatment.)

To relieve immediate pain at sting site the best treatment is applied ice.  As a general anaesthetic, to relieve discomfort use NSAIDs (aspirin, acetaminophen, ibuprofen).  For swelling and mild allergic reactions use antihistamines (Benedryl).

We must consider ourselves lucky to live outside the domain of the Asian Giant Wasp.  This insect is five times the size of a honey bee and twenty times as heavy.  They possess a stinger ¼" (6mm) long and powerful mandibles.  European honey bees are a favourite target and food for them.  In as little as two hours a raiding party of these wasps can kill every bee in a hive of thirty thousand or more . They easily decapitate and dismember the guard bees with their huge mandibles.

The venom of the Vespa mandarinia and its cousin the Vespa mandarinia japonica contains a powerful neurotoxin called mandaratoxin.  This wasp is credited with numerous killings of human beings.

Let us observe careful and strict import regulations to not allow this species a chance to invade our countryside.  Unlike the tropical Africanized honey bee – which remains a threat to people in the southern U.S. – this wasp can survive here in the temperate north.