Agustín Aragón-García

Description of the third instar larvae of five species of Cyclocephala (Coleoptera, Melolonthidae, Dynastinae) from Mexico

Description of the third instar larvae of five species of Cyclocephala (Coleoptera, Melolonthidae, Dynastinae) from Mexico. Larvae of four species of Cyclocephala are described for the first time based on specimens collected in Mexican localities: C. barrerai Martinez, 1969 from Puebla, C. sinaloae Howden & Endrodi, 1966 from Sinaloa, C. fasciolata Bates, 1888 from Veracruz, and C. jalapensis Casey, 1915 from Hidalgo. Larva of C. lunulata Burmeister, 1847, is redescribed based on specimens from the Mexican states of Morelos, Puebla, and Veracruz. Diagnostic structures are illustrated and the differences and similarities of each species with other previously described larvae of the genus are commented.

New saponins from Sechium mexicanum

The chemical study of Sechium mexicanum roots led to the isolation of the two new saponins {3‐O‐β‐D‐glucopyranosyl (1 → 3)‐β‐D‐glucopyranosyl‐2β,3β,16α,23‐tetrahydroxyolean‐12‐en‐28‐oic acid 28‐O‐α‐L‐rhamnopyranosyl‐(1 → 3)‐β‐D‐xylopyranosyl‐(1 → 4)‐α‐L‐rhamnopyranosyl‐(1 → 2)‐α‐L‐arabinopyranoside} (1) and {3‐O‐β‐D‐glucopyranosyl (1 → 3)‐β‐D‐glucopyranosyl‐2β,3β,16α,23‐tetrahydroxyolean‐12‐en‐28‐oic acid 28‐O‐α‐L‐rhamnopyranosyl‐(1 → 3)‐β‐D‐xylopyranosyl‐(1 → 4)‐[β‐D‐apiosyl‐(1 → 3)]‐α‐L‐rhamnopyranosyl‐(1 → 2)‐α‐L‐arabinopyranoside} (2), together with the known compounds {3‐O‐β‐D‐glucopyranosyl‐(1 → 3)‐β‐D‐glucopyranosyl‐2β,3β,6β,16α,23‐pentahydroxyolean‐12‐en‐28‐oic acid 28‐O‐α‐L‐rhamnopyranosyl‐(1 → 3)‐β‐D‐xylopyranosyl‐(1 → 4)‐α‐L‐rhamnopyranosyl‐(1 → 2)‐α‐L‐arabinopyranoside} (3), tacacosides A1 (4) and B3 (5). The structures of saponins 1 and 2 were elucidated using a combination of 1H and 13C 1D‐NMR, COSY, TOCSY, gHMBC and gHSQC 2D‐NMR, and FABMS of the natural compounds and their peracetylated derivates, as well as by chemical degradation. Compounds 1–3 are the first examples of saponins containing polygalacic and 16‐hydroxyprotobasic acids found in the genus Sechium, while 4 and 5, which had been characterized partially by NMR, are now characterized in detail. Copyright

Coleoptera Scarabaeoidea Collected with Light Trap in Deciduous Tropical Forest of Northern Sinaloa, Mexico

Abstract. Species richness, abundance, and seasonal distribution of Coleoptera Scarabaeoidea were evaluated in a deciduous tropical forest at Choix and El Fuerte, Sinaloa, Mexico, from July to October 2009 by means of nocturnal collections at three locations. More than 36,000 specimens were obtained, representing 45 species and 21 genera of Melolonthinae, Rutelinae, Dynastinae, Scarabaeinae, Hybosoridae, Ochodaeidae, Geotrupidae, Trogidae, and Passalidae. The genus with the highest richness index was Phyllophaga with 12 species, Phyllophaga opaca being the dominant species. The best represented species were Oxygrylius ruginasus (96.97%), Digitonthophagus gazella (1.18%), Cyclocephala freudei (0.34%), Pelidnota virescens (0.13%), and Phyllophaga opaca (0.04%). Adult activities were strictly seasonal, because the greatest abundance occurred during August (89.91%), where high rains were recorded, while during October no scarab beetle was collected.

Description of the Larvae of Three Species of Macrodactylus Dejean (Coleoptera: Scarabaeidae: Melolonthinae) from Mexico, with Notes on the Reproductive Behavior of Macrodactylus ocreatus Bates

ABSTRACT Third instars of Macrodactylus mexicanus Burmeister, Macrodactylus nigripes Bates, and Macrodactylus ocreatus Bates are described from specimens collected from soil in corn fields at Chignahuapan, Puebla and La Malinche, Tlaxcala, and from soil in an amaranth grain field at Zapotitlán Salinas, Puebla. Illustrations of diagnostic structures, comparative comments with similar species, and a key to known third instars of Macrodactylus Dejean in Mexico are included. Data on the habits and reproductive behavior of M. ocreatus in nature and in captivity are also provided.

Five new species of Phyllophaga (Coleoptera: Melolonthidae) of Northwestern Mexico

Abstract Five new species of Phyllophaga of northwestern Mexico are described: P. (Listrochelus) balacachiana sp. nov. from tropical thorny forests of northern Sinaloa and southern Sonora; P. (Listrochelus) tascatensis sp. nov. from pine and oak forests of northern Sinaloa and southwestern Chihuahua; P. (Listrochelus) choixiana sp. nov. from tropical deciduous forest of northern Sinaloa; P. (Listrochelus) reyesolivasi sp. nov. from pine and oak forest of southwestern Chihuahua; and P. (Phyllophaga) collaroides sp. nov. from pine and oak forests of northern Sinaloa and southwestern Chihuahua. Illustrations of diagnostic characters and comments on the differences from similar species are included.

Consumption and Developmental Capacity of Chrysoperla carnea (Stephens)1 on the Sugarcane Aphid (Melanaphis sacchari Zehntner)2 in Puebla, México

Resumen. Se evaluó bajo condiciones de laboratorio la capacidad de consumo y desarrollo de larvas de Chrysoperla carnea alimentadas con Melanaphis sacchari y con huevos de Sitotroga cerealella. El promedio de ninfas de M. sacchari consumidas por los diferentes estadios larvales de C. carnea fue diferente; el primer estado larval (L1) consumió 13.9 ninfas, el segundo 32.2, y el tercero 93.5. La duración de los estadios larvales no fue diferente en ambos tratamientos. El período larva-adulto, pupa y la longevidad de los adultos fueron menores, cuando las larvas se alimentaron con ninfas de M. sacchari. La supervivencia de los adultos de C. carnea fue mayor en el tratamiento de alimentación con huevos de S. cerealella (65.5%). La fecundidad en el tratamiento de alimentación de larvas con huevos de S. cerealella fue mayor (23 huevos/hembra/día), en comparación con el tratamiento de alimentación con ninfas de M. sacchari (18 huevos/hembra/día); la fertilidad no fue diferente en ambos tratamientos. Estos resultados, sugieren que Chrysoperla carnea puede desarrollarse, completar su ciclo biológico, y reproducirse de manera normal, al alimentarse en estado de larva con ninfas de M. sacchari. Chrysoperla carnea puede considerarse como una especie potencial para el control biológico de M. sacchari, sobre todo en liberaciones de larvas de segundo y tercer estadío, por tener mayor consumo, aunque es necesario realizar evaluaciones adicionales en campo que complementen esta información.

Rate of consumption, biological parameters, and population growth capacity of Orius laevigatus fed on Spodoptera exigua

Orius laevigatus (Fieber) (Hemiptera: Anthocoridae) is already successfully used to control Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) in protected crops. In the present work, the predatory capacity of O. laevigatus on the eggs and larvae of Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae) as well as the population growth capacity of O. laevigatus fed on eggs of the noctuid were determined. Fourth and 5th instar nymphs had a greater consumption of eggs than younger ones. Females consumed more eggs than males. Only 5th instar nymphs and adults preyed on the neonatal larvae of S. exigua. The intrinsic rate of natural increase did not differ between O. laevigatus fed with S. exigua eggs and those offered eggs of the substitute host Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae). Thus, O. laevigatus is a good candidate for the biological control of S. exigua, a cosmopolitan pest of many crops.

Actividad Biológica de un Extracto de Semillas de Trichilia havanensis Jacq.1 sobre Larvas de Spodoptera exigua (Hübner)2

Resumen. Se evaluó el efecto de un extracto acetónico de semillas de Trichillia havanensis Jacq. en estado sólido (resina) y de su aceite sobrenadante, a diferentes concentraciones, sobre la viabilidad y desarrollo de larvas neonatas del gusano soldado Spodoptera exigua (Hübner). Ambos estados del extracto mostraron mayor mortalidad larvaria a medida que se incrementó la concentración y el tiempo de ingestión a las concentraciones de 7500 y 10000 mg/l. De la misma forma se observó una reducción significativa en el peso de las larvas tratadas en comparación con el tratamiento testigo, a partir de la concentración de 100 mg/l de los dos estados del extracto a los 12 d de iniciado el ensayo, así como un notable retraso en el desarrollo de la larva, que se reflejó en un alargamiento del ciclo biológico del insecto a partir de la concentración de 500 mg/l de ambos estados del extracto adicionado a la dieta proporcionada a las larvas para su alimentación, manteniendo en primer estadio a las larvas supervivientes hasta el día 31.

Technological Model and Sustainable Rural Development for Rainy-Spell Corn Producers in Mexico

Mexican agriculture presents problems that affect the producers, the rural society and the alimentary security. The first one has to do with the poverty of the field inhabitants. Data from the Consejo Nacional de Evaluacion de la Politica de Desarrollo Social (CONEVAL), indicate that by 2008, 44.2% of the population (47.2 million Mexicans) was poor, having at least one social lack and an insufficient income to acquire alimentary and nonalimentary goods considered basic. Out of the total of the poor population, 63.2% inhabit the rural and 36.8% the urban surrounding (CONEVAL, 2010). Poverty tends to worsen because the prices of foods have increased; at the beginning of 2008 the real prices of foods were 64% higher than those of 2002 and the index of food prices marked a maximum of 214.7 points in December of 2010 (Diouf, 2011).