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Resumen: A lo largo de la historia las mujeres han luchado por ser incluidas y reconocidas en el desarrollo de la ciencia médica. En la actualidad, las mujeres tienen mayor participación no solo en el estudio y ejercicio de la medicina sino en el liderazgo de diversas áreas médicas. Este artículo ofrece un panorama histórico de las primeras mujeres que formaron parte de la Academia Nacional de Medicina de México, así como una recopilación de la participación de las mujeres en puestos directivos; desde Jefaturas de Departamentos Académicos en la Universidad Nacional Autónoma de México hasta el sector salud. Abstract: Throughout history women have been fighting to be included and recognized in the development of medical science. Actually, women have more participation not only in the study and practice of medicine, but in the leadership of various medical areas. This article provides a historical review of the first women it formed part of the National Academy of Medicine of Mexico as well as a compilation of the participation of women in management positions, from Headquarters of academic departments at the National Autonomous University of Mexico including health sector.

Bucking the trend Responses to climate change have been observed across many species. There is a general trend for species to shift their ranges poleward or up in elevation. Not all species, however, can make such shifts, and these species might experience more rapid declines. Kerr et al. looked at data on bumblebees across North America and Europe over the past 110 years. Bumblebees have not shifted northward and are experiencing shrinking distributions in the southern ends of their range. Such failures to shift may be because of their origins in a cooler climate, and suggest an elevated susceptibility to rapid climate change. Science , this issue p. 177

In 2 consecutive years, ground beetles (Coleoptera: Carabidae) were sampled in commercial organic and conventional potato fields, using pit fall traps. Four conventional and 3 organic potato fields were surveyed to determine ground beetle taxa composition. In a related study, potato fields were assigned to 1 of 4 transitional systems to include: organic, no spray (usually referred to as no control and/or only OMRI certified control), IPM-conventional (directed control, after sampling) and conventional (broad spectrum pesticides) systems. Seven taxa of ground beetles were identified: Anisodactylus kerbyi Lindroth 1953, Amara sp., Bembidion sp., Calosoma cancellatum Eschscholtz 1833, Calathus ruficollis Casey 1920, Calathus ingratus Dejean 1828, and Pterostichus adstrictus Eschscholtz 1823. With the exception of C. cancellatum, which was not identified from organic fields in the first yr of this study, all taxa were collected in both organic and conventional potato fields both yr. Based on total number of specimens collected, Bembidion sp., P. adstrictus and Amara sp. represented 42.8% of the total specimens collected. The smallest number of ground beetles was collected from no spray and IPM-conventional systems. This study provides basic valuable information regarding beetles populations for growers making transition from conventional to organic potato production.

Potato phytonutrients include phenolic acids, flavonols, anthocyanins, and carotenoids. Developmental effects on phytonutrient concentrations and gene expression were studied in white, yellow, and purple potatoes. Purple potatoes contained the most total phenolics, which decreased during development (from 14 to 10 mg g(-1)), as did the activity of phenylalanine ammonia-lyase. The major phenolic, 5-chlorogenic acid (5CGA), decreased during development in all cultivars. Products of later branches of the phenylpropanoid pathway also decreased, including quercetin 3-O rutinoside, kaempferol 3-O-rutinoside, and petunidin 3-O-(p-coumaroyl)rutinoside-3-glucoside (from 6.4 to 4.0 mg g(-1)). Violaxanthin and lutein were the two most abundant carotenoids and decreased 30-70% in the yellow and white potatoes. Sucrose, which can regulate phenylpropanoid metabolism, decreased with development in all cultivars and was highest in purple potatoes. Total protein decreased by 15-30% in two cultivars. Expression of most phenylpropanoid and carotenoid structural genes decreased during development. Immature potatoes like those used in this study are marketed as "baby potatoes", and the greater amounts of these dietarily desirable compounds may appeal to health-conscious consumers.

This work reports on the use of cultural practices that influence grasshoppers' nymphal emergence. Grasshop- per eggs were buried at depths of 2, 14, 18, 22, and 26 cm in laboratory arenas. Nymph eclosion ranged from 77.5 to 87.8%. However, nymph emergence, measured as the number of nymphs that reached the soil surface, was estimated at 70.9% when eggs were buried at 2cm, but was reduced to 2.5 % at 18cm depth. No nymphs emerged at depths of 22 cm or more. The relative high percentage of nymphal eclosion and the low or no nymph emergence suggests that the depths tested on this trial do not affect egg development and nymphal eclosion, but affect the ability of the insect to emerge to the soil surface, thus increasing first instar mortality. The addition of sand to the soil reduced nymphal emergence. A signifi- cantly lower percentage of hoppers emerged from sand as compared to soil, vermiculite, or soil mixed with 25, 50 and 75% sand. This suggests that cultural practices, such as plowing can be used as a management tool to control grasshop- pers. Further research should investigate if nymphs died of suffocation at the eclosion site or in the process of emerging to the soil surface.

Summary Antioxidant activity (ABTS assay), total phenolics and total anthocyanins were determined in the petioles of twenty-nine rhubarb (Rheum spp.) varieties. Antioxidant activity ranged from 463 ± 50 (Rheum officinale) to 1242 ± 2 μmol Trolox per g DW (Valentine). The phenolic content varied from 673 ± 41 (Loher Blut) to 4173 ± 23 mg GAE/100 g DW (Plum Hutt) and had a low correlation (r = 0.663) with antioxidant results. Seven of the varieties (Plum Hutt, Valentine, Minnesota No. 8, Cherry Red, Cawood Delight, Coulter McDonald and OR 23) had higher total phenolics than kale, a vegetable rich in phenolics. The concentration of anthocyanins ranged from 19.8 ± 1.5 (Crimson Red) to 341.1 ± 41.6 mg/100 g DW (Valentine). The percentages of two main anthocyanins in rhubarb, cyanidin 3-glucoside and cyanidin 3-rutinoside varied from 66.07:33.93, respectively, in Valentine to 9.36:90.64, respectively, in R. officinale.

A molecular and biometric assessment and redescription of Myzodium mimulicola (Drews and Sampson) are provided. New North American host and distributional data are presented, including the first record from Alaska. Myzodium knowltoni (Smith and Robinson) is a junior subjective synonym of M. mimulicola, based on molecular-sequence and morphological evidence. A key to the known Myzodium species (apterae and alatae) is included.

Wireworms are becoming more of a problem in potato [Solanum tuberosum (L.)] producing areas, especially where potatoes are seasonally rotated with grasses, like in interior Alaska. The objective of this research was to study the species composition and seasonal biology of adult elaterids (Coleoptera: Elateridae) associated with potato production at two localities in interior Alaska: Fairbanks (N64.85°, W147.85°) and Delta Junction (N64.04°, W145.73°). A total of 1,329 elaterids were collected during the years 2006 and 2008. Ninety-three percent of the total number of specimens were either Hypnoidus bicolor (Eschscholtz) (29%) or Limonius pectoralis (LeConte) (64%). However, adult insect counts reversed between localities; 84% individuals from Delta Junction were H. bicolor, whereas 91% of the individuals from Fairbanks were L. pectoralis. The species composition was also different between localities. Five species were collected from the Delta Junction area, while seven species were collected from the Fairbanks area. The highest insect count observed was 62 adult L. pectoralis per 14-day sampling period on May 30 in the Fairbanks area. In spite of the highest insect trap catch recorded, insect counts in Fairbanks remained below 0.2 insects per trap per 14-day sampling period during most of the season. In the Delta Junction area, L. pectoralis was collected from late May until mid August with a population peak of 12 insects per trap per 14-day sampling period. Adult elaterid counts start to build up and end activities earlier in Fairbanks as compared to Delta Junction. This represents the first long term report on species diversity of elaterids in potatoes from interior Alaska. In addition, this is the first time elaterids have been shown associated with potatoes in Delta Junction, Alaska.

SPIDERS ASSOCIATED WITH PAPAYA, CARICA PAPAYA L., IN PUERTO RICO

The seasonal activity of adult elaterids (Coleoptera: Elateridae) associated with potato production was studied in Palmer, Alaska (N61.60°, W149.13°) from May 13, 2004 to October 17, 2006. Additionally, the University of Alaska Museum (UAM) Insect Collection was inspected for the presence of adult elaterids collected in Alaska. Eight species from seven genera were collected from the field study: Ampedus nigrinus (Herbst), Corymbitodes lobatus (Eschscholtz), Hypnoidus abbreviatus (Say), Hypnoidus bicolor (Eschscholtz), Neohydonus spp., Pseudanostrius propolus (LeConte), Selatosomus morulus (LeConte), and Sericus incongruus (LeConte). The UAM collection contained 157 specimens representing 10 genera with 18 species. During our study, six of the 18 species present in the UAM were collected in the field, while two of the species collected during our field study, H. abbreviatus and Pseudanostrius propulus (LeConte) were not present at the UAM collection. Species collected during our study and present at the UAM include three of the six most economically important genera (Limonius, Ctenicera, and Hypnoidus) in terms of potato production in North America. Nearly all (97%) of the specimens collected from the field study were either H. abbreviatus (38%) or H. bicolor (59%). The relative counts of H. bicolor and H. abbreviatus varied by years; during 2004, H. abbreviatus was the dominant species (71%), but H. bicolor outnumbered (95%) H. abbreviatus during 2006. During 2004 and 2006, adult activity for both species started to build up during mid June, but was delayed until mid July during 2005. Both species showed adult activity until mid September. No adult activity was detected for any species during October of any of the years studied.

Rhubarb includes approximately 60 species in the genusRheum. It has been utilized for thousands of years for medicinal purposes, but only recently identified for its culinary use. In the mid 1700s, edible petioles were discovered on seedlings from rhubarb species. Hundreds of cultivars have since been identified for a wide range of uses from tarts to wine. Unfortunately, propagation by seed and irregular naming has resulted in a plethora of similarly named cultivars and multitude of phenotypes. Fifteen morphological characters were evaluated to differentiate rhubarb cultivars in the USDA, ARSRheumcollection in Palmer, Alaska. Two years of morphological data, focusing on horticultural characteristics indicated variation between the years. To improve cultivar resolution, the results suggest using 1 year's data instead of combining data from different years. The mean °Brix observed was 3.8, with a range from 2.2 to 6.1. Flesh colour and basal skin colour were poorly correlated (R2 = 0.462); overall skin colour was more red at the base than in the middle of the petiole. Rhubarb character categories, in particular petiole number and petiole base thickness, need to be modified to better anticipate the range of expected values, and thereby contribute improved reproducibility and reliability to separate cultivars based on morphological characters.

Leafhopper transmitted phytoplasma diseases are an emerging problem for potato and vegetable producers in the conterminous US. Due to its geographical isolation and climatic constraints, Alaska is considered relatively free of diseases and insect pests; therefore growers in the state are exploring the potential of producing seed potato for export. However, the biology of agricultural insect pests in the circumpolar region is lacking or poorly understood. Research conducted from 2004 to 2006 in the main potato (Solanum tuberosum L.) production areas of Alaska resulted in the identification of 41 leafhopper species associated with agricultural settings. Twenty species were identified from sweep net samples and adhesive cards in association with potato. Two species, Davisonia snowi (Dorst) and Macrosteles fascifrons (Stal), made up approximately 60% of the total number of individuals collected, representing 34 and 26%, respectively. Both species, M. fascifrons and D. snowi generally arrived in fields by late May to early June and numbers peaked by late June to July, but in all years M. fascifrons populations peaked earlier than D. snowi. Twenty-three percent of the specimens were immature or could not be identified. Three of the species collected [Balclutha punctata (Fabricius), M. fascifrons, and Scaphytopius acutus (Say)] are known vectors of phytoplasmas of potatoes and other agricultural crops or have the potential to cause mechanical damage to potatoes. This report represents the first extensive study of cicadellids from potatoes in Alaska.

La mosca blanca, Bemisia tabaci Gennadius y B. argentifoUi Bellows & Perring (1994), son plagas de hortalizas y ornamentales en varias regiones del mundo. En el tomate (Lycopersicon esculentum Mili.), este complejo de insectos puede causar debilitamiento, clorosis en las plantas, necrosis, perdida de rendimiento y maduracion irregular del fruto (Stansly et al., 1991,1994; Schuster et al., 1992,1993; Naranjo et al., 1998; Hoddle, 2008; IFAS, 2008). Bemisia tabaci es ademas vector de geminivirus (Byrne et al., 1990; Bird y Brown, 1998; Mau y Lee, 2003; Hoddle, 2008; IFAS, 2008). En Puerto Rico, el control biologico y el dano combinado de la mosca blanca y virosis en tomate ha sido estudiado por Bastidas (1999) y Pantoja et al. (1999; 2005), determinandose que la especie predominante en los campos comerciales de tomate en el sur de Puerto Rico durante los anos 1997-1999 fue B. argentifoUi (Bastidas, 1999). Martorell (1976) reporta la presencia de dos species de Bemisia (B. tabaci y B. iconspicua) en Puerto Rico, pero no en el cultivo de tomate. La situacion taxonomica y la dinamica poblacional del complejo de moscas blancas en el campo ha sido estudiada por Byrne et al. (1990), Bellows et al. (1994), Bird y Brown (1998) y Hoddle (2008). La presencia de malezas en los campos es un factor importante en la incidencia de la mosca blanca (Salguero, 1993; Hoddle, 2008) ya que las malezas sirven de hospederos alternos del insecto y reservonos para enfermedades virales (GeminiDetective, 2008; Hoddle, 2008). Este trabajo presenta las principales malezas hospederas de la mosca blanca en siembras comerciales de tomate en el sur de Puerto Rico durante los anos 1997-1998. Las evaluaciones de mosca blanca se realizaron semanalmente en la Estacion Experimental Agricola de Juana Diaz y siembras comerciales de tomate en los pueblos de Santa Isabel y Salinas, Puerto Rico. Los muestreos se realizaron a partir de la segunda semana despues del trasplante del tomate. Las malezas fueron inspeccionadas para la presencia de ninfas de mosca blanca. Plantas con ninfas de mosca blanca fueron marcadas y colectadas cuando se observo presencia de la inflorescencia o estructuras que permitieran la identificacion taxonomica. Dado que B. argentifoUi era la especie predominante durante el periodo de estudio (Bastidas, 1999), las ninfas no fueron identificadas a nivel de especie. La presencia de ninfas fue considerada como indicativo de una planta hospedera para el insecto. Las malezas fueron identificadas por M.L. Lugo y por comparacion con plantas en la coleccion de malezas de la Estacion Experimental Agricola. De cada planta marcada o con presencia de mosca blanca se tomaron seis hojas al azar. Las hojas fueron transportadas al laboratorio e inspeccionadas bajo magnificacion para determinar el total de ninfas en 6.5 cm de hoja. Se identificaron 18 especies de malezas colonizadas por la mosca blanca (Cuadro 1). Las malezas mas frecuentes en la zona fueron Triantema portulacastrum, Portulaca ole

Traps baited with two types of chemical feeding attractants yielded 97 species of macrolepidoptera at three areas in Alaska (Fairbanks, Delta Junction, and Palmer). These were 16 geometrid, 1 thyatirid, and 76 noctuid moth species and 4 species of nymphalid butterflies. Potential crop pests trapped included Apamea devastator (Brace) (glassy cutworm), Xestia c-nigrum L. (spotted cutworm), Xestia smithii (Snellen) (Smith's dart), Euxoa ochrogaster (Guenée) (redbacked cutworm), and Discestra trifolii (Hufnagel) (clover cutworm). The clover cutworm was captured early in the season (May into June), while Smith's dart, glassy cutworm, spotted cutworm, and redbacked cutworm were captured in traps in mid to late summer. Many more species and greater numbers of moths were captured in traps baited with acetic acid and 3-methyl-1-butanol than in traps baited with a multicomponent floral lure (phenylacetaldehyde, methyl salicylate, methyl-2-methoxy benzoate, and β-myrcene). However, most of the geometrid moths captured (12 of 16 species) were in floral lure traps, while one species of Hadeninae (Noctuidae) and both species of Plusiinae (Noctuidae) were trapped exclusively in floral lure traps. The one thyatirid, both Catocalinae noctuid species, and most Amphipyrinae, Cuculliinae, Hadeninae, and Noctuinae noctuid species were captured in traps baited with acetic acid and 3-methyl-1-butanol. In addition, large numbers of bumblebees were captured in traps baited with the floral lure, while large numbers of yellowjackets were captured in traps baited with acetic acid and 3-methyl-1-butanol.

El umbral de acción para Tibraca limbativentris Stal (TL) en arroz fue calculado en 8.8 y 25.8 TL por 10 pases de red entomológica para plantas de 30 y 40 días, respectivamente. Estudios de la densidad poblacional de TL en dos localidades del Valle del Cauca, Colombia, indican densidades de 1.2TL por pase de red entomológica (12TL por 10 pases de red). Densidades equivalentes al umbral calculado no se observaron en los arrozales del Valle del Cauca, Colombia, durante los años de estudio. Infestaciones a plantas de 15 y 20 días de germinadas no se reflejan en daño o rendimiento, lo que sugiere que las evaluaciones para densidad insectil deben ser en plantas de 25 a 40 días de germinadas.

Lozier et al. accept our findings but take issue with a concluding sentence alluding to relocation to mitigate potential climate change impacts on bumblebee species. We welcome thoughtful discussion of this admittedly difficult area ([ 1 ][1]). However, Lozier et al. present an idiosyncratic view of

On the basis of head capsule widths of field-collected larvae, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) was found to have five instars. Mean head capsule widths were 0.44, 0.71, 1.04, 1.48, and 1.85 mm for the first to fifth instars, respectively. The greatest growth ratio was recorded between the first and second instar. Adult C. sordidus densities reached a peak in January with 2.4 adults per trap, and the lowest density recorded was during April with 0.7 adults per trap. Adult captures seems to be influenced by precipitation with higher captures after precipitation events.

Se recolectaron áfidos asociados a la papaya en dos lugares en Puerto Rico (Isabela y Corozal) y en tres fincas y un predio en el Centro de Investigaciones de la Universidad de Florida, TREC, en Homestead, Florida. Entre las dos regiones, Florida y Puerto Rico, se recolectaron veintiuna especies de áfidos de 12 géneros: Aphis sp., Aphis illinoisensis Shimer, Aphis spiraecola Patch, Aphis gossypii Glover, Aphis craccivora Koch, Aphis iddletonii (Thomas), Aphis nerii Boyer de Fonscolombe, Hyperomyzus carduellinus (Theobald), Hysteroneura setariae (Thomas), Lipaphis pseudobrassicae (Davis), Picturaphis sp., Pentalonia nigronervosa Coquerel, Schizaphis graminum (Rondani), Sarucallis kahawaluokalani (Kirkaldy), Shinjia orientalis (Mordvi- Iko), Schizaphis rotundiventris (Signoret), Toxoptera citricida (Kilkardy), Toxoptera aurantii (Boyer de Fonscolombe), Tetraneura nigriabdominalis (Sasaki), Uroleucon ambrosiae (Thomas), and Uroleucon pseudoambrosiae (Olive). El número de especies de áfidos fue mayor en Florida (n = 14) que en Puerto Rico (n = 11). En Puerto Rico, se encontraron diferencias en el número de especies por localidad, con 10 especies en Corozal y seis en Isabela. Solo una especie, A. illinoisensis, se encontró en todos los campos donde se tomaron muestras, mientras que A. spiraecola, A. gossypii y A. craccivora se recolectaron tanto en Corozal, Puerto Rico, como en Florida. La diferencia en composición de especies entre localidades en Puerto Rico (Corozal e Isabela) y regiones (Florida y Puerto Rico) parece estar asociada con la diversidad de los cultivos agrícolas y especies de malezas presentes.

The effect of the legume Mucuna deeringiana on Cosmopolites sordidus population dynamics and damage was studied in two planting systems: intercropping with mucuna and mucuna as green mulch before establishing the plantain. The relationship between C. sordidus adult density and larval damage was also studied. The presence of M. deeringiana affected the incidence of C. sordidus .The data suggest that C. sordidus adults are attracted by M. deeringiana , but additional studies are needed to better understand the relationship between the legume and the insect. The presence of M. deeringiana did not affect plantain height, stem diameter, or sucker production if the legume was eliminated four months after planting. However, management practices to establish and cultivate the legume increased production costs. Although C. sordidus population densities were low during most of the year, a high population density was recorded from November to January. A second population explosion was recorded between June and August. The highest insect density recorded was 3.5 insects per trap.

Se estudió el desarrollo de Tibraca obscurata Bergroth y T. limbativentris Stal en arroz en el suroeste de Colombia. Tibraca limbativentris requirió mayor tiempo para completar su desarrollo que T. obscurata. Las hembras de T. limbativentris requirieron más tiempo para completar su desarrollo que los machos, pero el desarrollo de T. obscurata fue similar en los dos sexos. Las hembras de T. limbativentris son más longevas que los machos. Tibraca limbativentris depositó aproximadamente 200 huevos en un periodo de 86 días. El tiempo de incubación de los huevos fue igual para los dos sexos (6.5 d).

Se estudió la distribución y establecimiento de controladores biológicos de la mosca blanca en Puerto Rico. Quinientos treinta parasotoides se recuperaron de 99 lugares de muestreo. El género Encarsia spp. representó sobre el 90% de las muestras estudiadas, mientras que el género Eretmocerus spp. representó solamente el 9.5%. La especie Eretmocerus hayati, de Pakistán, representó el 56% del total para ese género, seguido de Er. mundus, importado de España (38%). En el estudio, la especie Encarsia sophia proveniente de Pakistán fue la más abundante de su género, con un 26.6% de los especímenes para ese grupo y 26.8% del total de especímenes. Cinco especies de Encarsia, probablemente especies nuevas de Puerto Rico, se detectaron durante el estudio. Dos de las especies nuevas representaron aproximadamente el 23% del total de especímenes estudiados.

Se evaluó la incidencia de garrapatas, las prácticas de control y las pérdidas económicas asociadas con la presencia de éstas en los hatos lecheros de Puerto Rico. Se utilizaron datos obtenidos por medio de una encuesta realizada a ganaderos de 261 vaquerías, las que representaron el 85% del total en la isla. El 71 % de los entrevistados mencionó tener problemas de garrapatas en el hato. Para controlar las garrapatas, un 97% de los ganaderos aplicaba plaguicidas sobre los animales; 8%, sobre las estructuras. El método más común de aplicación de garrapaticidas (73%) fue por aspersión con bombas en el cepo. La incidencia de problemas con garrapatas en las vacas horras fue de 72%, mientras que en las vacas en ordeño fue de 54%. El análisis de regresión Poisson que se realizó no mostró diferencias significativas en mortandad de animales entre las zonas noroeste y nordeste de la isla. Sin embargo, hubo diferencias entre municipios. El costo anual promedio del programa de control de garrapatas que mantienen los ganaderos ascendió a $28.09 por vaca; las pérdidas por mortandad son mucho mayores.

Se estudió la herencia de resistencia al daño mecánico por sogata, Tagosodes orizicolus (Muir), en dos parentales con resistencia al daño mecánico por el insecto. La evaluación de las generaciones F1 and F3 que la resistencia al daño mecánico por sogata se debe a la acción de un gen principal dominante (A) presente en el estado homocigoto en los parentales Mudgo y Makalioka. Dicho gen confiere resistencia y su expresividad está condicionada por la acción de un gen modificador (B). El gen modificador condiciona la manifestación de resistencia. La modificación del gen puede ser dependiente del genotipo de la planta y del tiempo de exposición al ataque del insecto. Para Mudgo se propone que el gen modificador se encuentra en la forma homocigota recesiva (bb) lo cual acelera la expresión del fenotipo susceptible y para Makalioka en la forma homocigota dominante (BB), la cual retarda la expresión del fenotipo susceptible.

The development and reproduction of Oebalus insularis (Stal) and O. ornatus (Sailer) were studied on rice. Both females and males of O. insularis took longer to complete development than O. ornatus. Both species complete development in five instars. No significant differences in the number of days to lay eggs, the days ovipositing, and the number of eggs were detected between species.

Action thresholds were calculated to be 1.7 H. similis and 1.9 D. soluta per rice plant. These densities are equivalent to 7,140 H. similis and 7,980 D. soluta per 10 sweeps. Densities equal to the action thresholds of these two species have not been observed in rice fields of Valle del Cauca, Colombia.

LA PAPAYA COMO NUEVO HOSPEDERO DE EMPOASCA FABALIS EN PUERTO RICO

RECOVERY OF PLAESIUS JAVANUS ERICHSON FROM PLANTAINS IN PUERTO RICO

SEASONAL ABUNDANCE OF ANASTREPHA SUSPENSA (DIPTERA: TEPHRITIDAE) FROM CITRUS IN PUERTO RICO

PARACOCCUS MARGINATUS WILLIAMS AND GRANARA DE WILLINK (HOMOPTERA: PSEUDOCOCCIDAE) AFFECTING PAPAYA IN PUERTO RICO

Se estudió el desarrollo de Schizotetranychus oryzae sobre plantas de arroz. El tiempo de desarrollo de huevo a adulto alcanzó 16 días. La relación hembra macho fue de 3:1. El número de huevos por hembra fue de 18.6 y 14.1 en Bluebonnet 50 y Cica 8, respectivamente. El ácaro es capaz de duplicar su densidad poblacional cada ocho días.

The phylogeny of a previously unidentified, obligate laticifer-inhabiting bacterium associated with the papaya bunchy top disease was investigated. Portions of genes corresponding to those for 16S rRNA, the flavoprotein subunit of succinate dehydrogenase (SdhA), citrate synthase (GltA), and the 17-kDa rickettsial common antigen were isolated and sequenced from the non-cultivable bacterium from diseased plants. Comparative sequence analyses consistently indicated that the bacterium is a member of the alpha-subdivision of the Proteobacteria and of the genus Rickettsia. The rickettsia was detected by polymerase chain reaction in diseased, but not healthy, papaya tissues and in the leafhopper vector, Empoasca papayae, providing further evidence of the possible etiological role of the bacterium in the disease. Although Rickettsia have been found naturally in arthropods and can be pathogenic to humans and other vertebrates, this is the first evidence of its kind implicating a Rickettsia as a plant pathogen.

Relative abundance of stink bugs was determined from 01 May 1989 to 30 September 1992 in 80 commercial rice fields in Colombia and in 12 selected rice-producing countries of Latin America. Fifteen stink bug species from nine genera were found in Colombia. The species are Oebalus ornatus (Sailer), Mormidea maculata Dallas, Tribraca obscurata Bergroth, M. pictiventris Stål, O. pugnax torridus (Sailer), Proxys punctulatus (Palisot de Beauvois), O. insularis (Stål), T. limbativentris Stål, and O. ypsilongriseus (De Greer). In Valle del Cauca Department in southwestern Colombia, the most abundant species was O. ornatus representing 94.1% of the stink bugs collected. Seven species comprised the remaining 5.9%. Oebalus ornatus and O. ypsilongriseus were recovered from seven Latin America countries and had the widest geographical range of the stink bugs species collected during the study.

FACTORES QUE CAUSAN LA DECADENCIA DEL PLATANAL

Los insectos colectados por el personal del CIAT y sus colaboradores se encuentran orga­nizados en una colección central de índole taxonómica y económica que comprende los cultivos en los cuales trabaja el Centro: arroz, fríjol, yuca y forrajes tropicales. El objetivo primordial es utilizar esta colección como material de referencia, documentación y como instrumento para capacitación de personal. Adicionalmente se estableció una pequeña colección de demostración, con un número mínimo de insectos plagas y benéficos para ilustrar información esencial sobre la biología, los ciclos de vida, los enemigos naturales e hiperparásitos de las plagas más representati­vas. Los especímenes se obtienen mediante colecciones hechas por cada uno de los pro­gramas de Entomología, envíos hechos por personal de otras instituciones de investigación agrícola y por intercambio. Para la identifica­ción se han establecido contactos con servi­cios de especialistas de cada grupo con el fin de actualizar la información concerniente a la clasificación y revisión de las especies. Para sistematizar la información y recuperarla se estableció una base de datos en DBASE III, la cual está a disposición de personas o institu­ciones interesadas en la información ahí rete­nida. Actualmente se tiene un número aproxi­mado de 20.000 especímenes dentro de la co­lección, el 80% de los cuales corresponden a Colombia y el 20% restante a 28 diferentes países. Se han identificado 110 familias, 380 géneros y 412 especies. La base de datos tiene almacenados 1.687 registros, de los cuales 293 corresponden al Programa de Yuca, 370 al de Arroz, 507 y 517 a los Programas de Frijol y Forrajes Tropicales, respectivamente, con información valiosa sobre distribución geográ­fica, plantas hospedantes, enemigos naturales y clasificación taxonómica.

Las arañas son reguladores importantes de insectos plagas en agroecosistemas tropica­les. El presente trabajo tuvo como objetivos identificar las especies de arañas (Araneae) en cultivos de arroz en el Valle del Cauca, su fluctuación poblacional y la capacidad de con­sumo de las especies más frecuentes. Se regis­traron 11 familias, representadas en 29 espe­cies, siendo las mas importantes por frecuen­cia y abuudancia Tetraganatha sp., T. stra­minea Emerton (Tetragnathidae), Phidippus clarus Key (Salticidae), Synaemops rubro­punctatum (Thomisidae), Oxyopes salticus Hentz (Oxyopidae), Argiope argentata (Araneidae) y Pardosa sp. cerca saxatilis (Hentz) (Lycosidae). Para evaluar su acción como reguladores se efectuaron pruebas de exclusión a nivel de campo, registrando regu­laciones de poblaciones de Tagosodes orizicolus (Muir) (Homoptera: Cercopidae), entre el 25 y 68,6%, con una densild de cuatro Tetragnatha por metro cuadrado. En pruebas de consumo en cautiverio, Tetrag­natha sp. consumió entre 0,9 y 3,5 adultos de Tagosodes por día; S. rubropunctatum con­sumió 1,8 adultos/día, 2,5 larvas de primer instar de Spodopterafrugiperda Smith)/ día; 1,4 larvas de segundo instar/día y 0,6 larvas de sexto instar/día. Argiope argentata consume en promedio 4,1 adultosTagosodesl día. Phidippus clarus consume en promedio 1,8 ninfas de Tagosodes /día, y 1,4 ninfas de tercer instar y 0,6 ninfas de cuarto instar de Oebalus ornatus/día.

Summary This paper characterises resistance to rice hoja blanca virus (RHBV) which is transmitted by the planthopper Tagosodes orizicolus (Muir). Resistance is expressed as decreased proportion of plants infected compared to susceptible lines, although severity of symptom expression is similar in both types. This resistance is not due to differences in vector feeding behaviour. Vectors reared eight generations on resistant plants showed no increased ability to transmit to resistant lines or decreased ability to transmit to susceptible ones. Longevity of vectors was similar when reared either on virus-resistant or susceptible plants. Incubation period of the virus in resistant plants are significantly longer than in susceptible plants. Resistance increased with plant age in resistant and susceptible cultivars. Increased virus dosage, as determined by increased number of viru-liferous vectors per inoculated plant, caused an increase in transmission to both resistant and susceptible cultivars. However, the ranking of resistant and susceptible remained the same across the experimental range of dosage and plant age. It is concluded that the resistance studied is to virus infection and there is little risk of “breakdown” occurring as a result of genetic or behavioural changes in the vector population. This will permit the use of economic thresholds to planthopper feeding damage with little risk of RHBV epidemic outbreak.

En el Valle del Cauca, Colombia, se estudió la relación de un barrenador del tallo del arroz, Rupela albinella, con la pudricíón del tallo, Sclerotium oryzae. La larva y las heridas causadas por ella están asociadas a la aparición de la pudrición del tallo, pero la infección fungal no depende de la presencia de larvas. El número de larvas y las heridas causadas por ellas y los tallos con infección aumentaron con la edad de la planta.

Se estudió la oviposición y la supervivencia de ninfas de sogata, Tagosodes orizicolus (Muir), sobre 11 cultivares de arroz. Se iden­tificaron seis cultivares con bajo índice de daño mecánico por sogata. Estos materiales fueron: Tetep, Mudgo, IRAT 124, IRAT 120, Amistad 82 y Makalioka. Dos cultivares, IRAT. 124 y Makalioka, demostraron anti­biosis, mientras que Tetep presentó prefe­rencia como mecanismo de resistencia al daño mecánico. Se colectaron más huevos en el follaje que en el tallo. La hoja número dos fue preferida para oviposición por sogata sobre las hojas 1, 3 y 4.

Seeding rate and water drainage were studied as alternate control measures for management of Hydrellia wirthi Korytkowsky on rice. Plants subjected to permanent flooding had more eggs, mines, and pupae per plant than those subjected to a weekly flush. Increasing the seeding rate from 100 to 300 kg/ha had no significant effect on the number of eggs, mines, and pupae per plant. Yields were not affected by H. wirthi damage.

Oviposition by a rice stem borer, Rupela albinella (Cramer), was studied on rice plants. Moths preferred to oviposit on plants older than 50 days. Foliage was highly preferred over stems as oviposition sites. Three times as many egg masses were deposited on the abaxial leaf surface as compared with the adaxial leaf surface. Leaves two and three were preferred for oviposition. Of eight cultivars tested Viflor was preferred for oviposition, while Tapuripa, another Peruvian line, had fewer egg masses.

Se estudió el desarrollo de Bemisia tabaci en cuatro genotipos de Phaseolus vulgaris L. con diferentes grados de pubescencia. La proboscis de Bemisia es notablemente más larga que los tricomas de los cuatro genotipos de habichuelas, entre los cuales no hubo diferencias en cuanto al desarrollo del insecto. El desarrollo uniforme del insecto en los genotipos A-429, DOR-303, 27-R y PC-50 reflejado en la falta de diferencias en el tiempo para completar el desarrollo y en el tamaño de los diferentes estadios sugiere que la pubescencia no es un factor de importancia en el desarrollo del insecto sobre el cultivo de habichuela.

Se efectúo un estudio para determinar la densidad y tipo de pubescencia de cuatro genotipos de fríjol (Phaseolus vulgaris L.) y su efecto sobre el insecto Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae). Los genotipos evaluados fueron las líneas A-429 y DOR-303 y las variedades 27-R y PC-50. En el haz yen envés de las hojas de cada material se estableció la presencia de dos tipos de tricomas no glandulares: aciculares y unci­formes. Los cuatro genotipos presentaron variación en cuanto al tamaño y densidad de los tricomas. En términos generales, en el envés de las hojas los tricomas aciculares (TAE) y unciformes (TUE) de mayor tamaño correspondieron a las variedades 27-R (274,7p y 87,4p) y PC-50 (321, 8 p y 87,8p ). En las pruebas de alimentación y oviposición el insecto B. tabaci presentó mayor preferen­cia por la variedad 27-R. En este genotipo se recolectó el mayor número de adultos y hue­vos por planta. La variedad P( 50 fue seguida en preferencia por B. tabaci. El insecto mos­tró poca preferencia por las líneas A-429 y DOR-303, y en estos genotipos se recolectó el menor número de adultos y huevos del insecto. Los resultados demuestran que los dos tipos de tricomas de las hojas de A-429, DOR-303, 27-R y PC-50 no fueron obstáculo para el desarrollo y establecimiento de B. tabaci, aunque siempre prefirió a 27-R y a PC-50. El ciclo de vida del insecto fue similar en todos los genotipos (30,8 días en prome­dio). Igualmente, entre A-429, DOR-303, 27-R y PC-50 no se presentaron diferencias en el período de incubación (7,6 días en promedio) ni en el tiempo de duración de cada uno de los cuatro instares ninfales. Aparentemente, apar­te de la pubescencia, existen otros factores que indujeron al insecto a preferir las varieda­des 27-R y PC-50. Para el caso de A-429 y DOR-303, los resultados obtenidos sugieren que estos genotipos poseen o carecen de algunas características físico-químicas que hacen a estas líneas poco atractivas al insec­to.