Age matters: variations in parasitoid diversity along a successional gradient in a dry semi-deciduous tropical forest.

Parasitoids are an important group of insects because their species number is among the highest. Multiple studies have addressed the relationships between forest successional age and insect diversity by focusing on herbivorous organisms, but changes in diversity of parasitoids are still poorly known. This work analyses the diversity of parasitoids in tropical forests representing three successional stages. A total of 30 traps were placed, ten in each forest successional stages. We estimated true diversity of Ichneumonidae species and guilds and explored the relationship between their diversity and the abundance of plant species using an Indicator Species Analysis; the relationship between parasitoid species and plant richness and abundance was tested using a Redundancy Analysis. A total of 1522 individuals and 168 morpho-species were captured in four months. Species richness showed no differences; however, parasitoid abundance was higher in young forest, while intermediate forest had the highest true diversity values (1D) with 71.6 effective species. According to insect guilds, richness, abundance, and diversity were similar in the three vegetation successional stages. This finding may be explained based on the intermediate disturbance hypothesis, which postulates that moderate disturbance levels favor the highest diversity. In conclusion, successional age matters, i.e., diversity is the highest in intermediate stages, while the old forests harbors guilds unique to that successional stage, such as parasitoids of melitophagous larvae of bees. Other successional stages were characterized by a single species of parasitoid, belonging to the genera Eiphosoma and Anomalon, which may indicate altered and preserved forests, respectively.

Abundance and Seasonality of Aedes aegypti (Diptera: Culicidae) in Two Suburban Localities of South Mexico, With Implications for Wolbachia (Rickettsiales: Rickettsiaceae)-Carrying Male Releases for Population Suppression.

We conducted a baseline characterization of the abundance and seasonality of Aedes aegypti (Linnaeus, 1762)-a vector of dengue, chikungunya, and Zika-in two suburban localities of Yucatan, Mexico, as the first step in the implementation of an integrated vector management (IVM) plan combining 'traditional Aedes control' (source reduction/truck-mounted ultra-low volume [ULV] spraying) and incompatible insect technique/sterile insect technique for population suppression in Yucatan, Mexico. Weekly entomological collections with ovitraps and BG-sentinel traps were performed in 1-ha quadrants of both localities for 1 yr. Three distinct periods/phases were identified, closely associated with precipitation: 1) a phase of low population abundance during the dry season (weekly average of Aedes eggs per ovitrap and adults per BG trap = 15.51 ± 0.71 and 10.07 ± 0.88, respectively); 2) a phase of population growth and greatest abundance of Aedes (49.03 ± 1.48 eggs and 25.69 ± 1.31 adults) during the rainy season; and finally 3) a phase of decline among populations (20.91 ± 0.97 eggs and 3.24 ± 0.21 adults) after the peak of the rainy season. Seasonal abundance and dynamics of Ae. aegypti populations suggest that it is feasible to develop and implement time-specific actions as part of an IVM approach incorporating integrating novel technologies (such as rear-and-release of Wolbachia-infected males) with classic (insecticide-based) approaches implemented routinely for vector control. In agreement with the local vector control program, we propose a pilot IVM strategy structured in a preparation phase, an attack phase with traditional vector control, and a suppression phase with inundative releases, which are described in this paper.