Objectives: In many primates, one of the most noticeable morphological developmental traits is the transition from natal fur and skin color to adult coloration. Studying the chronology and average age at such color transitions can be an easy and non-invasive method to (i) estimate the 2 age of infants whose dates of birth were not observed, and (ii) detect inter-individual differences in the pace of development for infants with known birth dates. Materials and Methods: Using a combination of photographs and field observations from 73 infant chacma baboons (Papio ursinus) of known ages, we (1) scored the skin color of six different body parts from pink to grey, as well as the color of the fur from black to grey, (2) validated our method of age estimation using photographic and field observations on an independent subset of 22 infants with known date of birth, and (3) investigated ecological, social and individual determinants of age-related variation in skin and fur color. Results: Our results show that transitions in skin color can be used to age infant chacma baboons less than seven months old with accuracy (median number of days between actual and estimated age = 10, range=0-86). We also reveal that food availability during the mother's pregnancy, but not during lactation, affects infant color-forage and therefore acts as a predictor of developmental pace. Discussion: This study highlights the potential of monitoring within-and between-infant variation in color to estimate age when age is unknown, and developmental pace when age is known.

Successful implementation of the sterile insect technique (SIT) against Aedes aegypti and Aedes albopictus relies on maintaining a consistent release of high-quality sterile males. Affordable, rapid, practical quality control tools based on the male’s flight ability (ability to escape from a flight device) may contribute to meeting this requirement. Therefore, this study aims to standardize the use of the original FAO/IAEA rapid quality control flight test device (FTD) (version 1.0), while improving handling conditions and reducing the device’s overall cost by assessing factors that could impact the subsequent flight ability of Aedes mosquitoes. The new FTD (version 1.1) is easier to use. The most important factors affecting escape rates were found to be tube color (or “shade”), the combined use of a lure and fan, mosquito species, and mosquito age and density (25; 50; 75; 100 males). Other factors measured but found to be less important were the duration of the test (30, 60, 90, 120 min), fan speed (normal 3000 rpm vs. high 6000 rpm), and mosquito strain origin. In addition, a cheaper version of the FTD (version 2.0) that holds eight individual tubes instead of 40 was designed and successfully validated against the new FTD (version 1.1). It was sensitive enough to distinguish between the effects of cold stress and high irradiation dose. Therefore, the eight-tube FTD may be used to assess Aedes’ flight ability. This study demonstrated that the new designs (versions 1.1 and 2.0) of the FTD could be used for standard routine quality assessments of Aedes mosquitoes required for an SIT and other male release-based programs.

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