S Mathonsi1,2, L Malinga1,3, K Bambo1, ZT Hlongwane2 and C Munyai3
1South African Sugarcane Research Institute, South Africa; Shilombe.Mathonsi@sugar.org.za
2School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa
3School of Life Sciences, University of KwaZulu-Natal, Scottsville, South Africa
The selection of an oviposition substrate plays a crucial role in maximising egg-laying and hatching success in mass rearing for the sterile insect technique (SIT). However, using natural substrates in laboratory conditions is expensive and may not be effective for egg collection. We aimed to identify the most effective artificial substrates for Eldana saccharina oviposition and egg hatching through a 5-day no-choice test at the South African Sugarcane Research Institute (SASRI) and the X sterile insect technique (XSIT) facility. Seven substrates were evaluated: wax paper, perforated wipes, corrugated paper, blotting paper, bubble wrap, greaseproof paper, and paper towel (control). The number of eggs laid and hatching rates were recorded under controlled laboratory conditions. Paper towel was the preferred oviposition substrate, with irradiated females laying an average of 107.9 ± 7.0 (Mean ± SEM) eggs and unirradiated moths laying 385.2 ± 46.6 eggs. Wax paper had the highest hatching success for both groups (58.4% for irradiated and 3.6% for unirradiated moths). The highest number of eggs was laid on day 2 across all substrates, while the highest hatching rate was recorded on day 4. The findings emphasise the importance of selecting suitable oviposition substrates for improving mass rearing efficiency for SIT purposes. Incorporating paper towels for oviposition and wax paper for hatching into mass-rearing protocols could enhance pest control strategies and maximise egg production during mass-rearing. Future research should focus on further optimising these substrates to improve rearing outcomes.