Joseph P. Rinehart

Honey bees are very important to the ecological environment and human society, contributing significantly to biodiversity and global food security, with an estimated annual impact of $15 billion in crop pollination in the USA. Over 62% of honey bee colony decline has been observed between June 2024 and February 2025. This study investigates bee stress level monitoring due to external disturbances like mechanical vibrations by measuring internal air temperature, relative humidity, and CO₂ gas concentration levels of beehives. A new wireless sensor board for real-time monitoring of honey bee colonies was designed, built, and validated. The board incorporates NDIR-based SCD30 and SCD41 sensors for CO₂, temperature, and humidity monitoring, integrated with a custom-designed two-layer printed circuit board and a Particle Argon^TM microprocessor for Wi-Fi communication. The developed board was tested and validated with live beehives in summer and winter of 2024 and 2025. The experimental study results showed the adequacy of the built sensor board. Bee colony responses on the applied stimuli (knocks) show that bees responded with a temperature increase of over 5 °C, CO₂ concentration increase by 3000 to over 10,000 ppm, and, at the same time, relative humidity drop by about 10% inside beehives.

Performance tends to decline with age, including muscle function and stress tolerance. Yet, performance can vary widely among individuals within the same age group, showing that chronological age does not always represent biological age. To better understand ageing, we need to examine what drives some individuals to age faster than others. In order to achieve this, first we need to be able to predict whether an individual will have a long or short lifespan. In this study, we conducted a longitudinal study tracking individual-level locomotor activity, chill-coma recovery time, and metabolic rates, and assessed whether early-life performance is linked to lifespan using the solitary bee Megachile rotundata . We found that locomotor activity and chill-coma recovery times decline in old adults. However, resting metabolic rate did not change with age. We also found low cold tolerance and low mass at emergence in early-life are linked to shorter female lifespans, showing that early-life performance can explain some of the variation in lifespan in a population. Finally, these results also show that not all traits decline with age within the same species, and shed new light on sexual dimorphism in physiological traits and ageing.

Bumble bees are the primary commercial pollinators for greenhouse‐grown crops and managing them requires insight into the Bombus life cycle. However, some aspects of the life cycle are not fully understood. Once mated, adult Bombus gynes can be stored for a short term at a constant low temperature (CLT). However, survival rates for some species are low during CLT, particularly when storage periods exceed a month. To address this, we tested the hypothesis that Bombus gynes stored in a fluctuating thermal regime (FTR) have increased survival compared to gynes stored in CLT. Specifically, the FTR had a baseline temperature of 2°C, with a daily fluctuation to 20°C relative to the CLT of 2°C with no warming pulse. We tested the effects of FTR on gyne survival and post‐cold storage lipid content in three species used for commercial pollination in North America: B. vosnesenskii, B. huntii and B. impatiens. We further assessed how additional factors influence cold storage survival, including gyne body weight, body size and colony age. Survival responses varied among species. Bombus vosnesenskii and B. huntii had a lower survival rate in FTR compared to CLT, but B. impatiens gynes had a significantly higher survival rate in FTR. We did not observe significant effects of FTR on lipid stores for any species, but survival increased with an increasing initial weight prior to cold storage. Moreover, gynes produced later in the colony life cycle had lower body weight and decreased survival compared to early emerging gynes. Our study provides insight into how cold storage conditions interact with colony and gyne characteristics to influence captive overwintering survival. Our findings have economic applications for improving commercial rearing and efforts for conservation rearing of at‐risk Bombus species.

Embryos of the sunflower moth, Homoeosoma electellum (Hulst), were cryopreserved after modification to the method that was previously described for Pectinophora gossipiella. The workflow to develop the protocol consisted of methods to weaken the embryonic chorion followed by the application of various methods to disrupt the sub-chorionic wax layer. These steps were necessary to render the embryos permeable to water and cryoprotectants. Initially, the embryos were incubated at 21° and 24 °C, and the development of the double pigment spots/eyespot and eclosion were tracked every two hours. The embryos at 24 °C showed eyespots as early as 30 h, while in the case of the embryos that were incubated at 21 °C, there was a developmental delay of approximately 20 h. The embryos at 24 °C showed peak eclosion between 55 and 70 h, and the embryos at 21 °C eclosed between 80 and 100 h of development. Estimating this range is crucial for the purposes of stage selection and treatment initiation for cryopreservation protocol development for the embryos. The control hatch percentage at either developmental temperature was >90%, and the sodium hypochloride, 2-propanol and alkane-based treatments reduced the embryo hatchability to <10%. Hence, a modified surfactant—hypochlorite mixture—was used to destabilize the chorion and solubilize the hydrophobic lipid layers. Water permeability assessments using the dye-uptake method show that polysorbate 80 in combination with sodium hypochlorite alone is capable of permeabilizing the embryo as efficiently as sequential hypochlorite—alkane treatments, but with significantly higher hatch rates. A vitrification medium consisting of ethane diol and trehalose was used to dehydrate and load the embryos with the cryoprotective agent. The median hatch rates after vitrification were 10%, and maximum was 23%.

Oxygen consumption is difficult to measure in small insects and those with very low metabolic rates, such as insects undergoing diapause or during exposure to low temperatures. One method that works well is the use of closed system respirometry. In this study, we validated the Loligo Systems microplate system for measuring individual respiration in air using the alfalfa leafcutting bee, Megachile rotundata . The Loligo system is a closed system that uses optical fluorescence and was designed for use with aquatic systems, with few studies in insects. We placed overwintering, pre‐pupal bees in 29°C to initiate metamorphosis. After 2 weeks, bees were placed in 6, 10, 14, 18, 22, 26, 29, 33, or 35°C, and metabolic rate was measured using the microplate system. Bees (n = 32 for each temperature) were placed into one well of the 24 well‐plate and oxygen consumption was measured for 3 hours. We also compared pupal bees dissected from brood cells to those that were undisturbed. Not surprisingly, oxygen consumption increased with temperature. Interestingly, there appeared to be a breakpoint around 18°C, which is the developmental threshold for M. rotundata . Bees remaining in the brood cells had metabolic rates that were not different from those that had been excised. Not only does this system allow for measuring low respiration rates, it opens the possibility of reducing abiotic stressors incurred during oxygen consumption measurements, including the low humidity required for most measurement devices and, in the case of M. rotundata , the need to remove the developing insect from its protective cocoon.