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Abstract Lightning strikes are a common source of disturbance in tropical forests, and a typical strike generates large quantities of dead wood. Lightning‐damaged trees are a consistent resource for tropical saproxylic (i.e., dead wood‐dependent) organisms, but patterns of consumer colonization and succession following lightning strikes are not known. Here, we documented the occurrence of four common consumer taxa spanning multiple trophic levels—beetles,Aztecaants, termites, and fungi—in lightning strike sites and nearby undamaged control sites over time in a lowland forest of Panama. Beetle abundance was 10 times higher in lightning strike sites than in paired control sites, and beetle assemblages were compositionally distinct. Those in strike sites were initially dominated by bark and ambrosia beetles (Curculionidae: Platypodinae, Scolytinae); bark and ambrosia beetles, and predaceous taxa increased in abundance relatively synchronously. Beetle activity and fungal fruiting bodies, respectively, were 3.8 and 12.2 times more likely to be observed in lightning‐damaged trees in strike sites versus undamaged trees in paired control sites, whereas the occurrence probabilities ofAztecaants and termites were similar between damaged trees in lightning strike sites and undamaged trees in control sites. Tree size also was important; larger dead trees in strike sites were more likely to support beetles, termites, and fungal fruiting bodies, and larger trees—regardless of mortality status—were more likely to hostAzteca. Beetle presence was associated with higher rates of subsequent fungal presence, providing some evidence of beetle‐associated priority effects on colonization patterns. These results suggest that lightning plays a key role in supporting tropical insect and fungal consumers by providing localized patches of suitable habitat. Any climate‐driven changes in lightning frequency in tropical forests will likely affect a broad suite of consumer organisms, potentially altering ecosystem‐level processes.
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Host switching by an ambrosia beetle fungal mutualist: Mycangial colonization of indigenous beetles by the invasive laurel wilt fungal pathogen
Abstract Ambrosia beetles require their fungal symbiotic partner as their cultivated (farmed) food source in tree galleries. While most fungal‐beetle partners do not kill the host trees they inhabit, since their introduction (invasion) into the United states around ~2002, the invasive beetleXyleborus glabratushas vectored its mutualist partner (but plant pathogenic) fungus,Harringtonia lauricola, resulting in the deaths of over 300 million trees. Concerningly, indigenous beetles have been caught bearingH. lauricola. Here, we show colonization of the mycangia of the indigenousX. affinisambrosia beetle byH. lauricola. Mycangial colonization occurred within 1 h of feeding, with similar levels seen forH. lauricolaas found for the nativeX. affinis‐R. arxiifungal partner. Fungal mycangial occupancy was stable over time and after removal of the fungal source, but showed rapid turnover when additional fungal cells were available. Microscopic visualization revealed two pre‐oral mycangial pouches of ~100–200 × 25–50 μm/each, with narrow entry channels of 25–50 × 3–10 μm. Fungi within the mycangia underwent a dimorphic transition from filamentous/blastospore growth to yeast‐like budding with alterations to membrane structures. These data identify the characteristics of ambrosia beetle mycangial colonization, implicating turnover as a mechanism for host switching ofH. lauricolato other ambrosia beetle species.
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- Award ID(s):
- 2418026
- PAR ID:
- 10413932
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- Environmental Microbiology
- Volume:
- 25
- Issue:
- 10
- ISSN:
- 1462-2912
- Format(s):
- Medium: X Size: p. 1894-1908
- Size(s):
- p. 1894-1908
- Sponsoring Org:
- National Science Foundation
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