Entomopathogenic fungi as the microbial frontline against the alien Eucalyptus pest Gonipterus platensis in Brazil

The eucalyptus snout beetle (ESB), Gonipterus platensis, is endemic to Australia but has become a major invasive, destructive pest of Brazilian eucalyptus plantations. Efforts to develop insecticides based on entomopathogenic fungi against ESB are limited by the lack of known virulent strains. We therefore explored the virulence of indigenous Brazilian strains of major entomopathogenic fungi—Beauveria spp. and Metarhizium anisopliae—against ESB adults. We found widely varying virulence and later capacities for conidial production on infected adult cadavers. Two strains stood out, B. bassiana IBCB-240 and M. anisopliae IBCB-364, as especially lethal for ESB adults under laboratory conditions, sporulated abundantly on infected insects, and also outperformed comparable strains used in commercial mycoinsecticides. Notably, B. bassiana IBCB-240 exhibited lower LT50 values at low inoculum levels (≤ 107 conidia mL−1) and smaller LC50 values than M. anisopliae IBCB-364. Taken together, this study emphasizes natural variation in virulence among indigenous Beauveria and Metarhizium strains against ESB adults and identifies fungal strains with superior lethality to existing commercialized strains for managing this eucalyptus pest in Brazil.

In-vitro effectiveness test of leaf extract of cattapa and derris to control anthracnose in chili

Anthracnose disease (Colletotrichum capsici) is one of the main problem in the cultivation of chili. This study was aimed to discover about the extract of leaf extract of cattapa (Terminalia catappa L) and leaf extract of derris (Derris elliptica) against the growth of Colletotrichum capsici causes anthracnosis in chilli. The study was conducted at the Mycology Laboratory of Institute Vegetables Research Indonesia, on July - September 2018. The study used a randomized design complete (CRD) with nine treatments and three replications. The treatment consisted of: leaf extract of derris (0.5%; 1.0%; 1.5%; 2.0%), leaf extract of cattapa (0.5%; 1.0%; 1.5%; 2.0%), and control (without treatment). The result showed that the leaf extract of derris more effective to suppress the conidial production of C. capsici. Development of colonies diameter leaf extract of derris was relatively smaller (3.24-4.31 cm), while for the treatment of leaf extract of cattapa showed larger colony size (6.02-6.82 cm).

HYDRATION LEVELS ON CONIDIAL PRODUCTION OF Metarhizium rileyi (Ascomycota) IN SOLID GROWING MEDIUM

This study aimed to evaluate the conidial production of Metarhizium rileyi in rice with different water volumes. The bioassay was composed by completely randomized design (CRD), with four treatments (20, 30, 40 and 50 mL of distilled water), being added 100 g of rice thin and long, making a total of 10 plastic bags per treatment, which were autoclaved for 15 minutes at 1.0 atm pressure, to 120 ºC. After the cooling of the rice, were added in each plastic bag, 2.0 mL of suspension containing 1 × 108 conidia mL-1. Then the bags were incubated for ten days in a germination chamber (BOD type) at 25 °C (±1 °C), 80% (±10%) relative humidity and 12h photoperiod to promote conidial germination and growth of the fungus, being performed a mild agitation every two days. The use of higher water volume resulted in greater conidial production and greater number of viable conidia. However, the highest rate of conidia germination was obtained with the use of 30 mL of water, is this the volume of water that corresponds to the best results.

Lesion development and conidial production of Neonectria ditissima on apple trees in four New Zealand regions

This study examined incubation period, lesion length and conidial release in Neonectria ditissima (European canker) in four New Zealand regions in relation to climatic factors. Incubation period was studied on potted ‘Royal Gala’ trees inoculated with N. ditissima. One week after inoculation, symptomless trees were dispatched to Waikato, Hawke’s Bay, Tasman, Otago and positive controls remained in a glasshouse. Conidial release was studied in trees with lesions that were dispatched to the same regions. Rain traps were placed under each lesion and conidia quantified after each rain event. Disease progress and conidial production were examined in relation to weather. Lesions developed significantly slower in Otago and faster in Waikato and the glasshouse, compared with Tasman and Hawke’s Bay. Symptom development accelerated with increasing daily hours of 11–16°C and humidity (74.6–87.2% RH). The highest conidium counts occurred in Waikato and the lowest in Otago, while conidial production started earlier in Tasman than elsewhere. Temperature is the main driver for symptom development during the incubation period and rainfall is not required. Rainfall frequency drives conidial production.