The rice water weevil, Lissorhoptrus oryzophilus Kuschel (Coleoptera: Curculionidae), is an important insect pest of rice, Oryza sativa L., in the United States and Asian countries. Previous reports indicated that most first-generation adults (summer weevils) entered reproductive diapause with only a few of the population reproducing to form a second generation. However, the environmental factors responsible for diapause induction have not been thoroughly studied. Southern cutgrass, Leersia hexandra Swartz, is a widely distributed perennial grass in the rice ecosystem of regions where rice water weevil occurs. After feeding on cutgrass for 30 days, summer weevils initiated oviposition rapidly after being transferred to young rice plants, and the percentage of ovipositing weevils was 80–100% after 2 weeks. Summer weevils feeding on southern cutgrass did not enter diapause but developed into a reproductive state, suggesting the grass might allow rice water weevils to avoid summer diapause. Such “diapause-avoiding” weevils laid an average of 7–21 eggs within 30 days feeding on rice plants, which was substantially less than that of nondiapausing weevils (overwintered weevils, 45 eggs), suggesting great plasticity of the insect during summer diapause. Our data suggested many weed hosts, such as southern cutgrass, affect the population dynamics of summer rice water weevils and their offspring.

We investigated foraging movements by adult female convergent lady beetles, Hippodamia convergeas Guerin-Meneville, on wheat, Triticum aestivum L., growing in 1.8 × 1.8 m plantings in a greenhouse with a soil floor. The wheat was planted to simulate wheat in a typical production field. One planting was infested with English grain aphids, Sitobion avenae L., whereas the other planting was not infested. Beetles were maintained on one of two feeding regimes, partially starved (light-fed) and fed excess aphids (heavy-fed). The average distances moved by beetles per minute were 20.3 and 21.3 cm for light- and heavy-fed beetles in aphid-free plots compared to 4.6 and 10.1 cm by light- and heavy-fed beetles in aphid-infested plots. Light- and heavy-fed beetles moved almost the same distance per minute in the absence of aphids. However, in the aphid-infested plot, light-fed beetles moved a shorter distance than did heavy-fed beetles. The numbers of turns per minute were 0.29 and 0.49 for light- and heavy-fed beetles in aphid-free plots, and 0.75 and 0.81 for light- and heavy-fed beetles in aphid-infested plots. The number of turns a beetle made per minute was greater for heavy- than light-fed beetles in both the aphid-free and aphid-infested plots. Beetles in all treatments took few flights per minute, averaging less than 0.02 flight per minute for heavy-fed beetles in the aphid-free plots (the treatment with the greatest flight frequency). Light-fed beetles flew less frequently than did heavy-fed beetles in both aphidinfested and non-infested plots. Both light-fed and heavy-fed beetles flew less frequently in the aphid-infested than non-infested plots. The horizontal distance traversed by beetles, presumed to be related to prey searching, was affected by the presence of aphids, feeding regime (presumed to determine the physiological state of the beetles), and temperature. The reduced flight frequency and reduced rate of movement by walking observed in this study for light-fed beetles may be significant in assessing the potential for convergent lady beetles to exert effective biological control of aphids. The reduced dispersal rates, presumably resulting from insufficient energy for optimal dispersal, would reduce the likelihood that adult convergent lady beetles would find and exploit patchily distributed aphid infestations. For a population of beetles exploiting aphids within a landscape, the outcome would be less than optimal biological control.

Cooperative projects by various national and state agencies in the last 10 years have resulted in the establishment of an effective saltcedar (Tamarisk sp.) biological control agent, the tamarisk beetle (Diorhabda spp.). Three species of tamarisk beetles have been established in different regions of Texas, typically based on their climatic adaptation. The beetles defoliate saltcedar over multiple seasons, weakening and, during 3 to 5 years, eliminating large stands of this invasive plant. Another saltcedar biological control agent, the splendid tamarisk weevil, Coniatus splendidulus F., is also established in the United States from undocumented introductions. Surveys of saltcedar for evidence of biological control in the eastern Texas Panhandle and western Oklahoma during the summer of 2012 following landowner reports of beetle infestations, and previous release efforts along the Canadian River in Texas resulted in new state and county records for Diorhabda carinata (Faldermann), D. elongata (Brullé), and C. splendidulus F. D. carinata × D. elongata hybrids were recorded for the first time in Oklahoma, from five western counties. In Texas, hybrids of D. carinata × D. elongata, D. carinata, D. elongata, and C. splendidulus were recorded from five, 16, one, and three eastern Panhandle counties, respectively. A history of the release efforts for establishment of Diorhabda spp. from 2004–2010 in the Texas Panhandle is included.

Passage of Iris yellow spot virus, Tospovirus sp., in its vector, as well as its spatial and temporal distribution in an onion (Allium cepa L.) field, have been described. However, little is known of the distribution of the virus within onion hosts. The temporal dynamics of Iris yellow spot virus titer in leaves of ‘Colorado 6’ and ‘Talon’ onion cultivars in a greenhouse were investigated with or without thrips by using double antibody sandwich enzyme-linked immuno-sorbent assay. There was no significant difference in titer between the two cultivars (P = 0.1224); however, titer was significantly greater with thrips than without (P < 0.0001). Plant leaves, divided into top, middle, and base sections, showed that virus titer significantly increased from 1.813 and 1.854 optical densities in top and middle, respectively, to 2.065 in base sections. Leaves of field-infected plants were categorized by age into older, intermediate, and younger leaves. In pre-bulb (6- to 8-leaf-stage) plants, Iris yellow spot virus was most frequently detected in intermediate leaves; however, there was no significant difference in virus titer between leaf age categories. In post-bulb (11 leaf-stage) plants, frequency of virus detection was almost the same in older and intermediate leaves (P = 0.7217) but significantly less in younger leaves. Virus titer was greater in younger, then intermediate, and older leaves, with optical densities of 2.778, 2.649, and 2.349, respectively. Virus was not detected in dead leaves, bulb scales, basal plates, or roots. Information on Iris yellow spot virus distribution in host tissues is vital in epidemiological studies, evaluations of germplasm, and quarantine control of this tospovirus.

The potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae), is a pest of potato, Solanum tuberosum L., and other solanaceous crops in North and Central America. This insect transmits Candidatus Liberibacter solanacearum, the putative causal agent of zebra chip disease of potato. Recent studies identified three genetically distinct haplotypes of B. cockerelli in the United States, correlating to geographical regions: Central, Northwestern, and Western. Although biological differences among the haplotypes, including how effective they transmit the bacterium and their dispersal and overwintering capabilities, are currently being determined, identification of regional psyllid haplotypes is essential to effectively manage diseases caused by the pathogens they transmit to plants. Here, the same haplotyping tool used previously in the United States, high-resolution melting analysis targeted to the B. cockerelli mitochondrial cytochrome c oxidase I gene, was used to identify the psyllid populations in Mexico and Central America. Potato psyllids from Mexico, El Salvador, Honduras, and Nicaragua, were identified as belonging to the Central haplotype.

The agave weevil, Scyphophorus acupunctatus Gyllenhal (Coleoptera: Curculionidae), causes economic damage to Agave tequilana F.A.C Weber var. ‘Blue’, A. fourcroydes Lem., A. angustifolia Haw, and Polianthes tuberosa Lem. Currently, the synthetic compound 2-methyl-4-octanone is used to monitor S. acupunctatus, but factors involved in chemical communication by S. acupunctatus need to be better understood. We used electroantennography, olfactometer bioassays, and analysis of the COI mitochondrial region to study the effect of sex, age, and genetic structure on the electrophysiological response and search behavior by S. acupunctatus to 2-methyl-4-octanone. We showed that electrophysiological and behavioral response to 2-methyl-4-octanone differed among populations of agave weevils from different crops and geographical regions. Furthermore, it was determined that the age of the insect was involved in both responses. Also, genetic changes in mitochondrial DNA suggest groups that differ in their response of S. acupunctatus to 2-methyl-4-octanone. This information provides a baseline to design a method to control agave weevil based on geographical region and type of host.

White mango scale, Aulacaspis tubercularis Newstead, was sampled to better understand its biology and fluctuation in abundance in relationship to environmental variables and agronomic management in organic and conventional orchards of mango (Mangifera indica L.) in ‘El Llano’ and ‘Aticama’, Nayarit, Mexico. Sampling was done from January to June 2010 and 2011. White mango scale males group in colonies in the lower canopy of trees (P = 0.0007), while females are isolated and more homogeneously distributed (P = 0.2970) in the whole plant, with a tendency to migrate to the lower canopy when the temperature warms. Females are most abundant between 18 and 22°C and 73 and 78% relative humidity, while males reach maximum abundance at temperatures between 25 and 28°C and 66 and 71% relative humidity. As peak abundance was reached, the proportion of male colonies was more than 20 per individual female. This was more evident in 2011, a year of drought, unlike 2010 that was wet and maintained an average of 0.98 male colony per female. Management practices in organic and conventional plantations of mango influenced the abundance of the insect pest. More abundant females (3.25 per leaf) coincided with the use of humus in organically managed plantations. Tree pruning significantly decreased females from 1.8813 to 0.6456 per leaf (P = 0.0253), but an increase of 0.1750 to 0.4177 male colonies per leaf was observed, although the difference was not statistically significant (P = 0.0681).

Serology of West Nile virus vectors and non-human reservoirs was surveyed at Acapulco, Jose Azueta, and Ometepec, three Pacific Coast localities of Guerrero State, Mexico. The objectives of this study were to use enzyme-linked immnosorbent assay (ELISA) to assess West Nile virus antibodies of bird and equine serum samples and use reverse transcription of polymerase chain reaction (RT-PCR) to detect the virus in field-collected resting mosquitoes. Forty birds trapped using mist nets yielded 10% seroprevalence. Similarly, 18.6% of 102 equine blood samples had West Nile virus. In addition, 4,854 mosquitoes were caught using motorized backpack aspirators and grouped into 116 pools. Of the 16 species and seven genera, no mosquito was positive for West Nile virus. Our study demonstrated West Nile virus seroprevalence on resident birds and equines in Guerrero State, Mexico.

Sand flies (Diptera: Psychodidae: Phlebotominae) are the main vectors of human leishmaniases worldwide. In the tropical forests of the New World, sand flies use large trees as resting, mating, and blood-feeding aggregation ecotopes. On the Peninsula of Yucatan, localized cutaneous leishmaniasis is endemic, and in recent years, progress has been made to identify the putative vectors. But, nothing is known about the natural resting sites of sand flies. The objective of this study was to use aspiration to collect sand flies in different resting micro-habitats mainly on tree trunks and other natural crevices. Sand flies also were collected using funnel traps in mammal burrows. At resting habitats, we collected 95 adult sand flies of nine species, with Lutzomyia trinidadensis (Newstead 1922) most common. Sixty-eight specimens of eight species were collected in funnel traps, with Lutzomyia deleoni (Fairchild & Hertig 1947) most abundant.

The external morphologies of the eggs of seven species of grasshoppers were studied with the aid of an electron microscope. The species were Boopedon diabolicum Bruner, Schistocerca cohni Song, Sphenarium purpurascens (Charpentier), Brachystola mexicana Bruner, Melanoplus differentialis (Thomas), Syrbula admirabilis (Uhler), and Melanoplus lakinus (Scudder). The eggs were elongated with rounded ends and provided reliable characteristics that allow identification of the seven species. Eggs of some of the seven species were hexagonal. Brachystola mexicana and Sphenarium purpurascens produced fewer eggs that were larger. The differential characteristics of the seven species and their general systematics are described to differentiate the taxa.

We describe and compare the egg chorion of five species of three genera of Pierinae: Pieriballia, Itaballia, and Perrhybris. Their characterizations and illustrations include the main structural features: number and arrangement of longitudinal axes (short and long), and quantification of ribs or cells, projections and vestiges or reminiscent ribs. Also, we describe the color and size of the egg. We typify two egg models: elongated ellipsoidal or fusiform and oblong ellipsoidal, both with projections in the apical area, around the micropyle. Comparisons are made between features present in different species and genera. We discuss their phylogenetic and taxonomic implications.

A great diversity of trichogrammatids (35 genera) has been reported for Mexico. Particularly, several species of the genus Trichogramme are widely used as biological control agents in integrated agricultural pest management programs in Mexico. The identification of trichogrammatid wasps based on morphological characters is complicated. A feasible alternative to those taxonomic problems is the utilization of molecular techniques. Therefore, the objectives of the present study were to differentiate the most common genera of Trichogrammatidae, and infer their phylogeny, based on the molecular markers ITS2 and 18S of the rDNA and COII of the mDNA. Thus, individual wasps of Ittys, Aphelinoidea, Paracentrobia, Pseudoligosita, Ufens, Burksiella, Zagella, and Trichogramma were subjected to DNA extraction, DNA amplification by PCR, and phylogenetic analysis by the maximum parsimony (MP) method, based on the use of the molecular markers ITS2 and 18S of ribosomal DNA (rDNA) and COM of mitochondrial DNA (mDNA). PCR-product sizes of the region ITS2 varied from 450 to 700 bp for the more common genera of Trichogrammatidae from Mexico, which is useful for the taxonomic studies of these parasitic wasps. On the contrary, PCR-product sizes of the regions 18S and COII did not vary among genera, whose values were about 790 and 300 bp, respectively. PCR-product sizes of the regions ITS2 Y COII for most of trichogrammatid genera are reported for the first time. Phylogenies obtained based on the sequences of the ITS2 region were congruent with the current classification of Trichogrammatidae based on morphological characters.

Una gran diversidad de tricogramátidos (35 géneros) se han reportado para México. Particularmente varias especies del género Trichogramme se utilizan ampliamente como agentes de control biológico en los programas de manejo integrado de plagas agrícolas en México. La identificación de las avispas tricogramátidos mediante caracteres morfológicos es compleja. Una alternativa factible a la problemática anterior, es la utilización de técnicas moleculares. Por lo anterior el objetivo del presente estudio fue diferenciar los géneros de Trichogrammatidae más comunes de México, e inferir su filogenia basándose en los marcadores moleculares ITS2 y 18S del ADNr y COII del ADNm. Los tamaños de los fragmentos de PCR de la región ITS2 del ADNr variaron de 450 a 700pb en los géneros de Trichogrammatidae, lo cual es de gran utilidad en estudios taxonómicos de estas avispas parasíticas. Por el contrario, las regiones 18S del ADNr y COII del ADNm no mostraron variación en los tamaños de los fragmentas de PCR, siendo éstos de alrededor de 790 y 300pb, respectivamente, para los diferentes géneros. Se reporta por primera vez los tamaños de productos de PCR de las regiones ITS2 Y COII para la mayoría de los géneros analizados. Las filogenias inferidas mediante el mátodo de maxima parsimonia (MP), difirieron entre marcadores moleculares. Las filogenias inferidas mediante las secuencias de la región ITS2 fueron congruentes con la clasificación basada en caracteres morfológicos de géneros de Trichogrammatidae actualmente aceptada.

The pathogenicity of 10 isolates of Beauveria bassiana (Balsamo) Vuillemin, and two of Metarhizium anisopliae (Metschnikoff) Sorokin, was evaluated against adults of the maize weevil, Sitophilus zeamais (Motschulsky). All isolates were pathogenic at a concentration of 1×109 conidia/ml, averaging 53 to 93% mortality, and a lethal time TL₅₀ of 3.5 to 5.1 days. The B11-1 isolate from B. bassiana caused 93.3% mortality in 3.5 days, whereas M21 of M. anisopliae showed a rate of 53.5% mortality in 5.1 days. Under different temperature regimes (28, 30, 32, and 34°C) the fungal growth decreased. Cluster analysis resulted in medium, high, and low levels in relation with the percentage of mycelium growth inhibition by each isolate. The isolates of B. bassiana showed a diminution of growth of 28 to 79%, while isolates of M. anisopliae were 24 to 31%. The B. bassiana isolates were most patoghogenic than M. anisopliae against the insect; however, these fungi were most tolerant to warm temperatures at range of 28 to 34^°C Therefore, M. anisopliae can be considered more useful for effective control of S. zeamais in maize storage facilities under these temperatures, a common scenario in Sinaloa, Mexico.

The aim of this study was to evaluate the pathogenicity and virulence of 16 native isolates and three collection strains of three species of entomopathogenic fungi that may have the potential for affecting Asian citrus psyllid nymphs, Diaphorina citri Kuwayama (Hemiptera: Liviidae), by developing an effective methodology for their evaluation. Bioassays were conducted in a laboratory using shoots of Citrus aurantium L., infested with second to fifth instar D. citri nymphs placed in Petri dishes and sprayed with 1 × 10⁸ conidia mL^-1 suspensions of the entomopathogenic fungi Beauveria bassiana, Isaria fumosorosea, and Metarhizium brunneum. Infested insects were incubated in a growth chamber at 26 ± 2°C, 60 ± 5% relative humidity, and 16:8 lightdark hours. The results showed that /. fumosorosea Pfr-612 strain scored the highest mortality (84.2%), while the isolate HIB-14 of B. bassiana induced the development of mycosis more effectively on psyllid nymphs.

Thirteen-hundred larvae of Spodoptera frugiperda were collected from infested maize fields in Nayarit in 2011 and 2012. These larvae were examined for natural enemies. Six parasitoid species were found and identified such as Cotesia sp. (0.3%) and Chelonus insularis (3.9%) (Hymenoptera: Braconidae), Pristomerus spinator (1.1%), Campoletis sp. (0.3%) and Hyposoter sp. (0.1%) (Hymenoptera: Ichneumonidae), and one tachinid fly Archytas marmoratus (0.07%) (Diptera: Tachinidae). Also two entomopathogenic fungi were isolated: Beauveria bassiana (3.7%) and Nomuraea rileyi (8.9%), and one nucleopolyhedrovirus (11%) SfMNPV (Baculoviridae). Total percentage of parasitism was 29.7%, which generates a potential use in biological control programs by conservation.

The functional response of the third instar larvae of Chrysoperla carnea (Stephens) on densities of Trialeurodes vaporariorum (Westwood) eggs was evaluated under controlled conditions. A functional type Il response (Holling's disk) was observed. Holling and Livdahl & Stiven models gave similar values for estimating parameters of the Holling's disk equation; however, estimates produced by the Rogers were higher. According to the results obtained of predation, C. carnea has considerable potential for the control of T. vaporariorum.