Detection of rhynchophorus palmarum (Coleoptera: Curculionidae) and identification of associated nematodes in South Texas

This study reports a survey conducted to find the South American palm weevil Rhynchophorus palmarum (L.) and the red palm weevil R. ferrugineus (Olivier) (Coleoptera: Curculionidae), 2 invasive species of palm trees. The study was performed in the Rio Grande Valley of south Texas and near the border with Tamaulipas state, Mexico. A total of 40 traps were inspected biweekly from 26 Sep 2011 to 20 Sep 2012 and 4 traps were inspected from 20 Sep 2012 to 4 Sep 2013. To attract R. palmarum and R. ferrugineus, the lures 2-methylhept-5-en-4- ol and 4-methyl-5-nonanol were used, respectively. We used these lures in combination with sugar and the ethyl acetate aggregation kairomone for both species, plus an ethylene glycol kill solution. Two specimens of R. palmarum were found and identified next to a commercial palm plantation on 11 Mar and 5 May 2012 near the city of Alamo, Texas, but no R. ferrugineus was detected during the entire study. Nematodes found in the 2 R. palmarum specimens were dauer juveniles of the order Rhabditida, and in one of these weevils only 1 nematode of an undetermined species within the family Aphelenchoididae was found. It is of great importance that Bursaphelenchus cocophilus Cobb Baujard (Nematoda: Parasitaphelenchinae), the nematode causal agent of coconut red ring disease, was not found within these insects. This is the first detection of R. palmarum in Texas, and the second in the United States.