Temperature-dependent development of the entomopathogenic fungus Nomuraea rileyi (Farlow) Samson in Anticarsia gemmatalis (Hübner) larvae (Lepidoptera: Noctuidae)

Abstract

Desenvolvimento Dependente da Temperatura do Fungo Entomopatogênico Nomuraea rileyi (Farlow)Samson em larvas de Anticarsia gemmatalis (Hübner) (Lepidoptera: Noctuidae)RESUMO -A influência da temperatura no desenvolvimento do fungo entomopatogênico Nomuraea rileyi (Farlow) Samson foi estudada em larvas no terceiro estágio de desenvolvimento de Anticarsia gemmatalis (Hübner), mantidas sob regime de temperatura constante. Um modelo não-linear foi utilizado para descrever as taxas de crescimento vegetativo e reprodutivo do fungo. A temperatura requerida para obter o maior crescimento vegetativo foi estimada em 25,5ºC, enquanto os limites mínimo e máximo foram estimados em 11ºC e 30ºC, respectivamente. A taxa de conidiação foi estável dos 18ºC aos 26ºC. As temperaturas mínima e máxima estimadas para o desenvolvimento vegetativo coincidem com as condições ambientais de ocorrência natural na Argentina Central. Efeitos não-lineares da temperatura no crescimento vegetativo e reprodutivo, bem como a probabilidade de distribuição in vivo de N. rileyi são descritos. PALAVRAS-CHAVE: Controle biológico, modelo matemático, dinâmica populacional, inimigo naturalABSTRACT -The influence of temperature on the development rate of the entomopathogenic fungus Nomuraea rileyi (Farlow) Samson in Anticarsia gemmatalis (Hübner) 3 rd -instar larvae was studied under constant temperature regimes. A non linear model was used to describe temperature-dependent vegetative and reproductive development rates of the fungus. The temperature required to reach the highest vegetative development rate was estimated to be 25.5ºC while lower and upper developmental thresholds were 11ºC and 30ºC, respectively. The rate of development for conidia release was stable from 18ºC to 26ºC. The estimated lower and upper thresholds of vegetative development coincide with conditions during the natural epizootics in central Argentina. Non-linear effects of temperature on vegetative and reproductive development rates and probability distributions of N. rileyi under in vivo conditions are described.

Studies on mycosis of Metarhizium (Nomuraea) rileyi on Spodoptera frugiperda infesting maize in Andhra Pradesh, India

“…Allen and Buren (1974) discussed the role of biotic and abiotic factors in the occurrence and outbreaks of M. rileyi on insect pests. Temperatures of around 25°C with high RH (70-75%) prevailing in tropical regions like India, Brazil, and Sub-Saharan Africa were found highly favourable for M. rileyi development (Edelstein et al 2005).…”

Sources and abundance of fungi with entomopathogenic potential for control of the cowpea pod borer, Maruca vitrata Fab. in Ibadan, Nigeria

“…Although the effects of growth rates on conidial production under the Nigerian climate were not part of this study, the possibility that conidial production potential may have a direct relationship to growth rates is speculated (De Cross et al, 1999). It is known also that the important factors that could significantly influence spore production especially by entomopathogens are light (Hajek and St. Leger, 1994;Butt, 2002;Sa´nchez-Murillo et al, 2004) and culture age (Edelstein et al, 2005) and these must be considered in order to optimize the conidial production. Our findings in this study also show that these entomopathogenic fungi could be cultured relatively easily in the laboratory on common solid media.…”

First Record of Clonostachys rosea (Ascomycota: Hypocreales) Entomopathogenic Fungus in the Mango Hopper Amritodus atkinsoni (Hemiptera: Cicadellidae)

“…Inoculation of 0.7 cm bits of pure culture for solid and liquid media was carried out according to the study parameters such as mean radial growth, mean conidia per bit, and mean germination percentage of conidia in case of solid media and mean fresh weight or mean dry weight in case of liquid media. All these factors were further studied at 15, 20, 25, and 30 • C considering temperature as a prime and relevant factor for the vegetative and reproductive development of entomopathogenic fungi [31].…”