Waxworms make Holey Shopping Bags

A shameless boast, I take fewer than a dozen plastic shopping bags home from the grocery store each year (a trillion are manufactured). Discarded in garbage for burial in landfill, this non-compostable stuff awaits a post-Homo sapiens archeologist who learns how Anthropocene people trashed their planet. But beekeepers have another option for disposing of polyethylene. A dead hive. Not really practicable, but the idea connects with a new channel for Earth care.

When a bee colony deserted the hive, I saved the frames containing honey, boarded the entrance, and didn’t return to clean the interior for several weeks.

I was gobsmacked when I opened the boxes. The combs eaten to shreds were festooned in silken threads. Wax moths had snuck inside.

Galleria mellonella
One hungry waxworm (Pixabay)

Greater wax moths (Galleria mellonella), originating in Asia and now worldwide, depend on beehives to reproduce. Their eggs turn into plumptious caterpillars gorging on beeswax, and only a strong colony can beat back the invaders. Along with mites and hive beetles, wax moths are the bane of beekeepers.

A few years ago, biologists noticed holes appearing in plastic bags used to collect waxworms. Trained to be inquisitive, they set up an experiment, finding the plastic was eaten at a rate of 2 holes per worm-hour. Their results were published and another paper appeared in Current Biology.

They spun some in a blender to test the effects of caterpillar mush on plastic. It degraded. So, the plastic was digested, not just chewed. It is likely that bacteria in their gut were responsible, and the process probably benefited them by generating energy for metabolism. The long chains of hydrocarbon that make polyethylene turned into ethylene glycol, a substance used as an antifreeze in automobile radiators that is rather toxic to us, although it degrades quickly in soil.

There are unrelated bacteria that digest plastic, albeit slowly. Neither they nor waxworms can consume the mountains of plastic we generate, but that a synthetic compound formerly thought to be stable for eons is biodegradable gives hope that genetic engineering will develop a more efficient agent. Perhaps that can soften absolutist objections some people have toward GMOs.

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Where the Bee Stings

Bee stings … an occupational hazard for beekeepers. The price paid for hosting hives and stealing their honey. I score about three hits per season, and they are generally deserved from carelessly zipping my beesuit. But honey bee stings don’t give the biggest punch: that dubious honor is held by the tarantula hawk and the bullet ant, each scoring 4 out of 4 on the Schmidt Sting Pain Index.

Beehive
Beeware

Dr. Justin Schmidt is a doughty entomologist at the University of Arizona (The Sting of the Wild). Over a career he has invited stings from every hymenopteran species he encountered. He gave a score of only 1 to some ants and small bees whose stings didn’t hurt much or for long. Most honeybee varieties scored 2, which I can report gets my attention. Red paper wasps and velvet ants were at 3. Few species reached the top of the range – a blinding pain that feels extreme/ excruciating/ electric – and yet the pain from a ¼” tarantula hawk sting is long over (if not forgotten) before a honeybee’s sting has started to fade. Why the difference? Why do some insect stings give crippling pain while others are as mild as pressing a pencil tip on the skin, and many fierce-looking bugs don’t or can’t sting? Nature presents many conundrums, but this isn’t one of them because stinging makes sense in biology.

The hawks lay their eggs inside tarantulas which are eaten alive after their larvae hatch. They rarely sting us unless we try really hard to annoy them, as Dr. Schmidt must have done to obtain “data”. Why should they shoot their big gun when we don’t normally threaten them? As solitary wasps they have no “home” to protect. The mud-dauber wasps are also solitary, often making a tubular nest of dried mud on the sidings of our home. Schmidt tried very hard to get them to sting him, and when one was sufficiently enraged it hardly hurt.

Honey bees and yellow jackets, on the other hand, are colony dwellers that store food during warm seasons to support them with their queen through the winter in readiness for a burst of foraging and reproduction in early spring. Their honeycomb must be defended at all costs, which they do aggressively whenever a beekeeper inspects his/ her hives. But honey bees rarely sting while they are feeding in a garden or meadow unless you trap them between your toes, etc.

During the hot Virginia summer large numbers of bees gather at the side of our pool to take water back to their hive for air-conditioning. I can impress visitors by nonchalantly wading through a buzzing cloud, trusting they won’t sting me clad only in swimming trunks. For the same reason that they are relatively docile away from their food store, a swarm of bees that is emigrating to create a new colony is quite passive, even though it may look terrifying. But there is a different explanation for the old trick of circus performers who dared to pour bees into their mouths – by carefully selecting drones they can’t be stung.

Queen bees possess a sting, but they leave hive defense to workers and reserve their swords for dispatching rival queens. There is another difference between them. Queens can sting repeatedly, whereas it is a death sentence for workers because their anatomy requires stings to be ejected with some of the viscera.

Human sensibilities might deem their sacrifice altruistic for defending the hive’s socialist society, but surely natural selection could have evolved a superior warrior bee that can sting and survive, just as many other species can and do? Perhaps the explanation is that death is required for the release of a special pheromone for attracting other bees to escalate attacking a threat. This pheromone is a mixture of volatile fatty acids said to smell like bananas, and beekeepers lightly smoke their hives to pacify bees by masking the scent. I can hardly blame them for being angry, and in a feminist poem Sylvia Plath sympathized with female workers whose bounty is stolen by (male) beekeepers:

Stings poem

One of the scariest encounters you might have on a hiking trail in the South-West is with a mountain lion, but I would rather take my chances with the big cat than with a swarm of Africanized bees (aka killer bees). They are spreading north in states from Texas to California. A young man died this summer after a bee attack, as have several dogs and even horses. Africanized bees can’t be outrun, wait for you to come up for air if you jump in a pool, and can’t be fought off except with fire. They don’t have a more painful sting but are more aggressive – much, much more aggressive.

The victim wasn’t reported to be allergic, but the thousand stings on his body exceeded the lethal dose for bee venom. The major active agent in venom is an acidic peptide, melittin, which has anti-inflammatory properties and is probably responsible for its long-supposed medicinal value in the Orient. So there may be virtue in it, even while we try to avoid stings or carry an EpiPen as a precaution.

There is an outsized fear of being stung that beekeepers have to shrug off. But, apart from the 30 minutes of pain, let’s put a perspective on the big risk – of dying from bee stings.

According to CDC statistics for human mortality from wild and domesticated animals for the fifteen years to 2014, 486 people died from dog attacks, 1,163 from other mammals (mostly cattle and horses), 9 from crocodilians, about 15 from black bears and only one from a mountain lion. But 921 people died after being stung by bees, wasps or hornets, although most of them are thought to have been allergic to the venom. This is not a huge risk compared to others we face, and it is one that I dare say beekeepers hardly think about, but if we could compare the total number of attacks from all these species, combining non-fatal and fatal ones, I am sure bee stings would soar above all. And what do all these figures reveal – that we put ourselves most at risk not from ferocious wild carnivores but from the creatures we choose to live with or steal from.

 

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Two Beekeepers in the New Zealand Bush

Honey is almost emblematic of New Zealand, like surf beaches, kiwis and hobbits, and Winnie the Pooh would drool thinking about it.  I leaped at the chance to spend a day with a professional beekeeper whose hives are in the bush for making Manuka honey.

We left home in the dark at 6 AM for a short drive to Steve’s depot where he picked up a portable incubator containing several dozen queen bee cells. He is passionate about the industry in which he has worked for over a decade, learning the ways of honey bees on the job. There is a Honey Research Center at the University of Waikato in Hamilton, but there are no professional qualifications for beekeeping, which is surprising for an industry so vital to New Zealand’s agriculture.

His firm has six fulltime staff plus a few students who are hired during the busy summer months, and that is how Steve got involved. Cambridge Bee Products currently manages around 5,300 bee colonies, and expanding. As a backyard beekeeper in Virginia I gasped at the scale, but evidently his company is far from the largest in the country. The industry is thriving and, compared with other sectors of agriculture including dairy, it has never suffered a recession. His company barely meets demand for its finest product—Manuka, the most highly prized honey in the world (see previous post) which, in good years, is more than 70% of his harvest, and 95% of which is exported.

The roads were wet from overnight rain when our truck pulled into his depot. Parking space was limited beside a forklift truck and the neat piles of Langstroth hive boxes and barrels containing 300 kg of honey when full. In the dim light I couldn’t see an alarm system, but the property had to be secure because I had seen the firm’s honey for sale in a local health food shop at over NZ$100 per kg. A quick calculation estimated that each barrel of the best grade is worth tens of thousands of dollars, though middlemen and retailers take a large bite of the raw value.

The honey harvest is brought to the premises from remote parts of the North Island. Manuka honey is certified by the UMF Honey Association to guarantee authenticity and grade it for quality because many brands contain only a fraction of the active product while others are fraudulently adulterated with cheap honey or syrup.

Barrels of honey, hive boxes and ingots of beewax
Barrels of honey, hive boxes and ingots of beewax

Inside the warehouse ranks of orange barrels and colorful hive boxes rose to the roof. The boxes were made by the staff from pine boards treated with a non-toxic preservative and paint; they have a lifespan of around 20 years in the field. In front of them large yellow bars were neatly stacked like gold ingots at Fort Knox, but weighing a mere 6 kg. They were pure beeswax extracted from old honeycomb for making candles and other molded products.

Honey is the company’s main business compared with big bee firms in America who make most of their income from pollination services for farmers by migrating thousands of hives around the country to crops as they blossom in turn. Only for a few weeks do some of Steve’s hives stand in fields for pollinating kiwi fruit, avocados and blueberries, and none of those crops produce quality honey.

Comb decapper and two honey extractors
Comb decapper and two honey extractors

I followed Steve into the honey production plant through a series of adjoining rooms to admire his automated equipment. Backyard beekeepers extract honey with heated knives to decap comb, but it’s a slow and messy process. His first machine decaps in seconds by piercing the comb with arrays of short spikes mounted on a metal plate that precisely match the centers of cells across the frame. Afterwards in groups of eight, frames are loaded into stainless steel extractors to centrifuge the honey to the sides where it drains for collection. The honey is then heated in a large vessel to kill yeast or other cells that might be present before filtration and storage in barrels. At the final stage a machine automatically fills bottles with 250 or 500 or 1,000 g of honey, and even puts on lids and labels.

I liked the clean facilities and that nothing was wasted. Frames were recycled about every five years with a fresh plastic base coated in wax for the bees to draw. Honey residues were collected as sticky molasses for farm animal food, the wax was extracted in a larger melter, and any comb that remained was used as fertilizer.

After the tour I was eager to meet the rest of the team who live in bush country north of Lake Taupo. It was getting light outside when we hopped back in the truck for a two-hour ride.

Hive-ho in a bee yard
Hive-ho in a bee yard

The hives were stationed in groups of two or three dozen in glades that he called “yards,” and out of sight from thieving eyes on country roads. Hive robbing and vandalizing happens. He lamented that at one time there was an unspoken gentleman’s agreement not to place hives within a kilometer or two of a competitor, but as profit attracts courtesy retreats. ‘tis often so.

The bee yards were chosen for local abundance of tea trees which provide the nectar for bees to convert into Manuka.  Steve groaned that too many trees are torn down by landowners who think they are eyesores and don’t realize or care that bees make a precious product from them, like turning base metal into gold. Of course, they never feed exclusively from tea trees, and the grade of Manuka depends on the location and season. The coconut-scented yellow blossom of gorse attracts insects in early spring, and purple heather feeds them at the end of the summer. A long blooming season offers a wide menu in the bush, but the rewa trees stand out for their fabulous red flowers for bees to drink from deeply.

When we arrived at the first yard, the hives looked pint-sized with only a brood box or no more than one super on top. Had I come before the honey harvest in January they would have been piled shoulder high with supers heavy in comb. A super full of honey can weigh 35 kg, enough to coin a name for a medical syndrome, “Apiarist’s Back.” I was too mortified to describe our tiny harvests.

We donned bee suits and started inspecting each hive in turn. Removing the galvanized roof and inner cover exposed the ends of nine full-sized frames, and encouraged a few guard bees to fly out to inspect us. The brood boxes had a couple of small entrances the size of a ten cent coin and stood on stout wooden frames with a wire mesh floor which was left uncovered year round.

Nice frame
Nice frame

As I probed Steve for statistics I wondered how kiwi apiaries can be so productive and colony losses so slight, rarely exceeding 10% a year. Could weather and climate be partly responsible? I was surprised that the climatic zone was not much different to ours in Tidewater Virginia (8 cf. 7b), because our summers are hotter and more humid, while our winters are longer and colder. Since his winters are almost frost-free, nectar flows for much longer and colonies only need feeding for 2-4 weeks if at all. Another factor I considered was the advantage that his colonies have out of range of sprays and other hazards in gardens and farmers’ fields. Then I thought about the lower load of parasites and diseases in a clean environment, although I was surprised how many of them have already reached New Zealand. American (though not European) foulbrood is there, I saw silken evidence of wax moths in some boxes, and that great foe the vampire mite, Varroa destructor, arrived in New Zealand over 15 years ago. Australia is the only country with a major honey industry free of mites, although it had a close call last year when dock officials in Brisbane found bees infested with them in a shipment of goods from Malaysia. It’s only a matter of time before Aussies share our woes. But we saw very few mites that day, which he credits to formic acid pads laid under inner covers and oxalic acid which he sprays through entrance holes. Both of these treatments are considered natural, and they don’t persist in honey or wax. Hive beetles were absent, but robbing bees and wasps sometimes stripped a hive, but that’s a universal problem. When I asked him about colony collapse disorder and killer bees, he nodded to acknowledge that it is a big issue in other countries.

I came away with the impression that no single reason explained the health and productivity of bees in New Zealand. There were additive advantages of a better climate, fewer parasites and less pollution. He didn’t and couldn’t make frequent inspections like we do, but was anxious to breed beneficial traits, by which he meant productive queens and docile worker bees.

His hives are re-queened annually and the company buys genetically superior queens every year from a specialist breeder who uses artificial insemination to guarantee the character of their progeny rather than leaving fertilization to the vagaries of a nuptial flight. In the field, bees hybridize with unknown drones, but he like to see more Carniolan character: “The blacker the better.”

We visited the yards not for mere inspection but to re-queen and split hives to make nucs for new colonies. Delicate queen cells that had been warming in an incubator plugged in the truck and protected inside conical plastic jackets were now placed inside hives, one or two per frame. “Sometimes by chance I see a resident queen,” he told me, “but I can’t go through every hive so they all get a potential heir or two to fight it out until the fittest survives.”  Weak colonies were ruthlessly culled, much like a farmer might eliminate animals too sick for veterinary care. I reflected on the pains we take to save a colony from fading away until I remembered the number in his care.

It seemed odd to split hives in late summer when we schedule it for springtime to avoid the risk of swarming and in time for nucs to establish while nectar flows. But he used a familiar procedure, transferring four frames from active colonies to each nuc box, including eggs, nectar and pollen, plus a shower of worker bees. He worked fast, watching the sun’s arc because he wouldn’t return to the yards for months.

End of the day
End of the day

This work quickly filled the air with thousands of angry bees that a smoker didn’t pacify. I took the precaution of wearing gloves, but Steve had bare hands. He worked more nimbly with uncovered fingers, even if they were crawling with bees. On the ride home I mentioned I had seen him rubbing his wrist. “Did you get stung?” I asked. “Na.  Maybe only ten today.” That reply reminded me of another plucky New Zealand beekeeper, and who first scaled Everest.

After we returned home to Cambridge I had much to think about. How to apply some of the practices I had to our modest endeavors? What is the future for bees in a changing world, and will they hold out longer in New Zealand and Australia?  And I was also thinking about the remote Blue Duck Station close to the pristine Whanganui National Park. That is where he keeps the most productive hives, and some of those yards are accessed by helicopter. I am already savoring that visit for next time.

Drafted in New Zealand

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