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Climate change has facilitated the introduction, establishment, and movement of invasive species in northern regions, enabling the colonization of previously unsuitable areas. While the responses of insects to these changes have been increasingly studied, our understanding of how such alterations impact trophic interactions still requires further research to make reliable predictions about the spread of diseases in a warming world. Phytoplasmas, a group of obligate parasitic unculturable Mollicutes, primarily rely on leafhoppers (Hemiptera: Cicadellidae) for transmission, spread, and survival. Phytoplasmas are associated with over 600 diseases affecting more than 1,000 plant species, including berries, grapevines, and other small fruits. In North America, diseases such as grapevine yellows, blueberry stunt, and strawberry green petal diseases have been linked to phytoplasma strains transmitted by known leafhopper species. However, the number of phytoplasma diseases has significantly increased in North America over the past decade, suggesting the presence of unidentified vectors or an abundance of leafhopper vectors. This short review provides an overview of the current knowledge on leafhoppers as vectors of phytoplasmas to berries, focusing on the last decade's research in Canada. This paper also explores the potential implications of climate change on this pathosystem, including the anticipated range expansion of leafhopper species, changes in phytoplasma acquisition and transmission, and the risk of new leafhopper-transmitted plant-pathogen introductions through the arrival of new leafhopper species. [ABSTRACT FROM AUTHOR]

Sustainable and effective means to control flying insect vectors are critically needed, especially with widespread insecticide resistance and global climate change. Understanding and controlling vectors requires accurate information about their movement and activity, which is often lacking. The Photonic Fence (PF) is an optical system that uses machine vision, infrared light, and lasers to identify, track, and interdict vectors in flight. The PF examines an insect's outline, flight speed, and other flight parameters and if these match those of a targeted vector species, then a low-power, retina-safe laser kills it. We report on proof-of-concept tests of a large, field-sized PF (30 mL × 3 mH) conducted with Aedes aegypti, a mosquito that transmits dangerous arboviruses, and Diaphorina citri, a psyllid which transmits the fatal huanglongbing disease of citrus. In tests with the laser engaged, < 1% and 3% of A. aegypti and D. citri, respectfully, were recovered versus a 38% and 19% recovery when the lacer was silenced. The PF tracked, but did not intercept the orchid bee, Euglossa dilemma. The system effectively intercepted flying vectors, but not bees, at a distance of 30 m, heralding the use of photonic energy, rather than chemicals, to control flying vectors. [ABSTRACT FROM AUTHOR]

One invasive species that decreases citrus fruit yield is the Asian citrus psyllid, Diaphorina citri Kuwayama. The psyllids are the carriers of Candidatus Liberibacter species, the pathogen that causes citrus greening disease (commonly called huanglongbing, or HLB), which is the most devastating citrus disease in the world. Originally from Southeast Asia, the Asian citrus psyllid, a highly invasive species, is spreading rapidly throughout the world. Regarding geographical distribution and population growth, climate change will aggravate its impacts on many citrus agroecosystems. However, limited information on the mechanisms underpinning the pest's invasion impedes the formulation of biosecurity risk measures. We highlight the potential suitable areas for D. citri, combining their climatic requirements, temperature and humidity, in the CLIMEX model. The model's performance was high, and it can be utilized for biosecurity risk assessment, as only 2.82% of the 496 known occurrence spots were located in areas deemed unsuitable by the model's fit. The potential habitat suitability for D. citri covered all continents except Antarctica, and the suitability ranges from unsuitable (EI < 0) to highly suitable areas (EI ≥ 30). Our model predicted suitable areas outside its known native and invaded regions, especially in Africa, South America, and Oceania. Most of these regions will remain suitable for D. citri in the future. This underscores the importance of our findings as a significant guide for future early detection and the development of climate-smart management strategies against D. citri. [ABSTRACT FROM AUTHOR]

Simple Summary: Our study shows that the African citrus psyllid, a vector of Huanglongbing disease, prefers to develop at mild temperatures and is not well adapted to dry regions, where relative humidity is around or below 40%. Its life cycle is not completed or is severely delayed at temperatures above 30 °C and below 10 °C. Eggs are unable to hatch at constant temperatures below 8 °C or above 33 °C. Thus, T. erytreae establishment and spread will be maximum in regions with a temperate and humid climate, being rare in regions where dry weather conditions predominate. The African citrus psyllid, Trioza erytreae, is one of the two vectors of Huanglongbing, the most serious citrus disease worldwide. The first detection of T. erytreae in the European mainland was on the northwest of the Iberian Peninsula in 2014. Since then, the pest has spread throughout northern Spain (Galicia, Asturias, Cantabria, País Vasco) and along the western Atlantic coast of Portugal (from the Douro e Minho region to the Algarve). We conducted a series of laboratory experiments on lemon plants at different temperatures (from 8 to 34 °C) and humidity conditions (from 40 to 90%) to find out the influence of extreme temperatures and relative humidities (RHs) on the mortality, development and reproduction of T. erytreae. Our results show that temperatures above 30 °C and below 10 °C are very detrimental for nymphal development and nymphs were unable to reach the adult stage. Furthermore, eggs were unable to hatch under temperatures above 33 °C and below 8 °C. Adult mortality was highest at 34 °C and killed more than 50% of the population. We also found that relative humidity is crucial for the development and survival of T. erytreae. Nymphs were unable to reach the adult stage at an RH of 90% and 40%. Also, fecundity was significantly reduced at 90 and 40% RH, and fertility was lowest at 40% RH. Nymphal mortality was highest at an RH of 40%, which was the most detrimental humidity among all tested for the survival and development of T. erytreae. Our work concludes that T. erytreae establishment and spread will be maximum in regions with a temperate and humid climate, being rare in regions where dry and hot weather conditions predominate. [ABSTRACT FROM AUTHOR]