Author
Alexis E Racelis
alexis.racelis@utrgv.edu
University of Texas Rio Grande Valley
Edinburg, TX
United States (US)
Coauthors
Pushpa Soti, University of Texas Rio Grande Valley, Edinburg, TX, United States
Marco Silguero, University of Texas Rio Grande Valley, Edinburg, TX, United States
Samikshya Subedi, University of Minnesota, United States
Greg LeFoe, Agriculture Victoria, Bundoora, Victoria, Australia
Rupesh Kariyat, University of Arkansas, Fayetteville, AR, United States
Abstract
We present observations from both field and laboratory studies to explore the impact and suitability of both the North American lacebug (Gargaphia arizonica Drake & Carvalho) and Texas false potato beetle (Leptinotarsa texana Schaeffer) as prospective biological control agents for silverleaf nightshade (Solanum elaeagnifoli Cav.; SLN). Data from a reverse-interspersion design common-garden field trial conducted over two years, where SLN was planted alongside two close Solanaceous relatives, eggplant (Solanum melongena L.) and potato (Solanum tuberosum L.), revealed that L. texana fed on eggplant and SLN but was rarely found on potato. G. arizonica was found solely feeding on SLN, except for a single adult observation on eggplant in year 1 (with no observed feeding). In laboratory no-choice experiments, while we found moderate feeding by G. arizonica on both eggplant and potato, survivorship was nil. Feeding damage by G. arizonica was most severe on SLN, where we found foliar damage within five days, progressing from leaf discoloration to partial defoliation, ultimately leading to complete defoliation within 28 days. Although some plants regenerated from rootstocks, lacebug populations re-established simultaneously. While these cumulative observations suggest promising potential of G. arizonica as a biocontrol agent for silverleaf nightshade, we suggest additional studies on the fundamental and realised host range of this insect, especially under differing abiotic conditions.
Keywords
Silverleaf nightshade
lacebug
Texas
Highlights
North American lacebugs show potential as biological control agents for SLN
Caged experiments demonstrate the potential of G. arizonica to reduce fitness of SLN
Reverse-interspersion design can reveal fundamental host range of potential biocontrol agents.