Newsletter of the Biological Survey of Canada (Terrestrial Arthropods)

The Quiz Page

News and Notes

— test your knowledge of Canada and its fauna —

1. What is the surface area of the very large lakes in Canada, as a percentage of the surface area of the Canadian mainland? answer

2. What is alluvium? answer

3. Name several ways in which insects are involved in the death of trees in Canadian forests. answer

4. Name some key features by which insects survive actual body freezing during the Canadian winter. answer

5. Name the food plants of the following well-known Canadian insects.
a) the butterfly Danaus plexippus
b) the beetle Dendroctonus rufipennis
c) the spittlebug Aphrophora cribrata
d) the moth Choristoneura fumiferana
e) the sawfly Pristiphora erichsonii
answer

Answers to Faunal Quiz

1. The very large lakes in Canada comprise about 2%, or about 200,000 km², of the surface of the country. 

2. Alluvium is relatively recent detrital deposits resulting from the operations of modern rivers, including the sediments laid down in river beds, flood plains, lakes, fans at the foot of mountain slopes, and estuaries. 

3. Insects are involved in the death of trees especially by single defoliations (which may kill conifers by removing up to five years of foliage), repeated defoliations (which will kill many deciduous trees), mass attack of woody tissues (e.g. some bark beetles) and transmission of fatal diseases (e.g. Dutch Elm Disease by elm bark beetles). In many cases, trees succumb only to a combination of factors, such as drought or fire damage, plus fungal attack, plus insect attack. 

4. In insects that actually freeze during the winter, only part of the total body water is frozen, because water closely associated with biological molecules, for example, does not freeze. The freezing normally is extracellular only. Protection is usually provided to membranes, proteins, and so on by the action of cryoprotectants, typically polyhydric alcohols (such as glycerol) and sugars. Many of the species make nucleators for the winter, ensuring that supercooling will be limited and freezing will take place at relatively sub-freezing temperatures, so that ice formation is not as rapid and injurious as it would be if beginning at lower temperatures.

5. The food plants of these insects are as follows:
a) the monarch butterfly Danaus plexippus feeds on milkweed, Asclepias  spp.
b) the spruce beetle Dendroctonus rufipennis feeds on spruces, Picea spp., including P. glauca and P. engelmani.
c) the pine spittlebug Aphrophora cribrata feeds on pines, Pinus spp.
d) the spruce budworm Choristoneura fumiferana feeds mainly on fir and spruce, especially on balsam fir, Abies balsamifera and white spruce, Picea glauca.
e) the larch sawfly Pristiphora erichsonii feeds on larches, Larix spp.