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V. Deva Prasad ¹, S. Jayaraj ¹, R. J. Rabindra ¹

Affiliations
1 Centre for Plant Protection Studies, Tamil Nadu Agricultural University, Coimbatore - 641 003, IN

Abstract

The use of botanicals for pest management is gaining importance and there is a possibility of integrating the use of botanical pesticides with entomopathogens (Jayaraj, 1980). Information on the compatibility of entomopathogens with insecticies of plant origin is scanty. Earlier, Dirimanov and Angelova (1962) reported that nicotine sulphate, an insecticide of plant origin, at 0.2 per cent was highly inhibitory to the growth of Beauveria bassiana (Bals.) Vuill. in in vitro tests. The present study was carried out with a view to find out the effect of certain botanicals, viz., Ocimum sanctum L., Allium sativum L ., Acorus calamus L., Tribulus terrestris L. as well as neem (Azadirachta indica A. Juss) seed kernel extract and neem oil on the coni dial germination of the entomofungal pathogen, B. bassinana.

Keywords

Beauveria bassiana, Conidial Germination, Botanicals.

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V. Deva Prasad ¹, S. Jayaraj ¹, R. J. Rabindra ¹

Affiliations
1 Centre for Plant Protection Studies, Tamil Nadu Agricultural University, Coimbatore-641 003, IN

Abstract

Five isolates of three entomogenous fungi were bioassayed for their infectivity to second instar larvae of Spodoptera litura Fab. by spraying the host larvae with the conidial suspension in the laboratory. Of them, Beauveria bassiana (Bals.) Vuill. (Bapatla isolate) was found to be the most virulent recording the lowest LC₅₀ of 19.90 × 10⁵ conidia ml^-1. Tbe LC₅₀ values of the Bangalore and New Delhi isolates of B. bassiana, Paecilomyces fumosoroseus (Wize) Brown and Smith and P. farinosus (Holm ex Gray) Brown and Smith ranged from 5.55 × l0⁸ to 5.58 × 10⁹ conidia ml^-1, Bioassay of second, third and fourth instar larvae of S. litura for their susceptibility to Bapatla isolate or B. bassiana showed that susceptibility decreased with increase in age of the larvae in terms of both LC₅₀ and LT₅₀.

Keywords

Beauveria bassiana, Paecilomyces fumosoroseus, Paecilomyces farinosus, Spodoptera litura, Susceptibility.

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A. Mani ¹, I. R. Murthy ², P. Kameswara Rao ², V. Deva Prasad ³

Affiliations
1 Regional Agricultural Research Station (APAU), Palem-509 215, Mahaboobnagar District, Andhra Pradesh, IN
2 Citrus Improvement Project and Department of Entomology, S. V. Agricultural College (APAU), Tirupati-517 502, IN
3 Department of Entomology, College of Agriculture, Bapatla, Guntur, IN

Abstract

Certain seeds, tubers and ischolar_mains of plants were evaluated as substrates for mass production of the nematophagous fungus, Paecilomyces lilacinus (Thom.) Samson. Growth of P. lilacinus as measured by diameter of the colony, spore production, weight of mycelial mat and rate of growth indicated that wheat, bajra, jowar, and rice were suitable substrates for the multiplication of P. lilacinus. The population of Tylenchulus semipenetrans Cobb decreased markedly with increase in the inoculum level of P. lilacinus, However, application of P. lilacinus in the form of spore suspension was more effective than infected wheat grains in controlling T. semipenetrans.

Keywords

Paecilomyces lilacinus, Substrates, Biocontrol, Tylenchulus semipenetrans.

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