scholarly journals The importance of environmentally-acquired bacterial symbionts for the squash bug (Anasa tristis), a significant agricultural pest

2021 ◽  
Author(s):  
Tarik S. Acevedo ◽  
Gregory P. Fricker ◽  
Justine R Garcia ◽  
Tiffany Alcaide ◽  
Aileen Berasategui ◽  
...  

Most insects maintain associations with microbes that shape their ecology and evolution. Such symbioses have important applied implications when the associated insects are pests or vectors of disease. The squash bug, Anasa tristis (Coreoidea: Coreidae), is a significant pest of human agriculture in its own right and also causes damage to crops due to its capacity to transmit a bacterial plant pathogen. Here, we demonstrate that complete understanding of these insects requires consideration of their association with bacterial symbionts in the family Burkholderiaceae. Isolation and sequencing of bacteria housed in midgut crypts in these insects indicates that these bacteria are consistent and dominant members of the crypt-associated bacterial communities. These symbionts are closely related to Caballeronia spp. associated other true bugs in the superfamiles Lygaeoidea and Coreoidea. Fitness assays with representative Burkholderiaceae strains indicate that the association can significantly increase survival and decrease development time, though strains do vary in the benefits that they confer to their hosts, with Caballeronia spp. providing the greatest benefit. Experiments designed to assess transmission mode indicate that unlike many other beneficial insect symbionts, the bacteria are not acquired from parents before or after hatching but are instead acquired from the environment after molting to a later development stage. The bacteria do, however, have the capacity to escape adults to be transmitted to later generations, leaving the possibility for a combination of indirect vertical and horizontal transmission.

2021 ◽  
Vol 12 ◽  
Author(s):  
Tarik S. Acevedo ◽  
Gregory P. Fricker ◽  
Justine R. Garcia ◽  
Tiffanie Alcaide ◽  
Aileen Berasategui ◽  
...  

Most insects maintain associations with microbes that shape their ecology and evolution. Such symbioses have important applied implications when the associated insects are pests or vectors of disease. The squash bug, Anasa tristis (Coreoidea: Coreidae), is a significant pest of human agriculture in its own right and also causes damage to crops due to its capacity to transmit a bacterial plant pathogen. Here, we demonstrate that complete understanding of these insects requires consideration of their association with bacterial symbionts in the family Burkholderiaceae. Isolation and sequencing of bacteria housed in the insects’ midgut crypts indicates that these bacteria are consistent and dominant members of the crypt-associated bacterial communities. These symbionts are closely related to Caballeronia spp. associated with other true bugs in the superfamilies Lygaeoidea and Coreoidea. Fitness assays with representative Burkholderiaceae strains indicate that the association can significantly increase survival and decrease development time, though strains do vary in the benefits that they confer to their hosts, with Caballeronia spp. providing the greatest benefit. Experiments designed to assess transmission mode indicate that, unlike many other beneficial insect symbionts, the bacteria are not acquired from parents before or after hatching but are instead acquired from the environment after molting to a later developmental stage. The bacteria do, however, have the capacity to escape adults to be transmitted to later generations, leaving the possibility for a combination of indirect vertical and horizontal transmission.


2021 ◽  
Author(s):  
Kayla Stoy ◽  
Joselyne Chavez ◽  
Valeria De Las Casas ◽  
Venkat Talla ◽  
Aileen Berasategui ◽  
...  

AbstractMutualism depends on the alignment of host and symbiont fitness. Horizontal transmission can readily decouple fitness interests, yet horizontally transmitted mutualisms are common in nature. We hypothesized that pairwise coevolution and specialization in host-symbiont interactions underlies the maintenance of cooperation in a horizontally transmitted mutualism. Alternatively, we predicted selection by multiple host species may select for cooperative traits in a generalist symbiont through diffuse coevolution. We tested for signatures of pairwise coevolutionary change between the squash bug Anasa tristis and its horizontally acquired bacterial symbiont Caballeronia spp. by measuring local adaptation. We found no evidence for local adaptation between sympatric combinations of A. tristis squash bugs and Caballeronia spp. across their native geographic range. To test for diffuse coevolution, we performed reciprocal inoculations to test for specialization between three Anasa host species and Caballeronia spp. symbionts isolated from conspecific hosts. We observed no evidence of specialization across host species. Our results demonstrate generalist dynamics underlie the interaction between Anasa insect hosts and their Caballeronia spp. symbionts. Specifically, diffuse coevolution between multiple host species with a shared generalist symbiont may maintain cooperative traits despite horizontal transmission.


2011 ◽  
Vol 403-408 ◽  
pp. 313-317
Author(s):  
Li Zhang

In China, the family business usually implement paternalistic management model at the startup. When the enterprise scale enlarged, along with the change of the outside environment, the risk and uncertainty of the enterprise management will be increased and the distortions of family management model will become increasingly clear. Therefore, it is an irresistible trend to carry out reforms on the family business governance model. This paper analyzed the current status of Chinese family management model, pointed out the opportunity under the market economy for family business accelerating its development, and summarized the four models of Chinese family business governance. Currently, under the market economy, the biggest problem faced by Chinese family business is not how to transform into modern enterprise, but how to realize their sustainable development. To build a modern enterprise system is just an important destination for family business development, but can’t be the only choose at the present stage. A precisely suitable enterprise system is established according to the time, place, different industry, scale, development stage and background, while there is no standard model of universal application.


2009 ◽  
Vol 75 (10) ◽  
pp. 3115-3119 ◽  
Author(s):  
Cara M. Gibson ◽  
Martha S. Hunter

ABSTRACT Heritable bacterial symbionts are widespread in insects and can have many important effects on host ecology and fitness. Fungal symbionts are also important in shaping their hosts' behavior, interactions, and evolution, but they have been largely overlooked. Experimental tests to determine the relevance of fungal symbionts to their insect hosts are currently extremely rare, and to our knowledge, there have been no such tests for strictly predacious insects. We investigated the fitness consequences for a parasitic wasp (Comperia merceti) of an inherited fungal symbiont in the Saccharomycotina (Ascomycota) that was long presumed to be a mutualist. In comparisons of wasp lines with and without this symbiont, we found no evidence of mutualism. Instead, there were significant fitness costs to the wasps in the presence of the yeast; infected wasps attacked fewer hosts and had longer development times. We also examined the relative competitive abilities of the larval progeny of infected and uninfected mothers, as well as horizontal transmission of the fungal symbiont among larval wasps that shared a single host cockroach egg case. We found no difference in larval competitive ability when larvae whose infection status differed shared a single host. We did find high rates of horizontal transmission of the fungus, and we suggest that this transmission is likely responsible for the maintenance of this infection in wasp populations.


2011 ◽  
Vol 77 (19) ◽  
pp. 7000-7006 ◽  
Author(s):  
Nicola M. Reid ◽  
Sarah L. Addison ◽  
Lucy J. Macdonald ◽  
Gareth Lloyd-Jones

ABSTRACTHuhu grubs (Prionoplus reticularis) are wood-feeding beetle larvae endemic to New Zealand and belonging to the family Cerambycidae. Compared to the wood-feeding lower termites, very little is known about the diversity and activity of microorganisms associated with xylophagous cerambycid larvae. To address this, we used pyrosequencing to evaluate the diversity of metabolically active and inactive bacteria in the huhu larval gut. Our estimate, that the gut harbors at least 1,800 phylotypes, is based on 33,420 sequences amplified from genomic DNA and reverse-transcribed RNA. Analysis of genomic DNA- and RNA-derived data sets revealed that 71% of all phylotypes (representing 95% of all sequences) were metabolically active. Rare phylotypes contributed considerably to the richness of the community and were also largely metabolically active, indicating their participation in digestive processes in the gut. The dominant families in the active community (RNA data set) includedAcidobacteriaceae(24.3%),Xanthomonadaceae(16.7%),Acetobacteraceae(15.8%),Burkholderiaceae(8.7%), andEnterobacteriaceae(4.1%). The most abundant phylotype comprised 14% of the active community and affiliated withDyella ginsengisoli(Gammaproteobacteria), suggesting that aDyella-related organism is a likely symbiont. This study provides new information on the diversity and activity of gut-associated microorganisms that are essential for the digestion of the nutritionally poor diet consumed by wood-feeding larvae. Many huhu gut phylotypes affiliated with insect symbionts or with bacteria present in acidic environments or associated with fungi.


2020 ◽  
Author(s):  
Georgia C Drew ◽  
Giles E Budge ◽  
Crystal L Frost ◽  
Peter Neumann ◽  
Stefanos Siozios ◽  
...  

AbstractA dynamic continuum exists from free-living environmental microbes to strict host associated symbionts that are vertically inherited. However, knowledge of the forces that drive transitions in the modes by which symbioses form is lacking. Arsenophonus is a diverse clade of bacterial symbionts, comprising reproductive parasites to coevolving obligate mutualists, in which the predominant mode of transmission is vertical. We describe a symbiosis between a member of the genus Arsenophonus and the Western honey bee. We then present multiple lines of evidence that this symbiont deviates from a heritable model of transmission. Field sampling uncovered marked spatial and seasonal dynamics in symbiont prevalence, and rapid infection loss events were observed in field colonies and individuals in the laboratory. Fluorescent in-situ hybridization showed Arsenophonus localised in the gut, and detection of the bacterium was rare in screens of early honey bee life stages. We directly show horizontal transmission of Arsenophonus between bees under varying social conditions. We conclude that honey bees acquire Arsenophonus through a combination of environmental exposure and social contacts. Together these findings uncover a key link in the Arsenophonus clades trajectory from free-living ancestral life to obligate mutualism, and provide a foundation for studying transitions in symbiotic lifestyle.


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