Larvae Mass Rearing Trays
Standardised larval rearing units for insect production are essential for the establishment of mass-rearing facilities. We offer mosquito mass rearing trays according to the specifications by the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture (FAO/IAEA-IPCL; see Balestrino et al., 2012). The trays are compatible with the VSI Tray and Rack systems / Mosquito mass rearing module; those hold 30 mass rearing trays each. The trays are optimized to work with the automatic larval feeding system.
The mosquito mass-rearing tray was designed to provide a large surface area of shallow water - closely mimicking natural breeding sites and allowing for the larval diet to be easily accessible.
According to research, the tray is applicable for rearing larvae of several mosquito species. For Aedes albopictus, for example, the optimal larval rearing density in the trays is about 18,000 larvae (3.6 larvae/cm2 inner surface). At thirty-four hours after the first pupation, the average male pupae production was found to be ca. 3.16 × 105; no impact on male mating competitiveness to wild type females was found and the tray was recommended to be used in mosquito mass rearing facilities (see Zhang et al., 2017 for details). Regarding Anopheles sp., each trays can hold about 4,000 larvae (Mamai et al., 2018). The use of the trays for rearing other insect species requiring similar environmental conditions for pupation is likely but can also be adjusted on request.
VSI Larvae Tray - Specifications
- Outer Dimensions: approx. 1000 x 600 x 25 mm
- Inner Dimensions: approx. 920 x 550 x 20 mm (approx. 6 l at filling depth of 12 mm)
- Material: ABS [Acrylonitrile butadiene styrene (Acrylnitril-Butadien-Styrol-Copolymer)], grey, 5 mm
Two ridges create an overflow system and increase the surface area / larval resting space. The underside of the tray ridges holds two plastic (PMMA) plates which deflect the overflowing water -avoiding water falling straight down (see image). Specifications are based on Balestrino et al., (2012) & technical requirements as given by IAEA/FAO Insect Unit (Seibersdorf, AT).
General Condiderations when designing Larvae Rearing Trays
Larval mass rearing trays are designed to provide the optimum conditions for larval growth as specific for each species, while in the best case allowing efficient and easy handling of the larvae in great numbers. Whilst there are large differences between insect species in terms of optimal rearing conditions, here some key characteristics of larval mass rearing trays can be defined:
- Material: Larval mass rearing trays are typically made of plastic or metal. Plastic trays are more lightweight (and often more cost-effective), while both are durable and easy to clean and disinfect.
- Size and shape: The size and shape of trays depend on the species of insect being reared and the volume of larvae required. Some trays are rectangular or square, while others are circular or oval. The depth of the tray can also vary depending on the size of the larvae, see e.g. the deep trays for flourworm rearing.
- Design: Larval mass rearing trays can have various design features, such as a mesh or perforated bottom to facilitate air circulation and drainage, or partitions to separate different larval stages. Some trays have mesh-screens or solid lids to prevent escape of larvae and/or contamination of the rearing environment.
- Substrate: Much of the above depends on the substrate required for the trays, e.g. between water and sawdust.
- Feeding: The trays may have automatic feeding mechanisms, such as a built-in feeding system or feeding cups, or be compatibel with such external systems, to provide the larvae with an appropriate diet. However, as the feeding system should be easy to clean and maintain and should not interfere with handling of the larvae, solid feeding is still performed largely manually.
- Handling: Larval mass rearing trays should be easy to handle and transport and should fit securely into incubators or tray and rack equipment. The trays may also be compatible with any automated systems for collecting, counting or sorting larvae.
Overall, a very large diversity of larval mass rearing trays sizes, shapes and forms exist. However, trays are an essential tools for efficient and effective mass rearing of insects and their design should be tailored to the specific needs of the insect species and the intended application. Vienna Scientific is happy to support his process and help you realize optimized trays for the insect species of choice.
Selected readings on mass rearing trays
- Balestrino F., Benedict M.Q. & Gilles J.R. (2012) A new larval tray and rack system for improved mosquito mass rearing. J Med Entomol 49.
- Gilkeson, L. A. (2021). Mass rearing of phytoseiid mites for testing and commercial application. In Advances in insect rearing for research and pest management (pp. 489-506). CRC Press.
- Parra, J. R. P., & Coelho Jr, A. (2022). Insect rearing techniques for biological control programs, a component of sustainable agriculture in Brazil. Insects, 13(1), 105.
- Mamai, W., et al. (2018) Optimization of mass-rearing methods for Anopheles arabiensis larval stages: effects of rearing water temperature and larval density on mosquito life-history traits. Journal of Economic Entomology 111(5): 2383-2390.
- Melis, R., Braca, A., Sanna, R., Spada, S., Mulas, G., Fadda, M. L., ... & Anedda, R. (2019). Metabolic response of yellow mealworm larvae to two alternative rearing substrates. Metabolomics, 15, 1-13.
- Zhang et al. (2017) Establishment of a medium-scale mosquito facility: optimization of the larval mass-rearing unit for Aedes albopictus (Diptera: Culicidae). Parasites & Vectors 10, 569.