Friday, August 22, 2014

Dog-day Cicada

These days there is a strange sound in the air. It’s not the power lines, nor is it crickets. It is a long, buzzing, high-pitch drone that we hear in Ontario in mid-to-late summer and it is the sound of very fascinating insects – the cicadas.

Cicadas such as our local dog-day cicada (Tibicen canicularis) make the loudest sound of all insects. They are also quite large, with about 4 cm in length. 

Each cicada species has a characteristic “song” and it is only the male insects that sing. Just like many birds they sing to attract females.

Young cicada larvae live underground for several years, using their piercing mouthparts to drink root juices of oak, willow, ash, and maple trees, among others. Once it is time for them to come to the surface, they find a nearby plant on which they shed their skins and emerge as fully formed adults. If you are lucky enough you might find one of their exoskeletons still attached to a tree or laying on the ground.

Thursday, August 21, 2014

Tarnished plant bug

It was rather late today when I finally had the time to go bug hunting for this post. It had already started to cool down a little and many insects don’t like that. They actually need heat from the environment to keep their body temperature on they same level. Therefore, it took me some time to find something interesting.

Eventually I was lucky and found a little plant bug.  It was the tarnished plant bug or scientifically Lygus lineolaris. This species comes in many varieties with different colors and markings. It is a typical plant sucking bug with a mouth that is shaped in a way that the insect can both pierce into a leaf and suck the plant sap.

This species has actually become a serious pest on small fruits and vegetables across North America.  Today scientists know of 400 different plant species the plant bug can feed on.  When they feed on a plant they can damage it by slowing down its growth or by transmitting plant diseases.

Wednesday, August 20, 2014

Common fruit fly

It's rainy outside which means no good time to find bugs. Well, there are some that live inside our homes quite happily. Even more so if you leave some ripe fruits and vegetables on the kitchen counter. The fruit fly can smell those from a good distance away.

These tiny insects will try to get in through window screens or through crevices around windows or doors. Often they simply hitch a ride on the skin of very ripe fruits or vegetables.

Once they are in the house it is difficult to get rid of them. They can quickly multiply in number because they have a very fast life cycle. It takes them only 8-10 days to go from egg to adult.

But the common fruit fly or Drosophila melanogaster is not only considered a nuisance. It is also a very important laboratory animal. It is widely used for biological research in studies of genetics, evolution, and physiology.  For example it was fruit flies that helped to unlock some mysteries about DNA.

Tuesday, August 19, 2014

American grass spider

Along the driveway of our house we have a patch of lilies of the valley and these days they are covered in silk webs.
I am a scientist which means that I am always curious. Today I had a closer look at those webs and the animals that constructed them. The webs look very interesting  as they have a funnel shelter leading into a curled leaf. That way the builders saved time and energy to build a shelter solely with silk. 

Sure thing, by now you must have figured out who the builders are - correct - those were spiders. More particularly, grass spiders with the scientific name Agelenopsis actuosa, also known as the Canadian funnel-web spider. 

These little guys are totally harmless unless you are an insect they'd like to eat. While other web building spiders build a very sticky web in which their prey is caught as soon as it touches the web. The web of the grass spider is not sticky and the only way the spider can catch insects is to be very fast.

Monday, August 18, 2014

Robin's pincushion gall

Today I found this strange thing on a rose bush in our backyard. Upon closer inspection it turns out that this structure was grown by the rose as if it had forgotten how to make a leaf, a thorn or a stem.
It is called a gall and if you cut it open and look inside you'll find a couple of small chambers that are home to a bunch of larvae. The gall provides food and shelter for these growing insects.
Galls are usually the plant's response to an injury or a foreign object, such as a small animal.
Once a larva turns into the adult insect through metamorphosis it looks like the image on the left. This is a rose gall wasp with the scientific name Diplolepis rosae.

Gall formation is not entirely understood, but it is more than just scar tissue. The insect or mite in the gall apparently causes the plant to form a gall by releasing chemicals that change the plant's growth program.