The Gut Microbiomes of Two Pachysoma MacLeay Desert Dung Beetle Species (Coleoptera: Scarabaeidae: Scarabaeinae) Feeding on Different Diets

Abstract

Micro-organisms inhabiting animal guts benefit from a protected and nutrient-rich environment while assisting the host with digestion and nutrition. In this study we compare, for the first time, the bacterial and fungal gut communities of two species of the small desert dung beetle genus Pachysoma feeding on different diets: the detritivorous P. endroedyi and the dry-dung-feeding P. striatum. Whole-gut microbial communities from 5 individuals of each species were assessed using 454 pyrosequencing of the bacterial 16S rRNA gene and fungal ITS gene regions. The two bacterial communities were significantly different, with only 3.7% of operational taxonomic units shared, and displayed intra-specific variation. The number of bacterial phyla present within the guts of P. endroedyi and P. striatum individuals ranged from 6–11 and 4–7, respectively. Fungal phylotypes could only be detected within the gut of P. striatum. Although the role of host phylogeny in Pachysoma microbiome assembly remains unknown, evidence presented in this study suggests that host diet may be a deterministic factor.

Effect of Different Lignocellulosic Diets on Bacterial Microbiota and Hydrolytic Enzyme Activities in the Gut of the Cotton Boll Weevil (Anthonomus grandis)

“…On the other hand, an important decrease in Proteobacteria occurred with CS diets; in this case, we could assign a high number of Spirochaetes OTUs. The same predominant groups have been previously reported in other weevils ( Rhynchophorus ferrugines and Rhynchophorus Vulneratus ), beetles ( Pachisoma endroedyi , Pachisoma striatum , Megetra cancellata , Epicauta longicollis , Gonasida inferna and Calosoma peregrinator ), cotton leafworm ( Spodoptera littoralis ), higher termites ( Nasutitermes aquilinus and Cortaritermes fulviceps ), honey bee ( Apis mellifera ), planthopper ( Lycorma delicatula ) and yellow ladybird ( Illeis koebelei ) (Colman et al, 2012; Shao et al, 2014; Yun et al, 2014; Ben Guerrero et al, 2015; Montagna et al, 2015; Franzini et al, 2016). Furthermore, Spirochaetes have been reported previously as a dominant component of the termite gut microbiota (Warnecke et al, 2007; Husseneder et al, 2010; Boucias et al, 2013; Benjamino and Graf, 2016).…”

“…were also reported as the most abundant genera in the weevil Rhynchoporus ferrugines olivers (Tagliavia et al, 2014; Montagna et al, 2015). The eleven OTUs mentioned above are members of families already reported in insect microbiomes (Hedin et al, 1978; Campbell et al, 1992; Priya et al, 2012; Prabhakar et al, 2013; Montagna et al, 2015; Xu et al, 2015; Franzini et al, 2016). …”

“…At this point we are not certain about the functional importance of these cores ( Figure 3 ). In some insects, the core microbiota is small; only two, nine, ten and fifteen OTUs taxa have been identified in Anopheles gambiae , Apis mellifera and Pachysoma sp., Cimex lectularius and Rhynchophorus sp., respectively (Wang et al, 2011; Moran et al, 2012; Sabree et al, 2012; Meriweather et al, 2013; Montagna et al, 2015; Franzini et al, 2016). …”

Seasonal shifts in the insect gut microbiome are concurrent with changes in cold tolerance and immunity

“…Because the composition of the microbiome depends on the physiological state of the host (Douglas, 2015), these seasonal changes in host physiology are also likely to influence the composition of the gut microbiome (Carey & Duddleston, 2014). Further, because the microbiome may differ depending on diet (Franzini et al, 2016;Maes, Rodrigues, Oliver, Mott, & Anderson, 2016;Wang, Gilbreath, Kukutla, Yan, & Xu, 2011), seasonal changes in food or microbiota in the external environment likely contribute to changes in the insect microbiome (Ludvigsen et al, 2015). However, we know little about the seasonality of the insect gut microbiome in the context of low temperatures and overwintering.…”

Interspecific and intraspecific variation in diet preference in five Atlantic forest dung beetle species

“…Bacterial symbionts present in the gut are thought to play a role in nutrient acquisition in dung beetles (Holter, ), and have been found to vary in composition between dung beetle species with different diets (Franzini et al ., ; Shukla et al ., ). Variation in gut microbiota between individuals may affect the ability to digest nutrients in the dung that would be otherwise unavailable, and could result in interindividual diet selection in dung beetles (Schwab et al ., ).…”