EDUCATION
University of
Maryland, Ph.D. in Entomology, 1999.
Cornell University,
B.S. with high honors in Biology, 1991.
COURSES TAUGHT
Insect Pest
Management, PLSC 288.
Plant Pest Control,
SAPL 041.
Introduction to
Entomology, Master Gardener Program.
RESEARCH
INTERESTS
Tritrophic level interactions in agricultural systems. Behavior
and ecology of insect predators.
Biological control and
its integration with host plant resistance for insect pest management.
CURRENT PROJECTS
Influence of variation in plant morphology on insect predator
efficacy
My
current research efforts focus on the influence of plant morphological variation
on the control of pea aphid by its complex of predators and parasitoids. I am
taking advantage of pea lines that possess single gene mutations that drastically
alter the shape of leaves and stipules. By using near-isogenic lines I can control,
as much as possible, other non-morphological factors such as phytochemicals and
surface waxes. I have shown that changes in plant morphology did not influence
the performance
of the pea aphid. Subsequent research tested the hypothesis that predator
efficacy should decrease as plant complexity increased. For experiments, we used
near-isogenic pea lines that could be ranked from low to high complexity. Indeed,
we obtained support for our hypothesis but it appears that predators have an
idiosyncratic response to plant complexity. While
foraging by ladybird beetle adults and larvae (Coccinella
septempunctata) is hampered by increases in plant complexity, lacewing larvae
(Chrysoperla rufilabris) are less affected.
In addition to exploring the effect on plant complexity, I have
also studied how two other plant morphological traits influence the foraging
success of coccinellid and chrysopid predators. For example, we found that the
reduced stipule trait enhances predation on pea aphids and this is a trait that
could be easily incorporated into pea cultivars with, presumably, no agronomic
disadvantages. I hope to continue field investigations on the advantages of this
morphological character. Currently, we are working on the influence of plant
complexity on the intraguild interactions of pea aphid predators and
parasitoids.
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Chrysoperla
rufilabris larva
on reduced stipule peas
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Coccinella
septempunctata larva
on reduced stipule peas
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PUBLICATIONS
Legrand, A.I. and A.G. Power. 1994.
Inoculation and acquisition of maize bushy stunt mycoplasma by
its leafhopper vector Dalbulus maidis. Annals of Applied
Biology 125:116-122.
Legrand, A.I. and P.B. Barbosa.
2000. Pea aphid Acyrthosiphon pisum Harris (Homoptera: Aphididae)
fecundity, rate of increase and within-plant distribution unaffected
by plant morphology. Environmental Entomology 29: 987-993.
Legrand, A. I. and P.B. Barbosa.
2003. Plant morphological complexity impacts foraging efficiency
of adult Coccinella septempunctata L. (Coleoptera: Coccinellidae).
Environmental Entomology 32(5): 1219-1226.
Legrand, A. I., and L. Los. 2003.
Visual responses of Lygus lineolaris and Lygocoris spp.
(Hemiptera: Miridae) on peaches. Florida Entomologist 86(4): 424-428.
Legrand, A.I Differential
effect of plant morphological complexity on the effectiveness of
chrysopid and coccinellid larvae. In preparation.
PROFESSIONAL
ASSOCIATIONS
Entomological Society of America
International Organization for Biological
Control
Connecticut
Association of Latin Americans in Higher Education
University of Connecticut Association
of Latino Faculty and Staff
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