ENT 205 HOMEWORK ASSIGNMENT 4: 25 points total The major goals of this assignmen

ENT 205
HOMEWORK ASSIGNMENT 4: 25 points total
The major goals of this assignment are to:
 Utilize information about a pest’s biology to predict its population over the course
of a year
 Depict EIL and AT on a graph
Format: You may format your assignment however you prefer. Part of this assignment
involves drawing a curved line on a graph – you could do this by drawing the graph with
your line and then taking a photo of your drawing and pasting it into your document, or
you could take a screenshot of the blank graph and put the screenshot in a blank power
point presentation and use the drawing tool to draw the line. If you have any questions
or are having trouble with this, please send me an email.
1. Start by watching the video linked in D2L to learn about the biology of aphids.
2. Then read the text excerpt below about the European Asparagus Aphid, excerpted
from Zsendrei & Schreiber, 2011:
Damage: Asparagus aphids cause damage to the plants by injecting a toxin when
feeding and a few aphids per plant are enough to lead to economic injury. Aphids
do not feed on the spear, but prefer to feed on fern, causing bushy, distorted
branching, yield loss for next year’s crop, and, if damage is severe, the plant may
be killed.
Biology: The asparagus aphid overwinters in the egg stage on the fern residue
left in the field. Eggs hatch in the spring; nymphs and adults feed on the spears
and fern. Their only host is asparagus. Throughout the summer, aphids reproduce
live nymphs without mating with males. In established asparagus fields in
Washington, aphids have two generations per season: one in August, followed by a
second generation in September. Non-bearing fields and nurseries can have three
or more generations in a season.
Management: Populations tend to build up later in the season in established
asparagus after the field is in full fern. Young fields where spears are not picked,
nurseries and volunteer plants outside the fields can be the sources of aphid
infestation for later in the season.
Zsendrei, S., & Schreiber, A. 2011. Check your asparagus for aphids. Michigan
State University Extension.

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