Revision of the Mesoamerican species of Calolydella Townsend (Diptera: Tachinidae) and description of twenty-three new species reared from caterpillars in Area de Conservación Guanacaste, northwestern Costa Rica

Abstract. BACKGROUND: Twenty-three new species of the genus Calolydella Townsend, 1927 (Diptera: Tachinidae) are described, all reared from multiple species of wild-caught caterpillars across a wide variety of families (Lepidoptera: Crambidae; Erebidae; Geometridae; Hesperiidae; Lycaenidae; Nymphalidae; Pieridae; Riodinidae; and Sphingidae). All caterpillars were collected within Area de Conservación Guanacaste (ACG), in northwestern Costa Rica. This study provides a concise description of each new species using morphology, life history, molecular data, and photographic documentation. In addition to the new species, we also provide a generic redescription and revised key to species of the genus Calolydella from Central and South America. NEW INFORMATION: The following 23 new species of Calolydella are described by Fleming and Wood: C. adelinamoralesae sp. n., C. alexanderjamesi sp. n., C. argentea sp. n., C. aureofacies sp. n., C. bicolor sp. n., C. bifissus sp. n., C. crocata sp. n., C. destituta sp. n., C. discalis sp. n., C. erasmocoronadoi sp. n., C. felipechavarriai sp. n., C. fredriksjobergi sp. n., C. inflatipalpis sp. n., C. interrupta sp. n., C. nigripalpis sp. n., C. omissa sp. n., C. ordinalis sp. n., C. renemalaisei sp. n., C. susanaroibasae sp. n., C. tanyadapkeyae sp. n., C. tenebrosa sp. n., C. timjamesi sp. n., C. virginiajamesae sp. n. Lydella frugale Curran, 1934 is proposed as a new synonym of Pygophorinia peruviana Townsend, 1927, syn. n., under the combination Calolydella frugale (Curran, 1934), comb. n.