Scaling relationships between horns and body size were analyzed for a population of male rhinoceros beetle Golofa xiximeca Morón. Recent accounts suggested that horns of several species of most of the genera in the rhinoceros beetle subfamily Dynastinae showed positive and breaking-point allometries. To learn if the pattern was the same in G. xiximeca, we used allometric analysis to search for linear and breaking-point allometries of 46 males. The results suggested that patterns of the head horn and the pronotal horn were linear. The scale of the pronotal horn and head horn was significantly positively correlated with body size. The analysis indicated steeper slope with 5.20 units for the pronotal horn than the head horn slope with 4.33 units, but comparison analysis showed differences in slope were not statistically significant. Results were discussed in the context of sole versus mixed data collection and positive allometric response to selection pressure.

Insecticides with new chemistries and botanicals were evaluated against the parasitoid Aenasius bambawalei Hayat. Ninety-four percent of the parasitoids died after application of least concentrations and 100% died after greatest concentrations of malathion, dimethoate, and curacron. Ninety-six percent of parasitoids died from acetamiprid at greatest concentration. Botanicals were safer. Maximums of 34.4 and 23.2% of parasitoids were dead at 48 hours after applications of neem, Azadirachta indica A. Juss., and mint, Mentha longifolia (L.) Huds., respectively. Lesser concentrations of botanicals can be used to manage cotton mealybug, Phenacoccus solenopsis Tinsley, and have non-toxic effects on natural enemies.

Laboratory measurements of susceptibility to Bt toxins can be a poor indicator of the ability of an insect to survive on transgenic crops. We investigated the potential of using leaf tissue for evaluating heliothine susceptibilities to two dualgene Bt cottons, Gossypium hirsutum L. A preliminary study with different cotton leaf disk combinations was performed to determine the best procedure for using cotton tissue to assay bollworm, Helicoverpa zea Boddie, and tobacco budworm, Heliothis virescens F. Neonate larvae from a laboratory colony were assayed simultaneously on leaf disks of non-Bt and two dual-gene transgenic cottons in addition to meridic diet overlaid with discriminating doses of a commerciallyformulated Bt product. The bollworm colony in the laboratory was more tolerant than tobacco budworm to the commercially-formulated Bt product. When corrected for the non-Bt check, percentage of bollworm larval mortality was 42.1 and 71.9 on leaf disks of the two dual-gene Bt cottons. No tobacco budworm survived on dualgene Bt cotton leaf disks in the study. Assays using transgenic cotton leaf disks may compliment current meridic diet-based methods by providing a linkage to insect survival on Bt cotton plants.

Termidor^®H•P ‘High Precision Injection System’ technology was used to create termiticide-treated ‘Hydraulic Trenches’ in soil around perimeters of six termite-infested buildings. Termidor^®H•P II High Precision Termiticide was applied at locations around the buildings where using the Hydraulic Trench mode was not practical. The H•P System ‘Standard Application’ mode was used to apply termiticide using drilling and rodding methods, thereby ensuring complete continuous termiticide treatment to soil around building perimeters. Treated soil around one of the buildings was sampled for fipronil residue. Soil classifications were pH-neutral sandy-loam topsoil underlain with a sandy-clay-loam base. Residue analyses within the 30.5-cm-deep soil profile found fipronil concentrations lethal to termites in both soil types. No termite activity was detected within the six buildings at 3-, 6-, 12-, or 24-months after treatments.

The aim of this study was to assess the biodiversity of mosquito species in houses of the five ecological regions and update the checklist of species previously reported in the state of Tabasco. In total, 325 dwellings at 43 localities in the five ecological regions were sampled. Collection was by entomological CDC backpack aspirator. The mosquitoes captured were identified using published taxonomic keys and the aid of a stereomicroscope. In total, 4,622 mosquitoes of 15 species in 10 genera were captured. Two species not previously reported in Tabasco State were found: Aedes (Ochlerotatus) angustivittatus (Dyar and Knab, 1907) and Mansonia dyari Belkin, Heinemann & Page, 1970. The mosquito fauna of the state of Tabasco, including the new species are 55 species in 17 genera. Most species found transmit diseases to humans and should be included in government mosquito control programs.

Leishmaniases are endemic in southwestern Mexico, and different sand fly species are infected with Leishmania mexicana Biagi. One of the most abundant vectors and dominant species is Bichromomyia olmeca olmeca (Vargas and Díaz-Nájera). We analyzed the genetic variability of Bichromomyia olmeca olmeca and the prevalence of Leishmania mexicana infections with an endemic focus: “the Ejido 20 de Junio” (Mancolona), Campeche, Mexico, where patients with leishmaniases are reported throughout the year. Genetic diversity analysis of 102 sequences of a 270-bp fragment of the 3´ end of mitochondrial cytochrome b (cyt b) gene of Bichromomyia olmeca olmeca revealed 17 haplotypes. The nucleotide diversity and nucleotide polymorphism index were low. The neutrality test and Mismatch test showed population expansion. Prevalence of Leishmania mexicana was 24.5% in 102 females analyzed. This is the first study showing the genetic diversity of Bichromomyia olmeca olmeca sand flies in the Campeche region of Mexico, and also provides novel information on the high infection rate of Bichromomyia olmeca olmeca by Leishmania mexicana. Our finding of high sand fly infection rates during the end of the dry and hot weather of July enriches the literature because high infection rates had been reported only during the rainy season (November) in the region.

A new Nearctic species of the fungus gnat genus Palaeodocosia Meunier was discovered in western Michigan. Two adult males flew to a Malaise trap in jack pine (Pinus banksiana Lambert) forest in early December, after the first snows of late autumn had melted. This brings the total number of known extant Palaedocosia species to four. Two are Palaearctic [Palaeodocosia alpicola (Strobl) and Palaeodocosia flava (Edwards)], one is Holarctic [Palaedocosia vittata (Coquillett)], whereas the new species is Nearctic only. Adult females and juveniles of Palaeodocosia michigana Taber are unknown.

Females of Phyllophaga obsoleta Blanchard (Coleoptera: Melolonthidae) display a typical “calling” behavior by protruding the abdominal tip and exposing their genital chamber. This is the moment when the sex pheromone is released into the environment. The genital chamber and accessory glands have a specialized epithelia involved in production of the chemicals. In other species of the group (e.g., Costelytra zealandica White), bacteria have been confirmed to be involved. We identified the microorganisms in the genital chamber of females of P. obsoleta. Two types of bacterial colonies were isolated from the inside of the genital chamber and identified using the 16S rRNA gene sequence. The sequence of one of the bacterial colonies was a 97% match with the Klebsiella oxytoca strain HP1 sequence, while the sequence of the other bacterial colony was a 98% match with the Klebsiella michiganensis strain VITSW4 sequence. Microbiological and biochemical tests were used for taxonomic identification. Both bacteria produce indole and acetoin, chemicals that have been reported as attractants and sex pheromones in other insects, showing they can potentially participate in production of sex pheromone of P. obsoleta.

The objective of this study was to evaluate the susceptibility of Bradysia difformis Frey to the entomopathogenic nematodes Heterorhabditis bacteriophora Poinar and Steinernema feltiae Filipjev, as well as the persistence of the nematodes in the substrate used for poinsettia production. No differences were found in the proportion of infection caused by the two nematode species on B. difformis (F_1,28 = 3.44, P = 0.542). However, significant differences were found in the susceptibility of larvae compared to pupae of B. difformis (F_1,28 = 1,760, P < 0.001). The type of substrate had a significant effect on the persistence of the two nematodes (F_2,94.8 = 62.83, P < 0.001). The persistence of both nematode species was affected by moisture in the substrate.

Conidia of four strains of H. citriformis Speare fungi grown on oat (Avena sativa L.), wheat (Triticum aestivum L.), and sorghum (Sorghum bicolor (L.) Moench) were evaluated for production and for viability and pathogenicity against D. citri Kuwayama adults. Substrates were inoculated with conidial suspensions (1 × 10⁶ conidia/ml) of INIFAP-Hir-1, INIFAP-Hir-2, IB-Hir-1, and IB-Hir-2 strains and incubated for 35 days. Pathogenicity on Asian citrus psyllid adults also was evaluated through contact bioassay. Significantly more conidia were produced on oat (58.5-28.83 × 10⁶ per gram) than wheat (50.9-29.4 × 10⁶ per gram) at 21 days. Production of most conidia (8.4-6.6 × 10⁶ per gram) required 28 days on sorghum and was less than on oat or wheat. Percentages of germination of conidia on the three substrates ranged from 96.25 to 98.0% without significant differences among them. Pathogenicity of the strains against Asian citrus psyllid were not significantly different when grown on agar (85.5–89.9%) or oat (85.8–89.3%). Results confirmed the possibility of increased production of H. citriformis conidia in natural substrates maintaining pathogenicity against Asian citrus psyllid.

At Chiapas, Mexico, Frankliniella invasor Sakimura (Thysanoptera: Thripidae) causes large economic loses to growers of mango (Mangifera indica L.), in addition to enormous ecological impact by insecticides used to control the thrips. We evaluated two commercial formulations Meta-TNK^® [a.i. Metarhizium anisopliae (Metsch.) Sorokin sensu lato (s.l.)] and BotaniGard^®, [a.i. Beauveria bassiana (Bals.) Vuill.] as potential alternatives for control of female F. invasor adults. We found 91 ± 2.0 and 95 ± 1.1% of individuals exposed to Meta-TNK^® and BotaniGard^®, respectively, dead by 48 hours after exposure. Both formulations have promising features to be used to control F. invasor.

The effect of four variables -- ratio of infected/healthy individuals, sex, interference from healthy males, and transmission time — was evaluated to know the potential of horizontal transmission of Beauveria bassiana (Balsamo) Vuillemin strain Bb-M to induce epizootics in controlled populations of tomato/potato psyllid, Bactericera cockerelli (Sulc). In addition, the time in which 50% of the conidia germinated (GT50) and response to humidity were evaluated. The Bb-M strain required high humidity to sporulate (≥ 93%) and had a GT50 of 12.7 hours. The proportion of infected/healthy insects was very correlated (r = 0.804, p ≤ 0.05) with dissemination of the entomopathogen, suggesting a larger number of infected insects increased the spread of the entomopathogen. The sex effect was not consistent in transmission of the entomopathogen, with tendency toward greater infection (94%) when only males were infected. Transmission by males fluctuated from 15 to 96.66%, with greatest transmission having a ratio of 1:10 (infected males:healthy females). The mean transmission time (Tt₅₀) was 5.8 days. The results showed the evaluated strain by the auto-dissemination technique has potential for use in management of tomato psyllid; however, future studies are needed to design and evaluate strategies for application in the field.

El cultivo de tomate de cáscara (Physalis ixocarpa Brot.) se produce en casi todo México, parte de Estados Unidos, y Centro América. Recientemente la producción de tomate de cáscara ha sufrido pérdidas económicas del 70 al 80% por la presencia de amarillamiento y aborto floral cuyo agente causal se le ha atribuido a la presencia de fitoplasmas. Un vector de estos fitoplasmas es el insecto Bactericera cockerrelli Sulc. Las alternativas de control de este psílido han carecido de eficacia, por lo que es importante realizar estudios que permitan hacer un mejor manejo de este problema fitosanitario. Este trabajo tuvo por objetivo determinar la distribución espacial de las poblaciones de adultos de B. cockerelli en cuatro parcelas de tomate de cáscara, la determinación de la distribución espacial se realizó por medio de la geoestadística. Se determinó el semivariograma experimental para ajustarse a un modelo teórico (esférico, exponencial, o gaussiano) a través de los programas Variowin 2.2, su ajuste se validó con el método de validación cruzada y se obtuvieron los mapas de agregación de la plaga a través del Krigeado con el programa Surfer 9.0. La estabilidad espacio temporal a corto plazo de la plaga se determinó con las pruebas de Crámer-von Mises y con el índice de asociación de SADIE. Los resultados mostraron que las poblaciones de B. cockerelli presentan una distribución de tipo agregada, que fue corroborada por los mapas de densidad. Las infestaciones no se presentaron en el 100% de la superficie de las parcelas experimentales, lo cual resulta importante, ya que así se pueden dirigir las medidas de control sobre áreas específicas de infestación.

Se evaluó el efecto de un extracto acetónico de semillas de Trichillia havanensis Jacq. en estado sólido (resina) y de su aceite sobrenadante, a diferentes concentraciones, sobre la viabilidad y desarrollo de larvas neonatas del gusano soldado Spodoptera exigua (Hübner). Ambos estados del extracto mostraron mayor mortalidad larvaria a medida que se incrementó la concentración y el tiempo de ingestión a las concentraciones de 7500 y 10000 mg/l. De la misma forma se observó una reducción significativa en el peso de las larvas tratadas en comparación con el tratamiento testigo, a partir de la concentración de 100 mg/l de los dos estados del extracto a los 12 d de iniciado el ensayo, así como un notable retraso en el desarrollo de la larva, que se reflejó en un alargamiento del ciclo biológico del insecto a partir de la concentración de 500 mg/l de ambos estados del extracto adicionado a la dieta proporcionada a las larvas para su alimentación, manteniendo en primer estadio a las larvas supervivientes hasta el día 31.

Durante más de cien años, Biologia Centrali-Americana ha sido una importante fuente de información para muchos grupos de artrópodos mexicanos y centroamericanos, y continúa como una piedra angular del trabajo taxonómico. Sin embargo, muchos nombres incluidos están desactualizados. En este trabajo presentamos una lista actualizada de los nombres de las especies de Diplopoda (milpiés) citados en el volumen 14 de Biologia Centrali-Americana. MilliBase, una base de datos mundial taxonómica en línea de los miriápodos de la clase Diplopoda, se utilizó para actualizar los nombres. Biologia Centrali-Americana incluye 205 nombres para 204 especies y una subespecie (la subespecie fue excluida) de Diplopoda. De éstos, 88 nombres fueron descritos como nuevos en la obra de Pocock. Actualmente, 130 siguen siendo nombres válidos en los mismos géneros, y 74 han sido transferidos a otros géneros.

In the Bajio región, natural parasitism is diverse against the sugarcane aphid, Melanaphis sacchari (Zehntner). The most abundant species, Aphidius spp. (Hymenoptera: Aphidiidae), parasitizes as much as 31% of sugarcane aphids. Binodoxys, Diaretiella, Lysiphlebus, and Praon were less abundant genera of parasitoids.

The influence of weather variables on temporal distribution of Scyphophorus acupunctatus Gyllenhal, 1838, Hololepta sp., and Hololepta yucateca Marseul, 1853 in Agave inaequidens Koch was analyzed. We evaluated the preference of the species for decomposed A. inaequidens or decaying squid. Carrion traps were used to collect and samples directly from agave plants for 7 months. Abundance of Hololepta sp. was conspecific with abundance of agave weevil. Temperature (rho = >-0.41 and <0.15) and humidity (rho = <0.39) were not correlated with phenology of the species.

We report for the first time the presence of the erythrina gall wasp Quadrastichus erythrinae Kim in Mexico.