Evaluation of water-soluble dyes to mark internal structures of Lepidoptera via larval feeding

ABSTRACT Understanding aspects of insect ecology is a key component for the applicability of control methods or pest resistance management. For instance, the comprehension of insect dispersal is crucial to determining insect gene flow and the maximum distance between refuge areas in Bt (Bacillus thuringiensis) crops. But, for such studies, insects need to be marked prior to release. Seeking to refine the technique of dispersion studies of the genetic material of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), this study aimed to determine the efficiency of water-soluble dyes for the internal marking of S. frugiperda immatures and adults via larval feeding, with emphasis on marking the spermatophore. Rhodamine B, Methylene Blue, Ponceau, Coomassie, and Eosin-Nigrosin were added to the larval artificial diet at concentrations of 0, 100, 200, 400, 600, 800, and 1000 ppm. Mortality and duration of the larval stage as well as the efficiency of marking internal structures of larvae and adults were evaluated. Rhodamine B and Methylene Blue increased the duration of the larval period, but the former caused higher mortality. The staining of the gut, hemolymph, and imaginal discs, in the larval phase, was observed for Rhodamine B, Methylene Blue, and Coomassie dyes. However, none of the dyes were efficient for marking spermatophores. Thus, the addition of these water-soluble dyes to the larval diet of S. frugiperda can mark internal structures of the larva, but not the adult. Therefore, these dyes have limited application once they may be used only for marking larvae.

¡El tamaño sí importa! Incidencia del tamaño del cebo en la captura de escarabajos coprófagos en el bosque seco tropical / Size does matter! Incidence of bait size on the capture of dung beetles in the tropical dry forest

Resumen Introducción: Tradicionalmente, los estudios de escarabajos coprófagos en los bosques secos tropicales (BST) del Caribe colombiano han aplicado metodologías diseñadas para zonas húmedas y andinas del país, lo cual podría estar incidiendo en el rendimiento y la eficiencia del muestreo. Objetivo: Con el fin de aportar a esta discusión, se analizó cómo la cantidad de cebo y el tiempo de operación de la trampa de caída inciden en la efectividad de captura de escarabajos coprófagos en un fragmento de BST en La Reserva Campesina la Flecha, San Jacinto, Colombia. Métodos: Para la captura de los escarabajos, se utilizó trampas de caída, cebadas con tres cantidades diferentes de atrayente: pequeño (34.6 g), mediano (53.8 g) y grande (114.9 g), las cuales permanecieron activas en campo durante 48 h. Cuatro muestreos fueron realizados entre marzo y septiembre de 2015, abarcando por igual la época seca y de lluvia. Resultados: Se registró un total de 4 563 individuos, agrupados en 10 géneros y 27 especies de escarabajos coprófagos. Los mayores valores de riqueza, abundancia y biomasa se presentaron en el cebo grande, a las 48 h, durante la época de lluvias. Sin embargo, el tiempo de operación de la trampa no tuvo efecto en la estimación de la riqueza, abundancia y biomasa de escarabajos independientemente de los tamaños de cebo. Los tres órdenes de la diversidad ( 0 D, 1 D y 2 D), presentaron valores similares entre las cantidades de cebo durante la época de lluvia, pero en la época seca, los cebos de mayor tamaño presentaron los valores de diversidad más altos. Por su parte con el cebo de mayor tamaño se capturó significativamente más riqueza, abundancia y biomasa de escarabajos de cuerpo pequeño y grande siendo esta situación más notaria durante la época seca. Conclusiones: Los resultados de este trabajo evidencian que para el estudio de los ensamblajes de escarabajos en el BST la utilización de un cebo de mayor tamaño contribuye a una mejor estimación de riqueza, abundancia, diversidad y biomasa, sobre todo durante la época seca, cuando las condiciones ambientales propician que los cebos pierdan su atractividad con mayor rapidez.

Abstract Introduction: Typically, research on dung beetles in the Tropical Dry Forests (TDF) of Colombian Caribbean region, have applied methodologies designed for wet or Andean areas of the country, which could be influencing the performance and efficiency of sampling. Objective: In order to contribute to this discussion, we analyzed how the bait amount and pitfall trap operating time influence the collection effectiveness of dung beetles in a TDF fragment at Reserva Campesina La Flecha, San Jacinto, Colombia. Methods: For the collection of beetles, we utilized pitfall traps baited with three different amounts of attractants: small (34.6 g), medium (53.8 g), and large (114.9 g), which remained active in the field for 48 h., 4 samplings between March and September 2015 were carried out, covering both, dry and rainy seasons. Results: A total of 4 563 individuals were recorded, grouped into 10 genera and 27 species of dung beetles. The highest values of richness, abundance and biomass were registered in the large bait, at 48 h, during the rainy season. However, the trap operating time had no effect on the estimation of beetles' richness, abundance, and biomass, regardless of bait sizes. The three diversity orders ( 0 D, 1 D y 2 D) showed similar values between the bait amounts during rainy season, but in the dry season, the largest baits displayed the highest diversity values. On the other hand, with the largest bait, significantly more richness, abundance, and biomass of small and large body beetles were registered, especially during the dry season. Conclusions: The results of this research show that, for the study of beetles' assemblages in the BST, the use of a larger bait contributes to a better estimate of richness, abundance, diversity and biomass, especially during the dry season, when environmental conditions promote a more rapidly loss of baits attractiveness.

Measurement of the Shoulder Motion Using 3-D Motion Capture Technique / 대한정형외과연구학회지

PURPOSE: Measurement of scapular motion as a component of shoulder motion is clinically limited. The purpose of this study was to measure the scapulothoracic motion and glenohumeral motion separately using the 3-D motion capture technique. MATERIALS AND METHODS: Twelve healthy adult male volunteers (Mean age: 28 years) without any history of shoulder pathologies were included for the study. Shoulder motions in 3 planes -forward flexion, abduction in scapular plane and abduction in coronal plane- were measured in 3-dimensions. And we estimated skin slippage of optical markers according to the flexion of the shoulder using ultrasonography. RESULTS: During forward flexion, abduction in scapular plane and abduction on coronal plane, scapula showed upward rotation, external rotation and posterior tilting. Especially, during abduction on coronal or scapula plane, scapula was upwardly rotated and posteriorly tilted in linear fashion. The scapulo-humeral rhythm was 6.7:1 in whole range of abduction on the coronal and scapular plane. Estimated skin slippage of the marker on the inferior angle of scapula was 4.3+/-1.7 cm and bigger than those of other markers. CONCLUSION: This study failed to get a useful data of shoulder motion due to marker position which did not reflect scapula motion actually. But this trial could be a help for the future study, as this study suggested the possibilities of 3-D motion capture technique for the measurement of shoulder motion.