Development of alternative strategies for pest control with reduced effect on beneficial organisms is a priority given the increasing global loss of biodiversity. Biological control with entomopathogenic fungi arises as a viable option to control insect pests. However, few studies have focused on the consequences of using these organisms on pollinators other than the honey bee ( Apis mellifera L.) or bumble bees ( Bombus spp). We evaluated the pathogenicity of commercial formulations of three widely used entomopathogenic fungi, Metarhizium anisopliae (Metschnikoff) Sorokin, Beauveria bassiana Vuillemin, and Isaria fumosorosea (Wize), to three species of stingless bees: Tetragonisca angustula Latreille, Scaptotrigona mexicana Guérin-Meneville, and Melipona beecheii Bennett. Bioassays consisted of exposing groups of bees to the recommended field concentration of each fungus using a microspray tower under laboratory conditions. Susceptibility to fungi varied greatly among species . Isaria fumosorosea (strain Ifu-lu 01) and the two formulations of B. bassiana (Bea-TNK and BotanicGard) caused <30.3% mortality in all bee species. Metarhizium anisopliae (Meta-TNK and strain Ma-lu 01) was highly active against T. angustula (94.2% mortality) and moderately active against M. beecheii (53.0% mortality) and S. mexicana (38.9% mortality). Though our laboratory-derived results suggest a moderate to high impact of these entomopathogenic fungi on stingless bees, further field studies are required to support this finding.

Purpureocillium lilacinum (Thom) Luangsa-ard, Houbraken, Hywel-Jones & Samson (Hypocreales: Ophiocordycipitaceae) is a fungus commonly used for controlling nematodes, and also has been reported as an insect pathogen. However, little is known about its effects on insects. Here, the pathogenicity of 9 isolates and the virulence and sublethal effects of 2 isolates were evaluated to control adult Anastrepha ludens (Loew) (Diptera: Tephritidae). The pathogenicity assays demonstrated that the 9 isolates were pathogenic, with mortality percentages ranging from 28.8 to 52.4% and LT50 values were 18 d or more. The strain CFFSUR-A53 was more virulent than CFFSUR-A60, with LC50 values of 7.62 × 106 and 5.2 × 109 conidia per mL, respectively. The isolates reduced the life expectancy of the flies by 65 and 37%, decreased fecundity by 78 and 36%, and reduced egg hatching by 31.4 and 18.5%, respectively.

Anastrepha ludens (Loew) (Diptera: Tephritidae) is a major pest of mango and citrus in Mexico. It is usually controlled by applying several strategies in a holistic approach. The entomopathogenic fungus Beauveria bassiana (Bals.-Criv.) Vuill. (Cordycipitaceae) is a biocontrol agent that infects adults of many tephritids pests including A. ludens. In this work, we carried out 4 experiments with the objective of estimating the mortality of A. ludens adults when different conidial concentrations of the fungus B. bassiana were applied to the soil at different humidity, texture, and temperature conditions under controlled laboratory conditions. In a first experiment, mortality ranged from 38.3 to 79.8%, with the highest mortality occurring at a concentration of 800 mg of formulated conidia per kg of soil, while the lowest mortality was recorded at a concentration of 400 mg/kg. In a second experiment, when soils with different texture were investigated at 12% humidity, the pathogenicity of B. bassiana on A. ludens adults was similar in sandy clay soil and sandy loam (64.0% mortality), but was lower in sandy soil with 36.0% mortality. In a third experiment on humidity tests, fly mortality of A. ludens adults ranged from 43.0 to 79.8%, showing the highest mortality at 12% soil humidity and the lowest at 21%. Mortality was similar between 15 to 35 °C (>83%). Emergence of A. ludens adults in the controls ranged between 94.5 and 98.3%. The soil humidity was the major factor that significantly affected fungal efficacy. The study demonstrated the potential of using B. bassiana applied to the soil for management of A. ludens and other tephritids. However, B. bassiana must be evaluated under field conditions before recommendations can be made. Anastrepha ludens (Loew) (Diptera: Tephritidae) es la principal plaga del mango y cítricos en México. Actualmente para su manejo se aplican varias estrategias de control con un enfoque holístico. El hongo entomopatógeno, Beauveria bassiana (Bals.-Criv.) Vuill. (Cordycipitaceae) es un agente de control biológico que ataca adultos de muchas tefrítidos que son plagas, incluyendo A. ludens. En este trabajo, realizamos cuatro experimentos y el objetivo fue estimar la mortalidad de adultos de A. ludens con diferentes concentraciones de conidios del hongo B. bassiana, que fueron aplicados en suelo con diferentes humedades, texturas y temperatura, en condiciones controladas de laboratorio. En el primer experimento, la mortalidad varió de 38.3 a 79.8%, ocurriendo la mortalidad más alta a la concentración de 800 mg del formulado de conidios/kg de suelo, mientras que la mortalidad más baja se registró en la concentración de 400 mg/kg de suelo. En el segundo experimento, cuando se evaluaron diferentes texturas de suelo con 12% de humedad, la patogenicidad de B. bassiana sobre adultos de A. ludens fue similar en suelo areno-arcilloso y areno-limoso (64.0% de mortalidad), pero fue más bajo en suelo arenoso donde hubo 36.0% de mortalidad. En el tercer experimento, cuando se evaluó la humedad del suelo, la mortalidad de adultos de A. ludens varió de 43.0 a 79.8%, donde la mayor mortalidad se registró en suelo con 12% de humedad y la menor mortalidad fue en suelo con 21% de humedad. En el cuarto experimento, la mortalidad fue similar cuando la temperatura del suelo varió de 15 a 35 °C, siendo siempre >83%. La emergencia de adultos en los testigos varió de 94.5 a 98.3%. La humedad del suelo fue el mayor factor que afectó significativamente la eficacia del hongo. En este estudio se demostró el potencial del hongo B. bassiana aplicado al suelo para el control de A. ludens y otros tefrítidos. Sin embargo, es necesario que B. bassiana sea evaluado bajo condiciones de campo antes de recomendar su uso.

The drosophilids Drosophila suzukii (Matsumura), Drosophila melanogaster Meigen and Zaprionus indianus Gupta (Diptera: Drosophilidae), are common pests of Mexican berry plantations. Attract-and-infect-based application strategies using entomopathogenic fungi (EPF), which are more environmentally friendly than synthetic chemical pesticides, are currently under evaluation for their potential at controlling insect pests, as compared to synthetic pesticides. In this study, we evaluated 15 EPF formulations against D. suzukii adults to determine which formulations would work best in an attract-and-infect device in terms of spore accumulation, pathogenicity, and mortality. Formulations of Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Cordycipitaceae), Cordyceps javanica (Friederichs & Bally) (Hypocreales: Cordycipitaceae), and Metarhizium anisopliae (Metschnikoff) Sorokin (Hypocreales: Clavicipitaceae) spores exhibited the highest levels of conidia attachment, pathogenicity, and virulence, making them effective against D. suzukii. In a subsequent experiment, these formulations were evaluated against D. melanogaster, Z. indianus, and the honey bee, Apis mellifera L. (Hymenoptera: Apidae). Our results revealed that the formulations containing C. javanica and M. anisopliae were highly virulent not only against D. suzukii, but also against D. melanogaster and Z. indianus, with minimal impact on honey bees. Our results showed that spore formulations of M. anisopliae and C. javanica were the most promising entomopathogens for further testing of attract-and-infect devices to manage D. suzukii, D. melanogaster and Z. indianus in berry crops.