Potential of Kaolin-based Particle Film Barriers for Formosan Subterranean Termite (Isoptera: Rhinotermitidae) Control

Authors: Wiltz, Beverly; Woodson, William - Dave; Puterka, Gary

Submitted to: Sociobiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/30/2009
Publication Date: 2/1/2010
Citation: Wiltz, B.A., Woodson, W.D., Puterka, G.J. 2010. Potential of Kaolin-based Particle Film Barriers for Formosan Subterranean Termite (Isoptera: Rhinotermitidae) Control. Sociobiology. 55(2):405-413.

Interpretive Summary: Treatment failure and concern over increasing insecticide usage have led to an interest in developing alternative methods for subterranean termite control. Inert particle film barriers based on the clay mineral kaolin have proven effective against several agricultural pests. We evaluated three particle films, hydrophobic M96-018 and hydrophilic Surround and Surround WP, against Formosan subterranean termites. All three products caused termite mortality when applied directly to the termites as a dust. M96-018 was effective as a barrier when mixed in dry sand. However, Surround and Surround WP were not effective barriers and none of the formulations deterred feeding on coated wood. Particle films were most effective when moisture levels were low, suggesting potential for use in above ground applications, particularly against drywood termites.

Technical Abstract: Effects of three particle film products on Formosan subterranean termites, Coptotermes formosanus Shiraki, were evaluated in feeding, tunneling, and contact assays. The particle films, hydrophobic M96-018 and hydrophilic Surround and Surround WP are based on the inert clay mineral kaolin. In 2-week long no-choice feeding tests, significant mortality occurred only with M96-018-coated wood. When a choice was provided, M96-018 and Surround were consumed at higher rates than untreated wood. Surround WP did not differ from controls in either test. In the tunneling assay termites were given the option of crossing a kaolin-sand mixture to reach an alternate food source. After 3-weeks, rates of 1% and 5% M96-018 provided an effective barrier to Formosan termite tunneling, while termites were not stopped by rates as high as 20% Surround and Surround WP. Dust treatments of all three formulations caused significant increases in mortality within 24 h, with mortality rates ranging from 72.0 – 97.3% within 72 h of treatment. The particle films were most effective when moisture levels were low, suggesting that desiccation was the mechanism for mortality. All particle films showed potential for use in above ground applications while hydrophobic M06-018 has the most potential as a soil barrier to subterranean termites.