The leaves kind of look like a purple leaf plum shrub . If the allergies are life threatening and that is the reason for the urgency, why not just spray with a permethrin based spray? (Or perhaps, better, have someone else do so since you probably don't want to get too close).
Are you sure that they are wasps? I had bees swarm my back yard area in my previous house once. ( I am not allergic). After about a day they swarmed off into the sunset never to be seen again in my back yard again.

Simply trying to answer your request for information on the plant, maybe a Purple Smoke Bush (Cotinus coggygria)?

(What this has to do with wasps, etc., I don't know. Whenever possible, I just leave them alone. Predatory wasps, like spiders, mantises, etc. are your allies!)

Perhaps a long shot but it occurs to me that maybe you have some other sort of infestation you may not even be aware of: Leaf roller moth larvae, mite, aphids, etc and the wasps are there feasting, cleaning up for you. Just thank them and leave them alone.

Here is a link that might be useful: Take a look at these

This post was edited by actionclaw on Wed, Jun 19, 13 at 15:41

purple smoke bush ...

no reason for wasps to be there.. so i dont know what the name of the bush does for you ... wasps dont 'do' flowers ....

but try just putting the sprinkler on... and see if you cant encourage them to leave ...

otherwise.. hit the yellow pages for pest control ...

no time to fool around with organic solutions and what not.. kill those .. well if i knew you well enough.. i would use some choice bad words..

take no prisoners..

ken

ps: if you figure out how to kill that bush.. let me know that also ... i once cut a 14 footer to the ground.. ran it over with the truck a few times.. and by next year.. it was 6 foot .. whatever need be done.. the shrub is not in the equation ....

But wasps DO prey on the pollinating insects that visit the flowers as well as make nests in shrubby plants such as yours. You might have someone not allergic to wasps give it a thorough inspection for wasp nests. I had a nest in a rose bush and one in a chinese witchhazel bush last year.

Wasps in this case are likely acting as pollinators, gathering pollen and nectar to feed themselves and their young. They will likely be gone in just a week or so when the flowering is done.

Agree that it is a purple smokebush as suggested.

Just curious, how allergic? As a matter of life and death from a snake bite I am willing to do way more than a matter of getting a rash from poison ivy.

Do wasps really eat nectar or any part of a plant? I thought that was bees? It shows I am not allergic to either so I am the guy who let a hornets nest live all year in a tree just to see how big it got.

The flowers of this plant are attractive to all nectar and pollen feeders, including wasps. I'd expect it to be busy with insects. But "covered " in wasps seems odd. Bees, yes......

Wasps do feed on nectar, sap, ripe fruit, etc. Put a plate of fresh cut fruit out and you are likely to attract a hoard of butterflies, hornets, wasps, and others.

wasps dont 'do' flowers

Come again?? Of course wasps "do" flowers!! Many feed on nectar and pollen and some are significant pollinators. Predatory wasps cruise flowers routinely looking for insect prey. And we only have the OP's thoughts that these are wasps - they could just as likely be other types of flying insects that somewhat resemble wasps - hover flies, bee flies, any number of bee species, etc. They all look pretty similar unless you are up close and very personal :-)

FWIW, very few wasp species create any sort of issues with humans (most of the others don't sting or prefer bugs to humans:-)) and those that do tend not to hang on out on flowering plants much. I doubt you have much to worry about.

Question........is your smoke tree even in bloom????? I have noticed that plants with heavy aphid infestations sometimes attract sugar-loving wasps because they are attracted to the honeydew the aphids secrete. That's why ants farm them.

"I doubt you have much to worry about"

Depending on the degree of an allergic reaction, a sting could be fatal. While it is comforting to know that stinging wasps may possibly not hang out on flowers, it is appropriate to be cautious if one has a grave allergy.

I agree. Working outside as a vocation around flowers and trees, I have developed an allergy to them over the years after repeated stings. I don't panic about it, but a healthy respect for them is appropriate. I have had to make two ER trips, one in the back of an ambulance after a sting. That being said, I have a huge and lovely bee colony perhaps twenty yards from my house........very docile honeybees. Never been stung. But have been stung by wasps and it's possible that there is a ground colony of something like Yellow Jackets in or around that bush. If that is the case, a professional on insect control might be suggested to identify the insect and if there is a colony of something like yellow jackets with potential aggression issues in defending a colony, it may be necessary. Is the poster sure they AREN'T honeybees just swarming? Mine have put out three swarms the last month. If that is the case, bee keepers would be thrilled to come harvest them for nothing. Before mine balled up to travel, they were flying crazily around two trees for a day or two.

The flowers are clearly visible in the picture.

Cool picture, calliope.

But I did not know when the picture was taken. I did see the poster is in the U.K. and thought his might have been more advanced than mine because we had an exceptionally cool spring and mine are still past bloom.

Calliope,

That is an awesome picture.

dont do flowers ...

===>>>> pretty bad choice of words on my part ...

what i was trying to express ... was to determine whether they are on a migratory hunt for flowers ... or building a home in the plant ...

think apple tree in spring... the thing can literally buzz... from the bees around ... but they are off for home after the harvest ...

i have never seen a large population of wasps in said circumstances ... to me.. they are simply not that sociable.. for lack of a better word ...

so i was wondering ... if they are not building a hive [whatever the word is for wasps] or paper house in the plant ...

i find such very informative.. when they are somewhere on the property ...

i paid good money to have one destroyed.. when it was 3 feet out the back door ...

i am the ruler of my domain ...

call orkin.. or some other pest control ... if you think its worth it ...

ken

call orkin.. or some other pest control ... if you think its worth it ...

Oh good grief! A pest company, really? Dude, this is just NATURE, not an infestation.

Ken we have lots of pollinating wasps (and other pollinators that are not bees) here that can cover a plant in bloom, often California natives with non-showy flowers (e.g. Rhamnus californica). They are not what we typically think of as wasps - yellow jackets, for example, that are meat-eaters and torture us at barbecues. The behavior described by the OP sounds nectar-seeking.

Most people with insect allergies are allergic to either bee or wasp stings but not both (which is possible but rare) so it's important to 1) know which you are allergic to and 2) how to distinguish between them!

The behaviors are different - bees die if they sting so they reserve it for threats to home, brood or food; wasps don't die so sting more readily.

In 47 years of gardening I have been stung by wasps several times but never by a honey bee unless I was opening a hive.

Maybe we should be on an insect forum!

Sara

My point is saying that there is minimal concern is that the type of wasps/bees that tend to visit flowers for nectar and pollen purposes are not aggressive creatures (unlike hornets or yellow jackets) and won't bother you unless you bother them. Of course one should exercise caution if one is allergic to their stings, but their visits tend to be highly seasonal and if the plant they are visiting is not along a major pathway or a prominent outdoor entertaining area, there is minimal chance of their "attacking" or stinging.

Bees and wasps will be drawn to flowering plants - that's just a fact of life. Unless one has a garden populated only with needled conifers or grasses, these creatures will be present from time to time.