Assessment of a Novel Adult Mass-Rearing Cage for Aedes albopictus (Skuse) and Anopheles arabiensis (Patton)

Abstract

Successful implementation of the sterile insect technique (SIT) against Aedes albopictus and Anopheles arabiensis relies on a continuous supply of sterile males. To meet this requirement, optimization of the mass-rearing techniques is needed. This study, therefore, aims to assess a new mass-rearing cage (MRC) in terms of egg production efficiency and egg hatch rate (quality). In addition, adult survival was evaluated based on a cage adult-index for Ae. albopictus. Moreover, the cage’s suitability for use in mass An. arabiensis egg production was compared to that of the FAO/IAEA Anopheles reference cage. In Ae. albopictus rearing, the new MRC produced 1,112,110 eggs per cage following six blood meals, with minimum loss of eggs in the egging water. Furthermore, the adult index gave a good proxy of daily mortality rates in Ae. albopictus. In An. arabiensis rearing, about 130,000 eggs per egg batch were collected both from the new and the reference MRC. These findings suggest that the new MRC prototype is efficient in terms of egg production and can be used for mass-rearing in SIT programs targeting Ae. albopictus as well as An. arabiensis. The adult index was also positively validated for the detection of unusual mortality rates in Ae. albopictus mass-rearing facilities. Overall, the new MRC has shown several advantages; however, further improvements are necessary to minimize escapes during the egg collection processes.

Sterile Insect Technique in an Integrated Vector Management Program against Tiger Mosquito Aedes albopictus in the Valencia Region (Spain): Operating Procedures and Quality Control Parameters

“…This methodology was used because the objective of the presented values was to evaluate the productivity of the rearing cages in a routine mass-rearing context. The survival of females was similar to that reported by Maiga et al [ 56 ] with a comparable methodology (88.5%). In our colony, the mortality of males was higher than females.…”

“…According to Balestrino et al [ 53 ], medium-sized cubic cages, such as the ones used in our program, are similar in productivity to large space-optimized cages, and Zhang et al [ 48 ] found that short cages allow for higher blood-feeding rates and egg production. The vertical resting surface density (1.56 mosquitoes/cm 2 ) was similar to the optimal density proposed by Zhang et al [ 47 ] (1.48 mosquitoes/cm 2 ), although both are high compared to the density of 0.8 mosquitoes/cm 2 used in similar experiments [ 53 , 54 , 56 ]. It should be noted that the results may have been affected by the method of estimating the number of produced eggs.…”

“…The number of eggs laid per initial female pupae reached an average of 21.03. Even taking into account differences due to biotic factors such as different strains, and also due to colonization processes, we consider that this productivity is relatively low compared to laboratory studies [ 20 , 47 , 54 , 56 ], although the rearing methods were basically equivalent. There is no comparable information for mass-rearing programs.…”

“…Concerning the life cycle of rearing adult cages, Zhang et al and Maïga et al [ 47 , 56 ] suggested a two-week cycle for A. albopictus in a medium-scale rearing facility to increase efficiency per cage. In our rearing process, 74% of the eggs were collected in the first two weeks, and 26% in the third one.…”

Optimization of Aedes albopictus (Diptera: Culicidae) Mass Rearing through Cost-Effective Larval Feeding

“…The most expensive component in the standard IAEA-BY mosquito larval diet developed by the international atomic energy agency (IAEA) [ 36 , 37 ] is the dehydrated bovine liver powder. Several studies focused on the reduction or replacement of the most expensive components were carried out [ 36 , 38 , 39 , 40 , 41 , 42 , 43 ]. Although very efficient, diets containing bovine liver powder were too expensive for the continuous process of mass rearing.…”