T. Prabhu ¹, J. Srikanth ¹, G. Santhalakshmi ¹

Affiliations
1 Section of Entomology, Sugarcane Breeding Institute (ICAR), Coimbatore 641007, Tamil Nadu, IN

Abstract

Compatibility of selected insecticides, fungicides and weedicides, commonly used in sugarcane, with Beanveria bassiana (Balsamo-Criv.) Vuill. Beauveria brongniarlii (Sacc.) fetch and Metarhizium anisopliae (Metschnikoff) Sorukin, the entomopathogenic fungi that occur naturally on several pests of the crop, was evaluated in in vitro assays. Radial growth, biomass and spore production used as parameters did not show consistent trend for the five insecticides tested. On the basis of per cent reduction in spore production, however, chlorpyriphos (0.04%) was most toxic to all three fungi (100%); lindane (0.04%) was most toxic to B. brongniartii (100%) but least toxic to B. bassiana (26.3%) and M. anisopliae (17.1%); monocrotophos (0.036%) was moderately toxic to B. bassiana (43.0%) and M, anisopliae (35.2%), and least toxic to B. brongniartii (13.4%); malathion (0.10%) was most toxic to M. anisopliae (88.2%) and B. brongniartii (69.1%), and moderately toxic to B. bassiana (43.0%); endosulfan (0.035%) was moderately toxic to all three species (49.5-58.1%). Carhendazim (0.05%) was completely toxic to all three fuugi (100%); maneozeb 0.08% was also equally toxic to all three fungi (69.5-100.0%). Glyphosate (0.205%) was most toxic (88.1%) to B. bassiana and moderately toxic to B. brongniartii (39.3%) and M. anisopliae (58.2%); atrazine (0.35%) was moderately toxic (40.5-55.7%) to all three fungi; 2.4-D (0.20%) was moderately toxic to B. bassiana (45.9%) and B. brongniartii (63.3%), and least toxic (17.7%) to M. anisopliae. The implications of the results in sugarcane pest management involving entomopathogenic fungi are discussed.

Keywords

Beauveria bassiana, Beauveria brongniartii, Compatibility, Entomopathogenic Fungi, Metarhizium anisopliae, Pesticides, Sugarcane.

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V. Tamizharasi ¹, J. Srikanth ¹, G. Santhalakshmi ¹

Affiliations
1 Sugarcane Breeding Institute (ICAR), Coimbatore, 641007, Tamil Nadu, IN

Abstract

The suitability and economics of molasses-based media supplemented with different nitrogen sources for mass production of the entomopathogenic fungi Beauveria brongniartii (Saccardo) Petch, Beauveria bassiana (Balsamo) Vuillemin and Metarhizium anisopliae (Metschinikoff) were evaluated. Radial growth of all three fungi on molasses agar media differed significantly among different nitrogen supplements. The salts NaNO, and KNO-supported the highest radial growth. Yeast extract, soyflour and defatted soyameal were next best while fertilizer grade urea inhibited growth of B. brongniartii. Spore production of B. brongniartii or M. anisopliae did not differ significantly among molasses broth media fortified with different nitrogen supplements. In B. bassiana, however, yeast extract supported significantly highest spore production and fertilizer grade urea the lowest. A comparison of cost of components for the production of the fungi showed that molasses medium without any nitrogen source was least expensive compared to all other media fortified with different nitrogen sources.

Keywords

Beauveria bassiana, Beauveria brongniartii, Entomopathogenic Fungi, Mass Culture, Metarhizium anisopliae, Molasses Medium, Nitrogen Supplements, Production Economics.

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S. Easwaramoorthy ¹, J. Srikanth ¹, G. Santhalakshmi ¹, N. K. Kurup ¹

Affiliations
1 Sugarcane Breeding Institute, Coimbatore 641 007, Tamil Nadu, IN

Abstract

Life-history and prey acceptance of commonly occurring spiders of sugarcane ecosystem were studied in the laboratory and field. In the laboratory, males and females of Hippasa greenalliae Blackwall passed through eight and nine instars, and the total life cycle lasted 263.3 and 371.6 days, respectively. In the field, females of Cyrtophora cicatrosa Stoliczka passed through nine instars and the total life cycle lasted 195.2 days. In laboratory no choice feeding tests, neonate larvae of shoot (Chilo infuscatellus Snelllen), internode [Chilo sacchariphagus indicus (Kapur)] and pink (Sesamia inferens Walker) borers were the most accepted stage followed by third instar larvae for the spiders H. greenalliae and Oxyopes shweta Tikader. Amongst four sucking pests tested, aphid (Melanaphis indosacchari David), leafhopper (Pyrilla perpusilla Wlk.) and pink mealybug [Saccharicoccus sacchari (Ckll.)] were the most accepted preys while scale insect (Melanaspis glomerata Green) was completely avoided by the above two species of spiders. In field cage studies with H. greenalliae against C. infuscatellus, deadhearts formed by 10 neonate larvae were reduced by around 50 per cent by one spider per cage whereas the same number of third instar larvae needed four to six spiders per cage to reduce deadheart formation.

Keywords

Life History, Prey Acceptance, Spiders, Sugarcane Ecosystem.

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