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The European honey bee, Apis mellifera L., is the single most valuable managed pollinator in the world. Poor colony health or unusually high colony losses of managed honey bees result from a myriad of stressors, which are more harmful in combination. Climate change is expected to accentuate the effects of these stressors, but the physiological and behavioral responses of honey bees to elevated temperatures while under simultaneous influence of one or more stressors remain largely unknown. Here we test the hypothesis that exposure to acute, sublethal doses of neonicotinoid insecticides reduce thermal tolerance in honey bees. We administered to bees oral doses of imidacloprid and acetamiprid at 1/5, 1/20, and 1/100 of LD 50 and measured their heat tolerance 4 h post-feeding, using both dynamic and static protocols. Contrary to our expectations, acute exposure to sublethal doses of both insecticides resulted in higher thermal tolerance and greater survival rates of bees. Bees that ingested the higher doses of insecticides displayed a critical thermal maximum from 2 ˚C to 5 ˚C greater than that of the control group, and 67%–87% reduction in mortality. Our study suggests a resilience of honey bees to high temperatures when other stressors are present, which is consistent with studies in other insects. We discuss the implications of these results and hypothesize that this compensatory effect is likely due to induction of heat shock proteins by the insecticides, which provides temporary protection from elevated temperatures.

Apicomplexa are ancient and diverse organisms which have been poorly characterized by modern genomics. To better understand the evolution and diversity of these single-celled eukaryotes, we sequenced the genome of Ophryocystis elektroscirrha , a parasite of monarch butterflies, Danaus plexippus . We contextualize our newly generated resources within apicomplexan genomics before answering longstanding questions specific to this host-parasite system. To start, the genome is miniscule, totaling only 9 million bases and containing fewer than 3,000 genes, half the gene content of two other sequenced invertebrate-infecting apicomplexans, Porospora gigantea and Gregarina niphandrodes . We found that O. elektroscirrha shares different orthologs with each sequenced relative, suggesting the true set of universally conserved apicomplexan genes is very small indeed. Next, we show that sequencing data from other potential host butterflies can be used to diagnose infection status as well as to study diversity of parasite sequences. We recovered a similarly sized parasite genome from another butterfly, Danaus chrysippus , that was highly diverged from the O. elektroscirrha reference, possibly representing a distinct species. Using these two new genomes, we investigated potential evolutionary response by parasites to toxic phytochemicals their hosts ingest and sequester. Monarch butterflies are well-known to tolerate toxic cardenolides thanks to changes in the sequence of their Type II ATPase sodium pumps. We show that Ophryocystis completely lacks Type II or Type 4 sodium pumps, and related proteins PMCA calcium pumps show extreme sequence divergence compared to other Apicomplexa, demonstrating new avenues of research opened by genome sequencing of non-model Apicomplexa.

Apicomplexa are ancient and diverse organisms which have been poorly characterized by modern genomics. To better understand the evolution and diversity of these single-celled eukaryotes, we sequenced the genome of Ophryocystis elektroscirrha, a parasite of monarch butterflies, Danaus plexippus. The genome is miniscule, totaling only 9 million bases and containing fewer than 3,000 genes. We then compared this new sequence to the two other sequenced invertebrate-infecting apicomplexans, Porospora gigantea and Gregarina niphandrodes, which have nearly twice the gene content and found that O. elektroscirrha shares different orthologs with each sequenced relative, suggesting the true set of universally conserved apicomplexan genes is very small indeed. We investigated sequenced reads from other potential hosts to explore the viability of in silico infection screening. We recovered a similarly sized parasite genome from another butterfly, Danaus chrysippus, that was highly diverged from the O. elektroscirrha reference, possibly representing a distinct species. Using these two new genomes, we investigated potential evolutionary response by parasites to toxic phytochemicals their hosts ingest and sequester. Monarch butterflies are well-known to tolerate toxic cardenolides thanks to changes in the sequence of their Type II ATPase sodium pumps. We show that Ophryocystis completely lacks Type II or Type 4 sodium pumps, and related proteins PMCA calcium pumps show extreme sequence divergence compared to other Apicomplexa, demonstrating new avenues of research opened by genome sequencing of non-model Apicomplexa.Competing Interest StatementThe authors have declared no competing interest.

Abstract The European honey bee, Apis mellifera L., is the single most valuable managed pollinator in the world. Poor colony health or unusually high colony losses of managed honey bees result from myriad stressors, which are more harmful in combination. Climate change is expected to accentuate the effects of these stressors, but the physiological and behavioral responses of honey bees to high temperatures while under simultaneous pressure of one or more stressors remains largely unknown. Here we test the hypothesis that exposure to acute, sublethal doses of neonicotinoid insecticides reduce thermal tolerance in honey bees. We administered to bees oral doses of imidacloprid and acetamiprid at 1/5, 1/20, and 1/100 of LD50 and measured their heat tolerance 4 h post-feeding, using both dynamic and static protocols. Contrary to our expectations, acute exposure to sublethal doses of both pesticides resulted in higher thermal tolerance and greater survival rates of bees. Bees that ingested the higher doses of pesticides displayed a critical thermal maximum from 2 °C to 4 °C greater than that of the control group, and a reduction in mortality from 69% to 96%. Our study suggests a resilience of honey bees to high temperatures when other stressors are present, which is consistent with studies in other insects. We discuss the implications of these results and hypothesize that this compensatory effect is likely due to induction of heat shock proteins by the insecticides, which provides temporary protection from extremely high temperatures.

Background Latinos enroll in Alzheimer's disease (AD) clinical trials at lower rates, yet it remains unclear whether their willingness differs from their non‐Hispanic White (NHW) counterparts. This study examined differences in trial willingness, along with barriers and motivators, among Latino and NHW adults in a nationally representative sample. Method A structured web panel survey was administered to 1,800 adults aged 50 and older with no self‐reported neurological disorders, including 600 NHW and 1,200 Latino participants across the U.S. Participants received a primer on AD and clinical trials before responding. Willingness to participate was assessed using Likert‐scale items on general and AD‐specific trial participation. Multinomial logistic regression examined willingness differences, adjusting for age, sex, education, income, and AD family history. Secondary analyses explored motivators and barriers. Result Among Latinos, 34.6% identified as Puerto Rican, 26.9% as Mexican, 14.4% as Central or South American, 8.5% as Cuban, 3.7% as Dominican, and 11.9% as other/mixed heritage. While overall trial willingness did not differ between NHW and Latinos, a trend in heritage‐specific differences emerged. Cuban (OR=2.30; 95% CI: 0.73–7.28) and Central American (OR=1.89; 95%CI: 0.45–7.93) participants showed a pattern of greater willingness compared to NHW, while Dominican (OR=0.60; 95% CI: 0.14–2.47) and Mexican participants (OR=0.78; 95%CI: 0.33–1.82) showed a trend toward lower willingness. Motivators also varied by heritage: Cubans prioritized health benefits (76.5%), research contributions (55.1%), and monetary incentives (40.9%), while Central Americans valued health benefits (68.2%), monetary incentives (50.6%), and physician recommendations (34.7%). Barriers also differed: Dominicans cited safety concerns (48.2%), visit burden (27.8%), and transportation (24.2%), while Mexicans noted visit burden (31.3%), safety concerns (29.3%), and time constraints (20.8%). More Latinos reported they would be “more willing” to participate in AD‐focused trials than NHW (42.6% vs. 36%, p = 0.0069). Conclusion Willingness is not universally a barrier for Latinos, but heritage‐specific trends underscore the need for culturally tailored recruitment strategies. Addressing logistical barriers, safety concerns, and emphasizing trust and societal benefits is key to improving Latino participation in AD trials.

Latinos enroll in Alzheimer's disease (AD) clinical trials at lower rates, yet it remains unclear whether their willingness differs from their non-Hispanic White (NHW) counterparts. This study examined differences in trial willingness, along with barriers and motivators, among Latino and NHW adults in a nationally representative sample. A structured web panel survey was administered to 1,800 adults aged 50 and older with no self-reported neurological disorders, including 600 NHW and 1,200 Latino participants across the U.S. Participants received a primer on AD and clinical trials before responding. Willingness to participate was assessed using Likert-scale items on general and AD-specific trial participation. Multinomial logistic regression examined willingness differences, adjusting for age, sex, education, income, and AD family history. Secondary analyses explored motivators and barriers. Among Latinos, 34.6% identified as Puerto Rican, 26.9% as Mexican, 14.4% as Central or South American, 8.5% as Cuban, 3.7% as Dominican, and 11.9% as other/mixed heritage. While overall trial willingness did not differ between NHW and Latinos, a trend in heritage-specific differences emerged. Cuban (OR=2.30; 95% CI: 0.73-7.28) and Central American (OR=1.89; 95%CI: 0.45-7.93) participants showed a pattern of greater willingness compared to NHW, while Dominican (OR=0.60; 95% CI: 0.14-2.47) and Mexican participants (OR=0.78; 95%CI: 0.33-1.82) showed a trend toward lower willingness. Motivators also varied by heritage: Cubans prioritized health benefits (76.5%), research contributions (55.1%), and monetary incentives (40.9%), while Central Americans valued health benefits (68.2%), monetary incentives (50.6%), and physician recommendations (34.7%). Barriers also differed: Dominicans cited safety concerns (48.2%), visit burden (27.8%), and transportation (24.2%), while Mexicans noted visit burden (31.3%), safety concerns (29.3%), and time constraints (20.8%). More Latinos reported they would be \"more willing\" to participate in AD-focused trials than NHW (42.6% vs. 36%, p = 0.0069). Willingness is not universally a barrier for Latinos, but heritage-specific trends underscore the need for culturally tailored recruitment strategies. Addressing logistical barriers, safety concerns, and emphasizing trust and societal benefits is key to improving Latino participation in AD trials.