More Like this

1. Freshwater snails and the green algae Cladophora are probably not hosts of Batrachochytrium dendrobatidis

   https://doi.org/10.1111/fwb.13662  

   McMahon, Taegan A.; Nordheim, Caitlin L.; Prokopiak, Devin M. (December 2020, Freshwater Biology)

   Abstract Batrachochytrium dendrobatidis(Bd) is a pathogenic fungus that has devastated amphibian populations globally by causing the disease chytridiomycosis.Batrachochytrium dendrobatidisis capable of infecting non‐amphibian hosts, such as crayfish, and has been detected on reptile and bird species. Given the taxonomic heterogeneity in the known hosts and vectors of Bd, it is likely that there is a diversity of undiscovered non‐amphibian hosts of the fungus.Here, we investigated whether Bd could survive on freshwater snails (Physella acuta) andCladophoraalgae. We exposed small and large snails (n = 15 snails/size category),Cladophoraalgae (n = 5), and artificial spring water controls (ASW;n = 5) to live Bd. We also maintained Bd‐free control snails (n = 5 snails/size category) in ASW. All treatments were maintained for 7 weeks at 18°C. Mortality was checked three times a week, snails were weighed every 2 weeks, and 7 weeks after exposure, the snails, algae, and water were tested for Bd using quantitative polymerase chain reaction.We found that Bd did not grow on live snails, algae, or ASW long term. Additionally, live snails (n = 20) collected from Bd‐positive ponds in California were all negative for Bd, as well. Given that we found no Bd on the experimentally exposed or field swabbed snails, snails are probably not a reservoir host of Bd.While negative results are often not published, Bd is one of the deadliest pathogens on earth; it is essential to know what is and is not capable of maintaining Bd for well‐designed disease models. 

   more » « less
2. Induced dormancy in Indian meal moth Plodia interpunctella (Hübner) and its impact on the quality improvement for mass rearing in parasitoid Habrobracon hebetor (Say)

   https://doi.org/10.1017/S0007485322000153  

   Hasan, Md. Mahbub; Hasan, Md. Mehedi; Rahman, A. S.; Athanassiou, Christos G.; Tussey, Dylan A.; Hahn, Daniel A. (December 2022, Bulletin of Entomological Research)

   Abstract A steady supply of hosts at the susceptible stage for parasitism is a major component of mass rearing parasitoids for biological control programs. Here we describe the effects of storing 5th instar Plodia interpunctella larvae in dormancy on subsequent host development in the context of host colony maintenance and effects of the duration of host dormancy on the development of Habrobracon hebetor parasitoids reared from dormant hosts. We induced dormancy with a combination of short daylength (12L:12D) and lower temperature (15°C), conditions known to induce diapause in this species, and held 5th instar larvae of P. interpunctella for a series of dormancy durations ranging from 15 to 105 days. Extended storage of dormant 5th instar larvae had no significant impacts on survival, development, or reproductive potential of P. interpunctella , reinforcing that dormant hosts have a substantial shelf life. This ability to store hosts in dormancy for more than 3 months at a time without strong negative consequences reinforces the promise of using dormancy to maintain host colonies. The proportion of hosts parasitized by H. hebetor did not vary significantly between non-dormant host larvae and dormant host larvae stored for periods as long as 105 days. Concordant with a prior study, H. hebetor adult progeny production from dormant host larvae was higher than the number of progeny produced on non-dormant host larvae. There were no differences in size, sex ratio, or reproductive output of parasitoids reared on dormant hosts compared to non-dormant hosts stored for up to 105 days. Larval development times of H. hebetor were however longer when reared on dormant hosts compared to non-dormant hosts. Our results agree with other studies showing using dormant hosts can improve parasitoid mass rearing, and we show benefits for parasitoid rearing even after 3 months of host dormancy. 

   more » « less
3. Effect of High-Density Polyethylene Microplastics on the Survival and Development of Eastern Oyster (Crassostrea virginica) Larvae

   https://doi.org/10.3390/ijerph20126142  

   Bhatt, Sulakshana; Fan, Chunlei; Liu, Ming; Wolfe-Bryant, Brittany (June 2023, International Journal of Environmental Research and Public Health)

   Microplastic (MP) pollution is a growing global concern—especially in estuarine areas that serve as natural habitats and nurseries for many marine organisms. One such marine organism is the Eastern oyster (Crassostrea virginica), which is a reef-forming keystone species in the Chesapeake Bay, the largest estuary in the United States. To understand the potential impacts of MP pollution on the estuary ecosystem, the effects of high-density polyethylene (HDPE) MPs on Eastern oyster larval survival and development were investigated. Three cohorts of larvae were exposed to HDPE MPs with a size of 10–90 µm at a 10 mg/L concentration, after 7 to 11 days of fertilization. After exposure, the number and size of oyster larvae were measured twice a week for approximately 2 weeks until larval settlement. The experiment found that there were no significant differences in the rate of survival between the control and MP-addition treatments. However, we noticed that larval development was significantly delayed with the MP treatment. The percentage of larvae that were ready to settle was 64% with the control treatment compared to 43.5% with the MP treatment. This delay in growth resulted in a delayed larval settlement, which could adversely affect the survival of the Eastern oyster due to the increased risk of predation. The current study demonstrates that MPs could be a risk to the ecology of estuaries, and plastic pollution management is needed for the preservation of these estuaries. 

   more » « less
4. A cryopreservation method to recover laboratory- and field-derived bacterial communities from mosquito larval habitats

   https://doi.org/10.1371/journal.pntd.0011234  

   Zhao, Serena Y.; Hughes, Grant L.; Coon, Kerri L. (April 2023, PLOS Neglected Tropical Diseases)

   Bartholomay, Lyric C. (Ed.)

   Mosquitoes develop in a wide range of aquatic habitats containing highly diverse and variable bacterial communities that shape both larval and adult traits, including the capacity of adult females of some mosquito species to transmit disease-causing organisms to humans. However, while most mosquito studies control for host genotype and environmental conditions, the impact of microbiota variation on phenotypic outcomes of mosquitoes is often unaccounted for. The inability to conduct reproducible intra- and inter-laboratory studies of mosquito-microbiota interactions has also greatly limited our ability to identify microbial targets for mosquito-borne disease control. Here, we developed an approach to isolate and cryopreserve bacterial communities derived from lab and field-based larval rearing environments of the yellow fever mosquito Aedes aegypti –a primary vector of dengue, Zika, and chikungunya viruses. We then validated the use of our approach to generate experimental microcosms colonized by standardized lab- and field-derived bacterial communities. Our results overall reveal minimal effects of cryopreservation on the recovery of both lab- and field-derived bacteria when directly compared with isolation from non-cryopreserved fresh material. Our results also reveal improved reproducibility of bacterial communities in replicate microcosms generated using cryopreserved stocks over fresh material. Communities in replicate microcosms further captured the majority of total bacterial diversity present in both lab- and field-based larval environments, although the relative richness of recovered taxa as compared to non-recovered taxa was substantially lower in microcosms containing field-derived bacteria. Altogether, these results provide a critical next step toward the standardization of mosquito studies to include larval rearing environments colonized by defined microbial communities. They also lay the foundation for long-term studies of mosquito-microbe interactions and the identification and manipulation of taxa with potential to reduce mosquito vectorial capacity. 

   more » « less
5. Evaluation of biofilm scouring methods on the nitrification efficiency in a pilot‐scale membrane‐aerated biofilm reactor

   https://doi.org/10.1002/wer.70044  

   Ali, Priyanka; Reeve, Matt; Carlson‐Stadler, Russell; Vela, Jeseth Delgado; Liu, Lu; Christenson, Dylan; Shaw, Andrew; Stadler, Lauren B (March 2025, Water Environment Research)

   Membrane‐aerated biofilm reactors (MABRs) are being increasingly being implemented at full‐scale for domestic wastewater treatment and effective biofilm control is critical to their performance. This study investigated the impact of three biofilm scouring strategies on nitrogen removal performance of a pilot‐scale MABR operated in Houston, TX: (1) regular air scouring, (2) high intensity air scouring, and (3) high liquid flow scouring. Normal and high intensity air scouring regimes and a high liquid flow scour (10× baseline flow) were each tested sequentially. High NH₄⁺‐N removal efficiency of 52% in flow‐through mode was observed post‐high liquid flow scouring, which was comparable to the performance during the intense scouring regime. The absolute abundance ofamoAgene for ammonia oxidizing bacteria (AOB) increased significantly by over 200%, between pre‐ and post‐high liquid flow scouring. The energy consumption was 43% lower for the combination of high liquid flow scouring with regular air scouring as compared to the intense air scouring. This study showed that high liquid flows may be utilized as an energy‐efficient biofilm control strategy in nitrifying MABR systems. Practitioner PointsPilot‐scale MABR reactors were operated with different scouring settings: regular aeration, intense aeration, and high liquid flow.High liquid flow scouring improved nitrification efficiency, comparable to intense scouring.High liquid flow scouring selected for nitrifiers as seen by an increase in AOB quantified asamoAgene abundance.Using high liquid flow with regular aeration scouring reduces electrical energy consumption by 43% as compared to intense aeration scouring.High liquid flows may be used as an energy‐efficient biofilm control strategy to improve nitrification performance in MABR systems. 

   more » « less