Investigating the Parasitoid Community Associated with the Invasive Mealybug Phenacoccus solenopsis in Southern China

Hua-Yan Chen,Hong Pang,Hong-Liang Li,Chao-Dong Zhu,Yan-Zhou Zhang

doi:10.3390/insects12040290

Hua-Yan Chen, Hong Pang + Show 3 more

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https://doi.org/10.3390/insects12040290

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Abstract

Simple SummaryThe cotton mealybug Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) is an emerging invasive insect pest in China. Hymenopteran parasitoids have great potential to be used as biological agents to suppress the populations of P. solenopsis in the field. We used an integrated approach of species delimitation, combining morphology with molecular data, to investigate the parasitoid community associated with P. solenopsis from south China. On the basis of both morphological and molecular evidence, we identified 18 hymenopteran parasitoid species belonging to 11 genera of four families. Among these species, eight species are primary parasitoids with Aenasius arizonensis (Girault) (Hymenoptera: Encyrtidae) being the dominant taxon, while the other 10 species are probably hyperparasitoids. These findings can assist in the utility of these parasitoids in the biological control of P. solenopsis.The cotton mealybug Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae), is an emerging invasive insect pest in China. Hymenopteran parasitoids are the key organisms for suppressing populations of P. solenopsis in the field, and therefore could be used as biological agents. Accurate identification of the associated parasitoids is the critical step to assess their potential role in biological control. In this study, we facilitated the identification of the parasitoid composition of P. solenopsis using an integrated approach of species delimitation, combining morphology with molecular data. Eighteen Hymenoptera parasitoid species belonging to 11 genera of four families are recognized based on morphological examination and molecular species delimitation of the mitochondrial cytochrome c oxidase 1 (COI) gene and the 28S rDNA using the automatic barcode gap discovery (ABGD) and the Bayesian Poisson tree processes model (bPTP). Among these species, eight species are primary parasitoids with Aenasius arizonensis (Girault) (Hymenoptera: Encyrtidae) being the dominant taxon, while the other 10 species are probably hyperparasitoids, with a prevalence of Cheiloneurus nankingensis Li & Xu (Hymenoptera: Encyrtidae). These results indicate that parasitoid wasps associated with P. solenopsis from China are diverse and the integrated taxonomic approach applied in this study could enhance the accurate identification of these parasitoids that should be assessed in future biological control programs.

Highlights

The mealybug Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae), which originating from the USA, has become an emerging invasive and polyphagous pest inAsia [1,2,3,4,5,6]
The initial morphological identifications suggested a total of 18 morphospecies belonging to four hymenopteran families as follows: Aphelinidae (3): Marietta picta (André), Myiocnema comperei Ashmead, Promuscidea unfasciativentris Girault (Figure 1C); Encyrtidae (11): Acerophagus sp1, Acerophagus sp2, Aenasius arizonensis (Girault) (Figure 1A), Anagyrus jenniferae Noyes & Hayat, Anagyrus kamali Moursi, Anagyrus tristis Noyes & Hayat, Cheiloneurus nankingensis Li & Xu (Figure 1B), Gyranusoidea indica Shafee, Alam & Agarwal, Prochiloneurus javanicus (Ferriere), Prochiloneurus stenopterus Wang, Huang & Xu, Prochiloneurus testaceus (Agarwal); Platygasteridae (1): Allotropa phenacocca Chen, Liu & Xu; Signiphoridae (3): Acerophagus sp1, Acerophagus sp2, Acerophagus sp3. (Table S1, Figure 2)
Aenasius arizonensis; (C) Promuscidea unfasciativentris parasitizing a mummy of Phenacus solenopsis via probably Aenasius arizonensis; (C) Promuscidea unfasciativentris parasitizing a mummy of Phenacoccus coccus solenopsis

Summary

Introduction

The mealybug Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae), which originating from the USA, has become an emerging invasive and polyphagous pest inAsia [1,2,3,4,5,6]. It has been reported to feed on at least 213 host plant species belonging to 56 families [7], including the economically important cotton [5,6,8]. This mealybug species has caused serious yield losses of cotton in some Asian countries, India and Pakistan [9,10]. Since its first report in mainland China in 2008, this mealybug has spread to 16 provinces of the country by the end of 2018 [11]. It was estimated that all cotton-growing regions of China could be infested by this mealybug [5].

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