Larval taxonomy of caddisflies (Trichoptera) lags behind that of adults. Taxonomic knowledge of Nearctic representatives of Polycentropus Curtis, 1835 (Polycentropodidae) is particularly poorly resolved with the larva of only one of 30 species described and with no western Nearctic larvae known. Herein, the late-instar larvae of four of seven western Nearctic Polycentropus species are described and figured for the first time. A diagnostic matrix to assist in their identification is provided, new state records are reported, and previous records clarified. Issues regarding existing keys for larval Polycentropus sensu lato (i.e., Holocentropus McLachlan, 1878, Plectrocnemia Stephens, 1836, and Polycentropus) are discussed in light of new findings.

Longileptoneta luokengensis, sp. nov., is described from Guangdong, China. Longileptoneta monodactyla (Yin, Wang & Wang, 1984), comb. nov., is transferred from Falcileptoneta Komatsu, 1970. The distribution of Longileptoneta is expanded into southwestern China. Detailed descriptions and illustrations of Longileptoneta luokengensis, sp. nov. are provided.

True flies (Diptera) are a hyper-diverse group of insects which are considerably under-studied compared to many other organisms. Here we report a list of taxa collected during the 2019 Fly School held in San Luis Obispo County, California, a region of the California Floristic Province biodiversity hotspot. From June 20th to July 6th, an international team of 35 entomologists collected and identified Diptera at 17 main sites across the county. The team identified a total of 68 families, 188 genera, and 133 species/species groups. Of these, we uncovered 21 potential new county records for California, expanding knowledge of geographic distributions for these taxa. We discuss the strengths and limitations of this list and suggest ideas for streamlining the publication of similar lists for other specialized taxonomic workshops.

Based on the differentiating external and genital characters of fundamental significance the subgenus Kubaniellus Kalashian 1997 is formally elevated to the generic rank; two new species of the genus Kubaniellus stat. nov. from China are described and illustrated: K. latipennis sp. nov. from Fujian province and K. olivaceus sp. nov. from Guangxi province.

A new species of Earomyia Zetterstedt, 1842, namely E. melnickae sp. nov., is described from Montana, U.S.A. The new species is compared with other Nearctic Earomyia species, and its association with a highly toxic plant Toxicoscordion venenosum (S. Watson) Rydb. (Melanthiaceae) is discussed.

Examination of museum records indicate that 358 species of Trichoptera belonging to 83 genera and 20 families have been collected in California. The families Limnephilidae and Rhyacophilidae exhibited the greatest richness. Museums holding species records from California are listed, which enables localities to be obtained digitally or through museum contacts. Far more digital records for Trichoptera are available from statewide, water-quality monitoring programs than from museums, but identifications are typically made at the generic level where metrics describing pollution tolerance are less valuable than when at the species level. Increased numbers of larval-adult associations may result when researchers can use these museum records to involve volunteer community scientists in making targeted collections to provide specimens for rearing, metamorphotypes, or molecular analysis. This approach could enhance both water quality monitoring and community ecology studies of Trichoptera and other aquatic insects.

There was a significant negative relationship between the density of Umbonia crassicornis (Amyot & Serville, 1843) aggregations and the average length of the newest growth on its host plant, Lysiloma latisiliquum Benth. (Fabaceae). There was also a significant negative relationship between aggregation size and the dry mass of the teneral adults of both sexes. Teneral female U. crassicornis were significantly longer and had a significantly greater dry mass than their male siblings. I suggest that feeding by treehopper nymphs reduces the nutrient pool of the host plant, resulting in reduced plant and treehopper growth.