New Invasive Leaf Gall-Inducing Wasps Ophelimus cracens sp. nov. and Epichrysocharis burwelli on Eucalypts in Taiwan

We identified two gall-inducing wasp species infesting eucalypts leaves, including an undescribed species, <i>Ophelimus cracens</i> sp. nov., and <i>Epichrysocharis burwelli</i>, which is a new record for Taiwan. The major hosts of <i>O. cracens</i> were <i>Eucalyptus grandis</i>, <i>Eu. urophylla</i>, and <i>Eu. camaldulensis</i> (Myrtaceae)<i>.</i> We observed failed galls of <i>O. cracens</i> at an early stage on <i>Eu. amplifolia</i> and <i>Corymbia maculata</i>. All <i>O. cracens</i> adults discovered on infected leaves were females, and four parasitoid species were identified in samples collected from two cities, three counties, and four municipalities across Taiwan. <i>Epichrysocharis burwelli</i> was exclusively found on <i>C. citriodora</i> in Hsinchu, Nantou, and Tainan Cities. This marks the first record of <i>Ep. burwelli</i> in Asia, accompanied by the identification of one parasitoid species. The adult longevity of adults which emerged from their major hosts, when provided with honey-water solution, was 5.5 days for <i>O. cracens</i> and 5.7 days for <i>Ep. burwelli</i>. Recognizing the potential damage by these wasps on <i>Eucalyptus</i> production areas in the absence of parasitoids, further investigations of their biology and control are warranted.