Todd D. JohnsonLouisiana State University | LSU · Department of Entomology
Todd D. Johnson
PhD Entomology
About
19
Publications
4,160
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189
Citations
Introduction
I am a behavioral and chemical ecologist who uses laboratory bioassays and field experiments to ask fundamental and applied questions about trees, their herbivores, and the natural enemies of herbivorous insects in forest ecosystems. The central focus of my research program is to identify and describe the underlying factors that contribute to the evolution and maintenance of chemical diversity within insects and plants, and how this ultimately affects their behavior and fitness. The results from
Additional affiliations
May 2019 - June 2022
University of New Hampshire
Position
- Postdoctoral Research Associate
Description
- Research evaluating the role of ontogeny on defensive metabolite production in green and white ash, as well as studying the impacts of ontogeny on the fitness of the invasive emerald ash borer (Coleoptera: Buprestidae: Agrilus planipennis) and the introduced biological control agents, Spathius galinae and Tetrastichus planipennisi. This project has involved substantial field and lab work over three field seasons, felling and sampling of hundreds of ash trees, and the analysis of univariate and m
August 2013 - May 2019
Position
- PhD Student
Description
- Field and laboratory research on the chemical ecology of cerambycid beetles and their associates (i.e., potential competitors and natural enemies). This included the collection of volatile pheromones of cerambycids with aerations and SPME, identification and comparison of pheromones with authentic standards in GC/MS, and validation of identified compounds with subtractive trapping studies in the field. Additional work involved preliminary isolation of putative pheromones from elaterid and staphy
August 2010 - September 2013
Position
- Research Assistant
Description
- Studied the microbial associations of three buprestids, the invasive emerald ash borer and two native species of Agrilus, twolined chestnut borer (Agrilus bilineatus) and bronze birch borer (Agrilus anxius). I also began preliminary work examining the behavior of two parasitoids of A. planipennis, Spathius floridanus and Spathius agrili. Lastly, I was responsible for coordinating and executing Wisconsin's first biological control release against the emerald ash borer, a multi-agency effort (UW-M
Education
August 2013 - May 2019
August 2011 - September 2013
August 2005 - May 2009
Publications
Publications (19)
We examined parasitoids and other co-occurring insects associated with three native Agrilus species, twolined chesnut borer (Agrilus bilineatus), bronze birch borer (Agrilus anxius), and bronze poplar borer (Agrilus liragus), in Wisconsin. Wisconsin is on the western leading edge of the invasive Emerald ash borer, Agrilus planipennis, and has at le...
Many species of beetles in the family Cerambycidae use volatile pheromones to facilitate the location of mates. Visual cues may also influence the location of mates, as the adults of many species of cerambycids are often brightly patterned and diurnal. Theory predicts that combining signals or cues of different modalities (e.g., chemical, visual) t...
Longhorned beetles (Coleoptera: Cerambycidae) include many species that are among the most damaging pests of managed and natural forest ecosystems worldwide. Many species of cerambycids use volatile chemical signals (i.e., pheromones) to locate mates. Pheromones are often used by natural enemies, including parasitoids, to locate hosts and therefore...
Commentary on Gossner et al. (2023) discussing the evolution of generalized defense traits against invasive pests of multiple taxa
Purpose of Review
The invasion of North America by the Asian beetle Agrilus planipennis has caused severe economic and ecological damage to ash (Fraxinus) tree populations. Agrilus planipennis has recently entered eastern Europe and is spreading there. Many other Agrilus species can potentially become invasive pests due to the cryptic nature of the...
This article is a Commentary on Gossner et al. (2023), 240: 1219–1232.
We present research on the chemical ecology of 14 species of longhorned beetles (Coleoptera: Cerambycidae), in four tribes of the subfamily Cerambycinae, conducted in east-central Illinois over 8 yr. Adult males produce aggregation-sex pheromones that attract both sexes. Twenty independent field bioassays explored the pheromone chemistry of the spe...
An increasing body of evidence suggests that the volatile pheromones of cerambycid beetles are much more diverse in structure than previously hypothesized. Here, we describe the identification, synthesis, and field testing of (2E,6Z,9Z)-2,6,9-pentadecatrienal as a male-produced aggregation-sex pheromone of the cerambycid Elaphidion mucronatum (Say)...
This abstract describes a presentation given on the development of automated camera systems to quantify the behavior of arthropods in field-conditions.
The compound 1-(1H–pyrrol-2-yl)-1,2-propanedione (“pyrrole”) is an important pheromone component of several Asian and South American species of longhorned beetles in the subfamily Cerambycinae. Here, we report the first confirmed identification of this compound as a pheromone component of a cerambycine species native to North America, the rare beet...
Evaluating the responses of natural enemies to pheromones and eggs of a cerambycid beetle in a field setting.
To locate resources and mates, insects often use a combination of chemical and visual cues to orient to a particular habitat or individual. Beetles in the family Cerambycidae usually respond strongly to long-range pheromones emitted by potential mates. Visual cues may influence responses by these beetles to their pheromones. The objectives of our s...
A recent invader to N orth A merica, emerald ash borer A grilus planipennis F airmaire ( B uprestidae), is expanding its western range into new habitats. We examined how site factors affect the emergence and damage caused by this beetle on the western edge of its contiguous population in eastern W isconsin, U.S.A . We characterized forest structure...
Beetles in the family Cerambycidae often emit long-range pheromones to facilitate in the location of mates. Many species of parasitoids have been shown to use pheromones of Coleoptera as kairomones to locate hosts. Our objective was to identify species of parasitoids that are attracted by pheromones of cerambycids in the subfamily Cerambycinae. We...
The Muller F element (4.2 Mb, ~80 protein-coding genes) is an unusual autosome of Drosophila melanogaster; it is mostly heterochromatic with a low recombination rate. To investigate how these properties impact the evolution of repeats and genes, we manually improved the sequence and annotated the genes on the D. erecta, D. mojavensis, and D. grimsh...
Beetles in the family Cerambycidae often emit long-range, sex pheromones to facilitate mate-location. Several species of parasitoids have been shown to ’eavesdrop’ on olfactory cues emitted by potential hosts. Orienting towards the sex pheromones of potential hosts may be a reliable and efficient way to locate an opportunity to oviposit. Our object...
Two parasitoids, the introduced specialist Spathius agrili Yang (Braconidae), and the native generalist Spathius floridanus Ashmead (Braconidae), have been proposed as biological control agents of the emerald ash borer, Agrilus planipennis (Fairmaire). However, little is known about their host-location behaviors. We evaluated wasp responses to thre...