Effects of mating on reproductive\u2002performance of Coccophagus japonicus Compere (Hymenoptera: Aphelinidae)

Xian Li,Junhong Zhu,Junyu Chen,Lei Li,Fangping Zhang,Dongyin Han,Shunzhang Shen,Yueguan Fu

doi:10.1038/s41598-021-85351-x

Abstract

Coccophagus japonicus Compere, an endoparasitoid of Parasaissetia nigra Nietner, has great potential for biological control. To assess the influence of mating on the reproductive performance of this parasitoid, we examined the effects of mating on ovarian development, female longevity and number of eggs laid. The results showed that the egg volume in the ovary of C. japonicus first increased and then decreased with increases in the age of female adults. The peak egg volume in the ovary of mated females occurred 2 days earlier than that of virgin females. Within the female age range of 0–15 days, the numbers of eggs at stages I, II, and III first increased and then decreased with increases in the age of female C. japonicus, whereas the number of eggs at stage IV increased. The duration of the coexistence of females and males significantly influenced the length and width of the female ovaries, and the longest ovary tube and the highest number of eggs were obtained with a coexistence duration of 0 days. C. japonicus female longevity decreased with increases in the number of matings, and the number of eggs laid by females within 15 days decreased with increasing delays in mating. In conclusion, mating can shorten the longevity of C. japonicus females, and selecting newly emerged virgin females for mating can significantly improve the number of eggs laid and the breeding efficiency of the parasitoid.

Highlights

Parasaissetia nigra Nietner, one of the species in the main groups of Coccidae[1], is a notably polyphagous insect that attacks over 80 distinct plant families[2]
C. japonicus is a predominant natural enemy of P. nigra, our preliminary study found that mating seriously restricts the oviposition and parasitism of this parasitoid wasp
With the aim of controlling P. nigra, we examined the effects of C. japonicus mating on ovarian development, female longevity and the number of eggs laid by females

Summary

Introduction

Parasaissetia nigra Nietner, one of the species in the main groups of Coccidae[1], is a notably polyphagous insect that attacks over 80 distinct plant families[2]. 1st instars and adults (black), females of C. japonicus can feed on all life stages of P. nigra and they exhibit a preference for 3rd instars and adults (brown)[8] In the laboratory, this endoparasitoid can notably control 3rd instars of P. nigra[9,10]. With the aim of controlling P. nigra, we examined the effects of C. japonicus mating on ovarian development, female longevity and the number of eggs laid by females. These analyses clarify the effects of mating on reproductive performance, provide methods to increase the number of eggs in the parasitic wasp ovary, life span, egg production and parasitism rate, and provide a theoretical basis for the mass reproduction of this parasitoid. As to lay the foundation for realizing field application of this parasitoid wasp

Methods

Results

Conclusion