Microbial Associates of the Vine Mealybug Planococcus ficus (Hemiptera: Pseudococcidae) under Different Rearing Conditions

Abstract

Sap-feeding insects harbor diverse microbial endosymbionts that play important roles in host ecology and evolution, including contributing to host pest status. The vine mealybug, Planococcus ficus, is a serious pest of grapevines, vectoring a number of pathogenic grape viruses. Previous studies have shown that virus transmission is abolished when mealybugs are raised in the laboratory on potato. To examine the possible role of microbial symbionts in virus transmission, the archaeal, bacterial, and fungal microbiota of field and laboratory P. ficus were characterized using molecular and classical microbiological methods. Lab and field colonies of P. ficus harbored different microbiota. While both were dominated by the bacterial obligate nutritional symbionts Moranella and Tremblaya, field samples also harbored a third bacterium that was allied with cluster L, a lineage of bacterial symbionts previously identified in aphids. Archaea were not found in any of the samples. Fungal communities in field-collected mealybugs were dominated by Metschnikowia and Cladosporium species, while those from laboratory-reared mealybugs were dominated by Alternaria and Cladosporium species. In conclusion, this study has identified a diverse set of microbes, most of which appear to be facultatively associated with P. ficus, depending on environmental conditions. The role of various members of the mealybug microbiome, as well as how the host plant affects microbial community structure, remains to be determined.

An exceptional family: Ophiocordyceps‐allied fungus dominates the microbiome of soft scale insects (Hemiptera: Sternorrhyncha: Coccidae)

“…While the reason for this difference is not clear and should be further studied, it appears that lineages of these hypocrealean fungi have undergone a shift from insect pathogens to mutualists (or nonpathogens, or at least sublethal pathogens). Other fungi that were found in our study— Cladosporium , Alternaria and Wallemia —were also reported from a mealybug (Sternorrhyncha: Pseudococcidae, a sister taxon to Coccidae) (Iasur‐Kruh et al., ). In the light of our results, we postulate that these fungi are facultatively or opportunistically associated with soft scales.…”

Bacterial and fungal gut communities of Agrilus mali at different developmental stages and fed different diets

“…Ascomycetous yeast of the genus Candida and basidiomycetous yeast of the genus Asterotremella were shown to produce xylanase and carboxymethyl cellulose in insects and their natural habit 47 . Wallemia and Cladosporium are very common environmental fungal genera that associate with many plants as commensals and pathogens 48 . These microbial groups are widespread, ecologically diverse, and functionally redundant in organic matter decomposition and lignocellulose digestion and may be transiently acquired by insects from feeding materials and the environment 10 .…”

Diversity and dynamics of microbial communities in brown planthopper at different developmental stages revealed by high‐throughput amplicon sequencing

“…For the fungal community, Wallemia was more abundant in nymph and adult stages than in the egg stage; a similar trend was also observed in genera Papiliotrema . Wallemia could be transiently acquired by insects from feeding behavior and the environmental habitat, because this fungal group commonly acted as commensals and opportunistic pathogens for many plants (Iasur‐Kruh et al ., ). Exploring the accurate transmission patterns of these microbes associated with BPH would be the next step in further work.…”