Tuesday, September 30, 2014

Giant Robber Fly

Robber flies such as this species with the scientific name Promachus hinei are to other insects what falcons are to other birds: swift predators on the wing. 

These predators can be recognized by their usually bearded face and a concave top of the head between the eyes. This is a large robber fly which is approximately 2-4 cm in length. Females are larger than males. They act like flycatchers, perching on logs, leaves, twigs, or the ground, cocking their heads at insects passing overhead, and dashing out to apprehend a victim.

You might hear this species before you see it, as it departs its perch with a loud, buzzing flight, quickly landing again nearby, usually on a vertical branch or twig.

Monday, September 29, 2014

Common water strider

Water striders are also sometimes called pond skaters and that is actually a very suitable name for them. They move with quick, erratic actions, darting forward and then skating in place. Sometimes they jump in the air and land again without sinking. 

They are exploiting the surface tension of water which is a thin elastic “skin” every liquid has. You can see the effect of surface tension when you see a drop of water close up.  It looks like a little bead of water, a tiny dome. Surface tension is what makes the dome shape – the water doesn’t flatten out.

The common water strider (Aquarius remigis) has short front legs which are built for grabbing prey. The middle and hind legs are extremely long and covered in very fine hairs allowing the insect to rest and skate on top of water without breaking the surface film.

During breeding season, this species can communicate with potential mates by sending ripples over on the surface of the water. You should watch them for a while next time you see them on a pond.

Friday, September 26, 2014

Common green darner

The common green darner (Anax junius) is one of the most common and widespread dragonflies in North America. 

Dragonflies and damselflies have long captured people’s imagination and the animals became nicknames such as ‘snake doctors’ or ‘devil’s darning needles’. The latter explains the name of today’s species. Darners include our largest dragonflies. They have huge eyes the meet on the top of their heads. Their overall body shape might perhaps reminded people of a darning needle.
These insects spend much of their time flying, and at rest they hang vertically rather than sitting horizontally like many dragonflies. Green darners are migratory and clouds of them can be seen in spring and fall.

Green Darners are dimorphic, which means males and females look different. Both have a green thorax (middle section of body), but males have a blue abdomen (long back part of body), while females' abdomens are purplish-gray. Their bodies grow over 10 cm long, with a wingspan of 12 cm.

Thursday, September 25, 2014

Two-striped grasshopper

There are about 18,000 species of grasshoppers in the world. All of them are long, slender insects known for their strong mandibles, or jaws, which are adapted for chewing. Grasshoppers have two pairs of wings. The front pair is rigid, while the hind pair is larger, softer and often brightly coloured. These wings help some species fly very well, yet others fly poorly or not at all. It also has three pairs of legs, all of which are used for walking. The back pair is more muscular and used for jumping.

The two-striped grasshopper (Melanoplus bivittatus) occurs widely in North America. This grasshopper is normally living in thick low vegetation during summer and fall. Unfortunately, it is also known for an insatiable appetite.

This species and some of its close relatives are major crop pests causing much damage to small grains, alfalfa, and corn. During outbreaks, they may completely destroy crops. Scientists have calculated that just 10 adults per square meter in a corn field are able to eat all the leaves off the crop.

Wednesday, September 24, 2014

Giant waterbug

Yesterday I wrote about a dive beetle, a ferocious predator. Today I thought I just continue with large freshwater insects that prey on small fish, frogs, and even snakes. The giant water bug (Lethocerus americanus) can get up to 6 cm long which is fairly large for an insect.  It belongs to the large group of true bugs which means it is not a beetle. Actually it is more related to stinkbugs, leafhoppers and cicadas.

The adult bug swims with its hind legs. The front legs are used for capturing and latching onto its prey, which it then injects with digestive toxins through a stinger much like that of a mosquito. The giant water bug then let its prey pre-digest for 10–15 minutes before eating.

This bug is also known as "toe biter" as it can deliver a painful bite if handled or disturbed. 

And here a video I found on YouTube that shows that these bugs indeed attack animals that are much larger then they are. The beginning is a bit blurry but it gets better. I would recommend switching off the sound though.

Tuesday, September 23, 2014

Vertical Diving Beetle

taken from bugguide.net
Larvae of predatory diving beetles are also known as water tigers. They are predatory and their mandibles have grooves on their inner edge through which they are able to suck the body fluids of their prey. Some of them can kill small vertebrates such as tadpoles.

The beetle swims by moving its hindlegs in unison, like oars. Diving beetles collect air at the surface in a “bottoms-up pose, trapping a bubble beneath their wing covers. This allows them to breath under water similar to a scuba diver.

Members of this species are pretty big, ranging up to 4 cm long. The larva can even get as long as 5 cm. Nevertheless, they fly well and are often attracted to lights at night.

To us humans these beetles do a great service as they are predators that can reduce the number of mosquito larvae.

Thursday, September 18, 2014

Northern black widow spider

Photo by Vicki Simkovic
Today's bug is Latrodectus variolus, known commonly as the Northern black widow spider. It is true that they are venomous and they normally use their venom to paralyze their insect prey and as self defense. However, they are not aggressive; they actually are very timid spiders. Once they find a place they consider comfortable, they build a small web and stay put. It's only when you disturb them that there is a small chance that they might bite although the spider prefers fleeing when disturbed. That’s a good thing because the venom of a widow spider is 15 times more toxic than that of rattlesnakes. However, due to the small amount of the venom injected into the bite, widow bites are far less serious. 

Northern black widow spiders are not commonly observed here in Ontario, but a few months ago a colleague of mine, a spider expert, together with participants of a so called Bioblitz found one (the image today is from their report). These spiders are primarily found in habitats with sparse vegetation, stumps, hollow logs and piles of debris. They are rarely found indoors. However, they may enter buildings on piles of firewood or other items brought inside. 

Wednesday, September 17, 2014

Sweat bee

Have you ever heard of sweat bees? This is the common name for any species of the bee family Halictidae and their name comes from the fact that they are attracted to the salt in human sweat. Sweat bees can be smaller than 4 mm in length and often have metallic markings. Believe it or not but there are about 2,000 species of sweat bees known to science and over 500 of them live in North America.

Back in 2009 a doctoral student at York University discovered a new species in downtown Toronto on his way to the lab. The little animal now called Lasioglossum ephialtum is shown in today’s image. These sweat bees are common visitors to a wide range of plants, including fruit and vegetable flowers in our gardens. 

This species and all other bees together are responsible for pollinating many wildflowers and most agricultural crops. As much as one of every three bites of food that we eat depends on the pollination services of bees.

Tuesday, September 16, 2014

Assassin bug

There are currently 60 known species of assassin bugs, most of which are found in Central and South America, with only five species being present in North America. The one shown in the image is called Zelus luridus and it belongs to those five species.

Assassin bugs are as deadly as they sound to their prey of aphids, caterpillars and other common garden insects. After patiently lying in wait to ambush their next meal, the assassin bug strikes quickly and accurately to paralyze its victim by injecting a toxin that dissolves tissue. The assassin bug then sucks up the other insect’s tissue. Adult assassin bugs can measure up to 1 inch long, and have a cone-shaped head and wide curving beak which can cause a painful bite to humans if captured. Even though they have nasty bites, remember that these bugs play an important role in keeping pests under control.

In the video you can to watch an assassin bug ambush its prey:

Monday, September 15, 2014

Orange-belted bumblebee

My son requested ‘a bumble bee’ for today’s post and who am I to refuse his wish? I have a soft spot for these little furry creatures anyway. Bumble bees are actually North America’s only native social bees. All other bees that live here are either introduced species from other continents or they are solitary which means they live alone.

The dense blanket of hair helps to insulate the bumble bees, which allows them to fly at cooler temperatures than most other pollinators. If you encounter a bumble bee such as today’s bug of the day, the Orange-belted bumblebee (Bombus ternarius), at the end of the winter you know that spring can’t be far away. The only bumble bees to survive the winter are young queens that now come out to found new colonies.

Some bumble bees sometimes rob nectar by chewing a hole at the bottom of a flower. That means that they are not covered in pollen after finishing their meal.  Luckily that doesn't happen too often as they are very important pollinators.

Wednesday, September 10, 2014

False Honey Ant

Today's bug is pretty common around here. The one shown in the photo was actually collected right in front of our institute. The false honey ant (Prenolepis imparis) is also called Winter ant because these animals remain active at low temperatures during the winter months. This makes them visible to us, especially when they invade our homes in search of sweets or to nest.

These ants become less active as the weather warms, and appear to do very little feeding during the hot days of summer. They mobilize again with the return of cooler temperatures in the fall, so know might be a good time to look out for them.

They live in small colonies, containing only a few thousand individuals, with a well-defined caste system. Most queens and male ants have wings (as the one in the photo), which they often eat after their nuptial flight because they don’t need it anymore.

Here a little video made by a colleague of mine who is a professor here at the University of Guelph and an expert for ants.

Tuesday, September 9, 2014


Aphids are very small (only a few millimeters long), soft-bodied insects with usually fairly long antenna. They come in different colours, have small eyes, and sucking mouthparts. They move slowly, and don't jump or hop. 

Aphids are herbivores. They suck plant juices out of the leaves, stems, or roots of plants. The juices they drink often have much more sugar than protein. Aphids have to drink so much sugary juice to be able to build their own protein that they excrete a lot of the sugar. They don't need it. The sugary fluid they excrete is called "honeydew", and many other insects feed on it, e.g. ants. They also protect the aphids, and sometimes even keep them in their nests for the winter and put them on new plants in the spring.

Unfortunately, aphids are also one of the worst groups of pests on plants. They damage plants directly by feeding on them, and they carry plant diseases from plant to plant. There can be millions and millions of aphids in a farmer's fields which can cause a lot of damage to his crops.

Harlequin ladybird

I didn't get to post a new bug yesterday, so I have to do two posts today.

Our first bug today is a well-known beetle which is actually native to eastern Asia, and was introduced to North America and Europe to control aphids. Unfortunately, this species has itself become a pest. For example in the autumn, these beetles can aggregate in large numbers in vineyards and, if they are harvested along with the grapes, they release a chemical compound with the complicated name methoxypyrazine that can spoil the aroma and taste of the wine. 

This species is also known to invade homes in October in preparation for winter, a phenomenon which earned it the common name of “Halloween lady beetle”. Fittingly they are of orange colour with black spots. They try to overwinter indoors and there also have been reports that they occasionally bite humans.

Their scientific name is Harmonia axyridis.  I am not sure if Harmonia the ancient Greek goddess of harmony would like this ever hungry namesake so much. This beetle specie is also known to attack competitors.

Friday, September 5, 2014

Eastern Comma

This butterfly we encountered on a hike with the family.  The poor guy looks a little worn down and that made its identification a little difficult. After consulting an expert (my boss) I decided that it must be an Eastern Comma (Polygonia comma).

That’s a pretty strange name for a butterfly. It comes from a small white 'C' shaped marking resembling a comma on the underside of its wings (see second image). A dark form of the comma is often confused with the dark form of another butterfly with a strange name, the Question Mark (Polygonia interrogationis). A similar marking on the underside of its wings looks indeed a bit like a question mark.

These butterflies hibernate, so you can encounter them all around the year, but their most active flying period extends from April to October. It likes to feed on sap running from trees and sometimes sits on the ground, usually with the wings closed. Seems that we got lucky for our photo.

Thursday, September 4, 2014

German Yellowjacket

Today's bug is actually very common here in Southern Ontario. The photo has been taken on a hike last week but I am sure you can find them pretty much everywhere these days. 

I am sure you all know that the German Yellowjacket (Vespula germanica) in the photo is a wasp. It lives in colonies together with up to 3,000 other wasps. They build grey paper nests that are made from chewed plant fiber, mixed with saliva.

The wasps catch insects, including caterpillars, to feed to their larvae. The adults feed on nectar and sweet fruit, but they are also attracted to human food and food waste, particularly sugary drinks and meats. That explains why you will find them often swarming around garbage bins.

As the name suggests this is a wasp that is native to Europe, but it was introduced and is now well-established in many other places such as North America (since 1975). In fact most Yellow jackets you encounter throughout the summer will be Vespula germanica and not the native Eastern Yellowjacket (Vespula maculifrons).

Wednesday, September 3, 2014

Crane fly

Crane fly
Yesterday one of our cats caught an insect. I only noticed that she was chasing something bigger than the usual fly and by the time she was done I could only see a few long legs dangling from her mouth. I was curious and had a closer look when she spit it out to show me. Cats often do that waiting patiently in front of their victim for some praise by the owner. Only after that ritual they devour their meal, well in this case it was more of a snack.

The cat
What she caught was a crane fly (Tipulidae) which people often call “daddy longleg”. Crane flies are often mistaken for giant mosquitoes. These gangly, spooky insects are completely harmless. 

Even scientists are having trouble to identify which exact species a crane fly belongs to. There are roughly 1,600 species of Tipulidae in North America and they very much look alike. I really need a crane fly expert to figure out what species my cat ate.

Tuesday, September 2, 2014

Cat flea

Some of my colleagues have just found a new species of cat fleas. Actually, what they initially believed was one species turned out to be two of them.

Cat fleas (Ctenocephalides felis) are tiny blood-small sucking insects found mostly on cats, but also on dogs. So, if you dog has fleas for some reason those are actually cat fleas. 

The life cycle of a flea is very like that of a butterfly, but unlike the beautiful end result of those flower-friendly creatures, the adult flea is a menace to all it encounters. 

A flea can jump 33 cm in one leap which makes it one of the best jumpers of all animals as they can jump about 100 times their own height. For comparison - the long jump world record for humans is 8.95m so about 5 times the height of the athlete.

Fleas exist already for at least 165 Million years which means that some of today’s flea’s ancestors might have bitten a lot of dinosaurs.