Thursday, December 24, 2009

Curb Appeal, Co-existence & The Wildlife Garden

When the Home Bug Garden first started, I was worried that the neighbours might think I was an eccentric bugger with an eyesore frontage. As grass disappeared and the uniform mulch gave way to increasingly irregular eruptions of ‘wildflowers’, unmanaged horticultural variants of former wildflowers, grow-where-they-wish shrubs, and fallen autumn leaves, any claim to conformity with community norms was quickly lost. Nonconformity is rarely valued in our culture and under the relentless barrage of a monolithic media we are increasingly given one view of what is true, what we should think, and what we should not. Nonconformity, even in science, is denigrated and demonized. Living in Alberta, of course, I do have 6-7 months of a kind of conformity every year – the blanketing snow.

In Queensland, not smiling and saying hello to someone on a neighbourhood street would be unusual. Perhaps it is the constant sunshine, but an easy if superficial friendliness is the norm. Canadians seem far less welcoming to strangers on the street. I think the weather here encourages one to mind their own business and get where they are going before they freeze or are hailed upon. Most of those hurrying past the Home Bug Garden don’t stop to smile and pass the day. Those that do, however, have been uniformly pleasant and positive about my ‘woodland’. Even a door-knocking politician claimed to ‘like what you’ve done with your yard’. Well, maybe this office-seeker was just relieved there wasn’t a slavering dog or an old car up on cinderblocks. Still, none of these passersby had to say anything at all about the yard, let alone say something nice about something that is far from finished.

Of course, when neighbours ask, I am careful to describe my gardening as ‘wildlife friendly’, not as ‘bug friendly’: birds, bees, and butterflies come readily to my lips, wasps, spiders, and maggots almost never. I know then that I am on safe ground, because Wikipedia has pages for ‘Wildlife Garden’ and ‘Butterfly Gardening’. Never a reliable source of facts, Wikipedia, in its own 1984-ish kind of way, is a good guide to what are acceptable dogmas, politically correct attitudes, and proper forms of self expression. And according to Wikipedia (this morning anyway): “When one wildlife gardens, one acts always in accordance with the idea of keeping plants that are native to the area preeminent in the garden.” Sounds like a reasonable formula, I mean ‘native plants = native insects = native birds etc.’, right?

So how does one tell that a plant is ‘native to the area’? Unfortunately, ‘native’ isn’t a scientific term, but a collection of cultural concepts. As an adjective, it comes to us from Old French via the Latin ‘nativus’ for ‘produced by birth, innate, natural’. Appropriate to the season, ‘native’ has the same root as ‘nativity’, but also less savory derivatives such as ‘nativism’ and when used as a noun in Latin referred to a ‘natural slave’ – one born into bondage. As well as a plant bound to an area by birth, a ‘native plant’ is often taken to mean one that lived in an area ‘before people’ or, in a racist way common among some ideologies in North America, ‘before white people’.

The part of Edmonton that I live in was developed after World War II from a mixture of farmland and wetland. The wetland probably existed before European colonization, so its plants would count as ‘native’ by one usage. A pond is a great addition to any wildlife garden, but who wants to live in a slough?

Possibly there was some aspen forest earlier. That would be better, but if I converted my yard into an aspen forest there’d be little sun, lots of mosquitoes, clogged water and sewage pipes (aspen is bad), no veggies, and not many flowers. I suppose the largest plant in my garden is a ‘native’ spruce, so perhaps I could argue that I meet the ‘preeminent’ criterion, but a spruce forest would be a dark and oppressive place to live. If we try to expand our concept of ‘native’ and treat all peoples as equal, then the Clovis culture (~11,500-13,000 years ago) left the earliest human artifacts anywhere near here. But back then glacial ice covered all and algae was the only likely ‘native plants’. No thank you, I don’t think that kind of garden would be at all good for wildlife.

Should wildlife gardening be fun or a chore? Does ‘native’ have to imply a slavish devotion to what once grew in an area? Surprisingly, Wikipedia has a page called ‘Native Plant’ and (at least this morning) starts out with a not unreasonable definition: “A Native plant is one that develops, occurs naturally, or has existed for many years in an area.” Since I usually cannot afford the most recent horticultural fads and have no interest in putting in plants that are not going to develop, I think that a functional Home Bug Garden can be built around this concept of ‘native’. Moreover, such a garden could become a refuge of diversity in the increasingly developed and depauperate blotch of an ever-expanding Edmonton. Could be fun too.

Even for someone who has no interest in insect conservation, gardening does not have to be incompatible with bugs. Perhaps the biggest barrier is in the vegetable garden, because it is unfortunately true that there are a lot of insects that are far more efficient at harvesting our crops than we are. Tomatoes, potatoes, beets, spinach, radishes, arugula, lettuce, carrots, cabbage, and the like host far too many pests and many are of little use to foraging bees and butterflies. If you let your mustards (arugula, radish, and others in one of those plant families with two-names: Brassicaceae or Cruciferae) bolt they provide bees with some solace. Solanaceae (tomato, potato, pepper, ground cherry, eggplant) are better. But beans and peas (Fabaceae-Leguminosae) are probably the best veggies for bees. The more acceptable insects and the not too entomophobic gardener, however, can share the wealth of culinary herbs without any worries. That will be the topic of the next post.

Sunday, December 13, 2009

Winter Interest: Bye-bye Zone 3b?

The Home Bug Garden broke a record this morning: -40 C (aka -40 F) from at least 6:30 am until after 9 am. The previous record low, a smeary -39 C on our red alcohol thermometer, is burned into my memory, but alas, not recorded in my notes. My Garden Journal started on Canada Day (1 July) 2004, just in time for the 2 July flood. But regular recording of daily high and low winter temperatures didn’t start until 2006 – obsession with the weather takes a while to develop in a transplanted Queenslander used to constant warm, sunny days. So, this morning was the coldest in the HBG, but that’s a long shot from Edmonton’s coldest on record: -48.3 on 28 December 1938 (when Edmonton was a much smaller city) and matched at the International Airport on 26 January 1972 (just a few years after the airport opened).

When I checked the Environment Canada Weatheroffice website this morning, my clean, sharp -40 was perfectly bracketed by the -35 C at the City Centre Airport and the -45 C at the International Airport. Ten degrees Celsius seems like a startling difference for two airports so close together. The City Centre is a bit further north (53 34.2 vs 53 19.2 N), but ~50 m lower in elevation (671 vs 723 m). All else being equal, a site 50 m lower would be expected to average about 0.34 degrees warmer. The annual mean daily temperature of the City Centre (3.9 +/- 1.1), however, averages a full degree and a half Celsius higher than the International Airport (2.4 +/- 1.2).

This does seem strange for two weather stations only 30 km apart, and given the recent Climategate leak, perhaps a little paranoia is in order. The City Centre has been consistently claiming higher highs and higher lows than I can find on my thermometer (at almost the same elevation, 669 m, and only 15 km south). Could they be fudging the data to make things look warmer? I doubt it – as far as I can make out from the CRUtape Letters, all the value adding to the temperature data happens later, once the ‘scientists’ discover that the data does not agree with their models, and therefore, must be wrong.

Moreover, a simpler and well supported alternative answer is available – the Urban Heat Island Effect (UHI) - all the buildings and tarmac that absorb heat during the day and radiate it out at night and all the energy burned to keep the city going add up to a warmer local climate. So while the City Centre is usually warmer at night than my backyard, the backyard is often warmer than the International Airport. For morning lows, I’m often halfway in between – not surprising since the HBG is situated halfway in between the two airports and is in an area that is maybe half as urbanized as the City Centre. Daytime highs are more variable, but are more like the Airport than like downtown. UHI seems like a good explanation for these differences – and I would imagine that the International Airport is warmer than the rural areas around it.

My friend at Gardening Zone 3b near the City Centre seems to have an unfair share of UHI, but he displays the results beautifully on his blog, so I forgive him his 2-3 week advantage in spring bloom time and his later killing frosts (I’m a noble guy). I certainly don’t want my neighbourhood to get more urbanized, so I guess the HBG will just have to make do with the little UHI it has. The last couple of years, however, seem to be getting colder. That is a worry, as is the apparent correlation between sunspot activity and warmth (the Sun appears to be in a deep funk). If, as it seems, global warming was at best a delusion, then Zone 3 gardeners are going to miss it more than most people, except for Phil Jones and his mates, of course.

Saturday, October 31, 2009

CanBugs, CANPOLIN, Can Bulbs Survive

For those of you who answered the above pictured question with ‘where are the pollinators?’, well, that is a timely question as honeybees seem to be on the ropes and native pollinators in decline.

Or are they? Well, the truth be told, we don’t really know because with few exceptions we have pretty much put all of our bees in one basket. However, the time may be coming when the other 99% of pollinators – e.g. the for-get-me-not frequenting flower fly below– receive their due attention.

Flower flies (aka hoverflies, Syrphidae) were one of the pollinator groups that were well represented in presentations last week at the Joint Annual Meeting of the Entomological Society of Canada and the Entomological Society of Manitoba in Winnipeg. Usually I would consider attending such a meeting additional work, but this time it was vacation – perhaps the reason I had an unusually good time for a bug meeting. Not that sitting on one’s butt from 8 am until 5 pm listening to bug talks, not even with the aid of fly papers, is all that easy, but the friends, fine food, and Forks all made for a pleasant time. ‘Winterpeg’ was anything but wintry, the simple monument at Louis Riel’s grave among the Dutch doomed elms in the Saint Boniface churchyard strangely moving, and the bug science less debased by climate change hyperbole than has become usual. However, it was the plethora of papers on pollinators that made the meeting for me.

Anyone who answered the question in the picture above with the Laphria on the left (a robberfly, Asilidae) must have missed the doubly unfortunate damselfly and mites.

But if I were to ask harder questions, such as ‘what species is the bumblebee?’ or ‘how is it doing?’, I’d have no idea how to answer them.

Such ignorance, however, may be short-lived, thanks to the newly initiated CANPOLIN (Canadian Pollination Initiative). At long last the government seems to be getting serious about protecting this critical agricultural and natural ecosystem function. Let’s hope CANPOLIN can develop the basic tools and information Canadians need to answer basic questions about and to understand, utilize and conserve their pollinator heritage.

I hope to enlist the Home Bug Garden in this effort, and do what I can, but I don’t suppose I can do much this year. Winter is upon us in Edmonton. The trees are mostly bare, the ground cold and soggy, the days short, and what sun there is too weak to generate vitamin D. What a perfect time to plant Spring bulbs! Ha, well my bloody Dutch bulb growers seem to think so – the missing bulbs arrived yesterday in a box soggy with melting snow a month after the optimal time to put them in the ground.

Two hours after I got home, the bulbs were all planted in the long ago prepared beds or in pots as Adrian suggested (see Comments in previous post). I suppose I can look at this as an experiment. Hybrid tulips should have enough stored reserves to bloom next Spring, but probably won’t have enough of a root system to generate healthy new bulbs. As for the species tulips, grape hyacinth, and spring glories that made up most of the shipment, I don’t know, but I put in enough of these from local shops at the end of September to make a fair comparison. I'm just glad the ground thawed while I was in Winnipeg and I didn't have to break out the pickaxe.

Monday, October 12, 2009

Of Bulbs, Bugs, & Below Zero: Frozen in an Alien Landscape

Today is Canadian Thanksgiving and we are into our fifth day of subzero (Celsius) temperatures and snow in this Zone 3 Home Bug Garden. I’ve only been keeping good temperature records since 2005, but weather this cold (it hasn’t been above -2 C since last Wednesday) is unprecedented in my Garden Journal. It’s not the earliest for snow (that was 9 September 2004), but I'm afraid that 5 consecutive days below zero means that is it for the bugs and flowers this year and all I’ll have in store for this blog is dreams of bug gardens past. I left out the last of the Rainbow Swiss Chard, because it is supposed to be cold hardy. We will see.

The chard had a hard time this summer, with lots of beet leaf miners, probably Pegomya hyoscyami (Panzer). We may have pictures of the adults, but they are indistinguishable from the numerous other small grey flies in the Home Bug Garden fauna. The small white eggs are laid on the underside of leaves and the maggots penetrate the leaf, feed between the two surfaces of the leaf, and cause large brown blotches. At first I thought they were interesting, but several generations later, I hate them. There’s no chemical control for home owners, but crushing their eggs can feel rewarding, in an impotent, chemical-free way. Picking and destroying the older, outside leaves preferred by the flies is also recommended, but seems to have no effect– the neighbourhood seems to have a large endemic population of the flies, probably from many years of people growing beets and ignoring the blotches.

Well, so much for the flies, back to this cold, nasty weather – is it unprecedented? As a conservative check on just how unusual a long freeze in early October is, I went to the Environment Canada website and the Edmonton City Centre Airport and their Climate Data Online button. It is a bit complicated and unintuitive, but eventually I was able to find the monthly reports that included maximum and minimum temperatures for downtown Edmonton going back to 1937 (Edmonton City Centre AWOS [2009-2005], A (2005-1937]). You have to go back 50 years, to 1959, to find another stretch of 5 days with below zero maximum temperatures in the first half of October (and then again in 1957) – so very unusual, but not unprecedented. Below freezing daily highs are more common in the second half of October (e.g. in 2004 – the year of the 5 cm snowfall on September 9), but above freezing and even relatively warm temperatures are more the norm.

The City Centre Airport shows a distinct Urban Heat Island Effect (UHI) compared to my backyard records and is usually another several degrees warmer at night than the International Airport (records to 1961) in the countryside south of town. However, a long stretch of subzero days in the first half of October is unprecedented in the last 48 years at the International Airport (which opened in 1960 - presumably the fields where the airport would be in 1959 would have had the same cold stretch as Downtown in 1959). So, why all this harping on cold? Well, the ground is frozen and I’m still waiting for my Dutch Spring bulb order!

One could argue that a Home Bug Gardener would be better planting native, rather than exotic bulbs. After all aren’t native plants good and alien plants bad (or at least suspect)? Alas, the native-alien divide is one of those twilight zones where the science becomes gray and shadowed by politics and beliefs trump facts. My Australian instilled aversion to invaders is still trying to come to grips with Alberta’s recently deglaciated landscape awash with relatively recent invaders. But whichever side of the invasive species controversy I eventually come down on, science or xenophobia, I know that after the long nasty winters here, I need some cheerful flowers as early in the Spring as possible. So what does Alberta have to offer in the way of native bulbs?

To answer that question, of course, one has to first define ‘bulb’ (‘Alberta’ being well defined and ‘native’ seems okay when not scrutinized). Bulb does have a reasonably precise technical definition relating to food-filled underground shoots and leaves, but after the botany final exam is over, no one seems to adhere to the limited concept, but instead embraces any underground storage organ that looks bulbish to them. To avoid more confusion than is necessary, my definition of a bulb is anything listed in the bulb bible: “Bulbs” Revised Edition 2002 by John E. Bryan (Timber Press, Portland OR). So tubers, corms, rhizomes, and some fat roots qualify.

Much to my surprise, I find that I have planted 4 Albertan true bulbs (Allium cernuum, Allium schoenoprasum [chives], Lilium philadelphicum, Camassia quamash), one AB ‘bulb’ (Maianthemum canadense), and three ‘bulbs’ from nearby areas that might reasonably have been expected to eventually make it to Alberta on their own (Iris setosa, Iris versicolor, Liatris spicata). That’s the good news. The bad news is that none of these plants is so foolish as to produce flowers in the earliest spring! In fact the Liatris (aka Blazing Star or Gayfeather) is sitting frozen in mid-bloom at the moment. No, spring colour is up to the 60-odd accessions (i.e. named species, varieties, or cultivars) of exotic alien bulbs – the vast majority of which do their best to add some early spring colour to the HBG.

Yes, it is true, the Home Bug Gardener has planted almost 10 times as many species/varieties of alien bulbs as of North American natives. I’m a bad, bad, bad native gardener, or at least not much of a purist. And that’s okay with me, because after 8 months of winter, I need to see something attractive in the garden, even if it is an evil alien. Not that these plants are especially bug-friendly. It is true that the bees and flies that are around will visit many of them, but not with the same fervour that they go after later bloomers. The earliest HBG bloomer, the native coltsfoot (Petasites palmatus), really is a bee magnet. But then again, so are many of the exotics that put in an appearance later in the Spring. The bees and bugs may be particular about what they feed on, but I don’t think they have any bias about country of origin.

Sunday, October 4, 2009

Borage, Butterflies, and Bimbos: Reflections in the Rain

It was a grey and dreary morning in the Home Bug Garden, three days past the first killing frost of the Fall. The Home Bug Gardener and his wife were grumpy and poorly slept. On the positive side, the drought had relaxed a bit last night into an extended drizzle, doubly appreciated for its dampening effect on the party in the revolving rental next door. Not enough rain to short circuit the blasting boom boxes or drown out the bikinied bimbos blabbering in the rented hot tub. Nor enough to wet down to the buried bulbs that should be spreading roots in preparation for next Spring’s bursting forth. Enough, however, to keep me inside and blearily reading blogs, rather than ranting at the neer-do-wells next door, and to put me into an alliterative ambience about better times with borage, butterflies, and not so noisy neighbours.

Today, I’m beholden to The Far North Garden for my stringing consonants on my blog instead of spewing curses at the neighbours. Among the many well written and balanced postings available for whiling away a Sunday morning in a non-confrontational manner was a recent one on volunteer borage (Borago officinalis), one of my favourite alien plants. As a home bug gardener, I suppose I should claim that I plant borage for the bees, but really I like its “feed me” ‘Little Shop of Horror’ looks. Besides, I only planted it once five years ago and after that it has planted itself. Every year now I can enjoy its true blue flowers and spindly and spiny spread with no additional effort.

An added bug garden advantage of borage is that when the Painted Lady Butterflies (Vanessa cardui) make one of their rare, northward migrations into Edmonton (last one was 2005), their caterpillars love it. Of course, even a home bug gardener isn’t necessarily delighted with spiny black caterpillars devouring their plants (they hammered the lupines, yarrow, and globe thistle too), but a bit of plant biomass seems a small price to pay for the silent beauty of the Painted Lady. Also, those were the days when an acoustic guitar hootenanny was the worst we could expect from the rental neighbours and getting enough sleep is a pre-requisite to rational approaches to garden problems. Our rational approach was to let them feed (except on the newly planted globe thistle) and we now have enough of all of these plants that we would welcome another migration.

Although the rare Painted Lady migrations get the local Altalepers pretty excited, another rare migrant is far better known – the Monarch Butterfly (Danaus plexippus). Edmonton is far enough north and deficient enough in native milkweeds, the larval food, that the Monarch is a rare visitor. In 2007, however, we had the extraordinary delight to encounter a visiting Monarch in our backyard, watch it oviposit, and enjoy its larvae later chowing down on our ‘butterfly weed’.

Actually, although the seed packet from the Devonian claimed our milkweed was the Butterflyweed Asclepias tuberosa, a beautiful and not very aggressive plant with flat heads of orange flowers that would be marginally hardy here (usually rated to Zone 4), what actually emerged from the ground was a much more vigorous monster. I believe this is Swamp or Rose Milkweed, Asclepias incarnata, which has ball-like umbels of pinkish lavender flowers and wandering roots that quickly took over our primary potager bed. Once its roots were contained in a smaller bed, however, it became a welcome addition to our garden.

By an extraordinary stroke of luck, my wife and I also had the delight to watch a new Monarch Butterfly emerge from our milkweed and fly away, presumably to eventually head for Mexico. That is about as good as it gets in the Home Bug Garden – the rare opportunity to contribute to an insect phenomenon that actually has a lot of popular appeal. Alas, no monarchs or painted ladies have graced our garden since then, and with the climate seemingly in for a long cold spell, I wonder if we will ever see them again? On the other hand, as I recall the renters that summer were even worse than the current batch and we were treated to flashing red lights and a police helicopter with search light scanning the neighbourhood at 3:30 in the morning after one particularly violent party. No sense in dwelling on the negative though. Perhaps the sun will wake up and shed some extra warmth, another monarch will grace our milkweed, and the next batch of renters will be a nice, quiet family.

Saturday, September 19, 2009

Frog spit & colour morphs: Pseudodiversity & other false ideas

Frog spit and spittlebugs are one of those childhood memories that now evoke mixed feelings. Did I really eagerly plunge finger tips into poop and plant-sap spittle and react with joy when uncovering a frothing froghopper nymph?

Well, that’s how I remember it, but now things are different. Spittlebugs (true bugs: Order Hemiptera, Family Cercopidae) or froghoppers (as the adults are called) are interesting insects for any number of reasons. One of the primary is, of course, the protective envelope of bubbles that the nymphs generate around them as they feed. That’s cool, even if you aren’t a kid, but once you know that the bug anus is intimately involved, one is apt to get a bit skittish (NB – always wash your hands after playing with spittlebugs). Adult fastidiousness aside, the most likely spittlebug one is apt to encounter is two things you don’t want in a garden bug: polyphagous and exotic. Another way to say this is ‘an alien that eats everything’.

Summer before this, we had quite the explosion of just such a spitting machine in the Home Bug Garden: Meadow Spittlebugs (Philaenus spumarius). Bellflowers, globe flowers, Queen-of-the-Prairie, goldenrod, aster, yarrow, and many other cherished garden gems had hunks of spit sitting just below the flower buds – wilting the buds and terminating the flowers. Hundreds of soapy squirts and weeks of spit and green ocher stained finger tips later, the spit population appeared undiminished. It was enough to drive a knee-jerk environmentalist to the evils of synthetic insecticides – if only such a synthetic chemical alternative were available! Alas a history of insecticide abuse, and the inability of government to favour science over fervour, has left the home gardener with little to do other than pray for parasitoids. Unfortunately, spit and parasitoids don’t seem to mix.

Not that I am entirely the innocent victim in this outbreak. I suspect the main reason for our spit-drenched garden was that I left most of my perennial plant stems standing over winter. I could claim that I did this for aesthetic reasons (winter interest), horticultural reasons (plant tops trap snow and help plants to overwinter), or just plain knee-jerk environmentalism (it is natural for plant tops to last over the winter and cutting them down would be unnatural and wrong). Truth be told, being a lazy bugger (aka ‘overworked’) conspired with all of the before to let the tops stand. Unfortunately, it is inside the stems of perennial plants that the froghopper secrete their eggs – the eggs that turn into spit and dead flowers the next Spring.

This last year I cut down and composted my perennial tops before Spring had sprung. Leaving them up most of the winter looked good and trapped snow, and cutting them down before it got warm seems to have kept the spittlebugs down to squishable levels. Other insect pests and diseases also overwinter in plant tops, so ‘better late than never’ applies here. The only downside to this approach is that fewer spittlebugs means even fewer froghoppers – and the Meadow ‘Froghopper’ is a really interesting animal, if only because it looks like dozens of different species.

Bugguide Net has a great poster displaying some of the diversity of colour morphs found in this single species and this posting displays a few of the variants found in the HBG. It is a bit disappointing that we have so few froghopper species (only two, including the unidentified spittlebug on our birch), but the Meadow Spittlebug is a good reminder of the pitfalls of using skin colour as a guide in life. No matter what the colour on the surface, a miscreant may lie below.

Sunday, September 6, 2009

Biodiversity Gone Good: Our Friendly Wasps

Friendly?, well, I exaggerate a bit, but after the last posting on evil hornets, I thought I should exonerate all those wasps (Order Hymenoptera) that wouldn’t hurt us unless we really, really were asking for it. These are the so-called ‘solitary wasps’ – and in going it alone is their secret for getting along with us. Actually, I probably have that backwards: we tend to get along with solitary wasps because they can’t, and have no reason to,  gang up on us.

Like their freedom loving relatives, the ‘eusocial’ ('good', but actually bad, social) yellowjackets and hornets start out as solitary wasps each Spring when queens do all the normal wasp work themselves – find their own food, find a site for a nest, build the nest, lay the eggs, protect the nest, and feed their offspring until they are ready to pupate and become adults. Sounds all very noble and hard-working, but in reality queen yellowjackets and hornets aren’t adverse to stealing another queen’s nest and murdering the owner. In either case, the noble queen or insidious usurper rears grubs that develop into a worker cast – an army of so-called ‘non-reproductive’ or ‘sterile’ sisters (actually ‘suppressed’ would be a more accurate adjective, since workers may reproduce) that do all the work from then on and all the stinging.

These eusocial wasps have modifications in behaviour, chemicals, and stinging apparatus that have evolved to help defend large nests full of their sisters, half sisters (assuming their moms aren't monogamous), and drones. In fact, they have to defend that nest, since the chance of being able to found a new one is probably slim (and perhaps also the reason that stealing nests is common). Unfortunately, when they defend the nest against us, we suffer. Wasps that haven't become social, however, are much less aggressive. So, cheers for the solitary wasps!

Solitary wasps come in two forms: the hyperdiverse parasitic wasps (Ichneumonoidea and more) and the hunting wasps that are close relatives of the eusocial bees and wasps (and ants). Each female hunting wasp must build their nest(s) alone (males just dangle around), so the nests are small, and there is no other wasp to come to its aid if it is attacked. If fact, in spite of all the care and attention a hunting wasp mom will devote to rearing its offspring, it will never see them as adults and has no hope of recruiting them to defend a nest.

Thus, overly aggressive hunting wasps would tend to come to a bad end, but those with a more philosophical attitude, can move on, start another nest, and send daughters and sons into the next generation. That doesn’t mean they won’t put up a bit of a fight, many are capable of delivering a painful sting, but in general they aren’t going to slug it out with something as large as a human. It also helps that solitary wasps are only really interested in hunting down spiders or insects to feed their grubs and an occasional sip of nectar at a flower to keep them going. When a solitary wasp finds you at a picnic, it is most likely because you have attracted flies (which many take as prey) or you have put your blanket over their nest in the ground and they can’t find their way home. Some solitary wasps are members of the Vespidae, the home of hornets and yellowjackets, or close relatives like the mostly black spider hunting wasps in the Pompilidae, but most belong to other families.

When I was a kid and got to read excellent books like Wasp Farm by Howard Ensign Evans (sadly, now out of print - but try the library), the non-vespine hunting wasps all fit in one family, the Sphecidae. Now, alas, most of my bug reading is condemned to papers in scientific journals where any delight has been rigorously suppressed and the information is highly refined - like white sugar, but without the sweetness. Oh well, “Gracefully surrender the things of youth” and that includes a monolithic Sphecidae. The current hypothesis includes three families, and the one we definitely have in the Home Bug Garden, the Crabronidae are considered the sister group to the bees and only more distantly related to other hunting wasps. They do look a bit like bees, but go about their business stuffing flies, caterpillars, bark lice, or the like into their nests instead of pollen and honey. The Crabronidae has some giants, the Cicada Killer (Sphecius speciosus) being perhaps the most famous, but the largest I have seen in the HBG is about an inch long Bembix americana. This wasp nests in sand and feeds her grubs fly after paralyzed fly. I’m not sure what she was doing on a goldenrod in a yard surrounded by oppressive clay soils as far as the eye can see – but she now sits on a pin in a museum. I don’t have any pictures, but my friend The Bug Whisperer has an excellent shot of another, more fortunate, B. americana feeding at an aster.

Most solitary wasps, however, limit their parental care to choosing a host and ovipositing an egg. No nests are involved. These parasitic, or better, parasitoid wasps have no nest to defend, and their egg laying organ, the ovipositor (i.e. egg placer), is used to lay eggs in or on their prey, not to sting annoying humans. 'Parasitoid' is preferred in scientific circles because the end result is almost always a dead bug (whereas a parasite is happier when you keep on living – think head louse). Check out the aphid mummy above perving the mating Ancistrocerus parietum – it may look like an aphid, but it is just a hollow shell with a parasitoid wasp grub inside, undoubtedly a tiny member of the Ichneumonoidea (Ichneumonidae, Braconidae). Although I find hunting wasps more interesting,  it is the parasitoids that make up most of the - unidentified - species diversity of wasps in the HBG.

As far as we are concerned, parasitoid wasps are usually entirely good, except they are difficult to identify and their prey can expect a gruesome end – being eaten alive. That, however, is the fate of the prey of all wasps, including the paralyzed prey of hunting wasps or the mashed up prey of the social vespids. Well, if you want to nitpick, I guess hornets just cut-up insects alive, sort of like Dexter, and then feed the mashed bits to their grubs: nature ocher in sting and mandible. As long as the victim is an insect, though, do we really care?