Skip to main content
Article thumbnail
Location of Repository

Alteration of Forest Structure Modifies the Distribution of Scale Insect, Stigmacoccus garmilleri, in Mexican Tropical Montane Cloud Forests

By Heather A. Gamper, Suzanne Koptur, Jose García-Franco and Andres Plata Stapper


Stigmacoccus garmilleri Foldi (Hemiptera: Margarodidae) is an ecologically important honeydew-producing scale insect associated with oak trees (Quercus spp.) in highland forests of Veracruz, Mexico. The honeydew exudates of S. garmilleri serve as a significant nutrient source to many species of birds, insects, and sooty molds. Oak trees found in the forest interior, forest edge, and those scattered in pasture areas support scale insect colonies, though the pattern of insect infestations on trees within these varying landscape types has not been elucidated. This study aims to describe the distribution of scale insect infestation and any distinctions in honeydew production based on tree location. Scale insect density, honeydew volume, and sugar concentration were surveyed throughout a continuous landscape that included both patches of forest and scattered pasture trees. In addition, the anal filament through which the honeydew drop is secreted was also measured and was experimentally removed to test and measure regrowth. Scale insect densities on tree trunks were greatest on pasture trees, while intermediate densities were found on trees at the forest edge, and low densities on interior forest trees, suggesting that trees in disturbed areas are more susceptible to scale insect infestation. Trees with small diameters at breast height had significantly higher insect densities than trees with medium to large diameters. Trunk aspect (North, South, East, and West) was not a significant determinant of scale insect density. In forested areas higher densities of scale insects were found at three meters height in comparison to lower heights. Sugar concentrations and drop volumes of honeydew in forest and pasture areas were not significantly different. However, scale-insect anal tubes/filaments were significantly longer in pasture than they were in forests. Sugar concentrations of honeydew appeared to be positively correlated with temperature and negatively correlated with relative humidity. Experiments indicated that anal filaments could grow approximately 4 mm every 24 hours, and average tube growth was significantly faster in pasture than in forest, suggesting that there may be a physiological effect on the insect due to landscape disturbance. The results obtained in this study describe the increases in scale insect infestation of trees with forest disturbance. The effect of these increased scale insect densities on the host tree physiology is still to be resolved

Topics: Article
Publisher: University of Wisconsin Library
OAI identifier:
Provided by: PubMed Central

Suggested articles


  1. (2007). A dynamical model of honeydew droplet production by sooty-beech scale insects (Ultracoelostoma spp.) in New Zealand Nothofagus forest.
  2. (2000). A relict population of Fagus grandifolia var. mexicana at the Acatlan Volcano, Mexico: structure, litterfall, phenology and dendroecology.
  3. (2007). A taxonomic review of the Margarodoid genus Stigmacoccus Hempel (Hemiptera: Sternorrhyncha: Coccoidea: Stigmacoccidae), with some details on their biology.
  4. (1997). Adaptations in scale insects.
  5. (2001). Anthropogenic disturbance and tree diversity
  6. (1981). Beech honeydew: forest produce.
  7. (1989). Beech honeydew: seasonal variation and use by wasps, honeybees and other insects.
  8. (1989). Carbohydrate analysis of beech honeydew.
  9. (2004). Cloud Forest Agenda. UNEP-WCMC – World Conservation Monitoring Centre.
  10. (2006). Confounding factors in the detection of species responses to habitat fragmentation.
  11. (1993). Defense of homopteran honeydew by birds in the Mexican highlands and other warm temperate forests.
  12. (2000). Do oligosaccharides reduce the suitability of honeydew for predators and parasitoids?
  13. (2007). Ecological processes and spatial patterns before, during and after simulated deforestation.
  14. (2003). Effect of host-tree and environmental variables on honeydew
  15. (1980). Excretory behaviour in soft scales (Hemiptera: Coccoidae).
  16. (2004). Forest Canopies. In:
  17. (1983). Honeydew and its importance to birds in beech forest of the South Island, New Zealand.
  18. (1990). Honeydew density in mixed Nothofagus forest,
  19. (2010). Honeydew foraging by birds in tropical montane forests and pastures of Mexico.
  20. (1992). Honeydew standing crop and production over 24 hours in Nothofagus solandri forest in Canterbury.
  21. (2002). Hyperdynamism in fragmented habitats.
  22. (1991). Margarodidae (Insecta: Hemiptera). In: Crosby T, Editor. Fauna of New Zealand Ko te Aitanga Pepeke o Aotearoa. FNZ 21. Available online, matics/invertebrates/faunaofnz/
  23. (2001). Physical effect of exfoliation of guava tree bark on Capulinia sp. near to jaboticabae von Ihering (Hemiptera: Eriococcidae).
  24. (1998). Potential impacts of climate change on tropical forest ecosystems.
  25. (2006). Preliminary evidence suggests that beech scale insect honeydew has a negative effect on terrestrial litter decomposition rates in Nothofagus forests of New Zealand.
  26. (2001). Revising the convergence hypothesis of avian use of honeydew: evidence from Dominican subtropical dry forest.
  27. (2009). Scattered trees: a complementary strategy for facilitating adaptive responses to climate change in modified landscapes?
  28. (2007). Separating host-tree and environmental determinants of honeydew production by Ultracoelostoma scale insects in a Nothofagus forest.
  29. (1986). The bark of trees: thermal properties, microclimate and fauna.
  30. (1980). The effects of non-sugar nectar constituents on nectar energy content.
  31. (2008). The future of scattered trees in agricultural landscapes.
  32. (1993). The influence of honeydew on arthropods associated with beech trees in New Zealand.
  33. (2006). Vertical stratification in the spatial distribution of the beech scale insect (Ultracoelostoma assimile) in Nothofagus tree canopies in New Zealand.

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.