Néstor Bautista-Martínez

Toxicity and Residual Activity of Insecticides against Tamarixia triozae (Hymenoptera: Eulophidae), a Parasitoid of Bactericera cockerelli (Hemiptera: Triozidae)

ABSTRACT Bactericera cockerelli (Sulc) (Hemiptera: Triozidae) is one of the most economically important pests of potato, tomato, and peppers in Central America, Mexico, the United States, and New Zealand. Its control is based on the use of insecticides; however, recently, the potential of the eulophid parasitoid Tamarixia triozae (Burks) (Hymenoptera: Eulophidae) for population regulation has been studied. Because T. triozae is likely to be exposed to insecticides on crops, the objective of this study was to explore the compatibility of eight insecticides with this parasitoid. The toxicity and residual activity (persistence) of spirotetramat, spiromesifen, beta-cyfluthrin, pymetrozine, azadirachtin, imidacloprid, abamectin, and spinosad against T. triozae adults were assessed using a method based on the residual contact activity of each insecticide on tomato leaf discs collected from treated plants growing under greenhouse conditions. All eight insecticides were toxic to T. triozae. Following the classification of the International Organization of Biological Control, the most toxic were abamectin and spinosad, which could be placed in toxicity categories 3 and 4, respectively. The least toxic were azadirachtin, pymetrozine, spirotetramat, spiromesifen, imidacloprid, and beta-cyfluthrin, which could be placed in toxicity category 2. In terms of persistence, by day 5, 6, 9, 11, 13, 24, and 41 after application, spirotetramat, azadirachtin, spiromesifen, pymetrozine, imidacloprid, beta-cyfluthrin, abamectin, and spinosad could be considered harmless, that is, placed in toxicity category 1 (<25% mortality of adults). The toxicity and residual activity of some of these insecticides allow them to be considered within integrated pest management programs that include T. triozae.

Morphometrics of Eggs, Nymphs, and Adults of Bactericera cockerelli (Hemiptera: Triozidae), Grown on Two Varieties of Tomato Under Greenhouse Conditions

ABSTRACT The effects of 2 varieties of tomato, Solanum lycopersicum L., i.e., ‘Charanda F1’ and ‘Rafaello’, were evaluated on the morphometries of Bactericera cockerelli (Sulc). Eggs, nymphs, and adults of B. cockerelli were collected from 2 varieties of tomato, ‘Charanda F1’ and ‘Rafaello’, under greenhouse conditions in the Colegio de Postgraduados, Campus Montecillo, Texcoco, the State of Mexico, during the periods Oct-Dec 2009 and Jan-Mar 2010. Since 2000–2001 the B. cockerelli cultures were maintained on tomato with no exposure to agro-chemicals. Adult B. cockerelli were kept in individual growth chambers constructed of wooden frames covered with organza cloth, under 14:10 h L:D and temperatures ranging from 10 to 25 °C. For morphometric analysis of the eggs, the following variables were investigated: egg length (LH), egg width (AH), and pedicel length (PED). For nymphs, the variables were: body length (LC), body width (AC), and antennal length (ANT). For adults, the variables were: body length (LC), body width at thorax (ACT), wing length (LALA), and wing width (ANALA). The 2 tomato varieties were found to have differential morphometric effects on B. cockerelli as follows: no significant differences on egg length (F1,41 = 0.57; P = 0.4551), but egg width was differentially affected by the variety of tomato (F1,41 = 11.92; P = 0.0013). There were significant differential effects of tomato variety on nymphs: body length (F4,324 = 1199.2; P < 0.0001), body width (F4,324 = 900.72; P = 0.0001); and antennae length (F4,324 = 883.93; P = 0.0001). Body length of the adults (F1,117 = 7.11; P = 0.0087) was differentially affected by the 2 different tomato varieties. None of the plants showed any symptoms of infection by ‘Candidatus Liberibacter solanacearum’, which is known to cause effects on B. cockerelli fitness traits. Body width and antennal length of nymphs can be recommended to differentiate all 5 nymphal instars on this pest species, which has practical implications.

Life and Fertility Table of Bactericera cockerelli (Sulc) on Two Varieties of Tomato in a Greenhouse

Abstract. The lifecycle of Bactericera cockerelli was evaluated on the tomato varieties ‘Charanda F1’ and ‘Rafaello’, under greenhouse conditions at the Colegio de Postgraduados, Campus Montecillo, Texcoco, Mexico, during October–December, 2009 and January–March, 2010. A line of B. cockerelli dating from 10 years ago free from agrochemical applications was used. The adults were kept in individual growth chambers. The parameters measured were average life expectancy (ex), net reproductive ratio (Ro), time of generation (T), intrinsic natural increase ratio (rm), finite increase ratio (&lgr;), births (b), and mortality (d) in each of the varieties. For the October–December cycle, reproduction began at 34 days in the ‘Charanda F1’ variety, and at 41 days in January–March. The incubation period for the eggs was 7–13 days, with a nymphal period of 32–37 days in ‘Charanda F1’; in ‘Rafaello’, incubation took 8–10 days, with a nymphal period of 31–35 days. The lifecycle in Charanda F1 was 63–69 days, and was 68–70 days in Rafaello. The accumulated fecundity of the females was 3,426–3,200 eggs in Charanda F1 and 2,142–2,099 eggs in Rafaello.

Natural parasitism of leafminer Liriomyza trifolii (Burgess) in jalapeño pepper in northern Sinaloa, Mexico.

Pepper, Capsicum annuum L., is damaged by insect pests such as the pepper weevil, Anthonomus eugenii Cano; green peach aphid, Myzus persicae (Sulzer); western flower thrips, Frankliniella occidentalis (Pergande); and broad mite, Polyphagotarsonemus latus (Banks), among others (MacGregor and Gutierrez 1983, Bautista 2006). Recently, the leaf miner Liriomyza trifolii (Burgess) (Diptera: Agromyzidae) has become one of the most important pests of crops in the northern region of Sinaloa state. The leaf miner is usually abundant and causes severe defoliation of plants (Pacheco 1985, Bautista 2006). Extensive research worldwide reported more than 140 parasitoids associated with Liriomyza spp. (Liu et al. 2009). Noyes (2004) listed more than 300 species of parasitoids that regulated the family Agromyzidae, 80 of which were known to prey on Liriomyza spp. La Salle and Parrella (1991) reported 23 species of parasitoids of Liriomyza in the Neartic region and at least 14 of these were found naturally in Florida. The objective of this study was to determine the presence and identity of parasitoids of L. trifolii in the north of Sinaloa state, Mexico, and the percentage of natural parasitism they provide. The study was done from September 2008 to April 2009 in three municipalities in northern Sinaloa. An experimental plot was established in the Experimental Field Valle del Fuerte, ejido Las Vacas, in the municipality of Guasave (25o 45 ́ 36 ́ ́ N; 108o 48 ́ 41 ́ ́ O; 14 m elevation); a second plot was set up in ejido Flor Azul, in the municipality of Ahome (25o 52 ́16 ́ ́ N; 109o 00 ́ 48 ́ ́ O; 16 m elevation); and a third plot was in the school plot of the Centro de Bachillerato Tecnológico Agropecuario N° 81, in ejido 2 April, in the municipality of El Fuerte (25o 54 ́ 23 ́ ́ N y 108o 56 ́ 13 ́ ́ O; 18 m elevation). The plots were 625 m, planted with jalapeño pepper, variety ‘Grande.’ Agronomic management was the same as that used by local producers, with the difference that no insecticides were used so the pest insect and its parasitoids would occur naturally. To obtain parasitoid species associated with the leafminer in the jalapeño pepper crop, 29 samples were taken from the crops at weekly intervals during the fall-winter season. A systematic sampling technique consisting of four samples distributed at the border and one in the center of the plot was used. On each sampling date, 10 leaflets with evidence of leafminer larvae were selected from each plot; two samples were taken from five locations within each plot. The

First Report of “Hunter-Fly” Coenosia attenuata (Diptera: Muscidae) in Mexico

Summary Coenosia attenuata Stein (Diptera: Muscidae) is a predatory fly that feeds on other insects and can be used as a potential biological control agent. This insect is native to southern Europe; however, it has been distributed naturally to various continents, including North and South America, and is reported herein for the first time in Mexico. The flies were found preying on whiteflies, psyllids, fungus gnats, leaf miners, and vinegar flies in greenhouses with organic vegetable production.

Insecticidal Effect of Botanical Extracts on Developmental Stages of Bactericera cockerelli (Sulc) (Hemiptera: Triozidae)

Abstract. Insecticidal effect of aqueous and ethanol extracts of dried leaves of Ambrosia artemisiifolia L., Piper auritum Kunth, and Taraxacum officinale F. H. Wiggwere determined on developmental stages of potato/tomato psyllid, Bactericera cockerelli (Sulc). When aqueous extract at 0.2 g/ml was applied to psyllid nymphs, A. artemisiifolia extract was most toxic, P. auritum was moderately toxic, and T. officinale was slightly less toxic. Ethanol extract of A. artemisiifolia killed more than 50% of 2nd, 3rd, and 5th instar nymphs treated with 0.001, 0.01, and 0.1 g/ml, respectively. P. auritum was effective on 3rd and 4th instars and T. officinale on 5th and 3rd instars at 0.01 and 0.1 g/ml, respectively. Ethanol extracts of the three plant species killed 50 to 60% of adults with 0.1 g/ml and 30 to 45% with 0.01 g/ml. Extracts of Argemone mexicana L., Azadirachta indica A. Juss, Petiveria alliacea L., and Tagetes filifolia Lag. were evaluated on 4th and 5th instar nymphs. Ethanol extract of leaves of A. mexicana at 0.2 g/ml killed 100% of 5th instar nymphs at 24 hours and 93% of 4th instars at 72 hours. A. indica, P. alliacea, and T. filifolia at 0.2 g/ml killed 85, 88, and 87%, respectively, of 5th instar nymphs.

Percentage Damage to Tomatillo Crops by Heliothis subflexa (Lepidoptera: Noctuidae) at Various Altitudes

Summary Heliothis subflexa (Guenée) (Lepidoptera: Noctuidae) is a monophagous insect specialized in feeding on fruits of the genus Physalis (Solanales: Solanaceae). In Mexico this fruitworm is present in all producing tomatillo areas but at very different levels of infestation. The present study aimed to provide data on the damage percentages caused by H. subflexa along an altitudinal transect ranging from 660 to 2,300 m asl. Evaluations were carried out biweekly on 8 plantations located at various altitudes (m asl) at various locations in the state of Morelos. By random sampling of tomatillo fruits in 5 locations per plot, the percentage of damage was estimated. The results obtained indicate that this species is very damaging at all altitudes in the range of 660 to 1,320 m asl, whereas at altitudes progressively higher than 1,320 m asl, populations become progressively less dense and progressively less damaging, so that at the higher altitudes the pest is not considered to be a phytosanitary problem.

Logrank Test and Interval Overlap Test for Bactericera cockerelli (Hemiptera: Triozidae) Under Different Fertilization Treatments for 7705 Tomato Hybrid

Abstract It is known that some nutrients can have both negative and positive effects on some populations of insects. To test this, the Logrank test and the Interval Overlap Test were evaluated for two crop cycles (February–May and May–August) of the 7705 tomato hybrid, and the effect on the psyllid, Bactericera cockerelli (Sulc.) (Hemiptera: Triozidae), was examined under greenhouse conditions. Tomato plants were in polythene bags and irrigated with the following solutions: T1—Steiner solution, T2—Steiner solution with nitrogen reduced to 25%, T3—Steiner solution with potassium reduced to 25%, and T4—Steiner solution with calcium reduced to 25%. In the Logrank test, a significant difference was found when comparing the survival parameters of B. cockerelli generated from the treatment cohorts: T1–T2; T1–T3; T1–T4; T2–T3; and T3–T4, while no significant differences were found in the T2–T4 comparison in the February–May cycle. In the May–August cycle, significant differences were found when comparing the survival parameters generated from the treatment cohorts: T1–T2; T1–T3; and T1–T4, while no significant differences were found in the T2–T3; T2–T4; and T3–T4 comparisons of survival parameters of B. cockerelli fed with the 7705 tomato hybrid. Also, the Interval Overlap Test was done on the treatment cohorts (T1, T2, T3, and T4) in the February–May and May–August cycles. T1 and T2 compare similarly in both cycles when feeding on the treatments up to 36 d. Similarly, in T1 and T3, the behavior of the insect is similar when feeding on the treatments up to 40 and 73 d, respectively. Comparisons T2–T3 and T2–T4 are similar when feeding on both treatments up to 42, 38 and 37, 63 d, respectively. Finally, the T3–T4 comparison was similar when feeding in both treatments up to 20 and 46 d, respectively. RESUMEN. Se sabe que algunos nutrientes pueden tener efectos tanto negativos como positivos en algunas poblaciones de insectos. Para probar esto se evaluó la prueba de rango logarítmico y la prueba de Overlap intervalo de dos ciclos de cultivo (febrero–mayo y mayo–agosto) del híbrido de tomate 7705 y el efecto sobre el psílido, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae) fue examinado bajo condiciones de invernadero. Las plantas de tomate estaban en bolsas de polietileno y regadas con las siguientes soluciones: T1: Solución de Steiner, T2: solución de Steiner con Nitrógeno a 25%, T3: solución de Steiner con Potasio a 25% y T4: solución de Steiner con Calcio a 25%. En la prueba de Logrank se encontró diferencia significativa al comparar los parámetros de supervivencia que se generaron en las cohortes de los tratamientos, T1 – T2; T1 – T3; T1 – T4; T2 – T3 y T3 – T4. En la comparación de T2 – T4, no se encontraron diferencias significativas, entre los parámetros de supervivencia de B. cockerelli ; para el ciclo Mayo-Agosto, se encontró diferencia significativa al comparar los parámetros de supervivencia que se generaron en las cohortes de los tratamientos, T1 - T2; T1 – T3; T1 – T4; en las comparaciones de T2 – T3; T2 – T4; T3 – T4, no se encontraron diferencias significativas, entre los parámetros de supervivencia de B. cockerelli alimentados con el hibrido de tomate 7705. De igual manera se realizó la Prueba de Traslape de Intervalos para las cohortes de los tratamientos (T1, T2, T3 y T4) en los ciclos de Febrero-Mayo y de Mayo-Agosto, se puede observar que la comparación de T1 con T2, son similares cuando se alimenta en ambos tratamientos hasta los 36 días, respectivamente. De igual manera, en la comparación (T1 y T3), siendo similar cuando el insecto se alimenta en ambos tratamientos hasta los 40 y 37 días, respectivamente. Las comparaciones (T2 y T3) y (T2 y T4) es similar cuando se alimenta en ambos tratamientos hasta los (42, 38) y (37, 63) días, respectivamente. Finalmente, la comparación para (T3 y T4) fue similar cuando se alimenta en ambos tratamientos hasta los 20 y 46 días, respectivamente.

Population Fluctuation and Spatial Distribution of Trioza aguacate (Hemiptera: Triozidae) on Avocado (Lauraceae) in Michoacan, Mexico

Abstract The psyllid Trioza aguacate Hollis & Martin (Hemiptera: Triozidae) causes deformation of leaves and young shoots of avocado. In recent years, population densities of this pest in avocado orchards have increased. The objectives of this study were to determine seasonal fluctuations of the populations of eggs, nymphs, and adults of T. aguacate, how these fluctuations are related to the incidence of avocado vegetative shoots, temperature and rainfall at 3 different altitudes in Michoacan, Mexico, i.e., 2,130 m, 1,860 m and 1,293 m. In addition, we attempted to determine the spatial distributions of nymphs and adults found on avocado vegetative shoots. We sampled the populations of adult and immature T. aguacate every 20 days from Jan 2012 to Jul 2013. To estimate population densities, 9 trees were selected in each orchard, and the trees were distributed in the form of a cross. From each replicate of trees, 4 shoots were randomly collected, and the eggs and nymphs were counted on them. Adults counts were obtained from yellow traps established at the 4 cardinal points in each tree. During the same period, young vegetative shoots, temperature and rainfall were recorded. The results showed that this psyllid was not present at all in the orchard located at the low altitude level of 1,293 m. The psyllid was present at the medium altitude site from Jan to Jun, and from Dec to Jun at the high altitude site. All of the development stages were most abundant from Mar to May, when avocado vegetative shoots were most abundant in both years. The abundance of eggs and nymphs showed a positive relationship with young vegetative shoots, a negative relationship with rainfall, and the eggs showed a positive relationship with temperature. The incidence of adults was strongly related with spring budding, but not significantly correlated with temperature. Both nymphs and adults had an aggregated spatial distribution.

Ferrisia virgata (Cockerell) (Hemiptera: Pseudococcidae) and Formicidae Associated with Rambutan (Nephelium lappaceum L.) in Southeast Mexico

Rambutan (Nephelium lappaceum L.) (Sapindaceae) is a tropical fruit originally from Malaysia and Indonesia. Its name comes from the Malaysian word “rambut”, which means “hair”, referring to the long and soft trichomes that cover the surface of the fruit. It is widely distributed in Southeast Asia and has developed successfully in Africa, Australia, and Central America (Walker 1988, Watson 1988). De la Garza and Cruz (2006) reported it was first introduced into Mexico, in the states of Chiapas and Veracruz, where it was kept as an exotic and ornamental plant. It was first grown in the state of Chiapas in 1950, especially in the Soconusco region (Fraire, 2001). According to Ochse et al. (1976), the fruit is delicious and is an option as a crop in low-altitude areas between 100 and 700 m above sea level in the humid tropics (Perez and Jürgen 2004). Rambutan usually is eaten fresh, or industrially canned (Vargas 2003), and recently, medicinal properties have been found in it (Román 2002). In Mexico, the fruit is little known but has great potential for increased consumption, establishment, and development in all the humid and sub-humid tropical areas. In the Soconusco region, fruit is produced commercially in plantations on more than 200 hectares (PFPAS 2007). Rambutan from Chiapas has been planted on a small scale in Campeche, Guerrero, Oaxaca, San Luis Potosi, and Tabasco (Román 2002, Hernandez 2010). Most rambutan is produced in Indonesia, Malaysia, and Thailand, from where it is exported to Europe, Hong Kong, Japan, Singapore, and the U.S.A. The fruit from Mexico is destined for markets in the U.S.A., Canada, and Japan (De la Garza and Cruz 2006). Because rambutan is recent in Central America, and especially in Mexico, little sanitary and health research has been done on it. One of the most recent studies refers to a qualitative characterization of rambutan fruits, besides the identification of two fungi that affect the fruit post-harvest (Hernández 2010). With regard to insects, Román (2002) mentioned that pests with economic importance in Mexico were the mealybug Pseudococcus sp. and Tessaratoma longicornis Dohrn, 1863 (Hemiptera: Pseudococcidae). However, in Costa Rica, the PFPAS (2007) reported the following pests: soft scales Ceroplastes floridensis Comstock, ________________________ Entomología Agrícola, Fitosanidad, Colegio de Postgraduados, Carr. México-Texcoco, Km. 36.5, Montecillo, Municipio de Texcoco, Estado de México C. P. 56230. Autor responsible nestor@colpos.mx Fitopatología, Fitosanidad, Colegio de Postgraduados, Carr. México-Texcoco, Km. 36.5, Montecillo, Texcoco, Estado de México C. P. 56230. Departamento de Fitotecnia, Universidad Autónoma Chapingo, Km. 38.5 Carretera MéxicoTexcoco, Chapingo, Texcoco, Estado de México C. P. 56230.