Recent advances in understanding insect communities in tropical forests have contributed little to our knowledge of large-scale patterns of insect diversity, because incomplete taxonomic knowledge of many tropical species hinders the mapping of their distribution records. This impedes an understanding of global biodiversity patterns and explains why tropical insects are under-represented in conservation biology. Our study of approximately 500 species from three herbivorous guilds feeding on foliage (caterpillars, Lepidoptera), wood (ambrosia beetles, Coleoptera) and fruit (fruitflies, Diptera) found a low rate of change in species composition (beta diversity) across 75,000 square kilometres of contiguous lowland rainforest in Papua New Guinea, as most species were widely distributed. For caterpillars feeding on large plant genera, most species fed on multiple host species, so that even locally restricted plant species did not support endemic herbivores. Large plant genera represented a continuously distributed resource easily colonized by moths and butterflies over hundreds of kilometres. Low beta diversity was also documented in groups with differing host specificity (fruitflies and ambrosia beetles), suggesting that dispersal limitation does not have a substantial role in shaping the distribution of insect species in New Guinea lowland rainforests. Similar patterns of low beta diversity can be expected in other tropical lowland rainforests, as they are typically situated in the extensive low basins of major tropical rivers similar to the Sepik-Ramu region of New Guinea studied here.

Studies were conducted from 2015 to 2018 to evaluate spotted lanternfly (SLF) distribution and developmental suitability of different plant species in the U.S. Tree bands on 283 trees spanning 33 species captured 21,006 SLF in 2 yr. More SLF per tree were trapped on tree-of-heaven Ailanthus altissima (Mill.) Swingle (Sapindales: Simaroubaceae) than on other species, on average, and most adults were captured on tree-of-heaven. Frequency of detection of adult SLF was higher on tree-of-heaven than on other species but was actually equal or lower on tree-of-heaven than on all other species combined for younger SLF stages in 2015. An enclosed choice test between tree-of-heaven and black walnut Juglans nigra L. (Fagales: Juglandaceae) revealed nymphs showed little consistent preference, whereas adults consistently and significantly preferred tree-of-heaven. No-choice field sleeve studies evaluated SLF survivorship on 26 host plant species in 17 families. Ten plant species supported SLF for an average of ≥45 d, with the rest unable to support SLF for >30 d. Eight species were able to support development from first instar to adult: black walnut, chinaberry Melia azedarach L. (Sapindales: Meliaceae), oriental bittersweet Celastrus orbiculatus Thunb. (Celastrales: Celastraceae), tree-of-heaven, hops Humulus lupulus L. (Rosales: Cannabaceae), sawtooth oak Quercus acutissima Carruthers (Fagales: Fagaceae), butternut Juglans cinerea L, and tulip tree Liriodendron tulipifiera L. (Magnoliales: Magnoliaceae). The ability of SLF to develop to adult on hosts other than tree-of-heaven may impact pest management decisions.

Recent DNA barcoding of generalist insect herbivores has revealed complexes of cryptic species within named species. We evaluated the species concept for a common generalist moth occurring in New Guinea and Australia , Homona mermerodes , in light of host plant records and mitochondrial cytochrome c oxidase I haplotype diversity. Genetic divergence among H. mermerodes moths feeding on different host tree species was much lower than among several Homona species. Genetic divergence between haplotypes from New Guinea and Australia was also less than interspecific divergence. Whereas molecular species identification methods may reveal cryptic species in some generalist herbivores, these same methods may confirm polyphagy when identical haplotypes are reared from multiple host plant families. A lectotype for the species is designated, and a summarized bibliography and illustrations including male genitalia are provided for the first time.

The following checklist includes 2,955 species-group names and 553 genus-group names of weevils occurring in the Papuan region. Major islands treated are: Aru, Biak, Bougainville, Manus, Mysol, New Guinea, Salawatti, Trobriand, Waigeo, Woodlark, and Yapen Islands and the islands of the Admiralty, Bismarck, d’Entrecasteaux, and Louisaide Archipelagoes. Maps of the region with historically important collection localities are provided. Entomological expeditions to the region and collections containing significant weevil material are summarized. All available family-group, genusgroup and species-group names are arranged alphabetically for all families of Curculionoidea known from the region. All currently accepted species epithet are annotated with taxonomic references, notes on published distributions, past taxonomic changes, infrasubspecific names, and species-group synonymies. The following nomenclatural changes are proposed: the monotypic genus Neplaxa Casey is a new synonym of Pantoxystus Pascoe; its type species Neplaxa illustratus Casey is a new synonym of Pantoxystus rubricollis (Boisduval). Two subgenera of Neosynaptops, Neosynaptopsis Legalov and Pseudosynaptos Legalov are new synonymies of Euops (Neosynaptops) Voss revised status. Typespecies are designated for 25 genera, changes of rank or status are proposed for 19 taxa, and 88 new combinations are listed in “Nomenclatural changes.”

The Araucaria-associated weevils of the tribe Orthorhinini are reviewed, namely the genera