Longevity, fertility, and average eggs viability of parthenogenetic females of Cladomorphus phyllinus Gray (Phasmatodea - Phasmatidae) Lucas da Silva Torres 1 , Hugo Alejandro Benítez 2 & Jane Costa 1 1. Instituto Oswaldo Cruz/Fundação Oswaldo Cruz, Rio de Janeiro RJ, Brazil. 2. Universidad Católica del Maule, Talca, Chile. EntomoBrasilis 15: e998 (2022) Abstract. The order Phasmatodea includes insects known as stick insects. In Brazil, few taxonomic, ecological or evolutionary studies have been published in recent years, the reason is related to the few number of researchers dedicated to this particular group. Cladomorphus phyllinus Gray is one of the largest Brazilian insects and perhaps one of the most studied species of Phasmatodea in the country. It is considered as a phytophagous, generalist, and feeds mainly on guava leaves (Psidium guajava), powder-puf (Calliandra sp) or Angico (Piptania sp.). Females of this species reproduce in a sexual and asexual manner, by the production of diploid daughters from unfertilized eggs (thelytokous parthenogenesis). The absence of records on the reproductive capacity of virgin parthenogenetic females of C. phyllinus led us to record the longevity, fertility, and eggs viability of ten specimens. The results obtained were compared to those found in the scientifc literature for mated females of the same species. The fertility and eggs viability were observed to be much lower for the parthenogenetic females when compared to the mated females; however, the longevity for virgin females was longer than that recorded in the literature for mated females. Keywords: Bionomy; Phasmida; Stick animals; stick insect. Stick insects, from the order Phasmatodea, are the largest Brazilian insects, which present multiple forms of morphological and behavioral camoufage like sticks and leaves, including 3,423 species, of which 852 occur in the neotropical region, with 224 being recorded in Brazil (Brock et al. 2021; crispino et al. 2021). Due to the few Brazilian specialists in Phasmatodea, studies related to taxonomy, biology, ecology, and evolution have grown and new initiatives have emerged to contribute to the knowledge of this order and its state of the art (costa et al. 2019; chiquetto-Machado et al. 2020; heleodoro & rafael 2020, 2021; Madeira-ott et al. 2020; chiquetto-Machado & cancello 2021; Ghirotto 2021; heleodoro et al. 2021). In this group, which includes insects that have been poorly studied, the information available to researchers and the general population is also restricted. As result of the lack of knowledge, specimens of stick insects are often eliminated when found near residences. Nevertheless, scientifc dissemination initiatives have been carried out to inform that phasmatodeans are harmless and, therefore, must be protected, respected and, if possible, reintroduced into the environment when eventually found inside or around the houses (GoMes et al. 2010). In this line of scientifc dissemination, torres & costa (2019, 2020) published educational books presenting the insects as fun characters to bring young audiences closer to biodiversity. Another channel of information about this group to the general population is the “Ciência Cidadã from the “Projeto Phasma” (Citizen Science of the Phasma Project), which can be accessed on social networks, with various information and photographic records of the diferent Brazilian species. This project, which has been launched over a year, has even resulted in the publication of some studies (see the results of the project here: https://www.facebook.com/projetophasma). In Brazil, published records for stick insects are mainly distributed in the North (Pará, Amazonas), Northeast (Ceará, Bahia, Pernambuco, Rio Grande do Norte), Southeast (Espírito Santo, Minas Gerais, São Paulo, Rio de Janeiro) and South (Rio Grande do Sul, Paraná) (heleodoro & rafael 2021). They are considered animals of low biotic potential and, to date, few records in the literature categorize Phasmatodeans as a Brazilian agricultural pests or as animals of economic importance. However, some species have been considered harmful to agriculture. Baker (2015) provides a summary of the situation of damage caused by Phasmas in some parts of the world. Cladomorphus phyllinus (Phasmatidae: Cladomorphinae: Cladomorphini) is one of the most common and known stick insect species in Brazil, since it is often found in scientifc collections, museums, schools, and universities for educational purposes. The studied species feeds mainly on guava leaves (Psidium guajava), Angico (Piptania sp.) and powder-puf (Calliandra sp.), has nocturnal habits, and reproduces sexually and Edited by: Alberto Moreira Silva-Neto Article History: Received: 11.ii.2022 First Answer: 11.iv.2022 Accepted: 16.v.2022 Published: 28.vii.2022  Corresponding author: Jane Margaret Costa de Werneck  janecostabio@gmail.com Funding agencies:  Conselho Nacional de Desenvolvimento Científco e Tecnológico (CNPq) doi: 10.12741/ebrasilis.v15.e998 © The Author(s) 2022. Published by Entomologistas do Brasil This article is published by Entomologistas do Brasil and licensed under Creative Commons Licence 4.0 (CC-BY) Article Full Open Access Bionomy and Behavior EntomoBrasilis | 15: e998 (2022) 1 | 4