In Overton, Texas, we’re about done tying up crapemyrtles, getting them on drip irrigation, and starting pre-assessments. We have a total of 100 standard (Queen’s Lace) and 100 dwarf (Pocomoke) cultivars, all highly infested with crapemyrtle bark scale, for our research trial. Before deciding what insecticides and timing of applications we would try, we had to summarize some of our past results. All of our past work on crapemyrtle bark scale insecticide trials are available through Arthropod Management Tests (https://academic.oup.com/amt and search for “crapemyrtle bark scale”). If you’re feeling a bit intimidated by the papers in Arthropod Management Tests, I made a short video tutorial walking through some of the jargon used in insecticide efficacy work. The following table is based on data from our Overton Center:
|Talstar + Safari||Bifenthrin + Dinotefuran||3A + 4A||Bark Spray + Drench||2 & 1||Great|
|Mallet||Imidacloprid||4A||Drench||1||Moderate - Good|
|Grandevo & Venerate||Chromobacterium subtsugae strain PRAA4-1 & Burkholderia spp. strain A396||N/A||Bark Spray||2 & 2||Poor|
|SuffOil-X + Molt-X||Mineral oil + Azadirachtin||UNE + UN||Bark Spray||2||Poor|
|Velifer||Beauveria bassiana PPRI 5339||UNF||Bark Spray||2||In Progress|
|Xxpire||Spinetoram & Sulfoxaflor||5 + 4C||Bark Spray||2||In Progress|
|Ventigra||Afidopyropen||9D||Bark Spray||2||In Progress|
|Pradia||Cyclaniliprole + Flonicamid||28 + 29||Bark Spray||2||Inconclusive|
Table last update July 8, 2020.
We’re going to be testing some of the products that were considered “inconclusive” in our past trials, due to the untreated check having highly variable numbers of crapemyrtle bark scale, as well as test different timing of insecticide applications. I’ll provide updates here and on my social media (sixleggedaggie) as we move forward with the trial. I have posted a video about our trial as well, in case you’d like to learn more about he design and evaluation in our insecticide trials.
- Vafaie, E. & Gu, M. 2019. Insecticidal Control of Crapemyrtle Bark Scale on Potted Crapemyrtles, Fall 2018. Arthropod Management Tests, 44: tsz061.
- Vafaie, E. 2019. Bark and Systemic Insecticidal Control of Acanthococcus (=Eriococcus) lagerstroemiae (Hemiptera: Eriococcidae) on Potted Crapemyrtles, 2017. Arthropod Management Tests, 44: tsy109
- Vafaie, E & Knight, C. 2017. Bark and Systemic Insecticidal Control of Acanthococcus (=Eriococcus) lagerstroemiae (Crapemyrtle Bark Scale) on Landscape Crapemyrtles, 2016. Arthropod Management Tests, 42: tsx130.