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Entomology in Mauritius has historically been linked with the agricultural and medical fields but concern should now be directed towards the conservation of native forest insects given that they are key components of the local ecosystem. Despite its young age, small size and remoteness, the island has a well-developed native insect fauna with a high proportion of endemic species. A majority of the insect orders are represented on the island. We document the current state of knowledge for Mauritian arthropods, with particular focus on the Coleoptera. This is the most diverse order locally with 1,032 species. In addition, it is the best catalogued historically, providing a framework for future conservation studies to evaluate the current status of this group. We explore the current threats facing the native insect fauna and highlight the needs for concern on this vital component of local biodiversity. We recognize that the initial step for conserving the native insects will depend largely on the establishment of a local taxonomic knowledge base with international expert input.

Biological invasions by non-indigenous species are widely recognized as an important threat to biodiversity. However, the dimension, magnitude and mechanism of the impacts of invasive species remains poorly understood. We assessed the role of invasive plants by comparing vegetation changes that occurred between 1939 and 1999, a snapshot period that coincides with the onset of invasion, in Macabe Reserve in Mauritius. This Reserve was described as biotically homogeneous in 1939. In both surveys all native trees (> 10 cm DBH) were recorded from 10 1,000 m2 random plots. In 1999 the mean richness of plant species in plots was significantly lower: 15 species compared to 28 in 1939. The density and basal area of native species were both 70% lower in 1999. Plots with north and north-west aspects had significantly lower species richness and density than other aspects. We suggest that invasive plants have been the main trigger for the rapid and severe decline of native flora but we also observed that the decline of native species has been more spatially variable in the Reserve than the homogeneous distribution of invasive plants. This indicates that there are other feedback mechanisms driving biodiversity loss.

Catches of male moths of the Egyptian cotton leafworm, Spodoptera littoralis (Boisd.), in light traps and pheromone traps were compared at an experimental site at Sakha (Kafr El-Sheikh Province, Egypt) between June and November 1976. The catches in the pheromone traps were generally higher than those in the light traps, although the difference ratio varied from month to month. It was concluded that pheromone traps provided a useful ecological tool for S. littoralis in Egypt.