Arthropods of the great indoors: characterizing diversity inside urban and suburban homes

Abstract

Although humans and arthropods have been living and evolving together for all of our history, we know very little about the arthropods we share our homes with apart from major pest groups. Here we surveyed, for the first time, the complete arthropod fauna of the indoor biome in 50 houses (located in and around Raleigh, North Carolina, USA). We discovered high diversity, with a conservative estimate range of 32–211 morphospecies, and 24–128 distinct arthropod families per house. The majority of this indoor diversity (73%) was made up of true flies (Diptera), spiders (Araneae), beetles (Coleoptera), and wasps and kin (Hymenoptera, especially ants: Formicidae). Much of the arthropod diversity within houses did not consist of synanthropic species, but instead included arthropods that were filtered from the surrounding landscape. As such, common pest species were found less frequently than benign species. Some of the most frequently found arthropods in houses, such as gall midges (Cecidomyiidae) and book lice (Liposcelididae), are unfamiliar to the general public despite their ubiquity. These findings present a new understanding of the diversity, prevalence, and distribution of the arthropods in our daily lives. Considering their impact as household pests, disease vectors, generators of allergens, and facilitators of the indoor microbiome, advancing our knowledge of the ecology and evolution of arthropods in homes has major economic and human health implications.

The diversity of arthropods in homes across the United States as determined by environmental DNA analyses

“…Most of these unexpected taxa, however, appear to be associated with homes as highlighted by the fact that many of these same unexpected taxa were also found in homes where arthropod diversity was surveyed using a more traditional approach (Bertone et al . ).…”

“…To determine how the results from our DNA‐based survey compare to results obtained with surveys conducted using traditional sampling and morphology‐based identification methods, we compared our findings with those of a recent study that investigated the arthropods of 50 homes in Raleigh, North Carolina (Bertone et al . ). For these analyses, we focused just on those indoor dust samples collected from 87 North Carolina houses included in this study.…”

“…Arthropods likely represent the majority of these animal species (Bertone et al . ; Leong et al . ).…”

“…Yet, recent in‐depth studies of arthropods in houses in a single city, Raleigh, North Carolina, suggest that these relatively well‐studied species represent a miniscule fraction of household arthropod diversity (Bertone et al . ; Leong et al . ).…”

“…Bertone et al . () found species from an average of 62 arthropod families per home, with many hundreds of morphospecies identified across the fifty homes surveyed. How these arthropods might be distributed within or among cities and geographic regions remains largely undetermined.…”