Efficient Insect Oviposition Harvest With Brushing Machine
VSI IR-502 oviposition brushing machine. In insect rearing facilities, e.g. mosquito laboratories, females are often allowed to oviposit (i.e. lay eggs) in rearing cages on moist (sterilised) paper strips such as paper towels, seed germination paper or crepe paper (see below for details on oviposition paper properties). Typically, after the paper has dried, the eggs are collected by laboratory staff - using fine brushes to manually brush the eggs from the 'egg papers' into containers for maturation. However, this process is very time consuming and therefore not suitable for high-throughput mass rearing and research facilities. Together with entomologists working in mass rearing facilities (e.g. IAEA), Vienna Scientific developed and refined the VSI IR-502 brushing machine to automatically, carefully and efficiently remove and collect adherent eggs from oviposition paper strips.
VSI IR-502 Oviposition Brushing Machine - Specifications
Oviposition harvesting with the IR-502 involves the gradual introduction of oviposition paper strips between two counter-rotating barrels fitted with brushes. The brushing speed can be set variable. Ovipositions are subsequently collected from a removable storage tray at the bottom. The IR-502 is a straight-forward, user-friendly machine that significantly reduces the time spent collecting insect eggs in insect research and mass rearing environments. The design allows easy cleaning of all parts after removing the housing. Once the eggs are collected, they can be stored in a clean container or rearing trays with appropriate conditions, such as temperature and humidity, until they hatch.
VSI IR-502 Brushing machine - Details
Images for illustration purposes only, design subject to change without notice
General Properties of Oviposition Paper Strips
Oviposition strips are designated strips of paper used to collect insect eggs. These strips are usually made of filter paper or other porous materials that allow female insects to lay their eggs on them. The strips are placed in the insect's habitat or breeding area in insect rearing cages and female insects are attracted to lay their eggs on the paper rather than on other surfaces. While largely depending on species-specific preferences, some general benefitial characteristics of oviposition paper strips for insect egg collection include:
- Porosity: The paper strips should be porous enough to allow female insects to lay their eggs on them, but not so porous that the eggs fall through the paper or cannot be removed easily.
- Durability: The paper strips should be durable enough to withstand handling and transport without tearing or breaking. This is particular importent when strips are wetted over an extended period.
- Size: The size of the paper strips should be appropriate to the size of the insect, and the numbers of insects and thus the number of eggs expected to be laid.
- Attractiveness: The paper strips should be attractive to female insects and their colour, texture and scent can be adjusted to suit the preferences of specific insect species.
- Non-toxic: The paper strips should be non-toxic and free from substances that could harm eggs or subsequently developing larvae.
- Sterile: For certain applications, the paper strips should be sterile to prevent contamination of the eggs with micro-organisms. However, rearing conditions often inevitable result in some contamination of paper strips.
- Cost-effectiveness: The paper strips should be inexpensive and easy to obtain in large quantities for mass rearing settings with expected large amounts of egg collection. here, automation can further reduce the labour costs of egg collection, requiring oviposition papers of an appropriate size (i.e. not too small, short) to be fully effective for automated egg brushing machines such as the VSI IR-502.
SELECTED READINGS ON Insect egg collection
- Clemons A., Mori A., Haugen M., Severson D. & Duman-Scheel M. 2010. Aedes aegypti culturing and egg collection. Cold Spring Harbor Protocols 2010, pdb.prot5507-pdb.prot5507.
- Nordlund, D. A., & Morrison, R. K. (2021). Mass rearing of Chrysoperla species. Advances in insect rearing for research and pest management, 427-439.
- Ponnusamy L., Böröczky K., Wesson D.M., Schal C. & Apperson C.S. 2011. Bacteria stimulate hatching of Yellow Fever mosquito eggs. PLoS ONE 6, e24409.
- Zheng, M.-L., D.-J. Zhang, D. D. Damiens, H. Yamada, and J. R. Gilles. 2015. Standard operating procedures for standardized mass rearing of the dengue and chikungunya vectors Aedes aegypti and Aedes albopictus (Diptera: Culicidae) - I - egg quantification. Parasites & Vectors 8:42