First record of Zeugomantispa virescens (Neuroptera: Mantispidae) associated with egg sacs of Vectius niger (Araneae: Trochantheriidae)

Abstract Mantispidae is a small family of Neuroptera whose larvae are associated with spider egg sacs, where they consume the eggs before pupation. Herein, we report the first record of the mantidfly Zeugomantispa virescens (Rambur, 1842) associated with spiders of the family Trochanteriidae. The association was documented at the São Paulo State University (UNESP), Rio Claro campus, where mantidfly specimens were found inside the egg sacs of Vectius niger (Simon, 1880) beneath the bark of Cenostigma pluviosum Gagnon & G.P. Lewis. A total of 13 egg sacs of the host spider were collected between July and November 2025. Within these egg sacs, we recovered one first-instar larva, three third-instar larvae, and nine pupae of Z . virescens . Mantispinae larvae were identified based on chaetotaxy, whereas pupae and adults were identified through genital morphology. Spiders were identified using external morphology and coloration patterns. Pupae of Z . virescens maintained in the Laboratório de Biodiversidade e Sistemática de Insetos emerged two days after collection. General biological data, along with high-resolution images of the larvae and pupae of Z . virescens and the egg sacs and adults of V . niger , are provided.