Every year, the U.S. Department of Agriculture’s (USDA’s) Forest Service Forest Products Laboratory, Durability and Wood Protection analysis work unit (FS RWU 4723) installs and/or observes plots of soil handled with candidate termiticide merchandise. These merchandise might or might not be accessible to pest administration professionals (PMPs) for software, relying on federal and state registration.
This text reviews on the most recent outcomes of those research, and gives information for these merchandise which have reached federal registration. Knowledge offered are restricted to label-approved charges of software for these merchandise. This text gives data for PMPs in addition to householders, however limits the info to solely these software charges authorized to use. As a result of the U.S. Forest Service (USFS) observes some plot places late within the calendar 12 months, the earlier 12 months’s information are reported in every publication (for instance, this text will report on information collected in 2020; the 2019 data appears in the August 2020 issue of Pest Administration Skilled, or PMP). The Forest Merchandise Laboratory is maintained in cooperation with the College of Wisconsin, Madison, Wis.
This has been a long-term set of research. This system started in 1938 for the army, on plots situated within the Harrison Experimental Forest near Gulfport, Miss. Whereas the variety of places has expanded and diminished over time, the Gulfport location has at all times been the nucleus of our program. At present, two different take a look at websites are in use: the Chipola Experimental Forest in northwestern Florida, and the Calhoun Experimental Forest in western South Carolina. As a result of solely native subterranean termite species belonging to the genus Reticulitermes happen at these websites, our take a look at information solely applies to members of this genus. Incorporating a number of take a look at websites will increase data on how properly these therapies carry out below various climates, soil sorts and in differing geographic areas.
In 2020, no new merchandise have been put in on the USFS termiticide testing websites. Two candidate termiticides proceed to be evaluated. This report consists of two tables offering information for the entire present federally labeled termiticides in america. Producers of those candidate merchandise can withdraw merchandise from testing for any motive at any time. Our coverage has been to not report on any merchandise that don’t acquire federal registration; subsequently, no withdrawn merchandise or those who the U.S. Environmental Protection Agency (EPA) rejects seem within the information tables of this report. This prevents confusion and attainable off-label use of agricultural merchandise that include the identical energetic ingredient.
All lately collected information are for the 2 as-yet-unregistered merchandise stay confidential till after registration. Knowledge have been collected in 2020 as deliberate, following USFS guidelines for safeguarding workers from the COVID-19 virus.
The objective of the USFS termiticide testing program is to supply unbiased, third-party information on efficacy of candidate termiticides in cooperation with the producers of these merchandise. The efficacy information is gathered for eventual inclusion right into a registration packet that will likely be submitted to the EPA in search of federal registration. These assessments start when cooperators convey a candidate product to the USFS, and recommend the focus collection they’re excited by pursuing. From there, the corporate personnel might observe and help with the examine to a restricted extent. Common help, equivalent to digging holes or clearing bushes from a plot space, is permitted. Mixing product, treating plots or figuring out block injury (studying) is just not allowed.
The USFS gives set up and studying of plots utilizing the groundboard (GB), concrete slab (CS) and stake strategies, in addition to pesticide residual soil pattern assortment. Each the GB and CS strategies are assessments for soil barrier efficacy. The stake methodology is a barely totally different barrier take a look at for wooden embedded in handled soil, and has not been requested for many years. All three strategies are an identical to these required by the EPA’s Office of Poisons, Pesticides and Toxic Substances (OPPTS) 810.3600 doc. This doc requires efficacy information for candidate termiticides for 5 years. Subsequently, from product set up to completion, these research take six years. Yearly, the USFS gives product producers with updates on their product’s efficiency. The EPA, as properly state regulatory companies (as soon as the product obtains federal registration) are free to contact the USFS concerning the info or strategies used to acquire them.
The OPPTS 810.3600 specifies two protocols for testing these merchandise: the GB take a look at and the CS take a look at. The stake methodology is just not obligatory, although it may be requested by cooperators. Ten replicates of every focus (together with water-only controls) are put in for every candidate termiticide in every of the three nationwide subject websites.
The strategies are described within the annual termiticide report each year published in PMP magazine. As a result of no procedural modifications have been made, the language used to explain them stays comparatively fixed.
For the GB take a look at, a 17- by 17-inch space is cleared of particles, roots and rocks, and is handled with the candidate termiticide. After drying, a 6- by 6-inch sq. pine sapwood board is centered on the uncovered, termiticide-treated soil, and held in place with a brick.
The CS take a look at, also called the modified groundboard take a look at, may be very comparable. On this take a look at, the handled plot space can be 17- by 17 inches sq. and cleared as beforehand described. After remedy, the soil is roofed by a polyethylene vapor barrier, and a 21- by 21-inch concrete slab is poured round a 4-inch diameter PVC pipe positioned on the middle. As soon as the concrete has set, the vapor barrier is reduce out and faraway from the underside inside of the pipe, and a 3.5- by 2.5- by 1.5-inch rectangular pine sapwood block is positioned on the handled soil on the backside of the pipe. To stop weathering of the handled soil, a PVC cap is positioned on the pipe. Accomplished plots type a grid within the forest.
For each strategies, options of candidate termiticides are utilized to the soil on the pre-construction fee of 1.Zero gallon per 10.Zero sq. toes (or 0.2 gallons per 17- by 17-inch sq. plot). For every plot, the wooden is evaluated yearly for termite injury utilizing a easy scale known as the Gulfport scale, and the presence or absence of stay termites infesting take a look at blocks or boards is famous.
THE GULFPORT SCALE
Injury information are collected utilizing the Gulfport scale: 0 = no injury, 1 = nibbles-to-surface etching; 2 = mild injury with penetration; 3 = average injury; 4 = heavy injury; and 5 = board or block destroyed.
The Gulfport scale has been used because the late 1930s by the USFS termiticide unit to offer an estimate of the extent of termite feeding on wooden recovered in the course of the studying part of the research. The dimensions has been described beforehand by Arthur F. Verall in 1959 (Forest Merchandise Journal 9(1): 1-22).
The Gulfport scale could be in comparison with different termite-feeding requirements scales, such because the ASTM scale first described in normal D 3345 – 74 (1974). Determine 1 exhibits how these scales examine. Word that at one time, ASTM Worldwide added a 9.5 ranking. That ranking doesn’t seem in the newest replace from 2017 (D 3345-17). Regardless, the 9.5 ranking didn’t alter how the Gulfport scale converts, so 9.Zero and 9.5 ASTM have been each roughly equal to Gulfport 1.
Though each feeding scales are categorical, termite injury doesn’t bounce from one among these circumstances to the subsequent in nature. The block scores additionally will not be evenly distributed throughout these classes. That is partly as a result of breadth of the classes, with Class Three representing each a big portion of the potential block injury, in addition to the most important portion of examine information every year for merchandise reaching finish of life date.
Whereas it could be attainable to make statistical comparisons utilizing non-parametric strategies, these are pointless, as the usual established by the EPA is a cross/fail system. The classes can, nevertheless, be essential for state regulatory requirements. Florida, for instance, units percentages of allowable injury to blocks. A extra correct illustration of termite feeding could be to measure wooden block mass loss, however this could be troublesome to measure precisely within the subject.
Since 1998, the testing program has included further GB and CS plots for pesticide residue evaluation at every focus degree of a newly put in product. Soil pattern cores are 1 inch in diameter and Four inches in size, collected each after set up and on every subsequent 12 months of the examine.
The GB and CS plots designated for soil samples haven’t any wooden blocks and will not be learn for termite feeding. The soil samples are shipped to the product producer for residue evaluation of their product. Producers can analyze the samples or not; the outcomes of these samples will not be shared with the USFS. For that reason, not one of the soil pattern information seem within the annual termiticide report.
As has been reported in earlier annual termiticide reviews by the USFS in PMP, there’s a single normal for federal registration below the EPA, below which every state can create its personal normal. Beneath the EPA guideline, a candidate termiticide ought to forestall termites from penetrating handled soil in all (100 %) take a look at plots for no less than 5 years.
To satisfy this normal, all wooden specimens have to be rated “0” for termite injury below the Gulfport feeding scale. The EPA’s guideline is a troublesome normal for product efficiency, and the EPA might register merchandise that don’t strictly adhere to its efficacy guideline (see PMP, May 2015). The lead company for structural pest management in every state makes choices concerning the use or sale of a product through both a state-specific regulatory normal (such because the Florida Termiticide Efficacy Rule, 5e-2.0311, FAC), or its personal judgment of the USFS efficacy information on the product. At present, 39 of the 50 state lead companies select to make these choices collectively by the Association of Structural Pest Control Regulatory Officials (ASPCRO).
For the FS annual termiticide reviews, the info in Tables 1 and a pair of are introduced for every website individually, as evaluated utilizing the EPA guideline, and for example of a state normal, the Florida Rule (individually by website and collectively throughout all southeastern websites). Discussions of the variations between the 2 requirements have been lined in lots of the previous annual reviews (PMP, April 2016 and earlier).
The USFS is now in its 10th decade of offering unbiased candidate termiticide efficacy information for federal wants (army or regulatory). At present, this program has offered termiticide efficiency information for all federally registered merchandise, and has offered these information to PMPs and householders through this report. This data allows folks to make knowledgeable choices in regards to the safety of wooden in service from termite feeding. It additionally helps pest administration corporations make choices about termiticide merchandise to supply their prospects.
Editor’s Word: For the charts above, the info for this system that may be made public at press time have remained the identical since they have been first printed within the March 2015 subject of Pest Administration Skilled journal. Please observe the inclusion of brand name names and producer names are for information functions solely, and doesn’t Indicate endorsement by the USDA-FS.
DR. SHELTON is a supervisory analysis entomologist, FYE is a biologist, BELL is a organic science technician, DR. TANG is a analysis forest merchandise technologist, and DR. MANKOWSKI is a analysis entomologist.
All authors are with the USDA-FS Forest Merchandise Laboratory, Sturdiness and Wooden Safety Analysis Unit, Starkville, Miss. Contact them at [email protected].