Tag Archives: garden

Welcoming native bees

I gave a Zoom lecture last night on why people should care about native bees, and promised the audience (friends of Belmont Hills Library, in Bala Cynwyd, PA) that I’d share some links, photographs, and answers to some of the questions at the end. If you have any lingering questions or thoughts, please don’t hesitate to contact me. Good luck attracting bees, and thanks again for the invitation.

My blog posts I referenced

Links of interest

Articles

Bee books

Answers to questions

  • Good native ground cover to replace English ivy? A: golden groundsel (Packera aurea).
  • Honey from any native bees? A: yes, from stingless bees. I have a few photographs from Costa Rica and Mexico. It’s more liquidy than European honey bee honey.
  • Are yellow jackets wasps or bees? A: wasps
  • How deep do ground-nesting bees dig? A: I looked up the record and in some species the tunnels can extend down 10 feet or more. But 12 to 18″ is more typical.
  • Do figs actually eat wasps? A: Figs in the wild are pollinated by wasps, but as I mentioned, the varieties we grow in the United States don’t require pollination, so the crunch is not due to wasps within. Fig and biology fans should read Gods, Wasps, and Stranglers: the Secret History and Redemptive Future of Fig Trees.
  • Is it worth keeping hostas in pots for leafcutter bees A: It is never worth keeping hostas alive for any reason. But leafcutter bees will use them, I’ve read.

Photographs I showed or meant to show

For more photographs of bees (and wasps), my full collection is on SmugMug.

#BeeBest

Wine bottle drip irrigator

Instructions for making a drip irrigator out of a wine bottle. In case you’re bored out of your mind during the Covid-19 lockdown.

Wine bottle drip irrigator

Instructions

  1. Cut the bottom off the bottle. The above shows a 750-mL bottle but a 1.5-L works, too. I own a Creator’s bottle cutter kit (it’s fantastic) but there are videos showing other techniques.
  2. Drill a hole through the cork to accommodate 1/4″ tubing.
  3. Cut a length of 1/4″ drip irrigation tubing so that it is 1/2″ longer than the cork. Put a small piece of tape over the opening of one end.
  4. Put a few drops of outdoor glue into the hole. Gorilla Glue is nice because it tends to expand, filling gaps in the cork.
  5. Insert the taped-up end of tubing into hole, pushing until untaped part is flush. Take off tape (that was there to make sure it didn’t get filled with glue).
  6. Once glue is dry, insert cork into bottle so that the 1/2″ overhang is sticking out.
  7. Attach an adjustable valve to the tubing.
  8. Attach a 12″ (or so) length of 1/4″ tubing to the valve.
  9. Attach bottle to a 36″ stake (1×1″ wood, 1/2″ bamboo, or plastic-coated metal) using wire. Make it extremely snug so that when filled with water it won’t drift down.
  10. Crumple up some tulle (or flexible screening) to form a filter plug near cork. Tamp down using a long rod. This prevents hole and valve from clogging.
  11. Attach tulle (or flexible screening) to top with two rubbers bands. One rubber band is fine but the second is backup in case sunlight degrades one. The screening keeps out debris, but also prevents mosquitoes from ovipositing when valve is closed (and bottle is filled).

Here are some closeups:

Once done, situate the irrigator in your garden so that you can easily see the drip and adjust the valve without fighting foliage or stooping. This is why the instructions above call for a short length of tubing rather than something that fully extends into the soil near the plant (where you couldn’t see it). Evaporation from a falling drop of water is probably non-zero but I think the ability to see the drip rate is worth it.

When you water drop by drop, slowly, the soil has time to fully absorb the moisture. Drip irrigated plants thus need far less water, sometimes dramatically less. Another benefit is that water isn’t constantly splashed onto leaves, something that can distribute as well as activate pathogens. Some plants simply don’t like wet leaves (don’t judge). And many plants (such as tomatoes) also benefit from being constantly hydrated, something that is hard to accomplish with normal irrigation. Finally, plants tend to take up fertilizer better when it is slowly delivered.

Identifying mantid egg cases in Pennsylvania

There is one native and three introduced mantid species where I live in Pennsylvania (Delaware County), and I’m trying to get the word out that the invasive ones should be killed when found. This post has photographs of the oothecae along with some brief comments about what makes each species distinctive. At the end of the post I have suggestions on how to put the invasive oothecae to good use.

Carolina mantid (Stagmomantis carolina)

Carolina mantids (the only native species in my area) form relatively smooth, teardrop-shaped oothecae with a central portion that is lightly colored. Often found on tree trunks, rocks, and buildings.

Egg case of Carolina mantid (Stagmomantis carolina)

Chinese mantid (Tenodera sinensis)

Chinese mantid oothecae are typically round (or roundish) roughly textured, and uniform in color. Introduced from Asia, as you probably guessed.

Egg case of Chinese mantid (Tenodera sinensis)

Narrow-winged mantid (Tenodera angustipennis)

Narrow-winged mantid oothecae are usually rather elongate. They are also seem to have red streaks, though the color seems to be most noticeable after they age a few months. Introduced from Asia, too.

Egg case of narrow-winged mantid (Tenodera angustipennis)

European mantis (Mantis religiosa)

I’ve never encountered a European mantis ootheca, so here’s a photograph by Hans Hillewaert (via Wikipedia):

By © Hans Hillewaert, CC BY-SA 4.0

Another common name for the European mantis is praying mantis (not preying mantis).

More ID help

If you need help identifying an ootheca, I highly recommend posting a photograph on iNaturalist. If you post there, feel free to include my iNaturalist username (@colinpurrington) in your caption so that I can have a look. Not only will you get an answer from the iNaturalist community within a day or two, your submission helps scientists track the spread of invasive species.

For an excellent overview of all of these species, please see the Cape May Wildlife Guide’s page on mantids.

What should you do with the non-native oothecae?

Invasive mantids eat butterflies, native bees, honey bees, small birds, and also the native mantid, so when you find egg cases, dispose of them. Here are some suggestions on how to do that:

  • Give them to local bird rehabilitation centers — if local bird rehabilitation center doesn’t know what you’re talking about, inform them that insectivorous birds absolutely adore frozen mantid hatchlings.
  • Give them to a neighbor who has chickens.
  • Give them to a neighbor who has a pet tarantula, snake, lizard, or fish.
  • Put them in a freezer for a week.
  • Step on them.

But whatever you do, do not just relocate oothecae to some nearby field — that just transfers the problem to someplace where you can’t see the problem. I.e., even though you might pride yourself as being a gentle soul that wouldn’t kill a fly, releasing invasive predators will result in monarch butterflies being eaten alive. Don’t be that person. If you simply cannot bring yourself to kill the eggs, ask somebody to help you do the right thing.

But aren’t mantids great for pest control?

Many people (I include myself) grew up being told by highly-educated, seemingly trustworthy adults that mantids are ideal for providing chemical-free pest control in the garden. That view, it turns out, is a myth. Although it’s true that young mantids consume small, pestiferous insects, when mantids are fully grown they tend to camp out on flowers and wait for large butterflies (and even birds). I.e., when a mantid is fully grown it will not even look at an aphid. Mantids are, of course, excellent for controlling butterflies and hummingbirds, just in case you happen to hate those animals.

Some people even believe that mantids can control ticks. They don’t. They are equally ineffective at controlling mosquitoes.