Toxicology Commons^™

Acute Copper (Cu) Toxicity In Dragonfly Naiads (Insecta: Odonata), Jeff M. Simpson

Department of Entomology: Distance Master of Science Projects

The objective of this study was to examine the effects copper (Cu) on mortality within a pair of test groups of naiads in the order Odonata, and to replicate previous observations regarding their potential uses as indicators for water quality. Few past studies have examined toxicity within relation to the odonates. It has been suggested that this order may contain valuable model organisms (Tollett et al., 2008). Very little focus has been given to odonates as bioindicators, with the few studies done being performed on species that would typically inhabit lentic environments (Trevino, 1999). Similarly, the test subjects for this …

Neonicotinoids Can Cause Arrested Pupal Ecdysis In Lepidoptera, Niranjana Krishnan, Russell A. Jurenka, Steven P. Bradbury

Biological Sciences Faculty Research & Creative Works

Recently, we reported a novel mode of action in monarch butterfly (Danaus plexippus) larvae exposed to neonicotinoid insecticides: arrest in pupal ecdysis following successful larval ecdysis. In this paper, we explore arrested pupal ecdysis in greater detail and propose adverse outcome pathways to explain how neonicotinoids cause this effect. Using imidacloprid as a model compound, we determined that final-instar monarchs, corn earworms (Helicoverpa zea), and wax moths (Galleria mellonella) showed high susceptibility to arrested pupal ecdysis while painted ladies (Vanessa cardui) and red admirals (Vanessa atalanta) showed low susceptibility. Fall …

Toxicology Of Chemical Stress To Monarch Butterflies (Danaus Plexippus L.), Annie Krueger

Department of Entomology: Dissertations, Theses, and Student Research

Monarch butterfly (Danaus plexippus L.) population declines have caught the attention of the country and prompted nationwide conservation initiatives. The United States Fish and Wildlife Service has identified insecticide exposure and loss of milkweed (Asclepias spp.) reproductive habitat as primary threats to the monarch. In the Midwestern US, milkweed largely occurs around cropland borders where there may be a spatial and temporal overlap of monarch larvae, insecticide usage, and fertilizer applications. In this study, the acute toxicity and sub-lethal effects on growth and diet consumption of two commonly used pyrethroid insecticides, bifenthrin and beta-cyfluthrin, were characterized …

Evaluating Toxicity Of Varroa Mite (Varroa Destructor)-Active Dsrna To Monarch Butterfly (Danaus Plexippus) Larvae, Niranjana Krishnan, Maura J. Hall, Richard L. Hellmich, Joel R. Coats, Steven P. Bradbury

Biological Sciences Faculty Research & Creative Works

Varroa mites (Varroa destructor) are parasitic mites that, combined with other factors, are contributing to high levels of honey bee (Apis mellifera) colony losses. A Varroa-active dsRNA was recently developed to control Varroa mites within honey bee brood cells. This dsRNA has 372 base pairs that are homologous to a sequence region within the Varroa mite calmodulin gene (cam). The Varroa-active dsRNA also shares a 21-base pair match with monarch butterfly (Danaus plexippus) calmodulin mRNA, raising the possibility of non-target effects if there is environmental exposure. We chronically exposed the entire monarch …

Monarch Butterfly (Danaus Plexippus) Life-Stage Risks From Foliar And Seed-Treatment Insecticides, Niranjana Krishnan, Yang Zhang, Melanie E. Aust, Richard L. Hellmich, Joel R. Coats, Steven P. Bradbury

Biological Sciences Faculty Research & Creative Works

Conservation of North America's eastern monarch butterfly (Danaus plexippus) population would require establishment of milkweed (Asclepias spp.) and nectar plants in the agricultural landscapes of the north central United States. A variety of seed-treatment and foliar insecticides are used to manage early- and late-season pests in these landscapes. Thus, there is a need to assess risks of these insecticides to monarch butterfly life stages to inform habitat conservation practices. Chronic and acute dietary toxicity studies were undertaken with larvae and adults, and acute topical bioassays were conducted with eggs, pupae, and adults using 6 representative insecticides: beta-cyfluthrin …

Conservation Risks And Benefits Of Establishing Monarch Butterfly (Danaus Plexippus) Breeding Habitats Close To Maize And Soybean Fields In The North Central United States: A Landscape-Scale Analysis Of The Impact Of Foliar Insecticide On Nonmigratory Monarch Butterfly Populations, Tyler J. Grant, Niranjana Krishnan, Steven P. Bradbury

Biological Sciences Faculty Research & Creative Works

Establishing habitat in agricultural landscapes of the north central United States is critical to reversing the decline of North America's eastern monarch butterfly (Danaus plexippus) population. Insecticide use could create population sinks and threaten recovery. Discouraging habitat establishment within a 38-m zone around crop fields is a suggested risk mitigation measure. In Story County, Iowa, United States, this mitigation would discourage habitat establishment in 84% of roadsides and 38% of noncrop land. It is unclear if the conservation benefits from establishing habitat close to crop fields outweigh suppression of population growth owing to insecticide exposure. Consequently, monarch conservation …

Assessing Field-Scale Risks Of Foliar Insecticide Applications To Monarch Butterfly (Danaus Plexippus) Larvae, Niranjana Krishnan, Yang Zhang, Keith G. Bidne, Richard L. Hellmich, Joel R. Coats, Steven P. Bradbury

Biological Sciences Faculty Research & Creative Works

Establishment and maintenance of milkweed plants (Asclepias spp.) in agricultural landscapes of the north central United States are needed to reverse the decline of North America's eastern monarch butterfly (Danaus plexippus) population. Because of a lack of toxicity data, it is unclear how insecticide use may reduce monarch productivity when milkweed habitat is placed near maize and soybean fields. To assess the potential effects of foliar insecticides, acute cuticular and dietary toxicity of 5 representative active ingredients were determined: beta-cyfluthrin (pyrethroid), chlorantraniliprole (anthranilic diamide), chlorpyrifos (organophosphate), and imidacloprid and thiamethoxam (neonicotinoids). Cuticular median lethal dose values for …

Residues Of Thiamethoxam And Mefenoxam In Vegetative And Floral Tissue Of Soybean At The Early Reproductive Stage Resulting From Seed Treatments, Carolina Camargo, Daniel D. Snow, Sathaporn Onanong, Thomas Hunt, Blair Siegfried

Department of Entomology: Faculty Publications

Thiamethoxam with mefenoxam is the most widely used neonicotinoid insecticide/fungicide mixture applied to soybean (Glycine max [L]) as seed treatments. Based on the systemic nature of thiamethoxam and mefenoxam, residues of this insecticide/fungicide mixture may be present in soybean vegetative and floral tissue and negatively impact beneficial insects. Although neonicotinoids are often applied in combination with systemic fungicides, the research on ecological risks of neonicotinoids has been focused on the analysis of these compounds without considering their interaction with other agrochemicals. The objective of this study was to identify the concentration of thiamethoxam and mefenoxam in soybean flowers and …

The Effect Of Imidacloprid On Honey Bee Queen Fecundity, Jamilyn Martin, Julia D. Fine, Amy Cash-Ahmed, Gene E. Robinson

PRECS 2018

Imidacloprid is a neonicotinoid insecticide commonly used in agricultural settings to control insect pests by acting as an agonist of acetylcholine receptors and inducing paralysis and mortality. In small doses, imidacloprid can cause loss of memory and foraging ability along with impaired learning and a lowered immune response in western honey bees (Apis mellifera). Effects of neonicotinoid insecticides on colony reproduction have been documented including decreased colony expansion, queen failure and replacement, and decreased queen egg laying.

For this study, we examined the effects of imidacloprid on the fecundity of queen bees when their worker attendants were exposed to low …

Fate Of Methoprene In Temperate Salt Marsh Ditches Following Aerial Applications, David J. Tonjes, Anne E. Mcelroy, Robin K. Barnes, Dominick V. Ninivaggi, Walter Dawydiak, Gregory T. Greene, Bruce J. Brownawell

Technology & Society Faculty Publications

Aerial applications of liquid methoprene are used in salt marshes to control mosquitoes by preventing adult emergence. Despite concern about toxicity to non-target organisms, little is known about environmental concentrations after applications, nor methoprene's persistence in salt marsh environments. Aqueous and sediment samples were collected from two marshes receiving weekly applications. Aqueous samples were collected as early as 30 minutes after applications and as long as nine days afterwards; sediment samples were taken within hours of application and as long as 19 days post-application. Use of time-of-flight liquid chromatography – mass spectral analysis allowed for ultra low detection limits (0.5 …

Expansion Of The Knockdown Resistance Frequency Map For Human Head Lice (Phthiraptera: Pediculidae) In The United States Using Quantitative Sequencing, K J. Gellatly, S Krim, D J. Palenchar, K Shepherd, Kyong-Sup Yoon, C J. Rhodes, S H. Lee, J M. Clark

SIUE Faculty Research, Scholarship, and Creative Activity

Pediculosis is a prevalent parasitic infestation of humans, which is increasing due, in part, to the selection of lice resistant to either the pyrethrins or pyrethroid insecticides by the knockdown resistance (kdr) mechanism. To determine the extent and magnitude of the kdr-type mutations responsible for this resistance, lice were collected from 138 collection sites in 48 U.S. states from 22 July 2013 to 11 May 2015 and analyzed by quantitative sequencing. Previously published data were used for comparisons of the changes in the frequency of the kdr-type mutations over time. Mean percent resistance allele frequency (mean % RAF) values across …

Quantitative Sequencing For The Determination Of Kdr-Type Resistance Allele (V419l,L925i, I936f) Frequencies In Common Bed Bug, Cimex Lectularius L., (Hemiptera: Cimicidae) Populations Collected From Israel, Daniel J. Palencar, Kyle J. Gellatly, Kyong-Sup Yoon, Kosta Y. Mumcuoglu, Uri Shalom, J Marshall Clark

SIUE Faculty Research, Scholarship, and Creative Activity

Human bed bug infestations have dramatically increased worldwide since the mid-1990s. A similar phenomenon was also observed in Israel since 2005, when infestations were reported from all over the country. Two single nucleotide polymorphisms (V419L and L925I) in the bed bug voltage sensitive sodium channel confer kdr-type resistance to pyrethroids. Using quantitative sequencing (QS), the resistance allele frequencies of Israeli bed bug populations from across the country were determined. Genomic DNA was extracted from samples of 12 populations of bed bugs collected from Israel and DNA fragments containing the V419L or L925I and I936F mutations sites were PCR amplified. The …

Toxic And Repellent Effects Of Pyrethroids Used In Orchards On The Honey Bee, Apis Mellifera L. (Hymenoptera: Apidae), Erin M. Ingram

Department of Entomology: Dissertations, Theses, and Student Research

Managed honey bee colonies provide valuable pollination services and are rented by fruit orchards to improve fruit quality and yield. The placement of colonies in this agricultural setting increases the possibility of exposure to pyrethroids used for broad-spectrum pest control in orchards. Although highly toxic to bees, pyrethroids are believed to pose a relatively low hazard due to their low application rates in the field as well as their contact repellent properties. Previous studies have noted a decrease in foraging visits following pyrethroid application possibly preventing bees from acquiring a lethal dose in the field.

This research quantified behaviors associated …