Potential areas for the establishment of citrus leprosis virus vectors, Brevipalpus spp., in Mexico.

Citrus leprosis is a viral disease vectored by the mites Brevipalpus californicus and Brevipalpus yothersi. This work aimed to determine the potential areas for establishment of both mites and viruses in Mexico, based on the geographical distribution of the hosts and the climatic suitability for the vectors. Life tables of both mites were constructed to determine their thermal requirements-base temperature and degree-days required to complete life cycle-and population growth parameters-net reproduction rate, generation time, and intrinsic growth rate. For this, the mites were confined in Citrus aurantium fruits at 20, 22.5, 25 or 30 °C, 60 ± 5% RH and L14:D10 h photoperiod. Maps were generated where the climatic suitability for establishment of the mites and the citrus leprosis viruses was estimated in citrus-producing municipalities. The climatic suitability was determined through historical temperature records to calculate the potential number of generations per year, and ecological niche modeling based on collecting localities and bioclimatic variables using the algorithm Maxent. The base temperature was 9.5 °C for B. californicus and 10.2 °C for B. yothersi; degree-days required to reach adulthood were 372.1 and 331.7 °C, respectively. Potential sites for establishment of B. yothersi are mostly lowlands, whereas for B. californicus they are both lowlands and highlands. Temperature data indicate that B. californicus has fewer sites where it can develop > 16 generations per year than B. yothersi. According to our results, the sites where citrus leprosis is most likely to present high incidence are the sweet orange cultivars bordering the Gulf of Mexico.

Identification and motif analyses of candidate nonreceptor olfactory genes of Dendroctonus adjunctus Blandford (Coleoptera: Curculionidae) from the head transcriptome.

The round-headed pine beetle Dendroctonus adjunctus, whose dispersion and colonization behaviors are linked to a communication system mediated by semiochemicals, is one of the five most critical primary pests in forest ecosystems in Mexico. This study provides the first head transcriptome analysis of D. adjunctus and the identification of the nonreceptor olfactory genes involved in the perception of odors. De novo assembly yielded 44,420 unigenes, and GO annotations were similar to those of antennal transcriptomes of other beetle species, which reflect metabolic processes related to smell and signal transduction. A total of 36 new transcripts of nonreceptor olfactory genes were identified, of which 27 encode OBPs, 7 encode CSPs, and 2 encode SNMP candidates, which were subsequently compared to homologous proteins from other bark beetles and Coleoptera species by searching for sequence motifs and performing phylogenetic analyses. Our study provides information on genes encoding nonreceptor proteins in D. adjunctus and broadens the knowledge of olfactory genes in Coleoptera and bark beetle species, and will help to understand colonization and aggregation behaviors for the development of tools that complement management strategies.

Identification of Delia spp. (Robineau-Desvoidy) (Diptera, Anthomyiidae) and its cruciferous hosts in Mexico.

Soil pests of cruciferous crops in Mexico have been gaining importance in recent years; such is the case of Delia spp. (Robineau-Desvoidy) (Diptera, Anthomyiidae), of which, to date, there are no studies on the correct identification of associated species, as well as the range of hosts. In an integrated pest management program, it is essential to know this information to design and implement adequate phytosanitary measures. Plants infested by Delia spp. were collected in the states of Guanajuato, Puebla, and Mexico from June to November 2017 and March to December 2018 in commercial plantations of cruciferous crops (Brassica oleracea L. var. italica, botrytis and capitata), B. napus L., and Raphanus sativus L.) as well as some cruciferous weeds (R. raphanistrum L., Sisymbrium irio L., B. campestris L., Capsella bursa-pastoris L., and Lepidium virginicum L.) in the edges of these crops. The two species found in this study, Delia planipalpis (Stein) and Delia platura (Meigen), identified using male genitalia was corroborated by molecular techniques. Both species emerged from all the sampled hosts, except for C. bursa-pastoris and L. virginicum. The association of the two species in cruciferous crops and weeds, provides valuable information for the management of these insects not only in cruciferous crops but other ones that are strongly attacked by D. platura.

Corrections of some errors in the paper "Molecular delineation of the Agave Red Worm Comadia redtenbacheri (Lepidoptera: Cossidae)". Zootaxa, 4375 (3), 358-370.

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Molecular delineation of the Agave Red Worm Comadia redtenbacheri (Lepidoptera: Cossidae).

Comadia redtenbacheri (Hammerschmidt) (Agave Red Worm) is the only member of the family Cossidae that has been described as a phytophagous specialist of the plant genus Agave, which is mainly distributed in México. A new extraction protocol adapted from Stewart Via (1993) has been implemented for sequencing the COI gene from samples collected in five states of the North Central (Querétaro and Zacatecas), South Central (Estado de México) and East Central (Hidalgo and Tlaxcala) regions of México with the purpose of contributing to delineation of the species. A Maximum Likelihood (ML) tree based on these COI sequences as well as COI sequences from other Cossinae species was developed to complement the existing morphological and taxonomic approaches to delineation of this species. As expected, our Comadia samples cluster together within a monophyletic clade that includes four C. redtenbacheri sequences previously reported. This group seems to be consistent with our reconstruction, which is supported by a bootstrap value of over 99%. The closely related branches associated with the latter group include organisms known to be the plant and tree borers of the Cossinae subfamily. The COI sequences from our samples were analyzed to determine the percentage of identity among the C. redtenbacheri in a first attempt to detect differences in the sequence that matches a particular region of México.

Patrón espacio-temporal de larvas y huevecillos de nemátodos gastrointestinales en pastizales ganaderos de Veracruz, México / Spatio-temporal pattern of larvae and eggs of gastrointestinal nematodes in cattle pastures in Veracruz, Mexico

The spatial and temporal distribution of gastrointestinal nematodes of cattle has been little studied in Mexico. Previous studies have described periods of higher larval presence, vertical and horizontal migration in grasslands, and the frequency of adult nematodes; as well as the effect of pasture trichomes on the migration and survival of Haemonchus larvae. The aim of this study was to determine the time-space layout and spread of gastrointestinal nematode larvae on pasture, and to estimate the effect of ivermectin applied to cattle on the time-dependent abundance of their eggs in a ranch in Veracruz. To determine the spatio-temporal arrangement, monthly morning grass samples were obtained from 30 sampling points from July 2008 to June 2009. Third stage larvae (L3) from each point were counted, and aggregation patterns were estimated through variance/mean and negative binomial K indices. Additionally, the number of eggs per gram in cattle feces was determined, from samples with (CI) and without ivermectin (SI), using standard techniques. A total of 20 276L3 larvae were recovered in the pasture, of which an 80% corresponded to Haemonchus contortus. The highest nematode density with more than 5 000L3/kgDM was detected in October 2008, and the lowest in February and March 2009. The L3 showed an aggregated spatial pattern of varying intensity throughout the year. The number of eggs in the stool was not reduced with the ivermectin application to cattle, which suggested a failure of control. However, the highest parasite loads were observed from July to November 2008. We concluded that the application of ivermectin was not effective to control nematodes eggs, and that L3 populations fluctuated on pasture for ten months, providing an infection source to grazing animals afterwards. Rev. Biol. Trop. 61 (4): 1747-1758. Epub 2013 December 01.

El conocer la disposición espacio-temporal y diseminación de las larvas de nematodos gastrointestinales en los pastizales, y estimar el efecto de la ivermectina aplicada a bovinos sobre la abundancia de sus huevecillos, permite estimar dónde y cuándo se presentan las poblaciones más altas, que puede servir para establecer planes de muestreo y orientar medidas de control, así como para definir el riesgo de contaminación de los pastizales de manera diferencial. Para la determinación de la disposición espacio-temporal de L3 en el pastizal, se recolectaron, contaron e identificaron mensualmente las larvas en 30 puntos de muestreo, posteriormente se generaron mapas de disposición espacial con los datos obtenidos de los conteos de L3 en cada punto y mes de muestreo, y se calculó el patrón de disposición mediante los índices varianza/media y K binomial negativa. El número de huevecillos por gramo de heces de los bovinos con (CI) y sin ivermectina (SI), se calculó con la técnica de McMaster. En el pastizal se recuperaron 20 276L3, correspondiendo el 80% a H contortus. En octubre 2008 se detectó la más alta densidad de nematodos con más de 5 000L3/kgMS. Las L3 presentaron un patrón espacial agregado de intensidad variable durante todo el año. Las mayores densidades poblacionales de nematodos fueron en octubre 2008 y las menores en febrero y marzo 2009. La aplicación de ivermectina a los bovinos no redujo el número de huevecillos presentes en las heces, debido a que los tratamientos fueron estadísticamente iguales. De julio a noviembre 2008, se observaron las mayores cargas parasitarias.

Selection of a fungal isolate for the control of the pink hibiscus mealybug Maconellicoccus hirsutus.

BACKGROUND: Maconellicoccus hirsutus Green is a widely distributed pest of numerous crops. Although synthetic pesticides are used to control this pest, entomopathogenic fungi may provide an alternative control mechanism. Three experiments were carried out to select a fungal isolate with the potential to be used as a microbial control agent. The in vitro growth of five isolates of Beauveria bassiana sensu lato (Bals.) Vuill and Metarhizium anisopliae sensu lato (Metschn.) Sorokín, along with three isolates of Lecanicillium lecanii (Zimm.) Zare & W. Gams and Isaria fumosoroseus (Wize), was assessed at four temperatures. The in vivo sporulation of eight selected isolates was then evaluated, followed by the susceptibility of third-instar M. hirsutus to a single dose (1 × 10(8) conidia mL(-1) ) of each of these isolates. RESULTS: Growth was greatest by isolates of I. fumosoroseus and L. lecanii at 15 and 20 °C and by isolates of M. anisopliae at 25 and 30 °C. In vivo conidium production was greatest when infected with B. bassiana isolate GHA and M. anisopliae isolate Ma65. Mortality was greatest when inoculated with M. anisopliae isolates Ma65 and Ma129. CONCLUSION: Isolate Ma65 shows the best potential to be developed as a microbial control agent for M. hirsutus.

[Spatio-temporal pattern of larvae and eggs of gastrointestinal nematodes in cattle pastures in Veracruz, Mexico]. / Patrón espacio-temporal de larvas y huevecillos de nemátodos gastrointestinales en pastizales ganaderos de Veracruz, México.

The spatial and temporal distribution of gastrointestinal nematodes of cattle has been little studied in Mexico. Previous studies have described periods of higher larval presence, vertical and horizontal migration in grasslands, and the frequency of adult nematodes; as well as the effect of pasture trichomes on the migration and survival of Haemonchus larvae. The aim of this study was to determine the time-space layout and spread of gastrointestinal nematode larvae on pasture, and to estimate the effect of ivermectin applied to cattle on the time-dependent abundance of their eggs in a ranch in Veracruz. To determine the spatio-temporal arrangement, monthly morning grass samples were obtained from 30 sampling points from July 2008 to June 2009. Third stage larvae (L3) from each point were counted, and aggregation patterns were estimated through variance/mean and negative binomial K indices. Additionally, the number of eggs per gram in cattle feces was determined, from samples with (CI) and without ivermectin (SI), using standard techniques. A total of 20 276 L(3) larvae were recovered in the pasture, of which an 80% corresponded to Haemonchus contortus. The highest nematode density with more than 5 000L(3)/kgDM was detected in October 2008, and the lowest in February and March 2009. The L3 showed an aggregated spatial pattern of varying intensity throughout the year. The number of eggs in the stool was not reduced with the ivermectin application to cattle, which suggested a failure of control. However, the highest parasite loads were observed from July to November 2008. We concluded that the application of ivermectin was not effective to control nematodes eggs, and that L3 populations fluctuated on pasture for ten months, providing an infection source to grazing animals afterwards.

Effect of ivermectin on the survival and fecundity of Euoniticellus intermedius (Coleoptera: Scarabaeidae).

The State of Veracruz in Mexico is one of the main cattle producers, and uses several veterinary products for disease and parasite control. For parasite control, ivermectin is one of the most frequently used substances. Nevertheless, even though previous research conducted in other countries has found that this product has negative effects on beneficial coprophagous fauna, no studies have described its effects on coprophagous insects at a local scale in Veracruz, Mexico. This study evaluated Euoniticellus intermedius survival, fecundity, fertility and preimaginal development under laboratory conditions when ivermectin was added to cattle dung at three different concentrations. The design included two controls (spiked dung), and the following product concentrations: 0.01, 1.0 and 100ppm, which were homogenized with wet cattle dung. 20 female-male E. intermedius couples between five and 15 days old were used and kept at 27 degrees C, 70% RH, and 12h light for 10 days. The survival of all specimens, the fertility of 20 females and the gonadal maturity of 17 males were verified. The larval development in 162 pieces of brood-mass was examined, and a total of 974 larvae developed and reached adulthood. The highest ivermectin concentration was toxic at 1.0ppm dose, the survival of adults was reduced to almost the half, and at 100ppm, total mortality was observed. The effects on specimen reproductive systems showed that the ovary was not affected, that the testicle size increased, and that the fecundity and weight of brood-masses were reduced. Pre-imaginal development increased 0.5 times at 0.01ppm concentration, and the width of the cephalic capsule in third instar larvae diminished. The prolonging of development time may cause a phase lag in the field activity cycle, this lag may reduce the number of E. intermedius individuals and the efficiency of the environmental services that they provide.

Effect of ivermectin on the survival and fecundity of Euoniticellus intermedius (Coleoptera: Scarabaeidae)

The State of Veracruz in Mexico is one of the main cattle producers, and uses several veterinary products for disease and parasite control. For parasite control, ivermectin is one of the most frequently used substances. Nevertheless, even though previous research conducted in other countries has found that this product has negative effects on beneficial coprophagous fauna, no studies have descry ibed its effects on coprophagous insects at a local scale in Veracruz, Mexico. This study evaluated Euoniticellus intermedius survival, fecundity, fertility and preimaginal development under laboratory conditions when ivermectin was added to cattle dung at three different concentrations. The design included two controls (spiked dung), and the following product concentrations: 0.01, 1.0 and 100ppm, which were homogenized with wet cattle dung. 20 female-male E. intermedius couples between five and 15 days old were used and kept at 27°C, 70% RH, and 12h light for 10 days. The survival of all specimens, the fertility of 20 females and the gonadal maturity of 17 males were verified. The larval development in 162 pieces of brood-mass was examined, and a total of 974 larvae developed and reached adulthood. The highest ivermectin concentration was toxic at 1.0ppm dose, the survival of adults was reduced to almost the half, and at 100ppm, total mortality was observed. The effects on specimen reproductive systems showed that the ovary was not affected, that the testicle size increased, and that the fecundity and weight of brood-masses were reduced. Pre-imaginal development increased 0.5 times at 0.01ppm concentration, and the width of the cephalic capsule in third instar larvae diminished. The prolonging of development time may cause a phase lag in the field activity cycle, this lag may reduce the number of E. intermedius individuals and the efficiency of the environmental services that they provide.

El estado de Veracruz en México, es uno de los principales productores de ganado vacuno en México, asimismo utiliza diversas medicinas veterinarias para el control de enfermedades y parásitos. La ivermectina es una de las substancias más utilizadas para el control de parásitos. Sin embargo, se sabe por estudios hechos en otros países, que esta substancia tiene efectos negativos sobre la fauna coprófaga benéfica como los escarabajos del estiércol, pero no se han estudiado sus efectos sobre la fauna coprófaga de Veracruz o de México. Este estudio se realizó en condiciones de laboratorio, en donde se utilizó el estiércol vacuno a tres diferentes concentraciones de ivermectina para determinar su efecto sobre la supervivencia, fecundidad, fertilidad y desarrollo preimaginal de Euoniticellus intermedius. Por lo tanto, las tres concentraciones que se emplearon fueron: 0.01, 1.0 y 100ppm de ivermectina homogeneizada en estiércol vacuno fresco y dos testigos. Además, se utilizaron 20 parejas hembramacho por tratamiento, entre cinco y 15 días de edad y mantenidos por 10 días a 27°C, 70% HR y 12hr luz. Se determinó la supervivencia de todos, la fertilidad en 20 hembras y el estado de madurez gonádica en 17 machos. Se determinó el desarrollo preimaginal en 162 masas-nido y 974 se dejaron continuar el desarrollo hasta la emergencia de los adultos. La ivermectina es tóxica a mayor concentración. La supervivencia de adultos se redujo casi a la mitad a dosis de 1.0ppm y fue nula a 100ppm. El ovario no fue afectado. Los testículos incrementaron de tamaño. La fecundidad y el peso de las masas-nido se redujeron. El desarrollo preimaginal se incrementó 0.5 veces a concentración 0.01ppm y las larvas del tercer estadio redujeron el ancho de la cápsula cefálica. El alargamiento del tiempo de desarrollo puede causar desfase de su ciclo de actividad en campo, lo que podría reducir su número y la eficiencia de los servicios ambientales que proporcionan.

Factors affecting pheromone release by Scyphophorus acupunctatus (Coleoptera: Curculionidae).

Scyphophorus acupuncatus Gyllenhal is considered to be the most significant pest of cultivated agaves in the world. Recent studies on the chemical ecology of this weevil have shown that males release a pheromone that attracts both sexes. In this study, we investigated the effect of feeding, aging, photoperiod, and time of day on pheromone release by S. acupuncatus males under laboratory conditions. The pheromone released by individual males was sampled using solid-phase microextraction and analyzed by gas chromatography-coupled mass spectrometry. Our results show that food is an important factor because weevils deprived of plant material did not release any pheromone. In addition, we found that males fed with apple, a nonhost plant, released less pheromone than weevils fed with agave. Host odor does not seem to be important in stimulating pheromone release. We found that males as young as 1 mo were able to release pheromone, although the numbers of individuals releasing pheromone increased with age. Older males released more pheromone than younger males. We found that S. acupuncatus males released pheromone during the photophase and scotophase; there was, however, no significant peak in pheromone release. Also, the pheromone released by S. acupunctatus was not affected by the length of the photoperiod.

Factors influencing the release of volatiles in Anastrepha obliqua males (Diptera: Tephritidae).

During sexual signaling, males of Anastrepha obliqua (Macquart) form leks and attract females by producing sounds and releasing volatile compounds. The objective of this study was to investigate the influence time of time of day, age, irradiation, mating status, and the presence of host fruit on the release of volatile components by laboratory-reared A. obliqua males. A. obliqua males released four compounds identified by gas chromatography coupled with mass spectrometry (GC-MS) as (E,E)-alpha-farnesene, (Z,E)-alpha-farnesene, (Z)-3-nonenol, and a farnesene isomer during calling behavior. Although males released volatiles during the entire day, the amount of volatiles was higher in the early morning and afternoon hours. Males began to emit volatiles when they were 6 d old, but only the amount of (Z)-3-nonenol was affected by age. Irradiation of flies with gamma rays from a 60Co source at a dose rate of 80 [corrected] Gy significantly reduced the amount of volatiles released during calling behavior. The amount of volatiles was lower in recently mated males than virgin males. However, there were no significant differences between virgin males and males 24 h after mating. The presence of host fruit did not affect the amount of volatiles compared with the control.

Genitalia de tres especies de Heilipus Germar (Coleoptera: Curculionidae) que dañan frutos de aguacate (Persea americana Mill) en México y Costa Rica / Genitalia of three species of Heilipus Germar (Coleoptera: Curculionidae) that damage avocado fruits (Persea americana Mill.) in Mexico and Costa Rica

The male and female genitaliae of three species of the genus Heilipus Germar (H. lauri Boheman, H. pittieri Barber and H. trifasciatus Fabricius) that damage avocado fruits (Persea americana Mill.) in Mexico and Costa Rica are described and illustrated. The aedeagus, spiculum gastrale, styli of 8th sternite are different in each one of the three species studied and can be used for specific identification.

La genitalia masculina y femenina de tres especies de Heilipus Germar (H. lauri Boheman, H. pittieri Barber y H. trifasciatus) que dañan frutos de aguacate (Persea americana Mill.) en México y Costa Rica es descrita e ilustrada. El edeago, espícula gastrale, y estilos del esternitos VIII son diferentes en cada una de las tres especies estudiadas y pueden ser usadas para la identificación específica.

[Genitalia of three species of Heilipus Germar (Coleoptera: Curculionidae) that damage avocado fruits (Persea americana Mill.) in Mexico and Costa Rica]. / Genitalia de tres especies de Heilipus Germar (Coleoptera: Curculionidae) que dañan frutos de aguacate (Persea americana Mill) en México y Costa Rica.

The male and female genitaliae of three species of the genus Heilipus Germar (H. lauri Boheman, H. pittieri Barber and H. trifasciatus Fabricius) that damage avocado fruits (Persea americana Mill.) in Mexico and Costa Rica are described and illustrated. The aedeagus, spiculum gastrale, styli of 8th sternite are different in each one of the three species studied and can be used for specific identification.

Evidence for a male-produced aggregation pheromone in Scyphophorus acupunctatus Gyllenhal (Coleoptera: Curculionidae).

Olfactory response of male and female Scyphophorus acupunctatus Gyllenhal (Coleoptera: Curculionidae) to volatiles released from the same or opposite conspecifics alone, or combined with host plant volatiles, was evaluated in the laboratory and field. We also evaluated the response to synthetic Rhynchophorinae pheromones in the laboratory. In laboratory tests, attraction of males and females in Y-tube olfactometer to conspecific males was greater than to females and clean air. Males and females preferred the combination males + agave over agave alone. Both sexes were significantly attracted to 2-methyl-4-heptanol and 2-methyl-4-octanol compared with hexane control. In field trials, weevils were successfully caught in the traps baited with conspecifics and plant material. These field results support those of the laboratory bioassays, showing that males attracted conspecific males and females and addition of plant material enhanced the attraction. These results further suggest that S. acupunctatus produces an aggregation pheromone.