Insects are susceptible to dehydration and change in atmospheric humidity could affect their fitness. To understand the impacts of humidity changes on insect’s reproductive fitness we released an outcrossed Drosophila melanogaster population to outdoor mesocosm units and tracked their fecundity over ninety days under progressively developing summer season. The study was carried out in a tropical urban garden. Often temperature has been found to be the key player in changes in reproductive output in a considerable number of laboratory based studies. Our work suggested that temperature and humidity interactions determine the physiological state of an organism which could untimely impact organismal fitness in a given environmental set-up. This work suggested that fecundity in Drosophila populations was significantly influenced by relative humidity and its interaction with temperature. This together suggested that while temperature was an important parameter for fecundity, relative humidity individually and in combination with temperature also played an important role for fecundity in Drosophila. Thus, the combination of temperature and relative humidity was a better metric to predict the fecundity in Drosophila populations than considering these parameters individually under natural conditions. It clearly indicated that future warming events could drastically impact insects’ reproductive output.

File: Cages Fecundity and Climatic Data File:

For this, we used three indoor (Laboratory) and three outdoor cages (Ahmedabad University Experimental Evolution Station, East Campus). Each mesocosm was a 5x5x5 feet in dimension (custom designed at Ahmedabad University Workshop) outdoor insect rearing enclosure surrounding a mature (dwarf) sapota tree. Each cage was founded with 500 males and 500 females. Every morning 08.00 hr fresh food (75 ml of standard cornmeal–molasses medium) in a half-pint bottle was placed in each enclosure (3 indoor and 3 outdoor cages) for the entire duration of the experiment (4^th April 2018 to 2^nd July 2018). Flies were allowed to oviposit on the fresh food for 24 hours. Each morning, bottles were examined for eggs laid in the previous 24 hours. Data shows number of eggs laid each day.

Temperature and relative humidity in all six cages (3 indoor and 3 outdoor) were recorded using HOBO U23 Pro v2 data loggers (Onset Computer Corp., Bourne, MA, USA). This file contains data in °C and in percent for temperaature and relative humidity respectively.

All the data has been organized in MS Excel file. These files can easily be downloaded on a local PC or Laptop. No conversion or permision is required and data does not contain any missing values.