Species of Diolcogaster parasitize Lepidoptera pests of commercial plants. The diversity of this genus is high, but few species of Diolcogaster have been described. The description of a new Diolcogaster species provides information for the biological control using this insect. This study presents the description and key notes on the biology of a new Diolcogaster parasitoid wasp. This species was reared from a caterpillar of Hypercompe brasiliensis collected after feeding on a Gloxinia perennis plant important to floriculture. Two complementary identification analyzes were performed on Diolcogaster adult bodies. The first was the analyses of its external morphology and the second its molecular analysis (mitochondrial DNA). The morphological analysis defined the insect as a new species of Diolcogaster, named Diolcogaster joanesi sp. nov. A maximum-likelihood (ML) analysis partially confirmed the morphological analysis, placing D. joanesi within a cluster including a previously identified species (Diolcogaster choi) and seven other morphospecies. The proximity of D. joanesi to D. choi is discussed and an updated key for all New World species of the xanthaspis group is provided. Twenty-eight adult wasps were obtained (22 females and six males) out of 50 cocoons which larvae emerged from the caterpillar host. The findings contribute to the broader understanding of Diolcogaster in the Neotropics and its potential for the biological control of lepidopteran defoliators.

Diolcogaster物种寄生商业植物的鳞翅目害虫。该属的多样性很高，但描述的Diolcogaster种类很少。对一种新Diolcogaster物种的描述为利用这种昆虫进行生物防治提供了信息。本研究介绍了一种新的Diolcogaster寄生蜂的生物学描述和要点。该物种是由Hypercompe brasiliensis毛毛虫饲养的，该毛虫是在以对花卉栽培重要的大岩桐植物为食后收集的。对Diolcogaster成虫尸体进行了两次互补的鉴定分析。第一个是外部形态分析，第二个是分子分析（线粒体 DNA）。形态学分析将该昆虫确定为Diolcogaster的一个新种，命名为Diolcogaster joanesi sp。十一月最大似然 (ML) 分析部分证实了形态分析，将D. joanesi置于一个簇中，其中包括先前识别的物种 ( Diolcogaster choi ) 和其他七个形态种。讨论了D. joanesi与D. choi的相似性，并提供了xanthaspis组所有新大陆物种的更新密钥。从毛毛虫寄主中孵出幼虫的 50 个茧中，获得了 28 只成年黄蜂（22 只雌性和 6 只雄性）。这些发现有助于更广泛地了解新热带地区的Diolcogaster及其对鳞翅目落叶昆虫进行生物防治的潜力。