J. Refugio Lomeli-Flores

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.

First Record of the Bronze Bug, Thaumastocoris peregrinus Carpintero & Dellapé 2006 (Hemiptera: Thaumastocoridae), in Mexico1

Eucalyptus spp. (Myrtales: Myrtaceae) are a diverse group of fast-growing tree species that are grown in many parts of the world. They are important for the different uses of their wood, cellulose, hemicellulose, and lignin, and for byproducts such as honey and resins (Turnbull 1999, 2000, FAO 2007, Hiwale 2015). Eucalyptus camaldulensis Dehnhardt is widely planted throughout the temperate and tropical areas of the world (Turnbull 1999). In Mexico, seeds of this species were originally introduced and commercialized for medical purposes between 1860 and 1870 (Vega & Baez 2016). It was also used as an urban tree in several cities over the next few decades. E. camaldulensis and other species were subsequently used to reforest degraded and saline soils between 1890 and 1904 (Cervantes et al. 2008). This practice continued decades later when between 1970 and 1994, E. camaldulensis and E. globulus Labillardière were used to reforest several places in Mexico (Cervantes et al. 2008). Currently, these two species are some of the most common trees in gardens, parks, and along streets in Mexico City (Department of Environmental Protection of Mexico City [SEDEMA], person. comm.) and in other states of Mexico. Commercial plantations of Eucalyptus in Mexico are relatively new, with the first plantations being planted in the 1990s and with less than 1000 ha registered for 1995 (Sosa 2012). Nevertheless, by 2014 there were 31,000 ha located mostly in the southeastern portion of the country (National Forestry Commission of Mexico [CONAFOR], person. comm.). About 15 years ago, the global distribution of pests and pathogens that affect Eucalyptus began increasing (Paine et al. 2011, Saavedra et al. 2015a), and in some cases, the effects have been severe because of late detections and management. The Eucalyptus bronze bug, Thaumastocoris peregrinus Carpintero

Umbrales de Desarrollo de Tamarixia triozae1 Parasitoide del Psílido de la Papa2

Resumen. Tamarixia triozae (Burks) es un ectoparasitoide de ninfas del psílido de la papa, Bactericera cockerelli (Sulc), con niveles de parasitismo en el campo hasta del 85% que además se alimenta sobre su hospedero, lo que contribuye a ser un potencial agente de control biológico. Con el fin de determinar los requerimientos térmicos y las temperaturas efectivas para el desarrollo de T. triozae se estimaron los grados días de desarrollo (GDD) que se requieren para completar el ciclo de vida del parasitoide. Se utilizaron huevos de menos de 5 horas de edad y se colocaron a temperaturas constantes de 10, 15, 20, 25, 30, y 35°C (± 1°C, 70 ± 10% HR, y 12:12 L:O h), se observó su desarrollo hasta la emergencia de adultos. El ciclo de vida del parasitoide requirió de 243.9 GDD, un umbral de temperatura inferior (UTI) de 4.8° y a 35°C no se completó el ciclo de vida siendo este el umbral de temperatura superior (UTS).

Molecular Characterization of the Vitellogenin Receptor in Bactericera cockerelli (Sulc)1

Abstract. Potato purple top and zebra chip diseases are transmitted by potato psyllid, Bactericera cockerelli (Sulc), to tomato, Solanum lycopersicum L., and potato, Solanum tuberosum L., crops. The aim of this study was to characterize and quantify vitellogenin receptor in potato psyllid. We obtained partial characterization of the receptor by end-point PCR and sequencing using capillary electrophoresis. Relative quantification by real-time PCR was used to determine expression levels of the receptor in females and males. Similarity in vitellogenin sequence obtained in a laboratory was 89% compared with the sequence of the entire transcriptome of the species reported in GenBank. Expression analysis showed the vitellogenin receptor significantly expressed in potato psyllid females compared with males from potato plants. Further study of the vitellogenin receptor of potato psyllid is needed to determine its complete sequence and potential target to control the pest.

New Records of Species and Locations of Parasitoids of the Pepper Weevil1 in Mexico

Abstract. The pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae), is a key pest of cultivated peppers (Cepsicum spp.) in the southern United States, Mexico, Central America, and on some islands of the Caribbean. Control of the pest is difficult and dependant on insecticide, with no effective biological control program yet developed. New species and records of parasitoids collected from various localities within the probable regions of origin of the pepper weevil in Mexico are listed. In total, 102 parasitoid specimens of six genera were collected. Of these, Eupelmus cushmeni (Crawford) and Beryscepus hunteri (Crawford) were recorded for the first time as primary parasitoids of the pepper weevil. A key to identify the genera of hymenopteran parasitoids attacking pepper weevil is also presented.

Chalcids (Hymenoptera: Eurytomidae) in Vitaceae Seeds of Mexico

Abstract. Prodecatoma cooki (Howard) is reported for the first time as a seed borer in Vitaceae in Mexico. The insect was collected on different Vitaceae species between 2009 and 2012 in 10 regions of West-Central and Southeast Mexico to know their hosts and basic aspects of the biology of this species. The borer was recorded only in Jiquilpan, Sahuayo, and Tingüindin of Michoacan State, and Puerto Vallarta, in Jalisco. Vitis vinifera L., Partenocissus quinquefolia (L.) Planch, Vitis sp., and Cissus tiliacea H.B.K. were recorded as host plants for this species. This is the first record of this phytophagous insect on C. tiliacea. P. cooki was recorded all year in Jiquilpan, and presumably P. quinquefolia is the most important host for this insect in the region; it seems the different fruiting dates of the other hosts play an important role in insect permanence during the year. Although the insect has not been reported in vine-growing areas of Mexico, it is important to consider P. cooki as a potential pest.