The eucoiline genus Zaeucoila Ashmead is revised. Following a reevaluation combining previously published phylogenetic data and new specimens, Agrostocynips Díaz is synonymized with Zaeucoila. All species included in Zaeucoila are systematically treated, and now amounts to twelve, seven of which are described as new here: Zaeucoila bitiburculata new species, Z. fidalgoii new species, Z. infuscata new species, Z. johnsonii new species, Z. lignys new species, Z. normae new species, Z. patera new species. The following new combinations are proposed and species redescribed: Zaeucoila grenadensis (Ashmead), new combination; Z. robusta (Ashmead), new combination; Z. flavipes (Ashmead), new combination. Agrostocynips diastrophi (Ashmead), Agrostocynips clavatus Díaz, and Agrostocynips enneatoma (Díaz) are new synonyms of Zaeucoila robusta. Zaeucoila incompleta (Kieffer), Z. triangulifera Kieffer, and Z. unicarinata Ashmead are redescribed. Zaeucoila is an unusual genus of Zaeucoilini in its wide distribution area: it can be found from southern Argentina well into the eastern United States and southern Canada; no other zaeucoiline genus shows such a pattern. Host records and geographic data for Zaeucoila are brought up to date, as well as a key to species. Zeucoila are primary parasitoids of Agromyzidae, including Liriomyza trifolii and other species that are notable economic pests of agriculture. Tropideucoila fulvonotata (Kieffer) is transferred to Marthiella (new combination).

The new plant bug Eccritotarsus eichhorniae is described from specimens taken on water hyacinth, Eichhornia crassipes, in Maynas Province, Peru. This new species is extremely similar to Eccritotarsus catarinensis (Carvalho), a species described from Santa Catarina, Brazil. These two populations were considered conspecific until COI sequencing data and breeding studies indicated that the Peruvian material probably represented a new cryptic species. Subsequent morphological studies confirmed that two species were involved. In this paper diagnoses, descriptions, and illustrations of the adults, scent glands, and male genitalia are provided to distinguish these two closely related species, both of which are currently being used as biocontrol agents on water hyacinth in South Africa.

The East Asian buprestid Agrilus smaragdifrons Ganglbauer is reported for the first time in the Western Hemisphere. Specimens of this species taken from emerald ash borer (A. planipennis Fairmaire) monitoring traps in New Jersey in 2015–2016 suggest establishment of this metallic wood-boring beetle in the northeastern United States. The earliest known record of A. smaragdifrons in the U.S. is based on a verifiable image found on BugGuide, from a specimen collected in Hudson County, New Jersey in June 2011. Diagnostic information and high-resolution images of the adult male, female, and the male aedeagus are provided to help facilitate the recognition of this adventive buprestid from other North American Agrilus. A summary of information about the host plant (Ailanthus altissima), native distribution, and biology are given, and all known North American records are listed and mapped.

Valdiviomyia pucara new species is described from Neuquén Province, Argentina. A description of the new species is provided, as is a key for identifying the species of the genus. Type material of all known species, i.e. V. camrasi (Sedman), V. darwini (Shannon), V. edwardsi (Shannon and Aubertin), V. nigra (Shannon), V. ruficauda (Shannon), and holotype of Ocyptamus albimanus Bigot [=V. valdiviana (Philippi)], was studied. Morphological characters of the genus and the subgeneric groupings are discussed.

We describe and illustrate four new species of Struthoscelis: S. christianafigueresae new species, from Costa Rica; S. davisorum new species, from Costa Rica; S. konia new species, from Peru; and S. solamarita new species, from Venezuela. We report the first known biology for a species of Struthoscelis and revisit the generic diagnosis based on newly discovered morphology including a novel structure in the male forewing. We provide comparative illustrations of all new species and of the male genitalia of S. semiotarsa Meyrick, 1916.

Nematus spiraeae Zaddach, a European sawfly that feeds on Aruncus diocus (Walter) Fernald (Rosaceae), was discovered in Quebec. This probable introduction is the first report of N. spiraeae in North America and the first record of a sawfly feeding on Aruncus in North America. A diagnosis and some life history notes are given for N. spiraeae.

Astudy of insects associated with the guarumo de pava tree, Pourouma bicolor Martius (Urticaceae), in Panama resulted in the discovery of a new phycitine moth genus and species, Vorapourouma basseti, new genus, new species (Lepidoptera: Pyralidae), described herein. The immatures were collected by beating vegetation using the Fort Sherman Canopy Crane in Panama, and subsequently reared in the laboratory. Although a number of Lepidoptera have been recorded to feed on Pourouma, this is the first pyraloid recorded from this host plant.

Siamusotima disrupta Solis, n. sp., is a stem-boring musotimine from China. It was discovered in the stems of several Lygodium Sw. species (Lygodiaceae) during exploration for biological control agents of Lygodium microphyllum (Cav.) R. Br., the Old World climbing fern. This is the second report of a stem-boring pyraloid larva with a unique, cup-like modification of the anal segment. The larval morphology of S. disrupta is compared with that of the previously described S. aranea Solis and Yen. Observations on life history are presented; the adult has not been captured in the wild.

Three species of the aulacid genus Pristaulacus Kieffer are now known from the Philippines: P. erythrocephalus Cameron, P. bakeri, n. sp., and P. sibuyan, n. sp. The species are described and illustrated and a key is given for their separation. Two species of Pristaulacus were previously known from Borneo, both from the northern Malaysian state of Sarawak: P. erythrocephalus and P. fasciatipennis (Cameron). Additional records are given for these species, and P. iridipennis (Cameron) is newly recorded from Borneo (Malaysia: Sabah). Pristaulacus erythrocephalus is also recorded from the Malaysian Peninsula (Pahang).

Florida, Georgia, and Texas are the only previous records for the mainly Neotropical shield bug Symphylus caribbeanus Kirkaldy in the United States. The record for Georgia, however, is based on a misidentification of Stethaulax marmoratus (Say). The first valid record for Georgia and first record for South Carolina extend the distribution of Sy. caribbeanus based on recent collecting; new state records based on museum specimens are Alabama, Mississippi and North Carolina. Nymphs and adults were observed in South Carolina on fruits of yaupon (Ilex vomitoria; Aquifoliaceae) and in Florida on fruits of Brazilian peppertree (Schinus terebinthifolius; Anacardiaceae); an adult was taken in Georgia on fruits of wax myrtle (Morella cerifera; Myricaceae). Most previously recorded plant associations might not be true hosts that support nymphal development. Although the relatively late report of Sy. caribbeanus from the United States (1914 in Florida) suggests an adventive status, this scutellerid might be a native, but long unrecognized species of the Floridian fauna. The later report from southern Texas (1977) might represent range expansion from northern Mexico. Images of nymphs (instars IV, V) and adults of the color morphs observed in South Carolina are presented.

Vanduzea triguttata (Burmeister) is a wide-ranging, mainly North American membracid (Smiliinae: Amastrini) whose bionomics remain little known. Fieldwork in the Nebraska Sandhills indicated that this treehopper develops on leadplant, Amorpha canescens (Fabaceae). Its ant-attended aggregations, involving four species of Formica, were observed at 18 sites in nine counties. The treehopper was at least bivoltine; first-generation adults developed in late June to early July and second-generation adults were found as late as early October. Previously recorded hosts, certain composites (Asteraceae) and legumes (Fabaceae), are reviewed. Plants likely to support nymphal development (true hosts) are distinguished from those that probably are used only for food or shelter by adults, or represent incidental occurrences. Characters of the forewing that proved useful in differentiating Nebraska specimens of V. triguttata from the morphologically similar, black locust-feeding V. arquata (Say) are presented. Vanduzea vestita Goding is proposed as a synonym of V. arquata rather than a synonym of V. triguttata.