The Moths and the Trees
The Forest Ecosystem diagram shows part of a forest ecosystem. Tussock moths are
native to the forest ecosystem. In the fall, tussock moths lay eggs on Douglas fir trees.
In the spring, tussock moth larvae eat the needles of the Douglas fir trees.
- If the tussock moth population increases rapidly, trees that people want to use can be damaged. One solution is to use a pesticide that kills moths to keep the moths from damaging trees.
a)Describe two possible unintended consequences of using pesticides to remove the tussock moth.
In your description, be sure to:
- Describe two unintended consequencesof using pesticides to remove the
tussock moth. - Describe how each unintended consequence could affect another organism in the forest ecosystem.
One unintended consequence:
Another unintended consequence:
Task Title: The Moths and the Trees
Item number: 3 Cognitive Complexity: 2 (page 1 of 2)
Performance Description
A 4-point response demonstrates the student understands:
Content Standard APPC: Choosing the best solution involves comparing alternatives with respect to criteria and constraints, then building and testing a model or other representation of the final design.
Item Specification 2: Describe a method for testing the solution(s) given a problem that can be solved using a technological design process and possible solution(s).
AND
Content Standard APPE: Perfect solutions do not exist. All technological solutions involve trade-offs in which decisions to include more of one quality means less of another. All solutions involve consequences, some intended, others not.
Item Specification 1: Describe trade-offs and/or unintended consequences for one or more given solution(s) to a given technological design problem.
Item and example response / Points
APPE(1)
a)The response describes two possible unintended consequences of using pesticides to remove the tussock moth by:
- Describingtwo unintended consequences of using pesticides to remove the tussock moth AND
- Describing how each unintended consequence could affect another organism in the forest ecosystem.
Describes unintended consequence / Describes change in another organism
Water is polluted/pesticide gets into water / Fish/aquatic insects/aquatic plants are sick/killed
Air is polluted by the pesticide / Other insects/birds/animals get sick/killed
Pesticide kills insects other than tussock moth / There is less food for the predators of those other insects
Some plants are harmed by the pesticide / Less food/habitat is available for animals who use those plants
Biomagnification/pesticide builds up in food chain / The pesticide in small organisms kills/harms predators of those organisms
Trees grow bigger and produce more shade since no moths are eating them / Smaller plants are not able to grow in the shade
Note: Responses describing one unintended consequence of using pesticides and describing how that unintended consequence would cause a change in another part of the forest ecosystem may be credited one point.
Teaching Tips:
Make sure students check off each bullet point as they go. The two unintended consequences need to be different. Students need to then state another organism that is affected by the unintended consequence. If they mention an organism as an unintended consequence (such as plants affected by the pesticide), they then need to state another organism that is affected by the plant being affected.