Task 3: The Scale Insect
Task 3: What is the scale insect? How does it affect the Pinyon Pine tree?
Step 1
Access the following site. Read the information and record notes and drawings in your science notebook. Make sure you draw the life cycle of the scale: egg, larva, instars, and adults.
Step 2
Pinyons sometimes respond differently to scale. One tree may not be infested at all, while the neighboring tree is very infested. Scientists are not sure why this happens. The two types have been names as “resistant” if they don’t seem to be infested and “susceptible” if they are infested. Some scientists at NAU are studying the genetics of each kind of tree to see if they have different genes that cause the scale to react differently to them.
Some of the susceptible trees have been treated with Tanglefoot, a glue-like substance that traps the scale larvae as they crawl up the tree to attach to the needles. These treated trees have data collected every year along with the resistant and susceptible trees. As you would suspect, resistant trees grow more each year than susceptible trees do. What do you think might happen to the growth of trees after they are treated for scale?