My research interests are in the areas of biological control and tritrophic level interactions. One of my goals is to increase our understanding of tritrophic interactions occurring in managed systems. Knowing how plants influence both the pest insects and biological control agents will allow us to improve our pest management strategies. One area of work  focuses 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. Previous work had shown that variation in plant morphology can have a significant impact on the effectiveness of coccinellid predators. Recent efforts have studied the influence of plant morphology on the occurrence of intraguild predation (IGP) between coccinellid and lacewing insect predators. Experiments tested the hypothesis that  coccinellids foraging on morphologically complex plants will have better survival rates from IGP by lacewings. To test this idea, three near-isogenic lines of the garden pea that differed in leaf shape were utilized. Results so far show that coccinellids survive from potential IGP by lacewings in greater proportions when they forage in the most complex plants. Variation in plant morphology influences predator efficacy and it can also influence the frequency of IGP encounters. One given morphological trait may have diverging effects on the predator. For example, the more complex aftl (parsley) pea leaf structure hampers coccinellid predation efficacy but this leaf structure may also enhance coccinellid survival when intraguild predators are present.

Other lines of work deal with management of  insect pests of turf and ornamental plants.  Specifically, I have begun research evaluating the entomopathogenic fungus Metarhizium anisopliae against Japanese and Oriental beetles which are important pests of ornamentals and turf. I am also interested in developing more information about insect natural enemies of the Japanese and Oriental beetles. To this end, a recent project determined the presence and seasonal occurrence of the parasitoid wasp Tiphia vernalis which was released in Connecticut back in the early 1930’s for Japanese beetle control.

University of Maryland, Ph.D. in Entomology, 1999.                     
Cornell University, B.S. with high honors in Biology, 1991.

Assistant Professor in Residence, Department of Plant Science, University of Connecticut. 1999 - 2003

PLSC 125 - Insects, Food and Culture,  Fall semester, odd-years

PLSC 204/SAPL042 - Integrated Pest Management, Spring semester

PLSC 288 - Insect Pest Management, Fall semester, even-years

Entomological Society of America

International Organization for Biological Control

University of Connecticut Association of Latino Faculty and Staff

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.

Tiphia vernalis larva feeding on Japanese beetle grub          Coccinella septempunctata larva on reduced stipule peas

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Ricard, R., A. Legrand and D. Hirsch. 2007. A mixed-methods analysis of the educational needs of employers and non-English speaking workers in arboriculture. Journal of Extension: in press.

Legrand, A. 2007. The spring Tiphia: a natural enemy of the Japanese beetle. IPM Program, Biological Control Fact Sheet, University of Connecticut Cooperative Extension System.
PDF link: http://www.hort.uconn.edu/ipm/turf/htms/Spring%20Tiphia.pdf

Ramoutar, D. and A. Legrand. 2007. Survey of Tiphia vernalis (Hymenoptera:Tiphiidae) a parasitoid wasp of Popillia japonica (Coleoptera: Scarabaeidae) in Connecticut. Florida Entomologist 90(4): 780-2.  
PDF link: http://www.fcla.edu/FlaEnt/fe90p780.pdf

Legrand, A. 2006. Influence of plant morphology on the efficacy and intraguild interactions of pea aphid predators. XIV International Entomophagous Insect Workshop Abstracts. Journal of Insect Science 7:16. 
Online: Insectscience.org/7.16

D. Ramoutar and A. Legrand. 2006. Status of the Japanese beetle parasitoid Tiphia vernalis Rohwer in Connecticut. XIV International Entomophagous Insect Workshop Abstracts. Journal of Insect Science 7:16. 
Online: Insectscience.org/7.16

Gabany-Guerrero, T. and A. Legrand. 2004. Educational Needs Assessment of Non-English Speaking Agricultural Workers in Connecticut: a Pilot Study. University of Connecticut Cooperative Extension System.

Legrand, A. 2004. Plants documented as attractive to beneficial insects. IPM Program, Biological Control Fact Sheet, University of Connecticut Cooperative Extension System.

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): 424-28.
PDF link: http://www.fcla.edu/FlaEnt/fe86p424.pdf

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