As of October 2025, Puerto Rico has been experiencing an ongoing dengue outbreak that started in March 2024. The latest island-wide mosquito survey conducted in Puerto Rico during 2018 - 2019 covered 41 of the 78 municipalities and detected the presence of Aedes aegypti in 27 of the municipalities. Given the prolonged elevated circulation of dengue virus on the island, we carried out an additional Ae. aegypti survey in June 2025 across 44 out of 78 municipalities, including areas with no prior records of the species. Here, we report the occurrence of Ae. aegypti in 43 out of 44 municipalities surveyed, including ten new municipalities where Ae. aegypti has not been reported. These findings provide insight into the dispersal of Ae. aegypti in Puerto Rico, indicating that the species is much more widespread than previously known. We also provide the expanded species occurrence of Aedes mediovittatus and Toxorhynchites portoricensis, which share the same larval habitat as Ae. aegypti. Notably, 96% of cemeteries surveyed across 24 municipalities served as oviposition sites for Ae. aegypti. However, a few cemeteries demonstrated effective preventative practices that minimize mosquito breeding. This effective management, which resulted in no mosquito breeding in some cemeteries and a tire shop, brings hope that communication and education of property/facility managers can reduce the mosquito populations.

AbstractMosquito-vectored disease remains a significant global public health threat. One of the most significant barriers to mosquito control is the evolution of insecticide resistance and limited number of available insecticide classes. Isoxazolines and meta-diamides are two classes of insecticides targeting the gamma-aminobutyric acid (GABA) channel, a target site currently under-utilized in mosquito adulticides. Topical assays were conducted on laboratory colonies of the yellow fever mosquito, #Aedes aegypti L. (Diptera: Culicidae), and the common malaria mosquito, #Anopheles quadrimaculatus Say (Diptera: Culicidae), with three isoxazolines: afoxolaner, fluralaner, and fluxametamide, the meta-diamide, broflanilide, and the pyrethroid deltamethrin, a commonly used and well-studied insecticide for adult mosquito control. The insecticides were tested against susceptible and pyrethroid resistant Ae. aegypti and susceptible An. quadrimaculatus. Broflanilide and afoxolaner were found to be the most and least toxic, respectively, and all five compounds were more toxic to Ae. aegypti than An. quadrimaculatus. Cross-resistance to afoxolaner, fluralaner, and fluxametamide, and broflanilide was low or not found in the pyrethroid resistant CKR strain. Age ratios were low to insignificant, suggesting no difference in toxicity between younger and older #mosquitoes. While not as toxic as deltamethrin, the isoxazolines and meta-diamide, broflanilide, represent promising classes of insecticides that could be formulated for use against adult #mosquitoes, with the advantages of a favorable mammalian toxicological profile and no cross-resistance in pyrethroid resistant strains.

Very little is known about insect parasitoids or scavengers of scorpions. In this study we found three cases of endoparasitoidism by Sarcophagidae (Diptera) in three species of Tityus Koch: Lepidodexia sp. on Tityus festae Borelli and larvae of unidentified flesh flies on Tityus jaimei Miranda, Bermúdez, Flórez, Armas and Tityus cerroazul Lourenço. We recorded a case of scavenging by Puliciphora fenestrata Borgmeier on T.

Abstract#Aedes aegypti (Linnaeus) are rapidly spreading across the globe. Evidence suggests that a Type I hypersensitivity reaction, characterized by IgE-mediated mast cell degranulation, may enhance the blood-feeding behavior of Ae. aegypti. Chymases, the mast cell-specific proteases, may play a critical role in this process. To investigate the role of mouse chymase mast cell protease-4 (mMCP-4) on mosquito blood feeding, we incubated bone marrow-derived mast cells with serum from mice sensitized by female Ae. aegypti bites and subsequently challenged the cells with salivary gland proteins (SGPs) from female mosquito. And the degradation of SGPs by mMCP-4 was assessed. Then, the MCP-4 deficient mice were sensitized twice by Ae. aegypti, the first bite on day 0 and the second on day 3. Throughout these experiments, we recorded the total blood meal duration, probing time, and blood feeding of the #mosquitoes and analyzed the cutaneous microbiota. We discovered that serum from sensitized mice enhanced mast cell degranulation and chymase release. And mMCP-4 degraded some SGPs, in particular, potentially cleaving the blood-feeding-related salivary protein D7. Mcpt-4 deficiency resulted in prolonged blood-feeding duration during the second exposure, without affecting initial probing behavior. Moreover, Mcpt-4-deficient mice exhibited a reduced proportion of #mosquitoes achieving rapid engorgement. Skin microbiome profiling revealed that Mcpt-4 deficiency attenuated the bite-induced expansion of potentially harmful bacterial taxa, including the dominant genus Corynebacterium (Mycobacteriales: Corynebacteriaceae). These findings identify mMCP-4 as a critical mediator of mosquito blood-feeding behavior and a modulator of skin microbial ecology in response to Ae. aegypti bites.

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AbstractWe investigated the sand fly fauna and the presence of Leishmania spp. DNA in collected specimens, domestic animals, and military personnel. The 4th Mechanized Cavalry Brigade of Dourados, Mato Grosso do Sul, Brazil is located in an area that has characteristics conducive to the life cycle of Leishmania spp. An epidemiological questionnaire applied to military personnel, and whole blood samples were collected from them and domestic animals. Using the collected blood samples, PCR (Polymerase Chain Reaction) and serology tests were performed to detect Leishmania spp. DNA and anti-Leishmania antibodies, respectively. Additionally, CDC (Center on Disease Control) traps were installed at eight points over 12 months. In total, 652 sand flies belonging to 9 genera and 19 species were collected. Lutzomyia longipalpis, which is the main vector of Leishmania infantum, the etiological agent of visceral leishmaniasis was present in half of the collection points. The DNA detection rate of Leishmania spp. was 0.31% (one pool of Psathyromyia aragaoi and one pool of Brumptomyia spp.). We analyzed 35 animals (dogs and horses) and 235 military personnel. Analysis of samples from animals and soldiers was negative for Leishmania spp. About 30.2% (n = 71) of military personnel did not know about leishmaniasis. Although some vector species were found, no Leishmania spp. DNA was identified in species of medical and veterinary importance. The area investigated showed characteristics that can contribute to the proliferation of the vector and the spread of the disease. Long-term monitoring studies and activities that increase awareness in the population should be encouraged by research funding bodies and leishmaniasis surveillance and control programs.

AbstractSterile insect technique (SIT) is an effective method for controlling pests and has been increasing in popularity to control #Aedes #mosquitoes. SIT involves inundating an area with sterilized male #mosquitoes to reduce egg hatch by reducing the number of fertile matings and ultimately the number of wild adults. Enacting mortality early in the larval life of #Aedes #mosquitoes can result in counter-productive effects due to reduced competition among developing larvae. SIT projects targeting #mosquitoes have historically assessed effectiveness by monitoring egg or adult numbers, leaving out crucial information on what occurs at the larval stage. Our experiments involved collecting and hatching eggs from ovitraps in an SIT-treatment zone and 2 nearby non-SIT zones. We reared the resulting larvae in density and resource conditions similar to those in the field and compared numbers of emerging adults and sizes of emerging adult females from SIT and non-SIT zones. We hypothesize that the effectiveness of SIT in reducing adult populations is modified by density dependent mortality and density dependent growth among larvae. Our results indicate that SIT effectively suppressed the production of adult #Aedes aegypti (L) in the SIT zone compared to non-SIT zones. Additionally, female Ae. aegypti, collected as eggs and reared in laboratory-simulated field conditions were significantly larger from the SIT zone than those from the non-SIT zones. Larger SIT-zone females are consistent with reduced intraspecific competition among larvae. Suppression of adult production in the SIT zone resulted in reduced predicted vectorial capacity, despite the increase in female size.

As of October 2025, Puerto Rico has been experiencing an ongoing dengue outbreak that started in March 2024. The latest island-wide mosquito survey conducted in Puerto Rico during 2018 - 2019 covered 41 of the 78 municipalities and detected the presence of Aedes aegypti in 27 of the municipalities. Given the prolonged elevated circulation of dengue virus on the island, we carried out an additional Ae. aegypti survey in June 2025 across 44 out of 78 municipalities, including areas with no prior records of the species. Here, we report the occurrence of Ae. aegypti in 43 out of 44 municipalities surveyed, including ten new municipalities where Ae. aegypti has not been reported. These findings provide insight into the dispersal of Ae. aegypti in Puerto Rico, indicating that the species is much more widespread than previously known. We also provide the expanded species occurrence of Aedes mediovittatus and Toxorhynchites portoricensis, which share the same larval habitat as Ae. aegypti. Notably, 96% of cemeteries surveyed across 24 municipalities served as oviposition sites for Ae. aegypti. However, a few cemeteries demonstrated effective preventative practices that minimize mosquito breeding. This effective management, which resulted in no mosquito breeding in some cemeteries and a tire shop, brings hope that communication and education of property/facility managers can reduce the mosquito populations.

Abstract#Aedes aegypti (Linnaeus) are rapidly spreading across the globe. Evidence suggests that a Type I hypersensitivity reaction, characterized by IgE-mediated mast cell degranulation, may enhance the blood-feeding behavior of Ae. aegypti. Chymases, the mast cell-specific proteases, may play a critical role in this process. To investigate the role of mouse chymase mast cell protease-4 (mMCP-4) on mosquito blood feeding, we incubated bone marrow-derived mast cells with serum from mice sensitized by female Ae. aegypti bites and subsequently challenged the cells with salivary gland proteins (SGPs) from female mosquito. And the degradation of SGPs by mMCP-4 was assessed. Then, the MCP-4 deficient mice were sensitized twice by Ae. aegypti, the first bite on day 0 and the second on day 3. Throughout these experiments, we recorded the total blood meal duration, probing time, and blood feeding of the #mosquitoes and analyzed the cutaneous microbiota. We discovered that serum from sensitized mice enhanced mast cell degranulation and chymase release. And mMCP-4 degraded some SGPs, in particular, potentially cleaving the blood-feeding-related salivary protein D7. Mcpt-4 deficiency resulted in prolonged blood-feeding duration during the second exposure, without affecting initial probing behavior. Moreover, Mcpt-4-deficient mice exhibited a reduced proportion of #mosquitoes achieving rapid engorgement. Skin microbiome profiling revealed that Mcpt-4 deficiency attenuated the bite-induced expansion of potentially harmful bacterial taxa, including the dominant genus Corynebacterium (Mycobacteriales: Corynebacteriaceae). These findings identify mMCP-4 as a critical mediator of mosquito blood-feeding behavior and a modulator of skin microbial ecology in response to Ae. aegypti bites.

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