Liquid Termiticides Research Articles

Death zone minimizes the impact of fipronil-treated soils on subterranean termite colonies by negating transfer effects.

The use of nonrepellent liquid termiticides against subterranean termites has long relied on the assumption that foraging termites in soils could transfer toxicants to nestmates to achieve population control. However, their dose-dependent lethal time can lead to rapid termite mortality in proximity of the treatment, triggering secondary repellency. The current study characterizes the dynamic nature of the "death zone," i.e., the area adjacent to soil termiticides that termites would avoid owing the accumulation of cadavers. Using whole subterranean termite laboratory colonies of Coptotermes gestroi (Wasmann) with 3 × 15 m foraging distances, fipronil was implemented at 1.5 m, 7.5 m, or 12.5 m away from colony central nests, emulating a corrective action against an termite structural infestation. For treatments at 7.5 m and 12.5 m, the death zone stabilized at an average of ~2.56 m away from the treatment after 40 d post-treatment, and colonies suffered as little as 1.5% mortality by 200 d post-treatment. Colonies located 1.5 m away from the treatment minimized the death zone to ~1.1 m and suffered as little as 23.5% mortality. Mortality only occurred within the first few days of treatment from initial exposure, as the rapid emergence of the death zone negated further transfer effects among nestmates over time. In some cases, foraging termites were trapped within the infested structure. While technically nonrepellent, fipronil becomes functionally repellent from the rapid mortality onset near the treatment. Even if diligently implemented to successfully protect structures, surrounding termite colonies are minimally impacted by fipronil soil treatments.

Queen Egg Laying and Egg Hatching Abilities are Hindered in Subterranean Termite Colonies When Exposed to a Chitin Synthesis Inhibitor Bait Formulation.

Subterranean termite control methods using chitin synthesis inhibitors (CSIs) aim at eliminating colonies that feed upon a bait formulation. Several benzoylurea active ingredient formulations are currently commercially available as alternative termite management strategies to liquid termiticides. Individual workers need to molt on a regular basis and CSIs interfere with such molting process, allowing sufficient time for the acquisition of a colony-wide lethal dose prior to widespread mortality. As workers progressively die, the colony eventually collapses, leaving only soldiers and primary reproductives that starve to death. One common observation is that young workers often die early owing to their relatively short molting cycle. However, the absence of brood in dying colonies raises questions about the potential fate of eggs laid by the queen. This study aims to determine if CSI baits also terminate the ability of a colony to produce a new cohort of workers by disabling the ongoing brood development. Incipient termite colonies were used to test the impact of noviflumuron on the queen's ability to lay eggs and on the eggs' ability to hatch. Our results showed that queens in colonies exposed to CSI not only initially laid less eggs than the control queens, but eggs also did not develop and were progressively cannibalized, eventually leading to colony establishment failure. This result implies that queens of mature colonies exposed to CSI would lose the ability to lay viable eggs as the colony collapses, leading to an absence of worker replacement, aiding in colony elimination.

Subterranean Termite (Coptotermes gestroi (Blattodea: Rhinotermitidae)) Colony Elimination Through Exposure to a Novaluron CSI Bait Formulation in Laboratory.

The development of baits for subterranean termite control over the past 25 yr has provided cost-effective alternatives to liquid termiticide treatments. Current bait products use one of the few available benzoylurea chitin synthesis inhibitors (CSIs) labeled for subterranean termites. These insecticides are used because of their nonrepellency, their slow-acting mode of action, and their dose-independent lethal time. Although many studies have provided ample evidence of the efficacy of CSI baits for subterranean termite colony elimination, most have focused on hexaflumuron and noviflumuron. However, bait products using alternative CSIs have not received the same level of scrutiny, limiting the amount of evidence proving their efficacy. One such compound is novaluron, the active ingredient currently used in the Trelona ATBS-Advance Termite Baiting System bait product. The current study independently tested the efficacy of this commercially available bait formulation against whole colonies of Coptotermes gestroi (Wamann) (~63,910 workers) in the laboratory, using an extended experimental setup to simulate a 15-m foraging distance from the central part of the nest to the bait, while having access to alternative food sources. Treated colonies progressively ceased to feed on wood items within 45 d after being provided access to the novaluron bait formulation, with a subsequent progressive collapse of the population, leading to colony elimination by 91 d. This study therefore confirms the efficacy of novaluron baits against subterranean termites, and currently remains one of the few CSIs that can be applied for the successful control of Coptotermes infestations.

Advection of Liquid Termiticides within Building Foundation Aggregate Fill

Advection of two liquid termiticides was determined within two different building foundation aggregate fills, ODOT Base Type-A Gravel and Class A-#57 Crushed Rock, after over-the-surface applications. Residues within each aggregate were sampled as two composite soil cores taken in two 5.1-cm incremental partitions to a depth of 10.2-cm after 24 hours, and at 6 and 12 months post-application. Half the test plots were compacted and half remained not compacted. Advection was significantly influenced by aggregate type. Residues within compacted compared with not-compacted aggregates were similar for individual termiti-cides. Some termiticide dispersed completely through the aggregates to reach the soil beneath. Advection resulted in decreasing a.i. concentrations as depth increased within ODOT Base Type-A Gravel fill, with the greatest concentration located in the top 5.1-cm partition, likely due to the fine particle component, with almost no termiticide reaching underlying soil. In contrast, termiticides were more evenly distributed within Class A-#57 Crushed Rock fill, as residue amounts were similar throughout the 10.2-cm depth, with some reaching underlying soil.

Field Evaluations of Fluid Baits against Colonies of the Formosan Subterranean Termite (Blattodea:Rhinotermitidae).

Fluid baits comprised of 10% dry medium (impregnated with 0.5% hexaflumuron) and 90% methylcel solution were injected into foraging galleries of the Formosan subterranean termite, Coptotermes formosanus Shiraki (Blattodea: Rhinotermitidae), in trees and buildings. Elimination times at two of the six baited sites were longer than expected, possibly due to the application disturbance or the presence of an old and declining colony, but fluid bait treatments eliminated all baited colonies. Fluid baits were injected through drill holes behind infested wood surface, and bypassed the difficulties for installing above-ground (AG) bait stations on uneven surface or at tight corners. Because a large quantity of fluid baits could be applied at once, termite control professionals may be able to avoid revisiting the site to add more baits. The absence of unsightly AG station in a house will also make fluid baits more acceptable to homeowners than AG baits. Currently, local applications of liquid termiticides are common practices because termite control professionals are often urged by homeowners to take remedial actions when termites are found in a house, but such treatments only drive termites away from the active loci without affecting the termite colony(s). Remedial treatments with fluid baits would result in immediate bait consumption and shorten colony elimination time with or without the use of in-ground baiting systems. Introduction of fluid baits will add another tool to the termite control industry and will make it more plausible for the homeowners to accept baiting technology.

Efficacy of Chlorantraniliprole in Controlling Structural Infestations of the Eastern Subterranean Termite in the USA.

Subterranean termites are the most economically important structural pests in the USA, and the eastern subterranean termite, Reticulitermes flavipes (Kollar) (Dictyoptera: Rhinotermitidae) is the most widely distributed species. Soil treatment with a liquid termiticide is a widely used method for controlling subterranean termites in structures. We assessed the efficacy of a nonrepellent termiticide, Altriset® (active ingredient: chlorantraniliprole), in controlling structural infestations of R. flavipes in Texas, North Carolina, and Ohio and determined the post-treatment fate of termite colonies in and around the structures. In all three states, microsatellite markers indicated that only one R. flavipes colony was infesting each structure. A single chlorantraniliprole treatment provided effective structural protection as there was no further evidence of termite activity in and on the majority of structures from approximately 1 month to 2 years post-treatment when the study concluded. Additionally, the treatment appeared to either severely reduce the infesting colony’s footprint at monitors in the landscape or eliminate colony members from these monitors. A supplemental spot-treatment was conducted at one house each in Texas and North Carolina at 5 and 6 months post-treatment, respectively; no termites were observed thereafter in these structures and associated landscaping. The number of colonies found exclusively in the landscape (not attacking the structure) varied among the states, with the largest number of colonies in Texas (0–4) and North Carolina (0–5) as compared to 0–1 in Ohio, the most northern state.

Result of Controlling Drywood Termites (<i>Cryptotermes domesticus</i> Haviland) by New Method

The efficacy of injecting and liquid termiticide and covering the treatment area with cotton cloth saturated with insecticide for 48 hours was conducted in 2 areas of Tan Da Resort (central Area and Lac Viet area) that were damaged by drywood termite. The results showed that the drywood termite <i>Cryptotermes domesticus</i> was completely eliminated 5 days after the injection and covering treatment and there have been no signs of termite activity for 3 months.

Impacts on Reticulitermes flavipes (Infraorder Isoptera: Rhinotermitidae) by Chlorantraniliprole Applied to Soil Surrounding Established Tunnels.

Soil-applied liquid termiticides are the most common control measure for subterranean termites. Characteristics unique to insecticidal chemistries such as repellency, toxicity, and time between contact and mortality, influence the interaction of termites with treated soil and overall treatment success. Two different treated-tunnel bioassays were used to evaluate the behavioral impacts and mortality of termites from treatment with chlorantraniliprole (the active ingredient in Altriset® termiticide) to existing, mature tunnels. Termites that were provided constant access to a 10-cm-long mature tunnel within soil treated with 5 or 50 ppm chlorantraniliprole were not repelled by the treatment and began exhibiting slower, uncoordinated movement, and cessation of tunneling and feeding in as little as 1 h after access. Termites provided access for 7, 14, or 21 d to previously constructed tunnels recently treated with 50 ppm chlorantraniliprole exhibited complete or near complete mortality by 28 d. The second bioassay design resembled a more typical field situation with a 40-cm-long mature tunnel and termites allowed access for a maximum of 5 min. Termites collected after just 5 min of access to the previously constructed tunnels recently treated with 50 ppm chlorantraniliprole exhibited similar symptomology within an hour followed by complete mortality at 18 d after exposure. These test designs simulate what occurs in the soil around an infested structure at the time of treatment. Results from these evaluations suggest that termites readily crawl through chlorantraniliprole-treated mature tunnels, rapidly lose ability to feed, and acquire a lethal dose from brief exposures.

Efficacy of Altriset® on the Tropical Arboreal Termite,Nasutitermes corniger(Isoptera: Termitidae: Nasutitermitinae)

Nasutitermes corniger (Motschulsky), a memSpray Applications ber of the termite family Termitidae, is an im portant structural pest over much of Central and A 4.6-cm-diam, 1-mm-thick cellulose pad (Gel South America (Constantino 2002; Torales 2002) man inc.) was placed inside a 5.5 cm plastic Pe and the West Indies including Puerto Rico and the tri dish bottom and moistened with 1.25 mL of U.S. Virgin Islands (Scheffrahn et al. 2003). This water. Twenty-five workers of N. corniger, as ob termite has now invaded South Florida (Scheftained above, were placed on top of the pad. The frahn et al. 2002), the Bahamas (Scheffrahn et al. termites were taken from a whole field-collected 2006), and New Guinea (Scheffrahn et al. 2005). colony that was maintained in the laboratory in DuPontTM Altriset® is a newly registered termitia 40 gallon (148 L) aquarium tank. Eight repli cide containing the active ingredient, chlorantracates were sprayed with 500 ppm aqueous Altri niliprole, which is characterized by its extremely set® and eight control replicates were sprayed low mammalian toxicity (Lahm et al. 2007) and with water. The liquid spray concentration of its high efficacy against subterranean termites 500 ppm (0.05%) is the current label application (family Rhinotermitidae e.g., Mao et al. 2011; rate for the commercial product. The sprays were Neoh et al. 2012; Spomer & Ramble 2011). The deposited from a distance of 35 cm using a hand efficacy of Altriset® against higher termites (Tersprayer set to deliver medium/fine droplets. For mitidae) has not been evaluated. Given the toxiceach treatment (Altriset® or water) 4 pumps ity of Altriset® against conordinals, the purpose mL total) were applied. About 2 mL actually of this study was to assess the efficacy of residual landed inside all the replicates of each treatment, and spray treatments of Altriset® on N. corniger Within five minutes, the sprayed termites were workers using laboratory bioassays. transferred to identical clean, unsprayed, Petri dishes containing damp pads. Lids were placed on o „ the pads and the 16 dishes were placed in a labo oi xposures ratory incubator at 22 °C and 90% RH. Termite Altriset® (18.4% chlorantraniliprole AI, Dumortality and moribundity were recorded once or Pont Professional Products), was applied to sand twice Per day> a& time allowed, for 7 days, (natural play sand, Sakrete, Bonsai America, Table 1 and Fig. 1 summarize time versus Charlotte, North Carolina) in aqueous solutions mortality for the five treatments prepared for and thoroughly mixed by hand for final dry conthis study. In all Altriset® exposures, locomotion centrations (wt Al/wt sand) of 100 ppm, 50 ppm, of Ncorniger workers slowed markedly, followed and 0 ppm water only). The 50 ppm concentraby moribundity. Moribundity preceded mortal tion is approximately the conventional soil apity by about 0.5-2 days. The 500 ppm Altriset® plication rate. For each treatment, 9 g of the spray treatment yielded 44% mortality by 65 dry treated sand was poured into an 8.2 cm ID hours and reached 100% mortality in 161 hours plastic Petri dish bottom to which 6 mL of wapost-exposure compared to 4% mortality for the ter was added. Twenty five (25) workers of N. water-only spray treatment. The 100 ppm Altri corniger were then placed on top of the damp set® sand treatment produced 100% mortality sand and a matching lid was used to close each by 25 h while the 50 ppm treatment yielded 1% bioassay unit. Each treatment was replicated 8 mortality over this time period. However by 73 h, times. Termites were taken from a single large the 50 ppm sand exposure produced 45% mortal colony collected in Dania Beach, FL, in Dec 2011 ity and by 161 h, mortality rose to 99%. At 161 h, and maintained in the laboratory under ambithe mortality in the water-only sand treatment ent conditions in a 148-liter aquarium. Termites was 'ess than 4%. were fed dead Schinus wood and damp cellulose This laboratory study attempts to represent sponges. The 24 units were placed in a laboratotypical routes of field exposure to N. corniger. ry incubator at 22 ± 0.5 °C and 90% RH. Termite During a commercial application of liquid termiti mortality and moribundity were recorded once cide (surface spray and injection), most termites or twice per day for 7 days. will be exposed to the liquid termiticide through

Control of Subterranean Termites (Isoptera: Rhinotermitidae) Infesting Power Poles

A trial was conducted to determine the efficacy of termiticidal dusts (arsenic trioxide, triflumuron, and Metarhizium anisopliae), a timber fumigant (dazomet) and liquid termiticides (bifenthrin, chlorfenapyr, chlorpyrifos, fipronil, and imidacloprid) for controlling subterranean termites (Isoptera: Rhinotermitidae) infesting in-service power poles in New South Wales, Australia. Dusts were applied to parts of the pole where termites were present. Fumigant was inserted into holes drilled into the base of the pole. Liquid termiticides were mixed with soil around the base of the pole and injected into internal voids if present. Poles were inspected for up to 5 yr, and the time taken for reinfestation to occur was recorded. Before the start of the trial, the major Australian pole owners were surveyed to obtain an estimate of the annual national cost of termite infestation to the power supply industry. The annual costs of termite treatment and replacing damaged poles were estimated at AU$2 million and AU$13 million, respectively. Infestation rates were lower for all treatments compared with controls within the first 12 mo of the study. Dazomet, arsenic trioxide, fipronil, and chlorpyrifos were the most efficacious treatments. Efficacy was positively related to the amount of termiticide applied and negatively related to the infestation severity but was unaffected by geographical location. Survival curves were calculated of the time elapsed before the recurrence of termite infestations (survival absence of reinfestation). Survival was highest for poles treated with liquid termiticides.

Bioavailability of Chlorantraniliprole and Indoxacarb to Eastern Subterranean Termites (Isoptera: Rhinotermitidae) in Various Soils

A laboratory study was conducted to determine the toxicity of indoxacarb and chlorantraniliprole to Eastern subterranean termites, Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae) resulting from topical applications and exposure to treated soil. Soils with varying organic matter (0.57-3.64%) and chemical characteristics were used in termiticide bioassays. Lethal dose resulting from topical application indicated that chlorantraniliprole was two- to 11-fold more toxic than indoxacarb. Lethal concentration assays yielded opposite results where concentrations of indoxacarb in soil that caused either 50 or 90% mortality of R. flavipes workers at 48 and 144 h were two- to six-fold lower than chlorantraniliprole. The bioavailability of indoxacarb and chlorantraniliprole was negatively correlated with soil organic matter. Our results suggest that indoxacarb is more bioavailable to termites in soil than chlorantraniliprole based on calculated bioavailability ratios. However, how these laboratory results correlate to actual field application data and termite efficacy is unknown, and more research is needed. These compounds seem to have excellent activity on termites and have potential to provide new modes of action and new chemistry as liquid termiticides.

Degradation of Fipronil (Termidor®) in Aqueous Solution Stored in Polyethylene Tanks Exposed to Sunlight or Shade

Pest Management Professionals commonly use polyethylene or fiberglass tanks for mixing and applying termiticides. We investigated the stability of fipronil (Termidor SC) (0.06%, 0.09% and 0.125% active ingredient) in aqueous solutions stored in polyethylene tanks under sun and shade for 2 week. Chemical analysis of tank-mixed solutions sampled at 0, 24, 48, 72, 168 and 336 h indicated that fipronil remained stable. Our data indicated that polyethylene tanks prevent fipronil from photodegradation and these tanks can be safely used for short term storage (up to 2 week) of liquid termiticides.

VERSATILITY OF BAITS CONTAINING NOVIFLUMURON FOR CONTROL OF STRUCTURAL INFESTATIONS OF FORMOSAN SUBTERRANEAN TERMITES (ISOPTERA: RHINOTERMITIDAE)

Abstract Four buildings (two high-rise condominiums, a single-family residential structure, and a trailer) in Broward and Miami-Dade Counties, Florida, infested with Formosan subterranean termites (FST, Coptotermes fomosanus Shiraki) were treated with baits containing 0.5% wt/wt noviflumuron. Each building represented a challenging treatment scenario for liquid termiticides due to the location of the infestation within the structure and/or occupant refusal to permit pesticide application in termite-infested living and activity areas. Marking of FST by in-situ baiting with blank bait matrix treated with 0.5% wt/wt Neutral Red dye indicated only one FST foraging population infested each building. Two FST infestations were aerial in high-rise condominiums. Noviflumuron baits were applied to two buildings in aboveground stations, one building with in-ground stations, and the remaining building with both station types. All detected FST infestations were eliminated within 71-92 days after first application of n...

Polyethylene barrier impregnated with lambda-cyhalothrin for exclusion of subterranean termites (Isoptera: Rhinotermitidae) from structures.

Polyethylene film impregnated with lambda-cyhalothrin was placed over a sand plot and covered with a concrete slab to allow insecticide movement into the sand for a period of 5.5 yr. Discs of polyethylene film and sand beneath them were sampled annually for 5 yr and at 5.5 yr for bioassay with the Formosan and eastern subterranean termite. Results demonstrated that sufficient quantities of lambda-cyhalothrin were released from the impregnated polyethylene film into adjacent sand to prevent termite penetration. The impregnated film has less environmental impact than conventional liquid termiticides because the insecticide is held in the polymer. Other advantages include its dual function as a construction moisture barrier and ease in verifying its proper installation.