Agustín Hernández-Juárez

Evaluation of Foliar Damage by Spodoptera frugiperda (Lepidoptera: Noctuidae) to Genetically Modified Corn (Poales: Poaceae) in Mexico

Abstract The fall armyworm, Spodoptera frugiperda Smith & Abbot (Lepidoptera: Noctuidae), is a key pest of corn, Zea mays L. (Poales: Poaceae), in Mexico. The development of genetically modified (GM) corn hybrids for resistance to this insect, with the inclusion of several genes coding for proteins Cry1Ab, Vip3Aa20, and mCry3A of Bacillus thuringiensis Berliner (Bacillales: Bacillaceae) (Bt), offer an alternative to conventional insecticides to control this pest. Resistance to fall armyworms of the GM corn hybrids Agrisure 3000 GT, Agrisure Viptera 3110, and Agrisure Viptera 3111 was evaluated in 4 locations at Sinaloa for a 3 yr period. Damage evaluation showed that the maize hybrids with the Bt gene insertion were not affected by the fall armyworm as compared with their respective isolines, which were seriously damaged. The results reaffirm the insect control benefits provided by this technology and provide a baseline for resistance management.

Plant Oils to Control Sitophilus zeamais Motschulsky1

Abstract. The maize weevil, Sitophilus zeamais Motschulsky, is the most important pest of stored maize, Zea mays L. The pest causes estimated losses of 5–10% worldwide. Oil extracts from plants show promise to control maize weevil with important advantages over conventional insecticide, such as non-toxicity to humans, biodegradability, and ecosystem safety. The objective of this research on maize weevils in laboratory conditions was to determine the insecticidal effect of 10 plant oils: garlic, Allium sativum L.; cinnamon, Cinnamomum verum J.; hot pepper, Capsicum annuum L.; clove, Syzygium aromaticum L.; mint, Mentha piperita L.; black pepper, Piper nigrum L.; rosemary, Rosmarinus officinalis L.; rue, Ruta graveolens L.; thyme, Thymus vulgaris L. and allyl (commercial product). Residual film was used to test plant oils at five concentrations: 9,000, 7,000, 5,000, 3,000, and 1,000 ppm. The number of weevils killed was counted at 72 hours, and treatment means were compared using a Tukey multiple separation test. PC-Probit analysis determined LC50 and LC95. Most weevils, 52.47 and 60.38%, were killed by garlic and black pepper oils, respectively; at 9,000 ppm; fewer than 50% were killed with the other plant oils. Use of garlic and black pepper oil might be an alternative method to manage this insect pest in stored maize.

Efecto de Hongos Entomopatogenos Sobre Larvas de Mosca Sierra (Monoctenus sanchezi Smith) 1

Abstract. Monoctenus sanchezi is a sawfly of economic importance in forest management because of damage to the foliage of white cedar. Mortality by entomopathogenic fungi Metarhizium anisopliae, Beauveria bassiana, and Trichothecium sp. on M. sanchezi larvae was 98, 60, and 36% on the sixth day. Metarhizium anisopliae may be an alternative for biological control of the sawfly in México.

Efectos de Phytoseiulus persimilis (Athias-Henriot)1 Sobre Tablas de Vida de Tetranychus urticae Koch en Cuatro Variedades de Rosal

Resumen. Se estudió la supervivencia y esperanza de vida de Tetranychus urticae y Phytoseiulus persimilis, en cuatro variedades de rosal bajo condiciones de invernadero. Se observaron diferencias en el número de hembras de T. urticae por variedad. La curva de supervivencia de la población de T. urticae sobre las variedades Royal y Red Baiser fue de tipo I y sobre las variedades Selena y Anastasia coincide de tipo II, y entre estas curvas se encontraron diferencias significativas, dependiendo de la variedad de rosal la esperanza media de vida de T. urticae fue diferente, así como para P. persimilis. Phytoseiulus persimilis fue más eficiente sobre las variedades Selena y Anastasia, reduciendo la población de hembras adultas de T. urticae en 7 semanas.

Propagation and Evaluation in vivo of Granulosis Virus of Phthorimaea operculella (Zeller)1

Abstract. Four methods for propagation of Granulovirus phthorimaea on Phthorimaea operculella (Zeller) larvae were evaluated under laboratory conditions. The methods were: immersion of potato, Solanum tuberosum L., tuber; application by cotton swab to larvae; larval immersion and aspersion with viral suspension (homogenized water with one to 15 infected larvae). The objectives were to develop a method adapted to in vivo production of the virus and to determine susceptibility of P. operculella to the virus. Larval immersion was significant at 5, 10, and 15 days after evaluation, killing 55.0, 77.5, and 87.5%, respectively, of second and third instars. LC50 was estimated based on the number of first-instar larvae per liter of water (0, 1, 3, 6, 9, 12, and 15). LCs were 7.8, 3.7, and 2.0 larvae per liter of water at 2, 5, and 8 days, respectively, and varied according to the time data were collected.

Susceptibility of Genetically Modified Maize Hybrids to Sugarcane Borer, Diatraea saccharalis (F.)1, at Sinaloa, Mexico

Abstract. Use of genetically modified hybrids of maize, Zea mays L., is a pest management tool with special significance when a pest such as sugarcane borer, Diatraea saccharalis (F.) (Lepidoptera: Crambidae), becomes less responsive to conventional control methods. Resistance of genetically modified maize hybrids ‘AgrisureTM 3000 GT’ and ‘Agrisure® VipteraTM 3111’ were evaluated against stalk borers and compared with conventional hybrids with or without insecticide. During evaluation, few borers were found, especially during the first year (2012), but, in most cases, stalk damage by larvae was less in AgrisureTM 3000 GT and Agrisure® VipteraTM 3111 than in their conventional isolines. Insecticide did not prevent damage by the pest and even treated conventional maize was damaged. Use of AgrisureTM 3000 GT and Agrisure® VipteraTM 3111 hybrids can be a management tool to prevent damage by sugarcane borer in maize.