Tuesday, November 29, 2011

Insects of Nose Hill Grassland, by Justin and \Yuchen

Scientific Name: Mononychus punctumalbum
Comman Name: Thistle Head Weevil   
Located: Europe, North America
Length: Around 6 mm

Figure 1. A microscopic picture of the specimen we collected in a 10m by 1m radius on high power.

The family of curculionoidea or more commonly known as weevils have more than 60 000 species among its sub families. Weevils are relatively small, most of the time they are less than 5 mm long and usually feed on dry products such as grain and nuts. As a result many species of weevils are extremely harmful to crops.
            We have identified the specimen in figure 1 as Mononychus punctumalbum or more commonly known as a thistle head weevil.  These weevil species were native to Europe and were originally introduced in the US as a biological method of controlling thistle infestation. The thistle head weevils were used as a method of control because each female lays around 100 eggs in the receptacle of developing thistle flowers, when larvae hatch they are legless white grubs that feed on seeds inside the receptacle of the thistle. Adult thistle heads emerge during July then seek out overwintering sites under developing musk rosettes, ground litter and wooded areas until late spring. After the winter the adults then feed on the leaves of musk thistle rosettes and then they proceed with mating.
We had originally thought that we captured a deer tick or some type of wood tick that is commonly found on the prairies – it was both small enough (~3mm) and the head really did look like it can dig into animal flesh. Then came our revelation; while looking at ticks and thinking how nice we have rid for an animal this one bane, we noticed our tick only has 6 legs. Maybe a pair fell off when we took it out of the freezer? But then can it be so coincidental that exactly two opposing legs are missing? No, ticks have 8 legs and an especially small head, ours is a weevil.

Scientific Name: Lygus lineolaris
Common Name: Tarnished Plant Bug
Located: Around 6mm

Figure 2. A microscopic picture of the specimen we collected in a 10m by 1m radius on Medium power.

We have identified the specimen in figure 2 as a tarnished plant bug. Lygus Bugs, in the genus Lygus, were the most common bugs we snatched up on our hunt. In fact, I daresay that they comprise at least 60% of the total numbers of insects captured that day. These little bugs are dark in colour but can vary from pale-green to reddish brown and are beetle shaped with what appears to be wings hidden under their outer shells. Yet the sheer numbers of these little creatures that ended up in our zip-lock bags are simply awkward, for if they can fly, why not fly away? The answer is they indeed could fly, but we were probably just too fast.
These lygus bugs feed on almost any vegetation in Alberta, but especially on Canadian crops such as alfalfa and canola. In some reported cases they damage up to 30% of the crops in an agricultural area through the sucking of flowering buds and seeds which undermines their development and maturation. This extensive damage ( especially to canola crops) has made them a “serious economic pest of canola” by the Alberta government. 

Scientific Name: Delia radicum
Common Name:  Root Fly
Located: North Eastern Coast of North America, North Western Coast Europe, Middle East, Central Asia
Length: Around 1 cm

Figure 3. A microscopic picture of the specimen we collected in a 10m by 1m radius on high power.

We have identified the insect in figure 3 to be a root fly classified under the family Anthomyiidae. The life cycle of these fly species are usually as follows: Female flies lay their eggs near the stems of Brassicas (A genus of plants usually used for crops such as cabbages). When these eggs hatch into maggots they devour their way through the stem and roots of the brassica. After around three weeks the female maggots become fully grown and proceed to the soil and become pupa (A chrysalis stage), adult males mate with newly emerging female pupas. Signs of root flies include: wilted plant seedlings or scars and tunnels on the root of the plant.

Scientific Name: Coccinella septempunctata
Common Name: Seven Spotted Lady Bug
Located: North America, UK, Ireland, Australia, Pakistan, South Africa
Length: 1mm to 10mm
Figure 4. A microscopic picture of the specimen we collected in a 10m by 1m radius on medium power.
            We believe the specimen in figure 4 is identified as Coccinella septempunctata. The life cycle of lady bugs are as follows: Female ladybugs lay around ten to fifteen eggs on the underside of leaves to protect them from being seen by flying predators and harmful weather. After the Larvae hatch and begin to eat mites or aphids they will continually molt (shed their skin) until they are ready for the pupa stage. In the pupa stage the larvae will find a suitable leaf to attach itself to and proceed with its metamorphosis into a lady bug. When the metamorphosis is complete the fully grown lady bug will emerge. Since one of a the lady bug’s main diet are aphids lady bugs were introduced from Europe into North America as a biological control of aphids (common pests to agriculture) and succeeded around the 1970’s.

Scientific Name: Thanatus formicunis
Common Name: Running Crab spider or Wolf Spider
Length: 1mm - 30mm
Figure 5. A microscopic picture of the specimen we collected in a 10m by 1m radius on medium power.

We have identified the specimen in figure 5 as a wolf spider. These spiders are classified under the family of thomisidae who are known to be ambush hunters. These species can be identified by the fact that they have two larger eyes which give them superior eyesight and the second legs are usually longer then the other four. In addition these spiders do not build webs and only use silk for draglines and egg sacs. Although these spiders build trap doors for hunting much like tarantulas, they’re not tarantulas and are not closely related; the species found in Alberta are not harmful to humans.

            Thanks for reading our presenteation, we would like to thank our group members, Dr. Pike and Mrs. Miller for allowing us to have the chance to study the ecosystem in of Nosehill and providing us with the proper equipment. However we would like to say, identifying bugs is not an easy task, since some bug species can both be quite visually indiscernible and similar to others in its family. Also in the process of identifying and studying these insects I have learned to be less fearful of them, although my fear of spiders has remained relatively unchanged.

Figure 6. Yuchen holding our initial bag of specimens after catching them.

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.