J Appl Entomol. 2019;143:95–104. wileyonlinelibrary.com/journal/jen | 95 © 2018 Blackwell Verlag GmbH 1 | INTRODUCTION The key tortricid pests of temperate tree fruit crops have been monitored with an array of trap designs baited with sex phero- mones for >45 years (Beroza, Gentry, Blythe, & Muschik, 1973; Butt & Hathaway, 1966). These various trap types have almost exclusively used liners coated with sticky polybutene adhesives characterized here as a sticky gel (SG; Howell, 1972; Knight, Larson, & Christianson, 2002; Madsen & Madsen, 1980; McNally & Barnes, 1980). More recently, liners coated with hot-melt pressure sensi- tive (HMPS) adhesives have become available, and have been used in various trapping studies with moths (Jordan, Zhang, & Pfeiffer, Received: 22 March 2018 | Revised: 23 July 2018 | Accepted: 9 August 2018 DOI: 10.1111/jen.12564 ORIGINAL CONTRIBUTION Importance of trap liner adhesive selection for male moth catch (Lepidoptera: Tortricidae) with bisexual attractants Alan L. Knight 1 | William Stewart 1 | Esteban Basoalto 2 1 USDA, Agricultural Research Service, Wapato, Washington 2 Instituto de Producción y Sanidad Vegetal, Facultad de Ciencias Agrarias, Universidad Austral de Chile, Valdivia, Chile Correspondence Alan L. Knight, USDA, Agricultural Research Service, Wapato, WA. Email: alan.knight@ars.usda.gov Funding information Washington Tree Fruit Research Commission Abstract Studies compared moth captures of three pests (Lepidoptera: Tortricidae) of apple, Malus domestica Borkhausen, in delta traps using removable liners coated with either a sticky gel (SG) or a hot-melt pressure sensitive (HMPS) adhesive. Laboratory and field studies with Cydia pomonella (L.), Choristoneura rosaceana (Harris) and Grapholita molesta (Busck) demonstrated that traps with either liner, baited with a pair of virgin females catch males, but at significantly different levels. In the field, male moth cap- tures in traps with the HMPS liner were significantly greater than in traps with the SG liner for C. rosaceana, and G. molesta; but not for C. pomonella. Similar results were observed in laboratory studies using flight tunnels. Additional studies demonstrated that this difference in moth captures between liners was not due to levels of female mortality, but instead was correlated with the occurrence of the female’s ventral ab- dominal surface becoming stuck in the adhesive. Studies showed that a significantly greater proportion of females of all species had their ventral abdomen stuck in the SG than HPMS adhesive on day 1, but only G. molesta and C. rosaceana on day 3. In addition, the tackiness of the two adhesives affected moth movement on the liner with males and females of all species moving farther on liners with SG than HMPS adhesive. A greater proportion of female G. molesta and C. pomonella were either stuck supined or laterally on the SG than HMPS adhesive, and females in this position captured as many males as when prone and unstuck on the liner. Our studies demon- strate that adhesives can secondarily influence male moth captures on trap liners when used with bisexual attractants, and that adhesive type should be considered when developing action thresholds. KEYWORDS Choristoneura rosaceana, codling moth, Cydia pomonella, Grapholita molesta, obliquebanded leafroller, oriental fruit moth This artcle has been contributed to by US Government employees and their work is in the public domain in the USA