Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/23/2013
Publication Date: 12/1/2013
Citation: Esparza-Díaz, G., Olguin, A., Carta, L.K., Skantar, A.M., Villanueva, R.T. 2013. Detection of Rhynchophorus palmarum (Coleoptera: Curculionidae) and identification of associated nematodes in south Texas. Florida Entomologist. 96(4):1513-1531. Interpretive Summary: Invasive species cost billions of dollars to U.S. farmers and homeowners every year, and surveys are critical to detect their early appearance in a new location. Detection of invasive insect species and any associated nematodes is important to prevent the spread of South American palm weevils and red ring nematodes that kill palm trees. Therefore, a biweekly survey for the presence of palm weevils and weevil-carried nematodes was conducted for one year by researchers from Texas A&M University and APHIS. Two South American palm weevils were discovered and identified from survey traps; although ARS scientists found various nematodes associated with these insects, no red ring nematodes were identified. The results are significant because they provide the first discovery of South American palm weevils in Texas and the second in the United States. This research will be used by regulators and others to increase and refine surveillance efforts to protect ornamental and cultivated palms in the U.S.
Technical Abstract: 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), two invasive species of palm trees. The study was performed in the Rio Grande Valley of south Texas and near the borderline of Tamaulipas state in Mexico. A total of 40 traps were inspected biweekly from 26 September 2011 to 20 September 2012. 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 lures in combination with sugar and 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 March and 5 May 2012 near the city of Alamo, TX; no R. ferrugineus were found throughout the entire duration of the study. Nematodes found in R. palmarum were dauer juveniles of Rhabditida, and undetermined species within the family Aphelenchoididae. It is of great importance that Bursaphelenchus cocophilus, 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.