Host Suitability for Crapemyrtle Bark Scale (Acanthococcus lagerstroemiae) Differed Significantly among Crapemyrtle Species

Abstract

Crapemyrtle bark scale (CMBS, <i>Acanthococcus lagerstroemiae</i>), an invasive polyphagous sap-sucking hemipteran, has spread across 14 states of the United States since 2004. The infestation of CMBS has negatively impacted the flowering of ornamental plants and even the fruiting of some crops. Host identification is critical for determining potential risks in ecosystems and industries and helps develop strategic management. A host confirmation test was performed over 25 weeks using six <i>Lagerstroemia</i> species (<i>L. caudata</i>, <i>L. fauriei</i> 'Kiowa', <i>L. indica</i> 'Dynamite', <i>L. limii</i>, <i>L. speciosa</i>, and <i>L. subcostata</i>) and California loosestrife (<i>Lythrum californicum</i>). The 25-week observations confirmed all tested plants as the hosts. The repeated measures of analysis of variance (ANOVA; Tukey's HSD, α = 0.05) indicated that the average number of CMBS females differed significantly between <i>L. limii</i> and <i>L. speciosa</i>. The highest number of the females observed on <i>L. limii</i> was 576 ± 25 (mean ± SE) at 17 weeks after inoculation (WAI), while the highest number was 57 ± 15 on <i>L. speciosa</i> at 19 WAI. In addition, <i>L. subcostata</i> and <i>L. speciosa</i> had significantly high and low numbers of males, respectively, among the <i>Lagerstroemia</i> species. Our results suggest that <i>L. speciosa</i> could be incorporated in developing new cultivars with low CMBS suitability.