Abstract
Simple SummaryProducing and field releasing a large number of natural enemies within a short time for pest control helps biological control programs succeed. However, host eggs are often unsynchronized with pest occurrence. Storing host eggs can help synchronize the production of parasitoids with demands of the program. Anastatus fulloi is an egg parasitoid wasp that has been successfully used to control the Tessaratoma papillosa Drury populations in south China. Antheraea pernyi eggs are used as factitious hosts of Anastatus fulloi, and cold storage of these eggs is important for large-scale rearing and successful release of Anastatus in the field. We studied the effects of cold storage of A. pernyi eggs on host egg quality and the fitness of A. fulloi. Cold storage reduced host egg quality and the suitability of host eggs for A. fulloi. To minimize losses in the large-scale rearing of A. fulloi, A. pernyi eggs should be refrigerated in a 0–3 °C or −5 °C water bath. The storage period should not exceed 6 months. The results of this study provide technical support for mass rearing of A. fulloi in biological control programs.Chinese silkworm (Antheraea pernyi) eggs are used as factitious hosts of Anastatus fulloi, and refrigeration of these eggs is essential for large-scale rearing of A. fulloi. We studied the effects of cold storage of A. pernyi eggs on egg quality and the fitness of A. fulloi reared on the eggs. Four cold storage treatments and two cold storage periods were assessed. The 0–3 °C refrigerator treatment was unsuitable for long-term (>70 days) storage. Cold storage at −5 °C and −18 °C increased the loss rate of A. pernyi eggs, but there was no significant difference between the control and 0–3 °C water bath treatment. The parasitism rate of A. fulloi was reduced when A. pernyi eggs were refrigerated for 6 or 12 months. There were no obvious differences in eclosion rate and percentage of females between control and eggs subjected to 6-month storage in 0–3 °C, −5 °C, and −18 °C water bath treatments. However, the eclosion rate and percentage of females decreased sharply when the storage period was 12 months. The overall eclosion rate of A. fulloi was reduced at the prolonged refrigeration time. Cold storage reduced host egg quality and their fitness suitability for A. fulloi. To minimize losses in the large-scale rearing of A. fulloi, A. pernyi eggs should be refrigerated in a 0–3 °C or −5 °C water bath treatment, and the storage period should not exceed 6 months.
Highlights
Anastatus spp. are endoparasitoids of several insect orders [1,2] and are often used for the biological control of Hemiptera pests such as fruit-spotting bugs, Amblypelta nitidaStal and A. lutescens lutescens Distant [3,4,5]; citrus green stink bug, Rhynchocoris humeralisThunberg [6]; litchi stink bug, Tessaratoma papillosa Drury [7]; and the brown marmorated stink bug, Halyomorpha halys Stål [8]
We studied the quality of A. pernyi eggs when they were stored in different cold storage conditions and the corresponding effects on the fitness of A. fulloi
Cold storage at −5 ◦ C and −18 ◦ C resulted in an increased loss rate of A. pernyi eggs used for the mass rearing of A. fulloi, but no significant differences were observed among the fresh eggs and 0–3 ◦ C water bath treatment
Summary
Anastatus spp. are endoparasitoids of several insect orders [1,2] and are often used for the biological control of Hemiptera pests such as fruit-spotting bugs, Amblypelta nitidaStal and A. lutescens lutescens Distant [3,4,5]; citrus green stink bug, Rhynchocoris humeralisThunberg [6]; litchi stink bug, Tessaratoma papillosa Drury [7]; and the brown marmorated stink bug, Halyomorpha halys Stål [8]. The development of effective storage methods that do not affect parasitoid fitness is important for successful mass rearing [10]. Several studies on Anastatus spp. have mentioned cold storage of host eggs and its possible effect on Anastatus fitness, but the most effective methods for host egg storage have not been reported [7,9,11,12]. Parasitoids reared on refrigerated eggs may have reduced fitness, because long-term cold storage of host eggs can decrease their quality [10,12,13,14,15]. A study of Anastatus bifasciatus Geoffroy and Anastatus orientalis Yang Choi showed that cold storage of host eggs did not affect their fitness [9,11]. The fitness of parasitoids can be affected by various factors
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
