Showing posts with label bees. Show all posts
Showing posts with label bees. Show all posts

Wednesday, May 22, 2019

World Bee Day....A Little "Bee"hind

World Bee Day happened the other day, May 20, and it caught me off guard. I had never heard of it, and hustled to make some social media posts for the Facebook groups I founded or administer. I will plan a bigger campaign of celebration next year, but for now....

In fairness, World Bee Day has not been in existence very long. The date honors the birthday of Anton Janša of Slovenia, a pioneer of modern beekeeping in the eighteenth century. The United Nations passed a resolution submitted by Slovenia in 2017 to so honor him. While beekeeping in the northern hemisphere applies only to honey bees in the genus Apis, the U.N. has chosen to use World Bee Day as an opportunity to acknowledge all bee species, the vast majority of which are solitary and not managed by human beings.

North American bees range from giant "large carpenter bees" like this one....

Given the plight of pollinators in general, and the threats to apiculture (beekeeping) from mites, pesticides, industrial-scale agriculture, habitat destruction, and climate....anomalies of increasing frequency, it is easy to be pessimistic and sorrowful on World Bee Day. However, there are signs of hope all around us.

....to tiny Perdita mining bees like this one.

More people are taking up apiculture as a hobby, for example. Even better, many homeowners and small-scale farmers are recognizing the importance of native bees and building simple housing for them in the shape of "bee condos." Now a small movement is building to advocate for allowing those bare patches of soil in your lawn and flowerbed to lie fallow. The overwhelming majority of solitary bees in North America nest in burrows they excavate in the ground. Sometimes many females will nest in close proximity, giving the illusion of a "hive" or a swarm. This is not the case, and unless you step on a bee in bare feet or forcibly grab one, it is not going to sting you. Different bee species prefer different textures of soil, from sandy to clayey.

Leafcutter bees, Megachile sp., using "bee block."

Among the many reasons to celebrate World Bee Day this year is the rediscovery of the world's largest bee, Wallace's Giant Resin bee, Megachile pluto, nesting in termite mounds in Indonesia. It is an important reminder that the natural world is resilient, to at least some degree, and that most species can persist even in unfavorable circumstances.

Female cactus bee, Diadasia sp., entering her burrow.

Colorado, where my wife and I live, ranks fifth in bee diversity in the USA, boasting at least 946 species from huge bumble bees to tiny mining bees in the genus Perdita. California (1,651), Arizona (1,182), New Mexico (991), and Utah (979) rank ahead of us. That makes for a lot of bee species that need conservation if we want to continue enjoying wildflowers and eating everything from blueberries to squash to almonds.

We can encourage bees by....

  • landscaping with native trees, shrubs, herbs, and flowers.
  • Erecting bee blocks as supplementary housing for solitary bees (and wasps) that normally nest in the dead trees we cut down and logs we haul off.
  • Become "weed tolerant" of plants that volunteer in our yards, as long as they are not state-listed noxious weeds. Chances are they are native or naturalized wildflowers instead.
  • Leave a few bare patches in the lawn (if you still insist on having a lawn) and flowerbeds so that ground-nesting bees have a place to call home.
  • Advocate for changes to municipal and HOA codes and rules that currently discourage eco-friendly landscaping.

It goes without saying that eliminating pesticides and other chemicals from your yard and garden will greatly benefit all life, not just on your property but elsewhere, too, as pesticides drift on the wind and flow in runoff from rain and watering.

Female sweat bee, Agapostemon sp., living up to her name.

World Bee Day is behind us this year, but no worries. You can gear up now to celebrate National Pollinator Week next month, June 17-23, 2019. Tell me how you plan(t?) to respect that designated "holiday." Maybe you need to do what I should do, which is call my governor and ask why Colorado is not yet on the map for it....

Cuckoo bee, Nomada sp., leaving (left), small carpenter bee, Ceratina sp., arriving (right).

Friday, October 20, 2017

Are We Saving Species by Rescuing One Individual Bug?

NOTE: I had to change the original title of this post because, believe it or not, it is a trademarked phrase! The owner of said patent/copyright informed me of this on September 17, 2019 and asked that I remove the title.

Increasingly, thanks to social media, I am struck by how many people attempt to save individual insects they find injured or lethargic. On one hand this empathy for other life forms is encouraging, but on the other hand the energy investment is grossly misplaced.

© Youtube.com

The problem is that the media has painted honey bees and Monarch butterflies in particular as highly vulnerable if not on the brink of extinction. The implied message is that every individual of these species needs protection in every way possible! Consequently, people spend more time "rescuing" individual specimens than in protecting or creating habitat, working to curb pesticide use in their community, or engaging in other strategies that would have a far greater impact on improving the health of the entire species.

Another problem is that most people are not knowledgeable enough to recognize when a given insect really is in trouble. The wrong assessment happens over and over with bees in particular. Bees often become inactive when it gets too cold for them. They rest on whatever object is available and often this is a more conspicuous spot than normal. A good Samaritan human believes the insect is in peril and needs the equivalent of a sugar-water IV, stat! No, it does not.

Further, in late summer and fall, chances are you are saving a male bee, which is even less useful. Male bees live a short life in which their only purpose is to mate with a female. They do not possess pollen baskets, so are less effective pollinators than female bees.

Another aspect of life that we forget is that insects, like any organism, are prone to developmental problems that cannot be overcome. Improper emergence from a chrysalis will leave a butterfly crippled beyond repair. It happens. Insects reproduce in large numbers to overcome those deficits. Insects are incredibly durable once they mature, and losing half a wing barely slows down a butterfly or a bee. We should be in awe as much, if not more, than in sympathy, let alone pity.

Ok, so last month my wife and I were on vacation in Cape May, New Jersey, and we happened upon a Monarch trapped in a spider web. We intervened. It was a quick fix, simply disentangling the insect and sending it on its way. The whole investment was maybe forty seconds. We understood the insect could collide with a vehicle later that same day. Our expectations for the survival of individual insects are low, given our knowledge of their biology.

Contrast that example with an online video that shows how to mend a broken wing on a Monarch. More than a few such organizations have exploited the "sky is falling" scenarios centered on the Monarch, and one has to question the motives of some of them. Yes, older, established conservation organizations use overly alarming narratives, too, but the best ones measure their tone and can point to historic successes in legislation and habitat protection.

You want to curb insect mortality? Then give up driving. For every insect you nurse back to health, you kill dozens, if not hundreds in the course of operating your motor vehicle. Even bicyclists take their toll. I have seen countless insects mortally wounded, or crushed, on bike paths.

Basically, insects are better served by actions aimed at enhancing habitat health, and planting native vegetation in the landscape of your own property where you are able. Tear out the lawn, or most of it, and do your best to mimic the natural ecosystem where you live. Want to go a step farther? Start a dialogue with city and county officials to restructure weed ordinances and other codes that currently restrict the ability of homeowners to plant for wildlife. Educate your homeowners association to make those communities more wildlife-friendly without compromising safety and property values.

Also, stop insisting that one species is somehow more worthy of our attention than any other. Stop categorizing insects as "friend" or "foe." Such distinctions do not apply to the overwhelming majority of life on this planet.

Be proud of yourself for having empathy for other living things; but, channel that into something that will make a difference beyond the individual insect or arachnid. Do intervene for birds, mammals, reptiles, and amphibians, all of which have far longer lifespans than invertebrates, but make sure you do it legally and correctly. Carry on.

Wednesday, October 11, 2017

The Wasp Wall

South Cape May Meadows in Cape May, New Jersey is a property managed by The Nature Conservancy (TNC) for birds and other wildlife. Near the parking lot stands a shed that itself is something of a refuge for a whole community of insects. One wall, facing west and with beams that make something of an overhang or trellis, is being worked over by the Eastern Carpenter Bee, Xylocopa virginica. The abandoned nests of these solitary bees are then used by mason wasps, leafcutter bees, and other solitary Hymenoptera.

The shed at South Cape May Meadows, behind the arbor entrance

During our visit this past September 24, we noticed the holes, then soon saw females of the Four-toothed Mason Wasp, Monobia quadridens, exploring some of those cavities. I wrote about this species previously, detailing its life cycle, but this was the first time I had observed them coming and going from nests.

Female Monobia quadridens entering her nest

One female delivered a paralyzed caterpillar during our observations. It was a surprisingly small larva given the size of the wasp, but then she caches several victims in each cell before laying a single egg, putting up a partition of mud, and then starting a new cell along the length of the tunnel inside the wood.

Female cuckoo wasp, Chrysis sp., prospecting for a host

One might think that nests in such solid material would be impermeable to parasites, but not so. We watched a brilliant blue-green cuckoo wasp, Chrysis sp., investigate some of the holes for occupants. Given a nest in progress, she would infiltrate and lay her own egg inside. Her larva would then consume the prey items left by the rightful owner for its offspring. Cuckoo wasps are nearly impregnable, with a very dense exoskeleton that deflects the bites and stings of host wasps. Cuckoo wasps can roll into a ball to further protect themselves.

Female Leucospis affinis ovipositing in a host nest

A less common parasitic wasp also came to the wall. Leucospis affinis is a large chalcidoid wasp. The female is easily recognized by the whip-like ovipositor that curls over the top of her abdomen. The ovipositor is the organ she uses to lay her eggs....by drilling through the solid wood directly into one of the cells of her host. How she divines the location of a host larva through a layer of dense cellulose is a mystery to me, but her aim is usually true.

Nest closure of mason wasp or carpenter bee

A completed nest of a mason wasp is usually identified by the mud plug that closes the entrance to the hole in the wall. Because the soil at Cape May is essentially all sand, it was difficult to tell if we were looking at a sand closure or a sawdust closure that would be the work of one of the carpenter bees.

Nest closure of leafcutter bee, Megachile sp.

Easier to identify was the completed nest of a leafcutter bee, genus Megachile. Leafcutter bees snip oval pieces from leaves of living plants and fashion those clippings into barrel-shaped cells that they stack along the length of a tunnel in wood, or underground in the case of a few species. The female bee then cuts at least one perfectly circular leaf fragment that serves as a "lid" for the completed cell.

Nest of grass-carrier wasp, Isodontia sp.

We found one hole filled loosely with bits of grass, and we surmise this was the work of yet another kind of wasp, the grass-carrier. These solitary wasps, related to mud daubers in the family Sphecidae, use dry grass to fill, and/or partition, and plug their nest tunnels. Near Cape May Point State Park we did witness a female Isodontia mexicana select and bite off a dry grass stem to take back to her nest, so we know these insects were active.

Female grass-carrier wasp, Isodontia mexicana, cutting a piece of grass

Ironically, one other kind of wasp was tearing the wall down one mouthful at a time. Workers of the Bald-faced Hornet, Dolichovespula maculata, would alight on the wall and begin chewing off wood fibers to mix with their own saliva. This creates a pulp that they use to make durable paper nests. Looking more closely at the wall we realized that the scores of yellow streaks on the otherwise weathered gray wooden surface were where yellowjackets (of which the Bald-faced "Hornet" is just another species) had stripped fibers for use in building their nests.

Bald-faced Hornet gathering wood fibers to make paper

No doubt, earlier in the season there would be even more activity around this wall. The shed is still standing, sturdy as ever, so the insects are not doing much, if any, structural damage. Please consider that if you find that your own shed is becoming home to carpenter bees and other insects. You may find yourself as enthralled as we were by the little ecosystem started by carpenter bees.

Female Monobia quadridens exiting her nest

Sources: Evans, Howard E. 1963. Wasp Farm. Ithaca, NY: Comstock Publishing Associates (Cornell University Press). 178 pp.
Buck, Matthias, Stephen A. Marshall, and David K.B. Cheung. 2008. “Identification Atlas of the Vespidae (Hymenoptera, Aculeata) of the northeastern Nearctic region,” Canadian Journal of Arthropod Identification No. 5: 492 pp. (PDF version).
Krombein, Karl V. 1967. Trap-nesting Wasps and Bees: Life Histories, Nests, and Associates. Washington, DC: Smithsonian Press. 570 pp.
Krombein, Karl V., et al. 1979. Catalog of Hymenoptera in America North of Mexico Vol.2 Apocrita (Aculeata). Washington, DC: Smithsonian Institution Press. Pp. 1199-2209.

Wednesday, July 19, 2017

White Prairie Clover: An Awesome Blossom

I am not a botanist by any stretch of the imagination, but I am pretty sure that the insect magnets in the shortgrass prairie field up the hill from my home here in Colorado Springs, Colorado, are White Prairie Clover, Dalea candida. What follows is a sampling of the many bees, wasps, butterflies, flies, and other insects that come to the flowers of this plant; and a little information on Dalea in general. Much of the pollinator enhancement literature touts Purple Prairie Clover, D. purpurea, so one has to dive deeper.

A cuckoo bee, Nomada sp., forages while a male sweat bee, Lasioglossum sp., approaches

Prairie clovers are in the pea family Fabaceae. White Prairie Clover in Colorado occurs from 3,400-7,200 feet in elevation, and blooms from June to August. It is a low-growing plant, flowers on stalks up to two feet tall, but the ones I see are no more than one foot tall and sometimes difficult to discern among the tall grasses, cacti, and yucca they share the prairie habitat with. This species is widespread from the Front Range across the Great Plains, north to Saskatchewan and Wisconsin, and as far east as Tennessee, Georgia, and South Carolina.

Common Checkered-skipper, Pyrgus communis

The flowers are arranged in a cone, and bloom from the bottom to the top. The cycle can last up to a month, providing insects with pollen and nectar over a longer period than most flowers, and often at a time when few other plants are blooming. The down side to this plant, from the perspective of the photographer/entomologist is that insects quickly move to the side of the flower opposite the photographer, where they are hidden from view, then fly to another florescence and repeat. I missed a good number of opportunities because insects move across the flowers so speedily.

Male Hunt's Bumble Bee, Bombus huntii

Bees of all stripes seem to enjoy White Prairie Clover, and male bees may visit not only for nectar but for mating opportunities with foraging females. I saw far more male sweat bees, Lasioglossum (subgenus Dialictus), for example, than I did females. Even male bees can be sufficiently hairy enough to perform pollination services, even though they are not gathering pollen to feed to offspring. This is especially true for bumble bees and longhorned bees.

Sweat bee, family Halictidae

Female mining bee, Calliopsis sp.

Male longhorned bee, tribe Eucerini, family Apidae

Cuckoo bee, Triepeolus sp.

A second species of Triepeolus

Butterflies visit the flowers, too, mostly for nectar, but the caterpillar stage of some species feeds on the foliage of Dalea. This is the case for the Southern Dogface, a rather scarce species here in Colorado. In addition to the butterflies shown here, I also spotted a Variegated Fritillary making a brief stop on a blossom.

A "crescent" butterfly, Phyciodes sp.

Two Reakirt's Blues, Echinargus isola

At least one moth visited White Prairie Clover during my two separate observations: the Jaguar Flower Moth, Schinia jaguarina.

Jaguar Flower Moth, Schinia jaguarina

Wasps were highly diverse and plentiful visitors, but made some of the shortest refueling stops of all the insects observed.

Great Golden Digger wasp, Sphex ichneumoneus

Thread-waisted wasp, Ammophila pictipennis

Female Ammophila procera

Male Ammophila procera

Ammophila ferruginosa

Black & Yellow Mud Dauber, Sceliphron caementarium

Male sand wasp, Bembix sp.

Male beetle-killer wasp, Cerceris sp.

Male beewolf wasp, Philanthus ventilabris

Male thynnid wasp, Myzinum sp.

Female thynnid wasp, Myzinum sp.

Cuckoo sand wasp, Stizoides renicinctus

Flowers that are attractive to pollinators are also attractive to their predators and parasites, and that was certainly obvious during my watch periods. The bee assassin, Apiomerus sp., was somewhat surprising because the bug is so conspicuous atop such a small flower. I suspect it was having little or no success. Meanwhile, the odd, cream-colored ambush bug, Phymata sp., could achieve proper concealment, even to the point that I recall seeing only one when there were surely many.

Bee assassin bug, Apiomerus sp.

Thick-headed flies accost bees or wasps in mid-air and ram an egg between the victim's abdominal plates. The fly larva that hatches then feeds as an internal parasite. This often kills the host, but not always.

Thick-headed fly, Zodion sp.

Thick-headed fly, Physocephala sp.

My personal experience is that white flowers, or at least pale flowers, attract a far greater diversity of insects than red, blue, or purple flowers, and even more than yellow flowers in some cases. It is puzzling to me that few pollinator advocates bother to reveal that fact. Maybe because everything is bee- and butterfly-centered, and still color-intensive in the landscaping sense, white flowers get short shrift in recommendations for the garden.

Grasshopper wasp, Prionyx atratus or Prionyx subatratus

It may be worth it to harvest seeds from wild plants, but please do not dig up mature White Prairie Clover. The plant has a deep taproot. One may also wish to consult their state's Native Plant Society for potential sources of seed. The plant flourishes in full sun and dry soils, requiring only a medium quantity of water.

Green-eyed wasp, Tachytes sp.

I will try and produce more floral-themed, pollinator-rich posts in the future to help readers in making landscaping decisions that support native plants as opposed to exotic ornamentals and inappropriate cultivars. Feel free to make suggestions as to additional resources.

Mason wasp, Euodynerus sp.

Sources: Holm, Heather. 2017. Bees: An Identification Guide and Native Plant Forage Guide. Minnetonka, Minnesota: Pollination Press LLC. 224 pp. Useful mostly for Upper Midwest U.S.
Mader, Eric, et al. 2011. Attracting Native Pollinators. North Adams, Massachusetts: Storey Publishing. 372 pp. A Xerces Society guide.
EasternColoradoWildflowers
WildflowerDotOrg
Prairie Nursery

Friday, October 28, 2016

Review: The Sting of the Wild

Justin Schmidt is widely acclaimed for creating the Schmidt Pain Index that ranks the potency of the stings of bees, wasps, and ants, based largely on self-inflicted experience. It naturally follows that a book is in order to explain what most would consider a crazy person's pursuit. The Sting of the Wild, from Johns Hopkins University Press, is an odd combination of memoir and study in the scientific method. Does it succeed as either?

Full disclosure is also warranted here. I have known Justin as a friend, mentor, and colleague for decades, and am truly in awe of how his mind works. He asks questions that no other scientist does, then creates ingenious ways to test his hypotheses. No one I know is as innovative, persistent, and hard-working in the name of basic research. I was hoping that his personality and character would be reflected in this book.

The book contains what may be the best explanation of the attraction of certain people to scientific careers:

"Science is an exploratory process more so than a goal to realize. Yes, there are goals, and these must be clearly defined for funding agencies to support the research, but the real excitement and driving force in science is the adventure of seeking the goal, not in attaining the goal."

That is what I was anticipating from this volume: excitement and adventure. I have heard enough stories from Justin to know that he has a nearly limitless source of material, and is able to engage colleagues easily. So, what happened to that? Why did it not translate well to the written page?

If your usual reading in entomology is Howard E. Evans (Life on a Little Known Planet and Wasp Farm), May Berenbaum (Bugs in the System), or Bernd Heinrich (In a Patch of Fireweed), you will likely be disappointed by this book. Those unfamiliar with scientific terms, or chemical molecular structure, will find the book over their head at times, or at least dry and flat. Anecdotes from the field are lively enough, but too few and far between to sustain momentum of the narrative. The reader is forced to weave together the author's timeline from disparate passages and references, so the autobiographical aspect is also broken.

It stings me to say this about the book because its author is someone who should be admired and emulated. Schmidt is profoundly curious, a quality sadly lacking in too many scholars today, if not outright squelched by an academic environment that demands we be more concerned with "managing" nature than understanding it first. He is not some caricature or dare-devil as the media tends to suggest, but this book does little to change that impression, let alone create an understanding of what drives Schmidt's curiosity.

Despite its shortcomings, I learned a good deal from this book, and that alone may be enough to recommend it, at the very least as something worthy from your local library. A general audience is, unfortunately, not going to flock to this book. It reflects the novelty of the author's life, but lacks relevance to the reader unless he or she is also a scientist or aspires to be one. The complete "Schmidt Sting Pain Index," which makes up the appendix, is not enough to push the whole book into the limelight. The best natural history books ignite in the reader the urge to explore and discover. This one might keep them indoors, as a virtual spectator of other adventurers.

Saturday, August 20, 2016

Don't Sweat 'em

During the heat of summer, we all perspire. Some insects find that bodily function irresistible. Among them are sweat bees, various flies, and even butterflies. It is believed that the salts, minerals, and other compounds in our sweat are necessary for these insects, and difficult to find elsewhere. While you might assume that any insect landing on you intends to bite or sting, rest assured these insects are harmless.

Female sweat bee, Halictus rubicundus

Solitary and semi-social bees in the family Halictidae are collectively known as "sweat bees" because of their habit of lapping up human sweat with their short "tongues." They may tickle at most, but if you smack one absent-mindedly, it may indeed sting if it is a female bee. Male bees lack stingers.

Two different sweat bees, both Lasioglossum species

Sweat bees come in a variety of sizes and colors, from miniscule brassy Lasioglossum species to brilliant metallic Agapostemon species (and related genera). Members of the genus Halictus are medium-sized and brown or blackish with white bands across the abdomen. Nearly all species nest in the soil, each female excavating her own burrow.

Female sweat bee, Agapostemon sp.

Compounding the problem of recognizing the different insects that seek out your sweat is the fact that many flies in the family Syrphidae are wrongly called "sweat bees" in casual and regional language. Syrphid flies are more properly called "flower flies" here in the U.S. and Canada, and "hover flies" in Europe.

Tiny Toxomerus syrphid flies are often mistaken for sweat bees

Like bees, they can be important pollinators of flowers, but it is in their youth that they are most beneficial. The larvae of many flower flies prey on aphids, which are major crop and garden pests. Thus, the more syrphid flies, the better, even if they do want to drink your perspiration.

Unidentified syrphid fly on my arm, lapping sweat

Plenty of other flies, mostly blow flies (family Calliphoridae), and flesh flies (family Sarcophagidae), will land on us, too. Even some tachinid flies (Tachinidae) will wander around on bare hands and arms. They may not all be there for moisture or salts.

Tachinid fly using me as a lookout post

Some of these flies may be males that are simply using us as convenient perches from which to defend their territory. They will periodically fly off to chase away competing males, or pursue passing females.

Some butterflies are well-known for requiring certain minerals to complete their life cycle. Usually, male butterflies congregate around mud puddles, puddles of urine or piles of scat left by mammals, or even rotting carcasses, where they obtain nutrients that they will pass to females during mating.

Hackberry Emperor butterfly getting salts from animal dung instead of sweat

Males with a higher mineral content are more desirable to females, though how this is determined remains something of a mystery. She puts the transferred chemicals to good use in producing her eggs.

Occasionally, some butterflies will use us as substitutes for their usual mineral resources. I once had a Hackberry Emperor butterfly land on my toe while I was sunbathing in a park in Cincinnati. I had another land right on my sunglasses in a different location in Ohio, but he viewed me as a convenient perch from which to defend his territory.

Female Lasioglossum sweat bee with tongue extended, lapping sweat

Most research into the attractiveness of human sweat to insects has been directed at blood-feeding insects such as mosquitoes and other biting flies. Consequently, there is relatively little known, and much assumed, about the fascination non-biting "bugs" have with our skin pore excretions. One thing scientists can agree on? Don't sweat the sweat bees.

Tiny female Lasioglossum sweat bee on my fingernail

Source: Gibb, Timothy. 2015. "Do Not Confuse Hover Flies with Sweat Bees," Purdue Plant & Pest Diagnostic Laboratory, Purdue Extension, Purdue University.

Unidentified tachinid fly grooming itself on my arm