Rodolfo Osorio-Osorio

Fruit-scarring Beetle Myochrous melancholicus Jacoby1 as a Potential New Pest of Banana

Abstract. Production of banana (Musa spp.) is a major economic activity in the humid tropical region of Mexico. Any damage to the fruit is unacceptable for domestic and export markets. The aim of this study was to determine the pest species that damage the epidermis of banana fruit and evaluate the intensity of damage in different development stages of banana bunches and its incidence in commercial plantations. The study was at ‘Giant Dwarf’ Musa AAA Cavendish banana plantations at Teapa, Tabasco, from August 2010 to April 2012. The beetle Myochrous melancholicus Jacoby (Coleoptera: Chrysomelidae) was identified as the cause of the damage. Adults cause small, irregular and superficial cuts or incisions on the edges of the fruit, almost overlapping each other, which, when dry, form elongated scars. In infestations induced in the field, the species caused from 4.8 to 14.5% of damage fruits throughout the developmental period of banana bunches. The incidence of adults and damage was detected only during the wettest time of the year, and in isolation in some cultivated areas in the region. The beetle is voracious and under favorable conditions can become a major pest. This is the first report of M. melancholicus damaging banana fruit. A more in-depth study of the biological cycle, host plants, and feeding behavior of the beetle, is urgently needed as a basis to determine management strategies in case of outbreak.

Colonization, Abundance, and Damage of Raoiella indica Hirst 1 on Cultivars of Musa spp. at Tabasco, México

Abstract. The red palm mite, Raoiella indica Hirst, is a pest recently introduced and propagating in the Neotropical region where the extent of potential damage to cultivars of Musa spp. is not well known. Three basal leaves of each young ‘Dwarf Giant’ banana (Musa AAA Cavendish), ‘Horn’ plantain (Musa AAB Plantain), and ‘Date’ banana (Musa AA Sucrier) were experimentally infested with 200 adult mites per leaf. As a check, three coconut palms (Cocos nucifera L.) of cultivars ‘Pacific Tall’, ‘Malayan Dwarf’, and the hybrid (‘Pacific Tall’ x ‘Malayan Dwarf’) were infested. The objective was to evaluate colonize and increase in abundance of the pest, as well as damage it can cause in the humid tropics of Mexico. After 4 months, the number of adult mites per infested leaf had increased 2.4 to 5.3 times on Musa spp. cultivars and 43.4 to 54.1 times on cultivars of C. nucifera. Similarly, the rates of eggs, larvae-nymphs, and adults on nearby leaves were less on Musa spp. than on C. nucifera. Mild damage was observed on ‘Horn’ plantain and ‘Date’ banana, moderate damage on ‘Dwarf Giant’ banana, and the coconut palms were severely damaged. The rainfall had a negative effect on colonization and development of R. indica. Torrential rain and prolonged drizzle during most of the year in the study area regulated R. indica in host plant in the region. Effect of weather on decrease in abundance as well as phytosanitary practices should be considered when managing the pest.

Identidad de Mosca Pinta (Hemiptera: Cercopidae) y sus Hospederas en Cañaverales en Cárdenas, Tabasco, México

Resumen. Salivazo o mosca pinta aplica a varias especies de insectos de la familia Cercopidae, que constituyen una importante plaga de la caña de azúcar (Saccharum sp.) en el trópico mexicano, las cuales suelen completar su ciclo de vida en otras plantas que se desarrollan como arvenses. El objetivo de esta investigación fue identificar las especies de mosca pinta y de arvenses hospederas de éstas, confinando 127 ninfas, de las que se colectaron 76 adultos, 51 de Aeneolamia contigua Walker, y 25 de Prosapia simulans Walker, localizadas en 13 especies de plantas arvenses. La mayor abundancia de especies de mosca pinta se encontró en Paspalum fasciculatum, Rottboellia cochinchinensis, y Pennisetum purpureum. Aeneolamia contigua se reporta por primera vez en Panicum laxum, Pennisetum setaceum y Urochloa fusca, y Prosapia simulans en U. fusca y Synedrella nodiflora, esta última es el primer registro de una planta que no es Poaceae.

First Report of Siphosturmia rafaeli (Townsend)1 as a Parasitoid of Diatraea saccharalis (Crambidae) at Tabasco, México

Abstract. Sugarcane borer, Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae), is a key insect pest that affects crop yield in Mexico. Immature stages of the pest are naturally attacked by a complex of parasitoids. We identified the parasitoid Siphosturmia rafaeli (Townsend) to be a new record at Tabasco, Mexico, and reported a new host.

Damage by Diatraea sacharalis (Fabricius)1 to Sugarcane at la Chontalpa, Tabasco, México

Abstract. Sugarcane borer (Lepidoptera: Pyralidae) feeds on buds and shoots of young plants and tunnels in stalks, causing yield loss and affecting juice quantity and quality of harvested sugarcane (Saccharum officinarum L.). The objective of this research was to evaluate pest damage and identify borer species at La Chontalpa, Tabasco, Mexico. Samples were collected starting in February during plant growth and before harvest. Stalks were 8.9% infested and 1.9% damaged before harvest based on a damage scale for the pest, and 9.4% of plants had dead growing points. Diatraea saccharalis (Fabricius) was the only borer species found in the region. Infestation by D. saccharalis was low in sugarcane in the area.

Species of Stalk Borers (Lepidoptera: Crambidae) and Damage to Maize in Southeastern Mexico

Abstract. Stalk borers (Diatraea spp.) are important pests of maize, Zea mays L., in the Neotropical region. The objective of this research was to identify the Diatraea species and assess the injury they cause and their effect on yield of maize at Tabasco, Mexico. In total, 199 larvae and 54 pupae were found infesting 319 (62.4%) of 511 plants sampled. Species analyses showed 97.6% were Diatraea lineolata (Dyar) and 2.4% D. saccharalis (F). Despite the great amount of injury, no significant difference between yield and the number of nodes injured per plant was observed (R2 = 0.014, P > 0.05). This is the first report of corn borers injuring maize in this area, and the findings suggest economic damage does not occur when stalk injury is <63% and maize matures before the borers complete development.

Nitrogen Metabolism and Tomato Yield in Response to Organic Fertilization

We assessed the effects of organic fertilization on the response of biochemical and physiological indicators and the yield of saladette-type tomato (Solanum lycopersicum L.) grown under greenhouse conditions. Five fertilization forms [sand + inorganic nutrient solution (F1); sand + vermicompost tea (F2); a mixture of sand, compost, + vermicompost tea (F3); a mixture of sand, vermicompost, + vermicompost tea (F4); and a mixture of sand, compost, vermicompost, + vermicompost (F5)] and two genotypes (Cuauhtémoc and El Cid) were evaluated. The parameters analyzed were leaf pigments, enzymatic activity of nitrate reductase (NR) in vivo, and yield. A fertilizer source of sand + vermicompost tea resulted in the best assimilation of nitrate (NO3-), the greatest NR endogenous activity, the second highest foliar concentration of organic nitrogen (N), and the second best yield. In conclusion, for improved tomato cultivation during organic production, treatment F2 produced the maximum organic yield and resulted in more efficient N utilization.