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

The sterile insect technique (SIT) application, as an alternative tool for conventional mosquito control methods, has recently gained prominence. Nevertheless, some SIT components require further development, such as protocols under large-scale conditions, focusing on packing and shipping mosquitoes, and considering transporting time. Immobilization of Aedes aegypti males was tested at temperatures 4, 7, 10, and 14 °C, and each temperature was assessed for 60, 90, and 120 min. The recovery after 24 h was also studied. Chilled and control-reared males had comparable survival rates for all conditions, although 4 °C for 120 min impacted male survival. The male escape rate was affected after 60 min of exposure at 4 °C; this difference was not significant, with 24 h of recovery. First, we defined the successful immobilization at 4 °C for 60 min, thus enabling the evaluation of two transportation intervals: 6 and 24 h, with the assessment of different compaction densities of 100 and 150 mosquitoes/cm3 at 10 °C to optimize the shipment. Compaction during simulated mosquito shipments reduced survival rates significantly after 6 and 24 h. In the mating propensity and insemination experiments, the sterile males managed to inseminate 40 to 66% for all treatments in laboratory conditions. The male insemination propensity was affected only by the highest compaction condition concerning the control. The analysis of the densities (100 and 150 males/cm3) showed that a higher density combined with an extended shipment period (24 h) negatively impacted the percentage of inseminated females. The results are very helpful in developing and improving the SIT packing and shipment protocols. Further studies are required to evaluate all combined parameters’ synergetic effects that can combine irradiation to assess sexual competitiveness when sterile males are released into the field.

Section: Introductionmentioning

confidence: 99%

Exploring Conditions for Handling Packing and Shipping Aedes aegypti Males to Support an SIT Field Project in Brazil

Gómez

Macedo²,

Pedrosa³

et al. 2022

“…albopictus mass production requires larval rearing methods that would provide high larval survival, fast and homogenous larval development, size homogeneity within the population, and synchronized pupation onset, which would, altogether, finally result in the production of high-quality adults. The evaluation of adult quality is based on some key parameters, such as longevity, flight ability, mating capacity, fecundity, and fertility [ 43 , 47 , 48 , 49 ]. When a larval diet provides the key parameters of high quality, the next critical question is whether the diet components are easy to procure and are not expensive.…”

Section: Discussionmentioning

confidence: 99%

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

Kavran

Puggioli

Šiljegović

et al. 2022

Aedes (Stegomyia) albopictus (Skuse, 1895) is an invasive important medical and veterinary pest species. The sterile insect technique (SIT) involves the mass rearing of males, and their sterilization and release into the habitat to compete with wild males. Our research objective was to compare the effectiveness of three larval diet recipes (IAEA-BY, BCWPRL, and MIX-14) in the laboratory rearing of Ae. albopictus males to evaluate the available economical feeding alternatives. The separation of sexes was done in the pupal stage by sieving. Reared males were tested for flight capacity and longevity. The application of the BCWPRL diet resulted in a higher portion of sieved male pupae than females, but the development of males was the slowest, and the number of obtained males (pupae and adults) was lower compared to the other two diets. The adult mean survival time was the highest in males fed with MIX-14 and the lowest in males fed with IAEA-BY. Males fed by IAEA-BY also demonstrated higher initial mortality in the adult stage. The diets BCWPRL and MIX-14 are economically more convenient than IAEA-BY (2.28 and 5.30 times cheaper, respectively). The cheapest diet, MIX-14, might represent a candidate for replacing the effective but still expensive IAEA-BY larval diet, providing lower costs of sterile male production.

“…The mosquito colony was originated from eggs collected from different locations across the Valencian Region of Spain in 2014. The strain was maintained using standard laboratory procedures [21] until 2017, when a SIT pilot requiring the mass-rearing of mosquitoes began [22].…”

Section: Rearing and Biological Materialsmentioning

confidence: 99%

All-in-One Mosquito Containers: From the Laboratory to the Release Sites

Tur

Plá

Argilés-Herrero

et al. 2022

Self Cite

Integrated vector control programs that use a Sterile Insect Technique approach require the production and release of large numbers of high quality, sterile male insects. In pilot projects conducted worldwide, sterile males are usually kept in containers at low densities until their manual release on the ground. Although the quality of the released insects is high, these containers are only suitable for small-scale projects, given the fact that the manual labor required for release is significant and therefore untenable in large-scale projects. This study will compare and contrast the quality of the males reared in the proposed “all-in-one” containers which considerably reduce both the handling of the insects and the manual labor required for release. As a result, project costs are lower. The design of these “all-in-one” containers incorporates two important features: ventilation and the density of the vertical resting surface. Having evaluated both features, it can be concluded that ventilation does not directly affect the quality of the insects, at least in the range of dimensions tested. However, the quality of the male insects is reduced in relation to an increase in the number of mosquitoes, with 500 being the optimum quantity of mosquitoes per “all-in-one” container.