Armored scale insects (Hemiptera: Diaspididae) associated with avocados (Persea americana) in Mxicos main production areas, with keys for identification and natural enemies.

Avocado orchards in eight avocado-producing states of Mxico were sampled to collect and identify the armored scale insect species (Hemiptera: Diaspididae) that attack the crop and their natural enemies. Sixteen species of armored scales were identified, 12 from the subfamily Aspidiotinae and four from Diaspidinae. A dichotomous key is provided for the identification of the 18 armored scale species associated with avocado in central Mxico. Forty species of associated natural enemies were also recorded, the most important belonging to Hymenoptera: Aphelinidae, Encyrtidae, Eulophidae, and Signiphoridae, and to Coleoptera: Coccinellidae. For each species of armored scale, brief general information on its distribution, host varietal preferences and natural enemies is given.

Transmission of Citrus leprosis virus C by the Mite, Brevipalpus yothersi (Acari: Tenuipalpidae), on Four Species of Citrus.

Transmission of the virus, Citrus leprosis virus C (CiLV-C) (Cilevirus) by Brevipalpus yothersi Baker, on different citrus species was evaluated under greenhouse conditions. First, the relationship between acquisition access periods (AAPs; 1, 12, 24, 36, and 48 h) and virus concentration in mites was determined. Second, the ability of B. yothersi to transmit CiLV-C to orange, mandarin, grapefruit, and lime trees was measured. We then assessed the establishment of mites on the different citrus species as measured by their population increase on each species. We found no relationship between AAPs and virus load in mites. The virus was found in all mites tested but there was no difference in virus quantities among the treatments. We selected an AAP of 24 h for the transmission experiment. Brevipalpus yothersi transmitted the virus to all citrus species evaluated, but susceptibility was different. The number of infected leaves was greater on orange and mandarin compared with grapefruit and lime. Furthermore, populations of B. yothersi successfully established on orange and mandarin, but not on grapefruit and lime trees. The implications of our results in the virus-mite-citrus plant relationship are discussed.

Analysis of Genetic Variation in Brevipalpus yothersi (Acari: Tenuipalpidae) Populations from Four Species of Citrus Host Plants.

We studied species diversity and genetic variation among populations of Brevipalpus mites from four species of citrus host plants. We sampled mites on orange, lime, grapefruit and mandarin trees from orchards at six localities distributed in the five most important citrus producing states in Mexico. Genetic variation among citrus host plants and localities were assessed by analysis of nucleotide sequence data from fragments of the mitochondrial cytochrome oxidase subunit I (COI). Both Brevipalpus yothersi and B. californicus were found at these sites, and B. yothersi was the most abundant species found on all citrus species and in all localities sampled. B. californicus was found mainly on orange and mandarin and only in two of the states sampled. AMOVA and haplotype network analyses revealed no correlation between B. yothersi genetic population structure and geographical origin or citrus host plant species. Considering that a previous study reported greater genetic diversity in B. yothersi populations from Brazil than we observed in Mexico, we discuss the possibility that the Mexican populations may have originated in the southern region of America.

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

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.

Descripción de las larvas de tercer instar de Melolonthidae (Coleoptera) asociadas al cultivo de Agave tequilana var. Azul y su fluctuación poblacional en Jalisco, México / Description of Melolonthidae (Coleoptera) third instar larvae associated to Agave tequilana var. Azul and their population fluctuation in Jalisco, Mexico

Third instars of white grubs of six species associated to agave tequilero in Jalisco, México were described from 1,145 specimens collected from soil samples from September 2006 to August 2007, in the municipalities of Ixtlahuacán del Río, Tepatitlán de Morelos and San Juan de Escobedo, Jalisco, México. Diagnostic characters were illustrated and a key was also included. Cyclocephala comata (Bates) was the most abundant species (63.2 percent), followed by Phyllophaga ravida (Blanchard) (21.9 percent), Phyllophaga polyphylla (Bates) (9.4 percent), Phyllophaga misteca (Bates) (4.1 percent), Strategus aloeus (L.) (1.1 percent) and Anomala hoepfneri (Bates) (0.3 percent). Phyllophaga ravida and A. hoepfneri are reported for the first time on the agave plant and the latter is a new record for the State of Jalisco. All Melolonthidae species showed a marked seasonality with lower number of larvae in June 2007 and high number in August 2007, which is associated with the region's rainy season and the agave plant age, respectively.

Se describen las larvas de tercer instar de seis especies de gallinas ciegas asociadas al cultivo de agave tequilero en el estado de Jalisco, México, con base en 1,145 especimenes, de muestras de suelo, colectados de Septiembre de 2006 a Agosto de 2007, en los municipios de Ixtlahuacán del Río, Tepatitlán de Morelos y San Juan de Escobedo, Jalisco, México. Se incluyen ilustraciones diagnósticas y una clave para el reconocimiento de las especies. Cyclocephala comata (Bates) fue la especie más abundante (63.2 por ciento), seguida por Phyllophaga ravida (Blanchard) (21.9 por ciento), Phyllophaga polyphylla (Bates) (9.4 por ciento), Phyllophaga misteca (Bates) (4.1 por ciento), Strategus aloeus (L.) (1.1 por ciento) y Anomala hoepfneri (Bates) (0.3 por ciento). Phyllophaga ravida y A. hoepfneri se reportan por primera vez asociadas al agave tequilero y esta última es nuevo registro para el estado de Jalisco. Las especies de melolóntidos presentaron una marcada estacionalidad, con un más bajo número de larvas en Junio de 2007 y mayor en el mes de Agosto de 2007, lo que coincidió con el periodo de lluvias en la región y edad de las plantas, respectivamente.

[Description of Melolonthidae (Coleoptera) third instar larvae associated to Agave tequilana var. Azul and their population fluctuation in Jalisco, Mexico]. / Descripción de las larvas de tercer instar de Melolonthidae (Coleoptera) asociadas al cultivo de Agave tequilana var. Azul y su fluctuación poblacional en Jalisco, México.

Third instars of white grubs of six species associated to agave tequilero in Jalisco, México were described from 1,145 specimens collected from soil samples from September 2006 to August 2007, in the municipalities of Ixtlahuacán del Río, Tepatitlán de Morelos and San Juan de Escobedo, Jalisco, México. Diagnostic characters were illustrated and a key was also included. Cyclocephala comata (Bates) was the most abundant species (63.2%), followed by Phyllophaga ravida (Blanchard) (21.9%), Phyllophaga polyphylla (Bates) (9.4%), Phyllophaga misteca (Bates) (4.1%), Strategus aloeus (L.) (1.1%) and Anomala hoepfneri (Bates) (0.3%). Phyllophaga ravida and A. hoepfneri are reported for the first time on the agave plant and the latter is a new record for the State of Jalisco. All Melolonthidae species showed a marked seasonality with lower number of larvae in June 2007 and high number in August 2007, which is associated with the region's rainy season and the agave plant age, respectively.