INTEGRATED MANAGEMENT OF THE BOXWOOD LEAFMINER
INTEGRATED MANAGEMENT OF THE BOXWOOD LEAFMINER
Files
Publication or External Link
Date
1999
Authors
d'Eustachio, Gabriel John
Advisor
Raupp, Michael J.
Citation
DRUM DOI
Abstract
Landscape managers need durable, effective, and safe methods for
controlling key pests of valued plants in both landscape and nursery
settings. The boxwood leafminer (Monarthropalpus flavus, Diptera:
Cecidomyiidae) is a serious pest of boxwoods. Boxwoods (Buxus sp.) are a
key plant in suburban Maryland landscapes. They are the second most
common woody ornamental plant in these settings. In a recent study almost
43% of boxwoods surveyed required treatment for leafminer infestation.
Boxwood leafminers also pose a serious problem in historical gardens, such
as Longwood Gardens, PA, Dumbarton Oaks and the US National
Arboretum in Washington, DC. At the present time, there is a lack of a comprehensive, environmentally sound, management program for the
boxwood leafminer.
The first step toward an effective management strategy is a better
understanding of the boxwood leafminer's life cycle. Over the summers of
1994-1995, leafminer populations were surveyed and life cycles documented
and correlated with growing degree days. The first growing degree day
developmental chart for boxwood leafminer was developed.
Various pesticides were tested in 1995. Different chemicals and
application times were evaluated for control of both adults and larvae. At
present it appears that application of a translaminar pesticide such as Avid
or Merit at adult emergence (growing degree day 352) provides the best
control.
Resistant cultivars appear to be the most durable, simplest method to
control the leafminer. Some cultivars.are highly resistant to boxwood
leafminer attack while others are highly susceptible. The third goal of my
project was to identify resistant cultivars. This was accomplished by first
observing natural variation in leafminer populations in the field. Next I
caged ovipositing adults on terminal branches of various cultivars of
boxwood, and measured survival of larvae. All cultivars received heavy oviposition with equal frequency, although survival rates were very
different.
Finally, I tested the hypothesis that leafminers could discriminate
among resistant and susceptible cultivars. To test this emerging adults
were caged with different cultivars of boxwood and allowed to select plants
for oviposition. Plants were then analyzed to determine acceptance of
various host plants. I found that although survival on different cultivars
can vary dramatically, leafminers were unable to distinguish between
suitable and unsuitable host plants.