the beginning of the end…of summer

It’s down to the asters and goldenrods, among the last of the blooms for pollinators to visit before it’s too cold to visit anything.

Bumblebees sleeping in asters

A couple of very cold bumblebees must have spent the night in these asters. They were pretty comatose on this chilly morning.

Hoverflies on goldenrod

The yellow jacket mimicry of these very large hoverflies was so good, I almost walked away from this Stiff Goldenrod plant to avoid them.

Bumble bees on showy goldenrod

Later in the day, a hoard of bumblebees attacked the few remaining flowering stems of Showy Goldenrod. It’s a last chance to harvest nectar and pollen to store away for the winter.

All this work, and then what happens to these insects?

The bumblebee queen who founded her colony in the spring (the old queen) and all of the workers she produced will likely die in the first freezing weather of the winter.  All their work over the summer and fall was to ensure that new queens would be born and survive the winter to found new colonies the following spring.  New queens hatched during the summer feed voraciously on nectar and pollen in the fall to lay down fat stores that will carry them through the winter in their underground nest.

Bumblebees on dahlias

Dahlias keep producing their glorious blooms well into the fall until the first hard frost, another good source of nutrition for young queens.

Hoverflies (depending on the species) might overwinter as adults or as late-stage, fully grown larvae, by taking shelter in protected nooks and crannies of  tree roots or bark.  In Minnesota, they will have to withstand freezing solid, as temperatures drop well below zero.  Individuals that overwinter as adults (probably females) are the ones we see flying around in the spring looking for aphid-infested plants on which to lay their eggs before they die.  When the larvae hatch, they have a food source waiting for them. A second wave of hoverflies join the party after warmer temperatures have spurred them through the pupal stage to emerge as adults.

Hoverfly on New England aster

Hoverflies slurp up nectar from fall flowers to build up their fat reserves. Some of the fat will be used to produce a glycerol anti-freeze compound so that their cells can tolerate freezing without damage from ice crystal formation.

Beautiful, but deceitful and poisonous!

What is beautiful, but deceitful and poisonous?  This blog usually focuses on things biological, so it must be an animal or a plant, and perhaps it could be either.  In this case it is the oleander shrub that fits that description.

Nerium oleander flowers

Beautiful pink flowers of the highly poisonous oleander 

Oleander is such a popular addition to roadside plantings and gardens that it now occurs world-wide in warm, wet Mediterranean type climates where its long-lasting profusion of white, pink, or red flowers brighten up the landscape.  It is remarkably drought-tolerant and protects itself from being munched by herbivores by sequestering toxic cardiac glycosides in its tissues, from its roots to the tips of its leaves.  No wonder it’s the dominant plant along freeways in California.

Large milkweed bug on Nerium oleander flowers

An indicator of oleander’s toxicity is the presence of insects, like the large milkweed bug, with warning coloration feeding on flower parts and seeds.

Oleander is, in fact, one of the more poisonous plants, but mammals, especially humans seem to be more sensitive to its toxins than birds.  However, folk tales about drifters during the Dust Bowl years dying from having stirred their stew with oleander twigs are probably false.

Clearly, oleander is beautiful and poisonous, but what about being deceitful?  How can a plant be deceitful?

Nerium oleander flowers

Oleander flowers are brightly colored, sometimes fragrant, with a central opening meant to entice pollinators to explore.

But oleander flowers produce no nectar, and thus there is no reward for pollinators to keep exploring the profusion of flowers on the plant.  It’s false advertising and deceptive on the part of the plant.  But does it work, that is, does enough pollination occur to allow seeds to be produced?

flowers and seed pods of Nerium oleander

How many flowers with no nectar reward will a pollinator visit before it gives up and moves on?

Apparently, insects that pollinated this oleander explored many of the flowers in a cluster, moving enough pollen to produce several seed pods.  But the number of seed pods on the entire plant is scanty.

flowers and seed pods of Nerium oleander

Only a single pod was produced in this group of flowers

The only good news for bee pollinators is that the lack of nectar in the flowers means they would not contaminate their honey with cardiac glycoside poisons.

Roadside gardens

Quite a few years ago now, the city decided our street needed a walking trail, not just a mere sidewalk, along the roadside.  As a consequence, residences lost 10-20 feet of their front yards, and some embellishments like granite boulders or brick walls were added to separate hillsides from walking trails.  Somehow this spurred a roadside gardening movement, and the result is a long boulevard of very attractive gardens which have become a mecca for bees and butterflies.

Roadside garden

Monarch butterfly on Shasta daisy

A female monarch butterfly visiting a patch of Shasta daisy, but there is milkweed nearby as well.

Roadside garden

Daylillies of all colors brighten up the roadside.

Roadside garden

A profusion of pink and purple…

Roadside garden

Hoverflies love the pollen of these Asiatic lillies

Roadside garden

Thank you roadside gardeners for brightening up my morning walk!

A pretty pest

Looking for bees in the garden the other day, I came across an insect that looked a lot like a honeybee or small bumblebee, but something was not quite right.

Narcissus bulb fly on chive flowers

Right color, right hairy abdomen and thorax, expanded upper segment of rear legs where pollen baskets are located — but is this a bee?

It’s the eyes — they’re too large and round, and the antennae are too short.  It must be a bee mimic fly.

Honeybee, NPR science news, June 7 2018, photo by don Farrall/Getty images,

A honeybee, for comparison, has a triangular rather than round head, and ovoid eyes.  Photo from an article on NPR science news, June 7, 2018, by Don Farrall, Getty images.

I think my bee mimicking fly is a Narcissus bulb fly, and if so, my iris, lillies, and chives are in trouble. Adults feed on the nectar and pollen of a wide variety of flowers.

Narcissus bulb fly on chive flowers

A male Narcissus bulb fly dips its proboscis deep into the chive flowers. The two eyes touch at the center of the head of the male, but are separated by a small space in females.

But their larvae infest the soft tissues of the bulbs of these perennials.  Females lay from 40 to 100 eggs at the base of a leaf of bulb-forming plants, and the larvae crawl down into the soil and burrow into the bulb, eventually hollowing it out completely as they feed and mature to pupal stage.  Lillies, iris, daffodils, tulips, hyacinths, etc, are all susceptible to infestation.

Narcissus bulb fly on chive flowers

There doesn’t seem to be a good way to control these pests, introduced from Europe, probably along with bulbs, in the late 1800s. Their strong bee mimicry makes most insect predators leave them alone.  Apparently, if you grow bulb-bearing plants in your garden, you’re very likely to have these destructive pests present.

Pollinators, large and small

The purple flowers are blooming in my garden: spiderwort, weedy creeping charley, iris, bellflower, mountain cornflower, and lovely blue wild indigo. And there are a few bees around, doing their best on the limited amount of nectar and pollen available so early in the summer.

bumblebee nectarine on false wild indigo

This queen(?) common eastern bumblebee approaching a flower of the false wild indigo is faced with the task of getting to the nectar at the base of the flower through what appears to be closed “doors” (lateral petals) of the flower.  She is really too big to fit.

bumblebee nectarine on false wild indigo

Her weight is sufficient to separate the wings (lateral petals) of the flower, so she can poke her head (and tongue) deep into the base of the flower where there is nectar.

bumblebee nectarine on false wild indigo

The two halves of the keel petals at the bottom of the flower also separate under her weight, exposing the anther pollen and the bright, orange-yellow, three-pronged stigma (female receptive surface). Pollen she carries on her legs and body from another flower will stick to the stigma and travel down its tube to fertile ovules in the flower ovary to make seeds.

bumblebee nectarine on false wild indigo

Pulling away from the flower before flying to the next one, you can see the contact between bee and pollen.

Lady Bumble made the rounds of the newer flowers at the top of the raceme, working her way from oldest at the bottom to newest opened at the top, and then on to a different spike of flowers.  But the small solitary bee working these flowers had an entirely different strategy.

Solitary bee on false wild indigo

You can see how tiny this little bee is in comparison to the flower.  It preferred visiting the older flowers, whose petals were drooping and not fitting as closely together as in the younger flowers. 

Solitary bee on false wild indigo

Now, how to get inside the flower to reach the pollen? Squeeze through the tiny crack between petals.

Solitary bee on false wild indigo

Crawling inside finally, the bee disappears for a few minutes before crawling out and making its way to another, older flower.

Solitary bee on false wild indigo

Older flowers may not produce much nectar, But smaller bees don’t require as much as large bumblebees anyway. And perhaps pollen collection was of more interest to this tiny bee.

a rare beauty

Lady’s Slipper Orchid may be one of the slowest growing plants in the world, taking 6 to 11 years to reach the size when it first flowers.  But when it does, we rarely fail to notice, and marvel at its color and structure.  All this from a minuscule seed the size of a speck of dust!

(Yellow) Lady’s Slipper Orchid

I was quite excited when my neighbor showed me the Lady’s Slipper Orchids growing in his back yard.

(Yellow) Lady’s Slipper Orchid

The name, of course, comes from its shape, the swollen labellum appearing to be a dainty shoe for a pixie-sized lady.

Like many showy flowers, orchids are dependent on pollinators to transfer pollen from one plant to another.  But Lady’s Slippers and another 40 percent of the 20-30,000 orchid species of the world attract their pollinators with color, fragrance, or even by mimicking the shape of a female pollinator of the same species, and offer no nectar reward.  How do they get away with “cheating” their pollinators and still ensuring pollination success?

By “inviting” them in, trapping them momentarily, and then providing a narrow escape route that forces the pollinator to squirm by sticky pollen sacs on the anther as they exit.  Here’s how it works.

One way route through the (Yellow) Lady’s Slipper Orchid

It’s a one way route through the flower, in through the enticing, colorful and fragrant labellum, and out through the slit in the back, top of the flower.  When they visit the next Lady’s Slipper flower, they rub the acquired pollen onto that flower’s stigma.  Voila, Pollination!

Bumblebees are too large to fit through the narrow slit at the top of the flower, so they exit the way they came in.  Smaller bees land on the hairy pad at the back of the inside surface of the labellum, crawl toward the light showing at the top, and squeeze themselves through the slit, as shown on the video below.

Practicing this deception seems risky, especially since bees are less prevalent today than they once were.  This rare beauty, once found throughout North America, Europe, and Asia is in decline world-wide.  It suffers from being over-collected, loss of habitat, and now —perhaps, a decline in the numbers of its pollinators.

Into the rainforest

We left the delightful warm weather in Lima for the steamy jungle in northeastern Peru, where plants thrive, insects diversify to eat them, and birds that eat both the insects and or the plants adopt outlandish colors and decorative feathers to show off.  In other words, we are immersed in DIVERSITY.

Explorama lodge, Amazon river

Explorama lodge on the Amazon river

We headed down the Amazon river about an hour from Iquitos (in northeastern Peru) by motor boat, to Explorama Lodge, where we would stay in non air-conditioned lodging, with cold showers to cool us down after trekking through the steamy jungle. Boat trips out on the river and walks through the rain forest provided opportunities to see some of that diversity.

Passion flower butterfly

Passion flower butterfly

Heliconia flower

Heliconia flowers, a relative of banana, are actually colorful, waxy bracts, in which the actual flowers hide. They advertise their sweet nectar to hummingbirds with bright red and yellow colors.

Scarlet macaw

Scarlet macaw, really up-close, a family pet of river villagers

White-cheeked Jacamar, Explorama lodge, Amazon

The White-chinned Jacamar is shades of iridescent teal and green with a chestnut cap and a white chin of course.

Poison dart frog, Amazon forest

Poison dart frogs are tiny but bright and can be found in the moist forest floor or lower vegetation.

Are you seeing a pattern here of vividly bright colors of tropical flowers and animals?  I wonder why that is?  Your thoughts?

A good omen

I count it as a good omen that the first animal I saw on this trip to Peru was a Monarch butterfly.

Monarch butterfly, Lima, Peru

Monarch butterflies are probably resident year-round here in this equitable climate.  I hope these populations are healthier and more numerous than the ones that migrate to the U.S. from Mexico.

Walking among the high rise buildings and city industry of the Miraflores area of Lima, the only living things to be seen were people and plants.  So when we stumbled across a park dedicated to the fallen defenders of the city during the War of the Pacific between Peru and Chile in 1881, I was delighted to find a few birds in the trees and a few Monarchs nectaring on the Lantana blossoms.

War memorial Park in Miraflores, Lima, Peru

One of many statues in the park commemorating the fallen defenders, some of whom were apparently young children.  Colorful buildings, too.

Mug shots – take 1

It’s great when you can get really close to the wildlife, i.e., right in their “faces”, to grab a “mug shot”.  I didn’t get many this year, but there were a few opportunities, assisted either by my extremely long (600 mm) telephoto lens or my trusty macro, to get up close and personal with the local wildlife on our travels and in my backyard.

hoverfly-on coneflower

Hoverfly gleaning pollen and/or nectar from New England Asters.

american-painted-lady-on sedum

American-painted-lady-on fall-blooming Sedum; they came through by the dozens to congregate on late-blooming flowers

honeybees-on-new-england-aster

Honeybees foraged on New England Aster; I saw more of them this year than in the last 5 years combined.

small-carpenter-bee-ceratina-spp

A tiny carpenter bee feasting on pollen from newly opened anthers on a coneflower.

bullfrog-

We found a Bullfrog calling in a desert oasis in Arizona. Kind of ugly, but beautiful eyes…that might be a mosquito on his upper lip trying to get a meal.

chuckwalla-

A Chuckwalla was sunning itself at the Sonora desert museum in Tucson. Dark pigmented scales on its underside help it soak up heat from rocks. Chuckwallas love to hide in rock crevices and resist being pulled out from their hiding place by puffing up their body with air, expanding into any empty space in the crevice.

snapping turtle-

Snapping Turtles have large jaws and long necks, but this one was protecting itself by withdrawing into its carapace.  My what beady little eyes you have, Mr. Turtle.

Great Blue Heron-

Eye to eye with a Great Blue Heron

molting mallard ducks-

Male Mallard Duck before molting a new set of showy feathers

Black-capped Chickadee-

Chickadee with an attitude…

a pretty pest

Fall blooming plants attract such an interesting variety of pollinators.  Among the many species I was able to capture with my macro lens last week was this very pretty moth.

Flowerflies, or hoverflies as they are often called, feed on plant nectar and pollen. Their larvae, however, are often carnivorous and devour many species of plant pests, like aphids.

I didn’t know what this species was, and was surprised to see a moth out in the daytime.

There are a few moth species that do forage in the daytime, but this one really is largely a nocturnal forager and disperser, quite distinctive with its well insulated body of fuzzy tan “hairs” and huge green eyes.  It’s a corn earworm moth — the larvae of which are major agricultural pests on a variety of crops, especially corn, tomatoes, and cotton.

Corn earworm moth, Helicoverpa zea

Adults feed on flower nectar, but the larvae are not at all fussy about the host plant they feed upon. You have to admit, it’s an attractive looking moth, although its prodigious reproduction and polyphagous (eat lots of different plants) larvae make it a real threat to agricultural production.

As a major pest of commercial crops, corn earworm has been subjected to pesticide exposure for years, and over generations, the larvae have developed resistance to some pesticides, which makes controlling them even more difficult.  Each female can lay 500-3000 eggs in her lifetime, and the combined damage of corn earworm larvae runs in the 100s of millions of dollars in the U.S each year.

Fortunately for us (in the northern midwest), corn earworm is not a permanent resident but must re-invade with short, northerly directed migratory flights each summer.  They cannot survive sub-freezing temperatures and will die off each winter.