Hatching Response ofAedes aegypti(Diptera: Culicidae) Eggs at Low Temperatures: Effects of Hatching Media and Storage Conditions

Abstract

In temperate regions, Aedes aegypti (L.) (Diptera: Culicidae) populations remain in the egg stage during the cold season. To ensure the start of a new breeding season, eggs should hatch at the beginning of a favorable period. The aim of the current study was to investigate the hatching response of two Ae. aegypti egg batches collected and stored for 3 mo under different conditions, to different low immersion temperatures. Two different hatching media (water and yeast solution) were used for the first batch and only one (water) for the second egg batch. Eggs were immersed for 8 d, during which the number of hatched eggs was recorded daily. The proportion of hatched eggs, delay of the hatching response, proportion of dead larvae, and proportion of remaining eggs within the first egg batch were compared between the two hatching media at each temperature. These parameters also were compared between the two batches immersed in water. Hatching rates were higher and faster in the yeast solution. The hatching response was lower at lower immersion temperatures and among eggs stored under field conditions at colder temperatures (second batch). Among the eggs stored in the laboratory (first batch), older eggs exhibited lower hatching response. The proportion of dead larvae was higher in the yeast solution and in the eggs stored in the laboratory. The conditions that triggered a lower hatching response led to higher proportions of remaining eggs, allowing the population to maintain an egg bank for future favorable opportunities.

Field comparison of oviposition substrates used in ovitraps for Aedes aegypti surveillance in Salta, Argentina

“…Trap modifications have mostly focused on the addition of attractants or alternatively ovicides and/or insecticides, changing the function from a passive monitoring system to a means of population control (Abad‐Franch, Zamora‐Perea, Ferraz, Padilla‐Torres, & Luz, ; Gopalakrishnan, Das, Baruah, Veer, & Dutta, ; Harburguer, Licastro, Masuh, & Zerba, ). Also, ovitraps are used to collect eggs for further studies of insecticide resistance (Maciel‐de‐Freitas et al., ) or of population dynamics, for example to assess rates of egg predation or egg winter survival (Byttebier, de Majo, & Fischer, ; Fischer, Alem, De Majo, & Campos, ), among others.…”

Arbovirus Vectors of Epidemiological Concern in the Americas: A Scoping Review of Entomological Studies on Zika, Dengue and Chikungunya Virus Vectors

“…Gimenez et al [53] experimentally studied container condition determinants of Ae. aegypti egg survival, and Byttebier et al [54] studied the effects of growth medium and temperature among immatures. Giminez et al [53] did not observe any difference in larval survival between conditions in which eggs were versus were not protected from macroscopic predators, under rising temperature conditions.…”

“…Giminez et al [53] did not observe any difference in larval survival between conditions in which eggs were versus were not protected from macroscopic predators, under rising temperature conditions. Byttebier et al [54] found hatching response (time to onset of hatching) to be lower at lower temperatures, and hatching rate to be higher on yeast media, compared to reverse osmosis water. Grech et al [55] and Marinho et al [56] found that development time varied inversely with temperature.…”

Combining weather patterns and cycles of population susceptibility to forecast dengue fever epidemic years in Brazil: a dynamic, ensemble learning approach

“…Short-term climate conditions, particularly temperature and precipitation, can create favorable conditions for the breeding and survival of Aedes mosquitoes that may increase the transmission of the dengue fever virus in humans. Distinct ranges of temperature and precipitation have been observed to have an influence on the extrinsic incubation period 15,16 , mosquito maturation rate 17 , length of larval hatch time 18 , survival rate 19 , and biting rate 20 . However, the relationships that govern these parameters and give rise to dengue transmission are complex and dynamic, changing over time and across geographies.…”