No abstract

Increased production of the Cape gooseberry (Physalis peruviana L.) in Brazil has given rise to interest in identifying the phytophagous species that might damage this crop to inform preventive control and integrated pest management strategies. In this study, we report the occurrence and describe the damage that larvae and adults of Lema bilineata Germar (Coleoptera: Chrysomelidae) cause in P. peruviana. The number of L. bilineata individuals, both larvae and adults, significantly affected the total consumption of P. peruviana leaves. We also report, for the first time, three natural enemies, including a fungus, a fly, and an ant, which are associated with this pest in Brazil and may play a role in biological control strategies.

Histoplasmosis is a systemic fungal disease that occurs worldwide, causing symptomatic infection mostly in immunocompromised hosts. Etiological agent is the dimorphic fungus, Histoplasma capsulatum, which occurs in soil contaminated with bird or bat droppings. Major limitation in recognition of H. capsulatum infections is the low awareness, since other diseases may have similar symptomatology. The molecular methods have gained importance because of unambiguous diagnostic ability and efficiency. The aim of this study was to develop and evaluate a padlock probe in view of rolling circle amplification (RCA) detection method which targets ITS (Internal Transcribed Spacer) rDNA of H. capsulatum enabling rapid and specific detection of the fungus in clinical samples. Two padlock probes were designed and one of these (HcPL2) allowed specific amplification of H. capsulatum DNA while no cross-reactivity was observed with fungi used as negative controls. This method proved to be effective for H. capsulatum specific identification and demonstrated to be faster than the traditional method of microbiological identification.

Several species of the genus Exophiala are found as opportunistic pathogens on humans, while others cause infections in cold-blooded waterborne vertebrates. Opportunism of these fungi thus is likely to be multifactorial. Ecological traits [thermotolerance and pH tolerance, laccase activity, assimilation of mineral oil, and decolorization of Remazol Brilliant Blue R (RBBR)] were studied in a set of 40 strains of mesophilic Exophiala species focused on the salmonis-clade mainly containing waterborne species. Thermophilic species and waterborne species outside the salmonis-clade were included for comparison. Strains were able to tolerate a wide range of pHs, although optimal growth was observed between pH 4.0 and 5.5. All strains tested were laccase positive. Strains were able to grow in the presence of the compounds (mineral oil and RBBR) with some differences in assimilation patterns between strains tested and also were capable of degrading the main chromophore of RBBR. The study revealed that distantly related mesophilic species behave similarly, and no particular trend in evolutionary adaptation was observed.

Lema bilineata Germar (Coleoptera: Chrysomelidae) was recently reported to damage Physalis peruviana crops in Brazil. Given the potential for inflicting damage on other Solanaceae species and the lack of alternatives for controlling this pest, we assessed the pathogenicity of 15 Beauveria isolates against L. bilineata adults in vitro. In addition, three of these isolates were tested for their ovicidal effect against L. bilineata eggs. Fungal strains were isolated from mummified corpses of L. bilineata collected in a non-commercial field in Paraná, Brazil. The isolates were identified as Beauveria bassiana using molecular markers. Lema bilineata adults were susceptible to conidial suspensions of all these isolates at a concentration of 108 conidia mL−1. Deaths caused by fungal extrusion were confirmed. Three strains were found to be more virulent against L. bilineata adults and showed ovicidal effects. This is the first study on entomopathogenic fungi isolated from dead insects collected from P. peruviana crops and tested against L. bilineata carried out in Brazil. The results obtained in the laboratory indicate the high potential of the use of three B. bassiana strains against L. bilineata as a biocontrol agent.