Adopting Bacteria in Order to Adapt to Water—How Reed Beetles Colonized the Wetlands (Coleoptera, Chrysomelidae, Donaciinae)

Abstract

The present paper reviews the biology of reed beetles (Donaciinae), presents experimental data on the role of specific symbiotic bacteria, and describes a molecular method for the detection of those bacteria. Reed beetles are herbivores living on wetland plants, each species being mono- or oligo-phagous. They lay their eggs on the host plant and the larvae live underwater in the sediment attached to its roots. The larvae pupate there in a water-tight cocoon, which they build using a secretion that is produced by symbiotic bacteria. The bacteria are located in four blind sacs at the foregut of the larvae; in (female) adults they colonize two out of the six Malpighian tubules. Tetracycline treatment of larvae reduced their pupation rate, although the bacteria could not be fully eliminated. When the small amount of bacterial mass attached to eggs was experimentally removed before hatching, symbiont free larvae resulted, showing the external transmission of the bacteria to the offspring. Specific primers were designed to detect the bacteria, and to confirm their absence in manipulated larvae. The pupation underwater enabled the reed beetles to permanently colonize the wetlands and to diversify in this habitat underexploited by herbivorous insects (adaptive radiation).

Wolbachia in the Malpighian Tubules: Evolutionary Dead‐End or Adaptation?

“…Yet, and of particular relevance to our hypothesis, the MT (Fig. , left panel) has been described repeatedly as a site for somatic intracellular storage of endosymbionts (Noda et al, ; Kurtti et al, ; Goto et al, ; Ruang‐Areerate and Kittayapong, ; Klyachko et al, ; Bution et al, ; Kleinschmidt and Kölsch, ). Also, in the Drosophila holometabolous context and unlike most tissues, MTs are peculiar in that they maintain their integrity throughout metamorphosis (Beyenbach et al, ; Tapadia and Shukla, ).…”

Barcoding of Chrysomelidae of Euro-Mediterranean area: efficiency and problematic species

“…g ., number of generation per year, tendency to isolation of the populations due to the habitat structure or to the dispersal ability of the species 44 , and for this reason should be easier to define a reliable threshold between intraspecific and interspecific divergence. We can hypothesise that not all Chrysomelidae share the same rate in nucleotide substitutions, since different subfamilies are characterised by different morphological, ecological and physiological adaptation, as the Maulik’s organ that confers jumping capabilities to Alticinae 45 , 46 , the limited dispersal capabilities of Chrysomelinae and Cryptocephalinae 47 or the presence of bacterial endosymbiont that, in the case of Donacinae, allows the larvae to survive in anoxic conditions under water 48 . Moreover, the different OTs achieved for Chrysomelidae subfamilies underline that the use of a unique threshold for the entire family decreases the identification efficiency of DNA barcoding (Table 1 ).…”

Shared Ancestry of Symbionts? Sagrinae and Donaciinae (Coleoptera, Chrysomelidae) Harbor Similar Bacteria

“…For the Sagrinae, this is described as a lining of the pupal cell [ 29 ] located inside a plant stem/root, but effectively the result is a cocoon that can be removed intact from the substrate ( Figure 5 ). The same holds true for cocoons of Donaciinae, which the larva builds in the sediment attached to the root of the host plant [ 30 , 31 ]. This cocoon formation is peculiar and occurs in no other group of leaf beetles.…”

“…It is a thin, parchment like layer, flexible but brittle when dry. It is clearly more substantial than a surface secretion that can slightly stabilize the pupal chamber, as found in many leaf beetles [ 32 ] (and which is present in the initial phase of cocoon formation in the Donaciinae, [ 31 ]).…”