Abstract: The yellow stem borer (YSB), Scirpophaga incertulas (Walker), is a major pest of rice in Asia and pheromone trapping technology is emerging as a promising eco-friendly IPM tool for more sustainably managing this pest. To identify more efficient trap design so to maximize the efficiency of attracting and retaining the male moths in pheromone-based trapping system, a common methodology-based network study was taken up to compare the moth catches in alternative sex pheromone-baited Delta traps of varying attributes versus the commonly used Funnel (sleeve) trap at three major rice growing locations (Coimbatore, Tirurkuppam, Tirupathisaram) in Tamil Nadu, India within the same season during 2017-18. The results from the concurrent six week trap catch studies clarified that two superior Delta trap variants caught significantly more YSB moths than the funnel trap at all three locations. The moth catches were about 4-5 times greater in the normal size Delta trap (32x20x11cm) compared the Funnel traps, while even the smaller size Delta trap (22x12x7.5cm) caught nearly 2 times more moths than Funnel traps. The attribute of additional vents on the side roof of Delta traps was found to enhance the moth catch in Delta trap significantly. The relative moth catches among the five Delta trap variants versus Funnel trap at each location are also illustrated, along with results of pooled analysis over the locations, which confirmed the consistent superiority of Delta trap versions and the extra benefit from additional vents as trap attributes in enhancing the moth catches. The present results have shown the scope to enhance the impact potential of the improved Delta trap designs in monitoring and mass-trapping of YSB. The need for future population ecology R&D in linking the use of such improved Delta trap versions to fine-tuning the local action thresholds which are based on trap catches by relating to trapping efficiency as a factor is indicated.Abstract: The yellow stem borer (YSB), Scirpophaga incertulas (Walker), is a major pest of rice in Asia and pheromone trapping technology is emerging as a promising eco-friendly IPM tool for more sustainably managing this pest. To identify more efficient trap design so to maximize the efficiency of attracting and retaining the male moths in pheromone-based t...Show More
Abstract: A decaying cadaver is particularly attractive to necrophagous insects, more specifically Diptera. These are the first to lay their eggs on corpses. For the post mortem interval determination, the entomologist needs to know the precise time of the first egg-laying. The objective of this study is to determine the egg laying delay of these insects on a cadaver exposed in different conditions in the Guinean zone of Côte d'Ivoire. To do this, our work was been carried out in a natural environment at the National Agronomic Research Center. The experimental setup consisted of four types of wire mesh cages corresponding to the following cases: cadavers exposed to the open air or control cadavers, semi-immersed cadavers, cadavers wrapped in a shroud and suspended cadavers. Work on the site has been made from 29 October to 5 November 2019. The spawning period in species of Calliphoridae, was shorter on control and suspended cadavers. In Sarcophagidae, we noted a larviposition late on the suspended cadavers. Muscidae and Fanniidae, which intervened later on the decomposing corpses, were not observed on the suspended cadavers. These carcasses quickly dried out, no longer being able to provide nutrients essential for the proper development of larvae of species of these Diptera families. Depending on the accessibility of the corpses to necrophagous insects, the first egg-laying of Diptera were observed after 6 hours of exposure and the last after 174 hours. The exposure conditions of the corpses significantly influenced the time taken to lay the main necrophagous Diptera. As the first egg-laying of the flies occurs in the first moments after death, as long as the corpses is accessible, the results obtained during these experiments should be taken into account by the expert entomologist, in the estimation of the interval post-mortem upon discovery of a corpse.Abstract: A decaying cadaver is particularly attractive to necrophagous insects, more specifically Diptera. These are the first to lay their eggs on corpses. For the post mortem interval determination, the entomologist needs to know the precise time of the first egg-laying. The objective of this study is to determine the egg laying delay of these insects on ...Show More