Optimization of 13-tetradecenyl acetate sex pheromone for trapping Melanotus communis (Coleoptera: Elateridae)

Corn wireworm, Melanotus communis Gyllenhal (Coleoptera: Elateridae), is an economically important larval pest of root and tuber crops in the United States. Previous work to estimate field-level abundance of M. communis has focused on grain-based larval baits placed in soil. However, this sampling method is labor intensive and may not estimate population size accurately. Recent discovery of the M. communis sex pheromone, 13-tetradecenyl acetate, provides a new method to monitor this pest during the adult stage. Early studies with this pheromone showed that different trapping methods might enhance catch and improve trap servicing. We hypothesized that placing lures on elevated traps would increase M. communis capture relative to the in-ground pitfall trapping that is currently used. We had 2 objectives for this study: (a) to compare pheromone captures among in-ground pitfall traps, on-ground pitfalls, elevated pitfalls (1 m), or elevated sticky cards (1 m) and (b) test lure longevity by aging the lures outdoors at 8-, 6-, 4-, 2-, and 0-wk intervals prior to trap deployment in the field. Experiments were conducted in North Carolina, Virginia, South Carolina, and Florida during the 2021 and 2022 field seasons. Results highlight large variation in M. communis abundance across the 4 states. We showed that 1 m elevated pheromone traps caught the most beetles. The age of the lure prior to deployment had a significant effect on trap catch. The lures that were aged for fewer weeks attracted significantly more beetles, with 0- and 2-wk-old lures capturing the greatest numbers.

Inkjet Printed Textile Force Sensitive Resistors for Wearable and Healthcare Devices

Pressure sensors for wearable healthcare devices, particularly force sensitive resistors (FSRs) are widely used to monitor physiological signals and human motions. However, current FSRs are not suitable for integration into wearable platforms. This work presents a novel technique for developing textile FSRs (TFSRs) using a combination of inkjet printing of metal-organic decomposition silver inks and heat pressing for facile integration into textiles. The insulating void by a thermoplastic polyurethane (TPU) membrane between the top and bottom textile electrodes creates an architectured piezoresistive structure. The structure functions as a simple logic switch where under a threshold pressure the electrodes make contact to create conductive paths (on-state) and without pressure return to the prior insulated condition (off-state). The TFSR can be controlled by arranging the number of layers and hole diameters of the TPU spacer to specify a wide range of activation pressures from 4.9 kPa to 7.1 MPa. For a use-case scenario in wearable healthcare technologies, the TFSR connected with a readout circuit and a mobile app shows highly stable signal acquisition from finger movement. According to the on/off state of the TFSR with LED bulbs by different weights, it can be utilized as a textile switch showing tactile feedback.