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Abstract Understanding causes of insect population declines is essential for the development of successful conservation plans, but data limitations restrict assessment across spatial and temporal scales. Museum records represent a source of historical data that can be leveraged to investigate temporal trends in insect communities. Native lady beetle decline has been attributed to competition with established alien species and landscape change, but the relative importance of these drivers is difficult to measure with short‐term field‐based studies. We assessed distribution patterns for native lady beetles over 12 decades using museum records, and evaluated the relative importance of alien species and landscape change as factors contributing to changes in communities. We compiled occurrence records for 28 lady beetle species collected in Ohio, USA, from 1900 to 2018. Taxonomic beta‐diversity was used to evaluate changes in lady beetle community composition over time. To evaluate the relative influence of temporal, spatial, landscape, and community factors on the captures of native species, we constructed negative binomial generalized additive models. We report evidence of declines in captures for several native species. Importantly, the timing, severity, and drivers of these documented declines were species‐specific. Land cover change was associated with declines in captures, particularly forCoccinella novemnotatawhich declined prior to the arrival of alien species. Following the establishment and spread of alien lady beetles, processes of species loss/gain and turnover shifted communities toward the dominance of a few alien species beginning in the 1980s. Because factors associated with declines in captures were highly species‐specific, this emphasizes that mechanisms driving population losses cannot be generalized even among closely related native species. These findings also indicate the importance of museum holdings and the analysis of species‐level data when studying temporal trends in insect populations. 

Cities are generally hotter than surrounding rural areas due to the Urban Heat Island (UHI) effect. These increases in temperature advance plant and animal phenology, development, and reproduction in the spring. However, research determining how increased temperatures affect the seasonal physiology of animals in the fall has been limited. The Northern house mosquito, Culex pipiens, is abundant in cities and transmits several pathogens including West Nile virus. Females of this species enter a state of developmental arrest, or reproductive diapause, in response to short days and low temperatures during autumn. Diapausing females halt reproduction and blood-feeding, and instead accumulate fat and seek sheltered overwintering sites. We found that exposure to increased temperatures in the lab that mimic the UHI effect induced ovarian development and blood-feeding, and that females exposed to these temperatures were as fecund as non-diapausing mosquitoes. We also found that females exposed to higher temperatures had lower survival rates in winter-like conditions, despite having accumulated equivalent lipid reserves relative to their diapausing congeners. These data suggest that urban warming may inhibit diapause initiation in the autumn, thereby extending the active biting season of temperate mosquitoes.