Louis Bjostad

Professor

Louis.Bjostad@ColoState.edu  
E209 Plant Sciences
(970) 491-5987

Chemical ecology is the focus of the research in our laboratory, and this includes both basic and applied investigations of chemical relationships among insects and plants. Behavioral and physiological studies with insects, including bioassays both in the laboratory and in the field, are used as the basis for the isolation and chemical identification of natural products that are involved in these interactions. Our work entails purification of individual components of interest by gas-liquid chromatography and high performance liquid chromatography, and chemical identification of these compounds with spectroscopic techniques (principally, mass spectrometry and NMR) in conjunction with micro-derivatization reactions. Synthesis of these compounds is also carried out in our laboratory, and the synthetic materials are tested in the laboratory and in the field for behavioral and physiological activity.

Our project on chemical cues involved in host location by larvae of the western corn rootworm, one of the most important pests on corn in the United States, is concerned with compounds from the roots of corn plants that attract the larvae underground. We have completed the isolation and chemical identification of some of the important compounds, and behavioral bioassays in our laboratory with the synthetic compounds have verified that they are attractive. We are currently engaged in the isolation and identification of additional compounds that are involved in attraction of the larvae to corn roots. This basic line of research served as the foundation for applied research that we are conducting to reduce the amount of insecticide used in cornfields to control these insects, by using the corn attractants as larval baits on granules that have reduced amounts of insecticide. In addition, we are developing formulations that emit carbon dioxide slowly over the course of the field season, in order to interfere with the ability of rootworm larvae to use carbon dioxide gradients to locate corn roots.
Our research on termites has shown that termites are attracted to carbon dioxide at low concentrations in air, comparable to the concentrations that are found in the colony. We are presently investigating the potential for termite monitoring and control by using carbon dioxide to attract termites or otherwise influence their behavior.

Courses I Teach:

Insect Behavior (BSPM 507) (Spring Odd Years)

Chemical Ecology (BSPM 570) (Spring Even Years)

Techniques in Chemical Ecology (BSPM 571) (Spring Even Years)

Insects, Science and Society (BSPM 102) (Spring)

Representative Publications:

Broadbent S, Farr M, Bernklau EJ, Siderhurst MS, James DM, Bjostad LB Field attraction of termites to a carbon dioxide-generating bait in Australia (Isoptera) SOCIOBIOLOGY 48 (3): 771-779 2006

Siderhurst MS, James DM, Bjostad LB Ultraviolet light induced autophototoxicity and negative phototaxis in Reticulitermes termites (Isoptera : Rhinotermitidae) SOCIOBIOLOGY 48 (1): 27-49 2006

Siderhurst MS, James DM, Blunt TD, Bjostad LB Antimicrobial activity of the termite (Isoptera) alkaloid norharmane against the entomopathogenic fungus Metarhizium anisopliae SOCIOBIOLOGY 46 (3): 563-577 2005

Siderhurst MS, James DM, Rithner CD, Dick DL, Bjostad LB Isolation and characterization of norharmane from Reticulitermes termites (Isoptera : Rhinotermitidae) JOURNAL OF ECONOMIC ENTOMOLOGY 98 (5): 1669-1678 OCT 2005

Bernklau EJ, Bjostad LB Insecticide enhancement with feeding stimulants in corn for western corn rootworm larvae (Coleoptera : Chrysomelidae) JOURNAL OF ECONOMIC ENTOMOLOGY 98 (4): 1150-1156 AUG 2005