Light Conditions After Emergence Affect Food Consumption and Survival of Ceratitis capitata (Diptera: Tephritidae) Sterile Males.

To favor and standardize fruit fly production, many environmental factors are regulated in a mass-rearing facility. Specifically, in the holding rooms where sterile fruit flies are kept before releasing, they are exposed to constant darkness in order to reduce aggressive interactions and depletion of energy resources. However, such light conditions could negatively affect the quality traits and male mating performance. The objective of this study was to determine whether light conditions have an effect on quality traits in mass-reared 'Mediterranean fruit flies' Ceratitis capitata (Wiedemann) (Diptera: Tephritidae). Under laboratory conditions and in two sequential experiments, we studied the effect of 1) different light intensities and 2) photoperiods, on adult food consumption, adult body weight, survival, and percent of flying and calling males. In the first experiment, sterile male flies were exposed to different light intensities during 3 d after emergence: 1000, 500, or 250 lux, with a 12:12 photoperiod. Complete darkness was used as a control. In the second experiment, adult flies were exposed to the following photoperiods (L(1000 lux)-D): 14-10, 12-12, 8-16, 4-20, and 0-24 as a control. Our results showed that flies under darkness ingested less food, were heavier, and exhibited higher survival than flies under any treatment of light intensity or photoperiod. Furthermore, the percentage of fliers and number of calling males did not differ among treatments. We conclude that holding males for 3 d under darkness do not affect their quality; indeed, emerging under this condition appears to favor them. The implications of these findings for SIT programs are discussed.

Packing and Postirradiation Handling of the Anastrepha ludens (Diptera: Tephritidae) Tapachula-7 Genetic Sexing Strain: Combined Effects of Hypoxia, Pupal Size, and Temperature on Adult Quality.

The production of genetic sexing strains (GSS) of tephritid flies for sterile insect technique (SIT) programs convey the need to determine new conditions for packing and shipment since these flies are more susceptible to stressors than standard bisexual strains. We studied the effect of hypoxia, pupae size, and temperature on the new GSS Tapachula-7 of Anastrepha ludens flies (Diptera: Tephritidae). In one experiment, we tested the interaction size hypoxia using three pupae sizes, 6 (11.6 ± 1.1 mg), 7 (15.3 ± 1.5 mg), and 8 (17.9 ± 1.3 mg) (95% of produced pupae exhibit these categories of size), and four hypoxia periods, 12, 24, 36, 48 h and a control. In a second experiment, we tested two periods of hypoxia (24 and 48 h) and four temperatures: 15, 20, 25, and 30°C and a control (without hypoxia at laboratory temperature). Our results showed that the emergence and percent of fliers from the pupae exposed to hypoxia were adversely affected; however, emergence was higher in pupae of size 7. Treatment for 12 and 24 h hypoxia led to a higher number of fliers. In the case of the interaction of hypoxia and temperature, it was observed that those flies that emerged from the pupae exposed to hypoxia at 15 and 20°C exhibited quality control parameters similar to those that were not exposed to hypoxia. We discuss our results on the basis of the metabolic response to these factors and its application in the SIT programs.

Visibility and Persistence of Marker Dyes and Effect on the Quality and Mating Competitiveness of Mass-Reared Flies (Diptera: Tephritidae): Anastrepha obliqua and Bisexual and Genetic Sexing (Tapachula-7) Strains of A. ludens.

Fluorescent dyes are commonly used in the sterile insect technique (SIT) for marking insects for a proper identification after recapture. However, the quality of the mark must be balanced against insect performance, because dyes can negatively affect some parameters of insect performance and reduce their effectiveness in control with the SIT. We determined the visibility and persistence and the effect of dyes on the quality of Anastrepha obliqua (Macquart) and Anastrepha ludens (Loew) (bisexual and genetic sexing strains) by testing four concentrations of a dye (Day-Glo) from 0 to 2.5 g dye/kg of pupae. Visibility and persistence of the mark were positively affected by dose and negatively affected by the length of time the samples were kept in a solution of 75% alcohol. However, upon dissection, even the lowest dose of dye was visible under a fluorescence microscope. Between dyed and undyed pupae (control), no significant differences were observed in rates of emergence, fliers and flight ability, and survival in two tests, with water and without food and without water and food, at any of the concentrations tested. Furthermore, no significant difference in mating competitiveness was detected between control pupae and those dyed at 1.0 and 2.5 g dye/kg pupae. We discuss our results with the possibility of reducing the dose of dye in these three flies, because the heads are large enough to capture sufficient particles to permit identification with the current methods of detection.

Estudio multicéntrico de infecciones invasivas por Streptococcus pyogenes en niños de Argentina / Multicenter study on invasive Streptococcus pyogenes infections in children in Argentina

Introducción. Las infecciones invasivas por Streptococcus pyogenes (IISP) presentan elevada morbimortalidad aún en la actualidad; no obstante, a nivel regional, existen escasas publicaciones en pediatría. Objetivo. Describir la prevalencia, los factores predisponentes y las características clínicas de niños internados por IISP, analizar los factores de riesgo asociados a bacteriemia y letalidad. Material y métodos. Estudio retrospectivo, descriptivo de IISP en niños ≤ 18 años, internados en Pediatría de 20 centros asistenciales del país, entre 2010 y 2012. Variables evaluadas: edad, sexo, focos clínicos iniciales y tardíos, patología crónica previa, factores predisponentes, tratamiento y evolución. Resultados. Se analizaron 143 pacientes. Incidencia de 4,97 casos/10 000 egresos. Mediana de edad 54 meses; tenían patología crónica previa 11,2%. Tuvieron factores predisponentes 67,1%. Las formas de presentación más frecuentes fueron la piel y las partes blandas en 77, sepsis en 30, osteoarticulares en 19, fascitis necrotizante en 13, síndrome de shock tóxico en 11. Se aisló Streptococcus pyogenes en 56,6% de los hemocultivos; la presencia de más de un foco clínico y la ausencia de cirugía se asociaron a bacteriemia (OR 4,8; p= 0,003 y OR 3,1; p= 0,0012, respectivamente). El promedio de internación fue 13,4 días. La tasa de letalidad fue 7,6% asociada a síndrome de shock tóxico (OR 10; p= 0,005), fascitis necrotizante (OR 104; p < 0,0001) e ingreso a la Unidad de Cuidados Intensivos Pediátricos (OR 26; p < 0,001). Conclusiones. La mayoría de las IISP se presentaron en pacientes sin patología crónica previa. Los focos de presentación, frecuentemente con bacteriemia, fueron la piel y las partes blandas. Hubo asociación estadísticamente significativa entre bacteriemia y ≥ 2 focos iniciales y ausencia de cirugía. La letalidad, asociada a SSTS y fascitis necrotizante, fue similar a otras publicaciones.

Introduction. Invasive Streptococcus pyogenes infections (ISpIs) cause a high morbidity and mortality, even at present; however, at a regional level there are few publications on this subject in the field of pediatrics. Objective. To describe the prevalence, predisposing factors and clinical characteristics of children hospitalized for ISpI, and analyze risk factors associated with bacteremia and lethality. Material and methods. Retrospective, descriptive study on ISpIs in children <18 years old hospitalized in the Pediatric Ward of 20 healthcare facilities across Argentina between 2010 and 2012. Assessed outcome measures: age, gender, early and late clinical sources of infection, prior chronic condition, predisposing factors, treatment and evolution. Results. One hundred and forty-three patients were analyzed. The incidence of ISpI was 4.97 cases/10 000 hospital discharges. Patients' median age was 54 months old, and 11.2% had a prior chronic condition. Also, 67.1% had predisposing factors. The most common clinical manifestations were in the skin and soft tissue in 77 patients, sepsis in 30, bone and joint involvement in 19, necrotizing fasciitis in 13, and toxic shock syndrome in 11. Streptococcus pyogenes was isolated in the blood cultures of 56.6%. More than one clinical source of infection and no surgery were associated with bacteremia (odds ratio [OR]: 4.8, p= 0.003 and OR: 3.1, p= 0.0012, respectively). The average length of stay in the hospital was 13.4 days. Fatality rate was 7.6% in association with toxic shock syndrome (OR: 10, p= 0.005), necrotizing fasciitis (OR: 104, p < 0.0001) and admission to the Pediatric Intensive Care Unit (OR: 26, p < 0.001). Conclusions. Most ISpIs were observed in patients without a prior chronic condition. The most common manifestation was, frequently with bacteremia, in the skin and soft tissue. A statistically significant association was observed between bacteremia and ≥2 early sources of infection and no surgery. Fatality rate, in association with streptococcal toxic shock syndrome and necrotizing fasciitis, was similar to that observed in other publications.

Comparison of Anastrepha ludens (Diptera: Tephritidae) Bisexual and Genetic Sexing (Tapachula-7) Strains: Effect of Hypoxia, Fly Density, Chilling Period, and Food Type on Fly Quality.

The use of genetic sexing strain (GSS) insects in the sterile insect technique (SIT) makes necessary the revision of quality parameters of some stressful steps used during the packing process for aerial release because of possible differences in tolerance between fly strains. Here, we determined the effect of three periods of hypoxia (12, 24, and 36 h at pupal stage), three cage densities (1.0, 1.3, and 1.5 flies/cm2), two different foods (protein/sugar (1/24) and Mubarqui), and three chilling times (20 min [control], 90, and 180 min) on the quality parameters of flies of two Anastrepha ludens (Loew) strains (bisexual and GSS Tapachula-7). In general, the response to stressful conditions of both fly strains was qualitatively equivalent but quantitatively different, as flies of both strains responded equally to the stressful factors; however, flies of Tapachula-7 exhibited lower quality parameters than the control flies. Thus, hypoxia affected the flying ability but not the emergence or longevity of flies. The food type affected the adult weight; protein/sugar produced heavier flies that also survived longer and had a greater mating propensity. Flies under the lowest density were better fliers that those at the other two densities. Increasing chilling time reduced flight ability but not longevity or mating propensity. The implications of these findings for the use of A. ludens GSS in SIT programs are discussed herein.

Determination of the Host Status of the 'Persian' Lime (Citrus latifolia Tanaka) for Anastrepha ludens (Loew) (Diptera: Tephritidae).

Field and laboratory no-choice oviposition tests were performed to determine whether the 'Persian' lime (Citrus latifolia Tanaka) is a host of Anastrepha ludens Loew (Diptera: Tephritidae). Trapping and fruit sampling were performed to determine adult population densities and the level of infestation in the two lime orchards. Additionally, unharvested and harvested limes were exposed to sexually mature flies and the number of eggs laid and the immature developmental rates were determined. As a control, parthenocarpic 'Ataulfo' mangoes (Mangifera indica L.), a suitable host for A. ludens, were exposed to similar experimental procedures. The fecundity and fertility of adults obtained from limes and mangoes were compared. Our results demonstrate that A. ludens, under forced infestation conditions, oviposit on limes and also on control fruit. However, differences were detected in unharvested and harvested fruit, as unharvested limes were not infested. In the case of harvested fruit, the numbers of eggs laid and survival rates of immatures were significantly lower for 'Persian' limes compared with mangoes. Egg clutches were larger in limes than in mangoes, and most were deposited in the albedo rather than in the pulp. Moreover, oviposition rates were much higher in limes than in mangoes. Despite the fact that few of the immatures reached adulthood, the females obtained from limes were as fecund and fertile as those obtained from mangoes. Although adult A. ludens flies were captured in the two orchards, fruit sampling showed a complete absence of natural infestation among 'Persian' limes. We discuss the importance of our findings for determining the host status for 'Persian' limes.

Evaluation of the Host Status of Mature Green Papayas 'Maradol' for the Mexican Fruit Fly (Diptera: Tephritidae).

The suitability of mature green 'Maradol' papaya as a host of Anastrepha ludens (Loew) was studied under field and laboratory conditions. Field tests were conducted on commercial-ripened and spot-ripened fruit in two orchards and during two seasons in the state of Chiapas. Fruits at exportation ripeness are in "commercial ripeness", while fruits that are harvested immediately preceding exportation ripeness are in "spot ripeness." The field tests consisted of forced infestation experiments that evaluated papayas at two ripeness stages: the commercial- or exportation-ripened fruit (green fruits with one or two yellow stripes) and fruit before exportation ripeness called "spot ripeness." These tests were conducted in two orchards and during two seasons in the state of Chiapas, Mexico. Laboratory trials were performed with commercial-ripened fruit only. Fruit from four different postharvest periods (3, 24, 48, and 72 h) were exposed to groups of gravid flies. No larvae emerged from the fruit that was collected in the field experiments. However, some larvae and several fertile flies were obtained from the commercial-ripened fruit 72 h postharvest but not 3, 24, and 48 h postharvest in the laboratory. The results of this study indicate that the commercially ripe fruits of papaya Maradol were resistant to or free from infestation of A. ludens flies under field conditions, though these fruits must be considered nonnatural, conditional host because they became infested in the laboratory.

Packing of Fruit Fly Parasitoids for Augmentative Releases.

The successful application of Augmentative Biological Control (ABC) to control pest fruit flies (Diptera: Tephritidae) confronts two fundamental requirements: (1) the establishment of efficient mass rearing procedures for the species to be released, and (2) the development of methodologies for the packing and release of parasitoids that permit a uniform distribution and their optimal field performance under an area-wide approach. Parasitoid distributions have been performed by ground and by air with moderate results; both options face challenges that remain to be addressed. Different devices and strategies have been used for these purposes, including paper bags and the chilled adult technique, both of which are commonly used when releasing sterile flies. However, insect parasitoids have morphological and behavioral characteristics that render the application of such methodologies suboptimal. In this paper, we discuss an alternate strategy for the augmentative release of parasitoids and describe packing conditions that favor the rearing and emergence of adult parasitoids for increased field performance. We conclude that the use of ABC, including the packaging of parasitoids, requires ongoing development to ensure that this technology remains a viable and effective control technique for pest fruit flies.

Application of Nuclear Techniques to Improve the Mass Production and Management of Fruit Fly Parasitoids.

The use of irradiated hosts in mass rearing tephritid parasitoids represents an important technical advance in fruit fly augmentative biological control. Irradiation assures that fly emergence is avoided in non-parasitized hosts, while at the same time it has no appreciable effect on parasitoid quality, i.e., fecundity, longevity and flight capability. Parasitoids of fruit fly eggs, larvae and pupae have all been shown to successfully develop in irradiated hosts, allowing a broad range of species to be shipped and released without post-rearing delays waiting for fly emergence and costly procedures to separate flies and wasps. This facilitates the early, more effective and less damaging shipment of natural enemies within hosts and across quarantined borders. In addition, the survival and dispersal of released parasitoids can be monitored by placing irradiated sentinel-hosts in the field. The optimal radiation dosages for host-sterility and parasitoid-fitness differ among species, and considerable progress has been made in integrating radiation into a variety of rearing procedures.