Ga110

Seeds were arranged on white plastic dishes and pictures were taken using a Leica Z16apoA microscope. Images were converted to black and white using the ‘‘threshold” function in ImageJ (http://rsbweb.nih.gov/ij/) and seed size was measured using the ‘‘Analyze Particles” function. For seed weight, 30–150 seeds per replicate (three replicates per cross) were weighed with an Ohaus GA110 balance and the total weight was divided by the number of seeds.

Release rates of three different kinds of attractants, including acetoin (AT), ethyl octanoate (EO), and a blend of AT and EO (ratio = 1:1), were measured under controlled conditions in a laboratory fume hood. Each attractant (1 mL) was loaded onto cotton balls held in open micro-centrifuge tubes (1.5 mL, VWR International, Radnor, PA). Fifteen of these micro-centrifuge tubes (N = 5) were suspended on hooks in a fume hood (temperature 20–25 °C, face velocity 129 feet/min). Each tube was weighed using an Ohaus GA110 analytical electronic balance (Pine Brook, NJ) every 24 or 72 h (weekend), and the amount of attractant residue was calculated and recorded over a period of 2 weeks.

An aliquot of 50–80 mg of a neat repellent (DEET or picaridin) was loaded on a tared 10-ml beaker to form a thin layer at the bottom of the beaker with a surface area of approximately 3.8 cm². The amount of repellent was measured accurately with an analytical balance (Ohaus, GA110), which was then zeroed and the total weight recorded. The beaker was placed inside of a 500-ml larger jar prepared with a bed of desiccant (drierite anhydrous, WA Hammond Drierite Company) on the bottom, which was then placed inside an incubator for 24 h at 27 ± 1 °C. The percentage loss by evaporation was calculated by the loss of weight/amount of repellent x 100. Experiments were done in triplicate for each repellent.