Effects of cold storage on the life-history traits of Aphidius matricariae

Authors: REZAEI, MEHRAN - Tarbiat Modares University; TALEBI, ALI ASGHAR - Tarbiat Modares University; FATHIPOUR, YAGHOUB - Tarbiat Modares University; KARIMZADEH, JAVAD - Tarbiat Modares University; MEHRABADI, MOHAMMAD - Tarbiat Modares University; Reddy, Gadi V.P.

Submitted to: Entomologia Experimentalis et Applicata
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/19/2020
Publication Date: 8/26/2020
Citation: Rezaei, M., Talebi, A., Fathipour, Y., Karimzadeh, J., Mehrabadi, M., Reddy, G.V. 2020. Effects of cold storage on the life history traits of Aphidius matricariae. Entomologia Experimentalis et Applicata. 168(11):800-807. https://doi.org/10.1111/eea.12958.
DOI: https://doi.org/10.1111/eea.12958

Interpretive Summary: Mass rearing of biological control agents is an important tool for biological control programs, particularly for species used in augmentative releases. Storage at low temperatures is an important method for increasing the shelf life of parasitoids and predators to provide a steady and sufficient supply of insects for biological control programs. Cold storage also allows the synchronized field release of biological control when needed (such as when an outbreak occurs). Cold storage of biological control agents can affect various life history parameters that are used as quality indicators, and subsequently reduce the performance of the stored parasitoids. To optimize mass production and mass release programs of aphid parasitic wasp, we analyzed the effect of cold storage at a constant temperature of 5 ºC for different time periods on the life history traits of aphid parasitic wasp. We constructed the age-specific life table to comprehensively assess the quality of parasitic wasp adults after exposure to the low temperature. The present study has shown that the 1-day-old host mummies with aphid parasitic wasp immature stages can be stored at 5 °C for five days without loss of quality and for up to 15 days with some loss of quality (e.g., adult longevity). When the parasitoid is stored for longer than 15 days, quality was more strongly reduced. The results of this study can be used to improve the planning of mass rearing and mass release programs of parasitic wasp.

Technical Abstract: Aphidius matricariae Haliday (Hymenoptera: Braconidae) is a solitary endoparasitoid, attacking more than 40 species of aphids. This polyphagous parasitoid is one of the most important products of many companies that produce biological control agents. Storage at low temperatures increases the shelf life of many biological control agents, allowing companies to provide a steady and sufficient supply of insects for biological control programs. In the current study, the effects of cold storage of 1-day-old host mummies with A. matricariae for different time periods (5, 10, 15, 20 and 30 days) at 5 ºC on the parasitoid’s key life history traits were investigated. Parameters assessed after storage included adult emergence rate, sex ratio, adult longevity, oviposition period, fecundity, and life table parameters (R0, r, ', T and DT). Our results showed that the mummies of A. matricariae could be stored at 5 °C for five days without loss of quality and for 10 to 15 days with minimal reduction in quality (e.g., some reductions in adult longevity and R0). When parasitoids were stored for >15 days, quality was more strongly affected. In conclusion, A. matricariae pupae could be stored at 5 °C for up to 15 days without significant negative post-storage effects on fitness of the parasitoid. These results could be used to improve the planning of mass rearing and mass release of A. matricariae in augmentative biological control programs.