What About the Insects?

Blue Ridge PRISM Fall Meeting 2024 Bullet Points

Guest Speaker: Linda Fink, Professor of Biology, Emerita, Sweet Briar College, Virginia.

Featured image: Tiger Swallowtail (Pterourus glaucus) larvae feeding on garden dill.

  • Insects are the dominant multicellular life form on the planet in biomass as well as number of species and individuals.
  • Multiple reasons exist for overall insect success:
    • -Their small size results in rapid evolutionary change due to short generation times and large number of offspring.
    • -Ability to diversify along with the flowering plants needed to survive
    • -Many have developed ability to fly.
  • Metamorphosis allows for unique diversification and specialization of larvae vs. adult stage.
  • Fill varied ecological roles when it comes to diet: herbivores, pollinators, seed dispersal, nutrient recyclers (ie; dung beetles), or parasites.
  • Generalists do better than specialists in adapting to ecological change, especially when it comes to food preferences.
  • Many insects are beneficial, but at the same time can be bad (insect pests) depending on numbers and locale.
  • The IUCN (International Union for Conservation of Nature) documents insect population trends- many species are declining for multiple reasons with intensive agriculture, pesticides, urbanization, fertilizers and deforestation rounding out the top six.
  • The Monarch Butterfly may decrease in numbers but will not disappear, due to the work of conservation groups such as Monarch Joint Venture, Xerces Society, Monarch Butterfly Fund, and education groups including MonarchWatch.Org and Journey North.
  • Insects may serve as both prey and predators. For example, Compsilura concinnata, a parasitic fly introduced to control the gypsy moth also parasitized other native silk producing moths. Take home message “Some introduced species have negative effects on native insect populations.”
  • Speaker likes the online resource bugguide.net which offers “identification, images & information for insects, spiders and their kin for the United States and Canada”.

Tomato Hornworm (Manduca quinquemaculata) covered with cocoons from a parasitic braconid wasp (Cotesia congregates)