Friday, July 29, 2011

Heads or Tails?

In spite of its psychedelic complexion and robust build this Promethea Moth (Callosamia promethea) proved difficult to spot amongst the foliage.

I've inserted my pinky finger in the picture to give an idea of the size of this insect, but it's scared and has hunched itself up somewhat, making it about ten centimeters shorter than its normal length ... about the same as my finger.

Chowing down on some yummy White Ash leaves ...

Note in the images above that the head has no bold colors or patterns, and the insect pulls it under its body when it feels threatened. Now consider these views with an emphasis on the posterior end. The terminal pro-legs or pseudopods are large, bear a black circular mark that suggests an eye, and are left in plain sight. (Pseudopod → "false foot" ... insects have only six legs, they are visible just behind the head in this photo).

Eyes can betray an animal's position to a potential predator, and many organisms sport bars or camouflage patterns to disguise them. By the same token, note how many butterflies, fish, etc., often sport fake eyespots on hindwings or tail fins. Are the eyespots targets to draw a strike to a non-vital area, or to make an otherwise innocuous species look threatening to a hungry hunter? Here's some thought-provoking reading: Why eyespots?.

And where, you say, is the "moth" in these photos? That lies in the future ... first, this caterpillar will overwinter as a pupa, and with luck this story will continue next year ...

The Orange-Humped Mapleworm Moth (Symmerista leucitys) adopts similar "false head" plan of action if it feels endangered. Although the head is a bold shade of orange the back end also bears prominently colored red and orange markings, and it holds its posterior the air with the last pair of prolegs splayed open. Everything about the caterpillar's posture suggests a head with antennae – at the non-vital backside of the insect.

The two appendages at the tail end of this Furcula Moth (not sure what species) larva also look very much like antennae.

The slow moving, soft-bodied larva of the larva of the White Admiral (Limenitis arthemis) makes a yummy morsel for a hungry bird. This caterpillar increases its chances of survival by not only being colored like ...

... but adopting the posture of, an inedible and not-so-tasty bird dropping.

Some species make themselves distasteful or toxic to minimise predation. The larva of the Monarch (Danaus plexippus) ingests the toxins found in its food plant, the Common Milkweed. The caterpillar's bold yellow, white and black stripes advertise its unpalatability.

Presumably the Milkweed Tussock Moth (Euchaetes egle) also toxic for the same reason, and hair or bristles can also be a deterrent to being captured and swallowed. But what's with the grouping? Are they mimicking a larger animal? Or is it a matter of safety in numbers like a flock of birds or a school of fish ... any single individual is less likely to be targeted?

Pics of Summer Flowers ... The Fields

There are about five hundered and fifty species of common wildflowers in Ontario. The images collected in this post, in fact, this entire blog, represent but a very small sample of what's out there in our fields, wetlands, forests and byways ...

Fringed Loosestrife (Lysimachia ciliata) is so named because of the fringe of hairs along its leafstalks. This common member of the Primrose family (Primulaceae) has a preference for wet places but may be found in drier areas along roads and trails.

Common Fireweed (Epilobium angustifolium) adds a splash of color to the greenery along the Eastern Ontario Trail. This flower belongs to the Evening Primrose family (Onagraceae).

This Foxglove Beardtongue (Penstemon digitalis) was photographed near the Point.

An immigrant from Europe, Elecampane or Horse-heal (Inula helenium) has made itself right at home on this side of the pond.

Herb Robert (Geranium robertianum) is another introduced species, in some areas this small member of the geranium family is considered a weed. These photos were taken at the Frink Center.

It seems that every year I encounter a couple or three flowers whose identity remains a mystery. Eight or ten of these small white flowers were found growing along the shore of the Moira River near the Point. They appear to be members of the family Asteraceae. The closest things I can find on the 'net are White Hawkweed and Desert Pincushion, but it hardly seems credible that these two species would be growing so far from their normal range and in what is virtually a wetland habitat. Unless they've escaped from someone's flower bed, or were planted here on purpose?

A denizen of damp domains, the Swamp Vervain (Verbena hastata) is more properly classified as a wetland plant.

On the other hand this small group of Hoary Vervain (Verbena stricta) was found growing in dry, packed soil in full sun along the Eastern Ontario Trail. The two species can be distinguished by the shape of their leaves and the terminus of the flower spikes.

Spotted Knapweed (Centaurea maculosa) is considered an invasive species (funny how introduced plants and animals which have little competition in a new environment have a way of quickly making a bad name for themselves ...). These specimens were growing along "the Trail" near Drag Lake.

Note the black tips on the bracts ... hence "Spotted" Knapweed.

Thursday, July 28, 2011

Pics of Summer Flowers ... The Wetlands

It's easy to overlook the smaller flowers in favour of their gaudier cousins, but one does so at the risk of missing the breadth and diversity of life, the multitude of species that have evolved and adapted in so many different ways to the same environment by way of the sieve of countless years of natural selection. (OK ... millions, not "countless" years, but one also runs the risk of being poetic contemplating, in the words of Douglas Adams, "Life, the Universe, and Everything" ...)

Like many others of its family Kalm's Lobelia (Lobelia kalmii) likes to get its feet wet and may be found in a variety of wetland habitats. These photos were taken at the Stoco Fen.

Another denizen of (but not restricted to) the Stoco Fen is the Marsh Bellflower (Campanula aparinoides). While not the largest or showiest of our wetland flora, it nonetheless has a delicate charm and beauty all its own. Overcast skies and a paucity of color and contrast made this blossom a difficult subject to photograph.

I first stumbled across these tiny yellow flowers along the sandy north shore of Stoco Lake two summers ago and until today their identity was unknown to me. Today I blundered across my mystery plant while researching other wetland flora on the Internet ... this is Water Stargrass (Heteranthera dubia), a member of the family Pontederiaceae, related to the much more conspicuous Pickerelweed.

Pickerelweed (Pontederia cordata) is common wherever there is still or slow moving shallow water along lake or river shorelines. This is a view just to the east of the boat ramp on Stoco Lake.

Closeup shots of the flower spike

Today I encountered another "new" wetland plant growing in nearly the same place I found the Water Stargrass. This one didn't take too long to identify, it's a Water Plantain (Alisma plantago-aquatica). The flowers look similar to those of Arrowheads and Wapato (members of the same family, Alismataceae, a.k.a. Water Plantains) but are much smaller and grow in a panicle.

A closeup shot of the leaves ...

... and the flowers.

A couple of Water Plantain's more visible cousins, Wapato (Sagittaria latifolia) ...

... and Arumleaf Arrowhead (Sagittaria cuneata); these emergent plants also prefer quiet, shallow waters.

Whorled Loosestrife (Lysimachia quadrifolia) is a cousin of the dreaded Purple Loosestrife. This specimen was photographed at a marsh about one kilometer east of Actinolite and seemed to be the sole representative of its species at this locale. However, I later chanced upon several of these flowers along the shore of the Clare River near Otter Creek.

The colorful flowers of the Swamp Milkweed (Asclepias incarnata) are hard to miss. A favourite of many species of insects, this is obviously a plant that relies on pollinators to reproduce.

On the other hand the flowers of Pondweed (Potamogeton) are anything but showy. But since pondweeds can reproduce asexually by turions (overwintering buds) and broken off pieces of the stem the flowers are little more than an afterthought, nature's backup in case all else fails.