Flight Activity of Cyrtobagous salviniae Calder and Sands1 in Louisiana

• Published in: The Southwestern entomologist Vol. 41; no. 2; pp. 313 - 320
• Main Authors: Micinski, S, Fitzpatrick, B. J, Ferro, M. L, Johnson, S. J, Johnson, B, Williams, S
• Format: Journal Article
• Language: English
• Published: Society of Southwestern Entomologists 01.06.2016
• ISSN: 0147-1724; 2162-2647
• DOI: 10.3958/059.041.0207

Little is known of and no flight activity has been documented for the salvinia weevil, Cyrtobagous salviniae Calder and Sands, in the United States. A bucket-type blacklight was used to determine the flight activity of the salvinia weevil in Louisiana from 2013–2015. One trap was operated during summer and early fall 2013 at the LSU AgCenter weevil rearing facility at Houma, LA. Number of weevils captured in the trap ranged from 30 (18 July) to zero (11 September). Weevils per kilogram of salvinia from the adjacent pond ranged from 9.1 (15 August) to 41.5 (8 October). Another trap was run on Cross Lake at Shreveport, LA, during 2013–2015 in conjunction with weevil releases for biological control of giant salvinia, Salvinia molesta Mitchell. During 2013, nine and six weevils were captured in the light trap on 11 and 18 September, respectively. No weevils were captured in the light trap in 2014 because of the late release of weevils in August. During 2015, weevils captured in the trap ranged from eight (week ending 1 July) to a peak of 29 weevils for the week ending 30 July. Weevils per kilogram of salvinia increased from 7.2 (27 May) to 28.4 (2 September). Weevil flight activity might occur almost continuously when abundance and nighttime temperatures are sufficiently warm. Peak flight activity, as indicated by captures in light traps, occurred mid- to late-July. More research is needed on the factors influencing weevil flight activity, duration, and distance.