Title: Ground deposition impact of aerially applied fenthion on the fiddler crabs, Uca pugilator in Journal of the American Mosquito Control Assoc. 2003;19(1):47-52.
Authors: Zhong H, Dukes J, Greer M, Hester P, Shirley M, Anderson B.
Source: John A. Mulrennan, Sr., Public Health Entomology Research and Education Center, Florida A&M University, 4000 Frankford Avenue, Panama City, FL 32405, USA.
Abstract: Caged fiddler crabs, Uca pugilator, were exposed to field ULV applications to measure the impact of fenthion. Two nozzle systems, conventional flat-fan nozzles (Tee Jet 8002SS) and high- pressure hydraulic nozzles (1/8 MIS), were compared using single spray swaths. Fenthion residues were detected throughout the 4.83-km test zone for both systems. Heavy ground deposits (650-1,670 ug/m2) of fenthion were found within 1 km using the flat-fan nozzle systems, which resulted in 80% fiddler crab mortality. Less than 100 ug/m2 fenthion ground deposits were detected during the high-pressure nozzle trials. No fiddler crab mortality was observed within the first 1-km zone following 3 single swath applications repeated during 3 consecutive nights. We found also that when the fiddler crabs were exposed to 700-800 ug/m2 fenthion, mortality occurred. Significant crab mortality (>50%) was observed when residues exceeded 1,000 ug/m2.
Summary: Fenthion can have population impacts to fiddler crabs when aerially applied with agriculturally-purposed Tee-Jet Flat fan nozzles. These same impacts are not observed when fenthion is applied with modern technology designed to produce small droplets used in the mosquito control profession. It should be noted that fenthion is a legacy pesticide and no longer used in mosquito control although the Florida Coordinating Council on mosquito Control supported the manufacturer in the need to re-register this product as recently as 1999.
Title: Effects of Mosquito control Measures on Non-Target Organisms in the Florida Keys National Marine Sanctuary in International Journal of Tropical Biological Conservation 53: 117-125
Author: Richard H. Pierce
Source: Mote Marine laboratory, 1600 Ken Thompson Parkway, Sarasota FL 34236
Summary:
a) A study of naled and DDVP (a breakdown product of naled) residue collected and measured from mangrove community and near-shore aquatic habitats in Monroe County subsequent to aerial applications of this adulticide for mosquito control purposes. Permethrin residue was also measured in mangroves and canals following truck ULV spraying. b) This summary will focus on naled. c) Naled was sprayed at 0.75 oz/ac (a middle-rate for this product) at 7am. Two applications approximately 6 weeks apart. d) Established 18 sampling locations (control and treatment combined); 6 in the mangrove and 12 up to 1km offshore. e) Three sampling mediums at all 18 sites: Filter paper, surface and sub-surface (20cm deep) water.
f) Results: a. Virtually no naled was collected at any of the sites, in either the filter paper, surface water or sub-surface water collections on either of the 2 treatment dates b. DDVP: DDVP was collected in approx 50% of the subsurface water collections on the June 17 application date but on the (apparent) “upwind” side of the treatment area and only 2-4hrs post application. No DDVP was collected on filter paper or surface water on the June 17 application in either up-wind or down-wind locations. Also, the July 28 application of naled failed to collect any DDVP on any of the 3 collection mediums. None of the collections detecting DDVP exceeded the reported NOEL for the species Palaemonetes pugio (generally accepted at 1.0 ug/L or slightly under) for laboratory- based LC50 96-hour exposure studies.
g) The researches acknowledged the difficulty in sampling and measuring naled and DDVP even within spiked samples presumably due to the rapid breakdown of these products. h) Other researches and literature reviews have reported that naled applications for purposes of mosquito control have no lethal effects on grass shrimp collected from estuarine environments…… see the additional citation below
Title: Acute toxicity and acetylcholinesterase inhibition in grass shrimp (Palaemonetes pugio) and oysters (Crassostrea virginica) exposed to the organophosphate dichlorvos: laboratory and field studies. In Arch Environ Contam Toxicol. 2007 Feb;52(2):207-16
Author: Bolton-Warberg M, Coen LD, Weinstein JE.
Source: Grice Marine Laboratory, College of Charleston, 205 Fort Johnson Road, Charleston, SC 29412, USA.
Abstract: The use of various organophosphates to control mosquito populations is a common practice across the globe. We review the literature (LC50s) on dichlorvos, the primary breakdown product of Dibrom, and use laboratory and field experiments to determine the lethal and sublethal (bioassays) effects of dichlorvos on two widely distributed and ecologically important estuarine invertebrate species, the marsh grass shrimp, Palaemonetes pugio and the Eastern oyster, Crassostrea virginica. Laboratory results based on LC50s and sublethal acetylcholinesterase (AChE) inhibition activity bioassays indicate that adult grass shrimp are more sensitive (approximately 500 x ) to dichlorvos than juvenile oysters. Although potentially an important factor for intertidal or shallow-dwelling estuarine organisms, the toxicity of dichlorvos was not enhanced in the presence of simulated sunlight for adult P. pugio. The most notable decreases in AChE activity were for grass shrimp and oysters exposed to dichlorvos concentrations above those considered ecologically relevant. In field experiments, both species were deployed in cages in unsprayed (n = 2) and sprayed (n = 3) sites and water samples collected pre- and post-spraying. Quantifiable dichlorvos levels were measured at the two narrowest creek treatment sites following mosquito spraying, suggesting that overspray can occur and there was evidence of a sublethal AChE response at these same sites. However, experiments at the widest creek revealed no measurable dichlorvos or sublethal responses. (Italics added) Results from this research suggest that adult grass shrimp are more sensitive to dichlorvos than juvenile oysters. Spraying near small tidal creeks may have measurable impacts on resident species, while larger (wider) creeks appear to be capable of buffering organisms from transient fluxes of mosquito control agents that may enter the system. Summary: Mortality of grass shrimp is not seen in “real-world” conditions following mosquito spraying with naled.
Title: Toxicity and Risk of Permethrin and Naled to Non-target insects after Adult Mosquito Management, in Ecotoxicology, Online Publication, April 29, 2010
Author: Jerome J. Schleier III • Robert K. D. Peterson
Source: Department of Land Resources and Environmental Sciences, Montana State University, 334 Leon Johnson Hall, Bozeman, MT 59717-3120, USA
Abstract: We derived laboratory LC50 values, assessed non-target insect risks, and conducted a field bioassay for ultra-low-volume (ULV) aerosol applications of insecticides used to manage adult mosquitoes. The house cricket, Acheta domesticus, was used as an indicator species for medium- to large- bodied ground dwelling insects. The 24-h LC50 values for Permanone (formulated product of permethrin), Permanone/piperonyl butoxide (PBO), technical grade permethrin, and technical grade permethrin/PBO ranged from 0.052 to 0.9 ug/cm2. The 24 h LC50 for technical grade naled and Trumpet (formulated product of naled) were 0.038 and 0.44 ug/cm2, respectively. The synergist ratio was 2.65 for Permanone PBO and 1.57 for technical grade permethrin/PBO. The toxicity of technical grade permethrin was about 10-fold greater than Permanone. A risk assessment using modeled estimated environmental concentrations resulted in risk quotients (RQ) that exceeded regulatory levels of concern, but when compared to field-derived actual environmental concentrations RQs did not exceed a regulatory level of concern, except in the case of technical grade naled. These results were expected because higher tiered risk assessments using field-verified data generally lead to lower risk estimates. Field bioassays using caged crickets showed no significant mortality for permethrin or naled after a single truck-mounted ULV application. The results of the risk assessment using actual environmental concentrations are supported by the field bioassays and suggest that a single ULV application of synergized or unsynergized permethrin and naled most likely will not result in population impacts on medium- to large-bodied insects.
Summary: This article generates 2 conclusions: a) Risk assessment models tend to over-estimate environmental concentrations and over- predict biotic responses. b) A field bioassay of “real-world” applications of naled and permethrin found no mortality difference amongst treatment and control populations of medium-to-large” bodied arthropods using (caged) crickets as a surrogate.
Title: Mortality of nontarget arthropods from an aerial application of pyrethrins, in Journal of the American Mosquito Control Assoc. 25(2):218-220, 2009
Author: Jonathan A. Kwan, et.al
Source: Vector Borne Disease Section, Infectious Disease Branch, Division of Communicable Disease Control, Center for Infectious Disease, California Department of Public Health Abstract: Mortality of nontarget organisms from an ultra-low volume (ULV) aerial application of pyrethrins (Evergreen EC 60-6) was monitored by collecting arthropods from ground tarps placed at the interface of open and canopy areas. A larger number and greater diversity of arthropods were recovered from tarps in the ULV spray area. The observed mortality was approximately 10-fold greater than in the control area. Kruskal-Wallis tests revealed a significant difference in the abundance and diversity of arthropods collected at treatment and control sites at 1 and 12 h post spray. Arthropods, primarily insects, from the treatment area included representatives from 12 orders and > or = 34 families, as compared to 7 orders and 12 families in the control area. Chironomidae (midges) and Formicidae (ants) were the most commonly represented families, accounting for 61% of the arthropods collected from the treatment area; no large-bodied insects (>8 mm) were recovered. Mortality of sentinel mosquitoes in the treatment and control areas averaged 96% and <1%, respectively, at 24 h post-exposure. This study supports previous work that the impact of a single ULV application of pyrethrins was limited to a variety of small-bodied arthropods.
Summary: Aerial spraying for mosquitoes using pyrethrin has no effects on medium to large bodied organisms.
Title: Nontarget Effects of the Mosquito Adulticide Pyrethrin Applied Aerially During a West Nile Virus Outbreak in an Urban California Environment, in Journal of the American Mosquito Control Assoc. 23(3):335-339, 2007
Author: Walter M. Boyce et. al
Source: University of California (various Departments)
Abstract: In August 2006, a pyrethrin insecticide synergized with piperonyl butoxide (EverGreenH Crop Protection EC 60-6, McLaughlin Gormley King Company, Golden Valley, MN) was sprayed in ultra-low volumes over the city of Davis, CA, by the Sacramento–Yolo Mosquito and Vector Control District to control mosquitoes transmitting West Nile virus. Concurrently, we evaluated the impact of the insecticide on nontarget arthropods by 1) comparing mortality of treatment and control groups of sentinel arthropods, and 2) measuring the diversity and abundance of dead arthropods found on treatment and control tarps placed on the ground. We found no effect of spraying on nontarget sentinel species including dragonflies (Sympetrum corruptum), spiders (Argiope aurantia), butterflies (Colias eurytheme), and honeybees (Apis mellifera). In contrast, significantly higher diversity and numbers of nontarget arthropods were found on ground tarps placed in sprayed versus unsprayed areas. All of the dead nontarget species were small- bodied arthropods as opposed to the large-bodied sentinels that were not affected. The mortality of sentinel mosquitoes placed at the same sites as the nontarget sentinels and ground tarps ranged from 0% to 100%. Dead mosquitoes were not found on the ground tarps. We conclude that aerial spraying with pyrethrins had no impact on the large-bodied arthropods.
Summary: Aerial spraying for mosquitoes using pyrethrin has no effects on medium to large bodied organisms.