The effect of the egg storage time on the hatching success, morphometrics of larvae, and adult emergence of Aedes aegypti and Aedes albopictus

Aedes aegypti (L.) and Aedes albopictus (Skuse) are important vectors that transmit arboviruses such as Dengue virus (DENV), Yellow fever virus (YFV), Chikungunya virus (CHIKV), and Zika virus (ZIKV). Focusing on the unique characteristics of their eggs to withstand dry conditions, this study aimed to elucidate the viability of dry-stored eggs and the subsequent morphometric changes in larvae and adult mosquitoes upon rehydration. Experiments were carried out using ovitrap-collected eggs, which were reared in the laboratory until adult emergence. The resulting mosquitoes were fed on cattle blood and sugar solution and allowed to lay eggs on the paper strips, which were air-dried and stored for 6 months. The viability of these eggs was tested monthly. The head length and total length of fourth-instar larvae and head, thorax, abdomen, wing length, wing width, and total length of adults were measured, including the days needed for adult emergence. The results imply that the prolonging of the egg storage period led to a decline in viability, delayed emergence of adults, and a negative impact on the morphometrics of fourth-instar larvae in both Ae. aegypti and Ae. albopictus. Nonetheless, the morphometrics of the adults did not exhibit any significant differences compared to those of fresh eggs.