Mid-August at the Fletcher Wildlife Garden

by Christine Hanrahan

Mid-afternoon at the Fletcher Wildlife Garden, August 14th. A sunny and pleasant afternoon to be looking for things to photograph for the PBase Blog. My first sighting was of the Sphex ichneumoneus, the great golden digger as it is sometimes called, nectaring on swamp milkweed. Its counterpart, the great black digger, S. pensylvanicus, is often more numerous, but both are large and impressive.

Other insects found include numerous Acutalis treehoppers, one of our smallest treehoppers, tiny little green and black insects, usually found on the stems of plants such as goldenrod. The large (for a planthopper), Acanalonia bivittata, with its distinctive shape, is easily recognized. It is bright green, with reddish eyes and a dark stripe down its back. It also comes in a vivid pink form, something I’m still hoping to see. The large swathe of Monarda fistulosa, our beautiful lilac-coloured native species, in the butterfly meadow, is alive with bees and other nectaring insects, including a hummingbird moth and a very tattered silver-spotted skipper. The big Bicyrtes sand wasp, smaller mud daubing wasps, sweat bees, leaf-cutter bees, ragweed beetles, goldenrod leaf beetles, the predatory larvae of green lacewings sometimes called aphid lions because of their propensity for feasting on aphids, pennsylvania leatherwings (soldier beetles), tiny ragweed fruit flies, and a host of other insects can be found on the abundant flowering plants around the site.

In addition to the skipper, lots of cabbage whites, a few white admirals, and several newly emerged ringlets, the second generation in our area, were also seen.

Birds are vocal and active, with broods of young following the adults, calling and begging for food. House wrens are especially vocal these days, as are catbirds and song sparrows. Robins, baltimore orioles, chipping sparrows, chickadees, cardinals, cedar waxwings, and many other birds are very noticeable right now. While our tree swallows have long gone, barn swallows can still be found swooping over the garden. Shrubs such as elderberry and tartarian honeysuckle are providing much food for birds. Diane and I watched a cedar waxwing guzzling down the fruit of the honeysuckle as if he couldn’t get enough!

It is fascinating to see how the vegetation changes from year to year. New plants appear in odd spots, others vanish. All the annuals found last year in the old field’s rototilled section, have gone, but in their place scores of the biennial evening primrose (native plant), some big scotch (or bull) thistles, much beloved by insects, especially bees, and a variety of other species. The native wild cucumber plant is sending its sprays of creamy white flowers up in various spots including in the old field area.

There are lots of photos on the August 2013 Blog here:
http://www.pbase.com/fwg/fwg_blog_aug_2013

Be sure to visit so you can also see the great photos submitted by Diane and France, who photographed a gorgeous giant swallowtail at the garden on August 15.

June 4, 2013 at the Fletcher Wildlife Garden

by Christine Hanrahan

Tuesday afternoon at the garden, June 4th, and a lovely day to be wandering through the FWG.

Mating pair of silvery blue butterflies

Mating pair of silvery blue butterflies

Silvery blue butterflies were fluttering around in many locations, including this mating pair near the new woods. Common ringlets were indeed common that day but hard to photograph as they land low down in the vegetation much of the time. One posed briefly, however. Cabbage whites and a couple of hobomok skippers completed the butterflies I saw.

Still on insects, bumble bees were busy around the lupines, as were a few honey bees. I think the red squirrel, resident in one of the big roosting boxes, depleted the honey bee population over the winter. They made the mistake of deciding to make a hive in the box, and this spring when Barry and I checked it, the honeycomb was largely eaten and the bees were absent, likely also eaten by the red squirrel (these mammals will eat just about anything).

Mason bees are using the AAFC bee boxes, and a number of other bee species (Halictids, Andrenids, etc.) were actively feeding. Spittle bugs are mostly noted by the presence of their “spittle” on plants. These are actually protective coverings for the nymphs, keeping them moist, as well as hiding them from predators. There can be anywhere from one to four or more little nymphs inside these damp cases. Eventually the cases harden (they are a mix of fluid and a waxy secretion from the nymphs) and the nymphs have to create new ones.

Dame’s rocket is abundant. Yes it is not native, yes it can be invasive, but for the moment, the beauty of the flowers when seen en masse is stunning. This member of the mustard family is a common garden plant in Europe and is well liked here by pollinators. Claudia notes that she recalls it being planted in the BYG long ago to attract butterflies, but it was then weeded out, probably because it produces so many seeds. She thinks that may be where the plants we now see all over the garden, originally came from.

Various flies, including syrphids (hover flies), tachinids, root maggot flies, and so on, were found throughout. Not only are many syrphids excellent and important pollinators, but their larvae are formidable predators of aphids. A bit later in the season, carefully check out colonies of aphids and look for the flat larvae of syrphids working their way through them.

Green lacewing

Green lacewing

Also found, a couple of green lacewings. These beautiful insects in the order Neuroptera (Nerve-winged insects) are almost ethereal in appearance, with their golden eyes and see-through lacy wings, which of course, give rise to the common name. But their larvae are fierce predators of aphids, sawfly larvae and other insects. I have seen a single green lacewing larva work its way quickly through a colony of rose sawfly larvae, which are twice or three times its size!

All the usual birds are busy breeding now: yellow warblers, chickadees, cardinals, robins, house finches, etc. The phoebe is doing well, and I was happy to find a house wren nest. A lone cedar waxwing was near the birch grove, while a turkey vulture circled the garden overhead. The kestrels are still in their usual spot, so all is right with the world.

Isabelle (far left) and Renate (far right) showing members of the Ottawa Horticultural Society around the Backyard Garden

Isabelle (left) showing members of the Ottawa Horticultural Society around the Backyard Garden

On Tuesday evening, members of the Ottawa Horticultural Society came to the garden for a walk. There were two tours, ably led by Sandy (the first one) and Renate (the second one). Backyard Garden (BYG) habitat manager, Isabelle, gave Renate’s group a good intro to the BYG. Isabelle and I then hung around the BYG, keeping the centre open, and directing any stragglers onward to the tour.

Just as I was about to send this email, I rec’d one from Diane with some excellent photos which I will post to the blog very soon. There is a great shot of the pretty California calligrapha beetle and a golden image of the lovely syrphid Spaerophoria, a small, elongate fly, which is not at all easy to photograph. I’ve tried in other areas of Ottawa recently, but none of my photos comes close to the one you’ll see from Diane. There is also a very neat photo of a little scentless plant bug, new for our list of insects.

See more photos on the June Blog

Overwintering Butterflies

by Christine Hanrahan

Winter may seem an odd time to be thinking of butterflies, but on your winter walk, you may actually be passing a butterfly or two, without knowing it. How can that be, you may ask? Well, our overwintering butterflies frequently find hibernation sites under loose bark of trees or in crevices, cavities, and even caves. I’ve also seen butterflies emerging in spring from the eaves of old buildings.

Many folk find it astonishing that butterflies, which we think of as fragile creatures, can survive our cold winters. Not all butterflies overwinter as adults, of course. In fact, only a few do so in this region, but they fascinate us because of their ability to withstand snow and freezing temperatures. Around Ottawa, Mourning Cloak (Nymphalis antiopa), Eastern Comma (Polygonia comma), Green Comma (Polygonia faunus), Question Mark (Polygonia interrogationis), Milbert’s Tortoiseshell (Nymphalis milberti), and Compton Tortoiseshell (Nymphalis vau-album) overwinter in their adult form. Other species overwinter as adults further south, the most familiar example being the Monarch butterfly which winters in Mexico.

How do these delicate butterflies survive the winter? In a word, diapause. As explained by James and Nunnallee (2011), hibernating adults are dormant “and in a physiological state called diapause, characterized by a lowered metabolic rate and radical biochemical changes. Diapause is different from simple dormancy or inactivity as occurs in butterflies and their immature stages during cool periods in spring and autumn or overnight. It is a rigidly controlled physiological mechanism that is genetically fixed or induced by environmental cues.”

Before hibernating, these adult butterflies fatten up by feeding voraciously, often on rotting fruit and sap. This is no different from what hibernating mammals do (think of bears gorging on food to put on fat for the long winter months).

Warming weather encourages butterflies to become active again, even for just a brief period. During the very early, warm spring of 2010, I found butterflies taking advantage of the warmth in mid-March. Likewise, during the unusual heatwave of mid-March, 2012, when the temperature hit +30, I saw several Mourning Cloaks fluttering around the woods. But when the temperatures cooled again, they vanished until the next warm spell.

The most common species that I see, almost without fail, as soon as we have a few warm days in early spring are Mourning Cloak, Eastern Comma, and Compton Tortoiseshell – sometimes all three in the same general vicinity when walking through woodland sites.

How do other local butterfly species spend the winter? Most do so in the larval (caterpillar) stage, but some overwinter as pupae and some, such as hairstreaks and the European Skipper (Thymelicus lineola) in the egg stage. Just as it seems amazing that adult butterflies can survive our frigid winters, it seems to me equally miraculous that larvae and pupae can withstand the rigours of cold weather.

Last winter (2011/2012), I kept two Black Swallowtail (Papilio polyxenes) in a glass aquarium in my garden shed. I didn’t believe that the seemingly desiccated looking pupae could really become butterflies, but they did. In late April, I brought the aquarium outside into the garden and, on 26 May, a female Black Swallowtail emerged, followed a week later by a male from the second pupa. Like overwintering adults, larvae and pupae also prepare for hibernation. “By changing their physiology, butterflies, or their eggs, larvae, or pupae, are able to survive the winter for months in a state of suspended animation.” (James and Nunnallee, 2011)

Next time you are on a winter walk through a woodland, remember that you may well be passing some overwintering adult butterflies, just waiting for those first warm days of spring to fly once more.

References: James, David G. And Nunnallee, David. 2011. Life histories of Cascadia Butterflies. Oregon State University Press.