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

Abstract

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