Remarks on Oligotoma saundersii (Westwood, 1837), an invasive species of Embioptera in Brazil

. There are five families of Embioptera recorded in Brazil, namely: Anisembiidae, Archembiidae, Clothodidae, Teratembiidae, and Oligotomidae, the latter represented by Oligotoma saundersii (Westwood, 1837), an invasive species with worldwide distribution. In this work, we provide an update on O. saundersii distribution for three Brazilian states and the first record for Brazilian Amazon and Cerrado biomes. Additionally, we provide photographs of both sexes, a differential diagnosis for other families, and a distribution map with all records of O. saundersii for the country.

Insects of the order Embioptera Shipley, 1904 are popularly known as webspinners, due to their ability to weave silk (Szumik et al. 2019). They are terrestrial, dorsoventrally flattened, slightly sclerotized, and their body length ranges from 4 to 30 mm (Szumik 1999). Embiopterans have unique characteristics, such as modified fore basitarsus with the presence of numerous silk-producing glands and dilated posterior femora (Szumik 2012). The Order has 13 families, 101 genera, and 462 valid species distributed exclusively in warm and temperate areas of the globe (Szumik et al. 2008;Maehr et al. 2022). In Brazil it was recorded 56 species in 21 genera belonging to Anisembiidae, Archembiidae, Clothodidae, Teratembiidae and an invasive species belonging to Oligotomidae (Rafael & Krolow 2023).
Here we add new records for three Brazilian states and update the geographical records map, we also provide a differential diagnosis and photographs that allow a quick identification and distinction of local species.
The specimens used in the present study are housed at the Coleção  (Westwood 1837;Davis 1939). Images were obtained using a Leica MC120 HD digital camera coupled to a Leica M165 C stereomicroscope. Photographs were taken of the body (dorsal and ventral view) head (dorsal and ventral view), wing (anterior and posterior), and terminalia (dorsal and ventral view). Photos and plates were edited with Adobe Photoshop 2021 software, version 22.0.0.35. The geographical distribution map was elaborated with SimpleMappr web software (Shorthouse 2010). In the material examined section two slashes "//" indicate different labels. Anatomical structures are abbreviated as follows: Head: Sm, submentum; Wing: R1, anterior radius; Ma, anterior media; Cu, cubitus; Terminalia: 10Rp1, caudal process of the tenth right hemitergite (10R); LC1, basal left cercus; RC1, basal right cercus; Hp, process of Hypandrium; Lpp, left paraproct; 1°Vfs, rudiments of first valvifers.
Morphological variation: According to other authors the specimens vary in shades of brown (Davis 1939) and length of body, 6.4-9 mm for males and 6.1-12 mm for females (Davis 1939;Ross 1940;Poolprasert 2012).
Discussion: Oligotoma saundersii is the unique species of Oligotomidae registered for Brazil, so this family (and species) can be easily distinguished from other Brazilian families considering that only two of the five families found in Brazil have Ma vein simple (Anisembiidae and Oligotomidae). Of the two families, the tympanic organ is present in the femora of all three legs in Anisembiidae but only on the fore and middle legs in Oligotomidae. Moreover, O. saundersii has a remarkable Hp very elongated tube-shaped with a subapical falciform spine.  Although it is almost impossible to trace the arrival of O. saundersii in Brazil, the first records of this species were made based on species presently considered synomy of O. saundersii. The first in the state of Ceará based on O. rochai and the second in the states of Bahia and Santa Catarina (Davis 1939) based on O. latreillei. With the new records provided in the present work, the species extends its distribution to six states (Fig. 2), making it one of the species with the greatest Brazilian distribution encompassing the biomes of Amazonia, Cerrado (savannah), Caatinga and Atlantic Forest. It is expected that the species occurs throughout Brazil.
Distribution of embiopterans species within the Brazilian territory remains insufficiently known. The present state of knowledge seems to be strongly related to the geographical distribution of collectors/ experts rather than the actual distribution of the taxon. The records presented here highlight differences in the intensity of works carried out in the Brazilian States and makes evident that the collections and researches take place where specialist were or are working currently in the country.  (Westwood, 1837) in Brazil.