Blitzing the Day Away

Last week I went blitzing-BIOblitzing that is. What, you may ask is a BioBlitz? BioBlitz’s are biological surveys that are periodically held by conservation organizations or universities to identify the species of plants, animals and fungi that inhabit a particular tract of land. In Manitoba, the Nature Conservancy of Canada (NCC) periodically holds BioBlitz’s to identify the species on new properties that it acquires. The BioBlitz that I just participated in was of NCC’s recently acquired Fort Ellice property near the Saskatchewan border, just south of St. Lazare.

Having never been on a BioBlitz before, I wasn’t entirely sure what to expect. It turned out to be two days of hiking along the lovely Assiniboine River Valley, visiting with biologists I hadn’t seen for quite a while and seeing some beautiful rare plants, insects, and birds. It also meant getting covered in ticks and a boot-full of muddy swamp water but those are the normal hazards of field work.

Doing a survey with a large group of botanists made the event much more effective because if one of us didn’t know what a plant species was, someone else did. It was as if we had formed one big, really smart superbotanist! In addition to the plant people, there were also birders, a range manager, ecologists, bug catchers, a mammal expert, a couple of fungus guys, and even an archaeologist. We recorded all of the species we saw, and any plant, lichen, or fungus we couldn’t identify was collected to examine in the lab.

Highlights of the trip included spectacular sand dunes, a babbling brook, a recently hatched Sphinx Moth, mating Tiger Moths, and one of the largest morels I’ve ever seen. Now comes the sad part: waiting for the next BioBlitz so I can do it all over again!

Many people love to garden. But the way you garden can have a negative impact on the environment or a positive one. “Green” gardens are cheaper to maintain as they do not require high inputs of water, fertilizers, pesticides, or fossil fuels, and provide habitat for the many wild plants and animals that share our planet. Here are some tips to increase how “green” your garden is.

• Consider replacing some of the lawn you don’t use with trees, shrubs and/or flowers as they provide better habitat for beneficial insect and birds.
• Correct placement of trees and shrubs can also improve the energy efficiency of your home. Evergreens planted on the north side of your house block cold north winds while deciduous trees on the south side let the sun warm your home in winter but block it in the summer when it’s hot.
• Don’t even try to grow grass in dense shade. Cover with mulch or plant hardy, attractive, native ground covers like Western Canada Violet or Canada Anemone.

• Grow at least some native plants in your yard. Native plants are adapted for the climatic conditions that we get in Manitoba, requiring no fertilizers or supplemental watering when grown in the proper spot. Native plants provide food for many birds and beneficial insects like bees and hoverflies.
• If you like to grow exotic plants, include some that provide food for birds and/or insects. Many horticultural species like hydrangeas, peonies, begonias and fancy “double flowers” are not very attractive to our native pollinators. Exotic plants that do provide food for pollinators include: columbine, delphinium, globe thistle, mint, oregano, Goat’s-beard, and many more.

• Remember to put your yard waste  out for collection along with your recyclables and garbage if you live in Winnipeg.
• For more information on green gardening pick up the “Naturescape Manitoba” book published by the Manitoba Naturalists Society (Nature Manitoba).

Last summer I went to Spruce Woods Provincial Park to determine which insects pollinate the rare Hairy Prairie-clover plant, a species that only occurs in sand dunes. Oddly enough, even though Hairy Prairie-clover is rare, it was being visited more frequently than some of the common plants I have observed. But there was a dark side to all that activity: it was drenched in blood-the blood of innocents! Instead of the cute, fuzzy little bumblebees I had grown accustomed to watching, I encountered big, black and yellow or red wasps and large, colourful wasp-like flies! What were those crazy creatures? When I got my insect identifications back recently, I was shocked to discover that 40% of the species and 67% of the insect visits to Hairy Prairie-clover were by solitary hunting wasps and parasitic flies that prey on other insects.

The Sand Wasp (Bembix pruinosa) was the most frequent flower visitor to Hairy Prairie-clover. Although adult Sand Wasps consume pollen and nectar, the females also capture and paralyze small flies (e.g. Soldier and Horse Flies) to feed to their babies. The Sand Wasp larvae and paralyzed prey are well hidden in underground burrows. A related species of wasp called a “bee-wolf” (Philanthus sp.) was observed capturing and flying away with tiny Andrenid Bees (Perdita perpallida) that were busy pollinating Hairy Prairie-clover.

The Common Thread-waisted Wasp (Ammophila procera) is also a solitary hunting wasp but captures the caterpillars of Noctuid moths called Prominents (Notodontidae) instead of flies. A similar looking species, the Great Black Wasp (Sphex pensylvanicus), captures and paralyzes grasshopper or katydid larvae, and lays an egg on it to act as baby food. The Grasshopper Bee Fly (Systoechus vulgaris) also parasitizes grasshopper eggs. The female Grasshopper Bee Fly shoots her eggs in an area of loose soil suspected to contain grasshopper eggs. The hatched larvae crawl around in the soil until they find a suitable grasshopper host and then they suck it dry!

Similarly, the larvae of large Scoliid Wasps (Trielis octomaculata), are ectoparasites on Scarab Beetle (Scarabaeidae) larvae. The large females hunt down the beetle larvae in the soil, paralyze them and lay an egg on them. Some Scoliid wasps have even been used for the biocontrol of white grubs on sugar cane crops.

And those wasp-like flies? They were Conopid or Thick-headed Flies. The female flies lay their eggs inside bees or wasps. The hatched larva then slowly eats its host until it dies, eventually bursting from the exoskeleton after pupation.

Ironically, even the parasitic wasps are themselves parasitized. The females of the Bee Fly Exoprosopa shoot their eggs into the burrows of solitary hunting wasps, and the hatched larvae develop as external parasitoids. What a fascinating series of biological interactions surrounding just a single plant. Clearly it’s an insect-eat-insect-eat-insect-eat-plant world out there!

I was recently watching the hilarious yet scientifically accurate video on the mating habits of bees done by Isabella Rossellini (see more here). Coincidentally, I’ve also been reading about the quite bizarre and sometimes gruesome life cycles of wild pollinators for my upcoming Prairie Pollination exhibit. Inspired by Isabella, I found myself wondering what it would be like if people were like pollinators…

Ironically, some parasites of bees and butterflies are pollinators in their own right so their existence is ultimately beneficial to wildflowers in an ecosystem. In fact, the abundance of some of these parasites is actually an indicator of the overall health of the pollinator population. Essentially, if there aren’t enough bees to support their parasites then the population of bees must really be in trouble. Further, they may actually help improve the resilience and productivity of an ecosystem the way other top carnivores like wolves and sharks do. Unfortunately this topic has been virtually unstudied so we really don’t understand the true impact of pollinator parasites on ecosystem functioning. So don’t hate parasites because they kill – they’re just part of the sometimes morbid circle of life that we humans seldom see.