Seasonality of Xyleborus ferrugineus (F.) and other coleopteran borers of pecan trees was determined weekly in 15 ethanol-baited traps in commercial orchards of five counties of northern Coahuila, Mexico, from 2000 to 2004. Simple and inexpensive traps were made of 600-ml plastic water bottles filled with 300 ml of 50% ethanol, which caught as much as 10 times more insects than yellow sticky traps in preliminary observations. The most abundant beetle was X. ferrugineus, with 93% occurring from July to October, suggesting a multivoltinism for this species. Ocurrence of X. ferrugineus from December to May was practically zero, indicating a dormancy of the insect during this period. Abundance of X. ferrugineus was greater in 2000, decreased during 2001–2003, and increased again in 2004. Temperature and rainfall were not associated with these fluctuations. Captures of X. ferrugineus were significantly more abundant in Nava County than in the remaining counties. Other coleopterans caught in the traps less frequently included the buprestids Chrysobothris sp. and Agrilus sp.; the cerambycids Neoclytus acuminatus (F.), Megacyllene caryae (Gahan), Oncideres cingulata (Say), and Saperda sp.; and the bostrichid Xylobiops sp.