Dietary Benefits of Fungal Associates to an Eruptive Herbivore: Potential Implications of Multiple Associates on Host Population Dynamics
- 1 December 2007
- journal article
- Published by Oxford University Press (OUP) in Environmental Entomology
- Vol. 36 (6), 1384-1396
- https://doi.org/10.1603/0046-225x(2007)36[1384:dbofat]2.0.co;2
Abstract
We used the mountain pine beetle (Dendroctonus ponderosae Hopkins) and its two fungal associates, Grosmannia clavigera and Ophiostoma montium, to study potential nutritional benefits of fungi to bark beetles. We tested for potential effects of feeding on phloem colonized by fungi on beetle performance in field and laboratory studies. The fungi increased nitrogen levels in the phloem of attacked trees by 40%, indicating that it may be an important source of dietary nitrogen for mountain pine beetles. However, nitrogen levels of phloem inoculated with fungi in the laboratory were similar to uncolonized phloem, indicating that the fungi may redistribute nitrogen from the sapwood to the phloem rather than increase absolute levels of nitrogen. Beetles emerging from attacked trees carrying G. clavigera were larger than beetles carrying O. montium, which in turn were larger than beetles lacking fungi. Results of experimental laboratory studies varied, likely because of differences in the growth and sporulation of fungi under artificial conditions. Results indicate that the two fungi may offer complementary benefits to the mountain pine beetle because larvae preferentially fed on phloem colonized by both fungi together over phloem colonized by one fungus or uncolonized phloem. Teneral adults preemergence fed on spores in pupal chambers when they were produced and consumed little phloem before emerging. Teneral adults mined extensively in the phloem before emerging when spores were not produced in the pupal chamber. Our results provide evidence for a nutritional role of fungi in the diet of bark beetles and show that multiple associates may differentially affect beetle performance, which could have important implications for bark beetle population dynamics.Keywords
This publication has 32 references indexed in Scilit:
- Antagonisms, mutualisms and commensalisms affect outbreak dynamics of the southern pine beetleOecologia, 2005
- Growth and reproduction of fungal feeding Collembola as affected by fungal species, melanin and mixed dietsOecologia, 2004
- Physiological basis for flexible voltinism in the spruce beetle (Coleoptera: Scolytidae)The Canadian Entomologist, 2001
- Phylogeny of Asexual Fungi Associated with Bark and Ambrosia BeetlesMycologia, 2001
- Convergent Origins of Ambrosia FungiMycologia, 1996
- The ability ofOphiostoma clavigerum to kill mature lodgepolepine treesEuropean Journal of Forest Pathology, 1995
- PHYSIOLOGICAL ASPECTS OF LODGEPOLE PINE WOUND RESPONSES TO A FUNGAL SYMBIONT OF THE MOUNTAIN PINE BEETLE, DENDROCTONUS PONDEROSAE (COLEOPTERA: SCOLYTIDAE)The Canadian Entomologist, 1983
- Maxillary Mycangium in the Mountain Pine BeetleScience, 1970
- THE EFFECT OF REARING TEMPERATURE ON THE SIZE AND FAT CONTENT OF THE DOUGLAS-FIR BEETLEThe Canadian Entomologist, 1967
- On Optimal Use of a Patchy EnvironmentThe American Naturalist, 1966