Manduca sexta
Tobacco Hornworm
Thea Blue
Embedded Files
Introduction
Introduction
The common name for Manduca Sexta is the Tobacco Hornworm
comes from the fact that the caterpillar often eats tobacco leaves (Byron & Gillett-Kaufman)
Primary Literature Articles: Antibacterial proteins in the midgut of Manduca sexta during metamorphosis by Virginia Russell and Peter E. Dunn
Tobacco Hornworms primarily live in the southeast United States, especially near gulf coast
Taxonomy and Nomenclature:
Taxonomy and Nomenclature:
Domain: Eukaryota → Eukaryotic, Multicellular
Kingdom: Animalia → Animal
Phylum: Arthropoda → Arthropod
Subphylum: Hexapoda → Hexapod
Class: Insecta → Insect
Subclass: Pterygota → Winged Insect
Order: Lepidoptera → Butterflies, moths, papillons
Family: Sphingidae → Hawk moths, hornworms, sphinx moths
Genus: Manduca → Hawk moths
Species: sexta → Tobacco Hornworn
Background:
Background:
Eat solanaceous plants, such as tomato, eggplant, pepper, potato, as well as solanaceous weeds including horse-nettle, jimsonweed, and nightshade
Also eat tobacco leaves (Byron & Gillett-Kaufman)
Tobacco hornworm moths mate and lays eggs on a variety of plants, including tomato, potato, pepper, and tobacco plants
Caterpillars will hatch about a week after the eggs are laid (Wisconsin Horticulture)
Young caterpillars rely on camouflage for protection
They will strip the plants of the leaves to survive until they are full grown caterpillars (Wisconsin Horticulture)
They then go into the soil to pupate and become moths, when they then disperse
Wasps, especially the cotesia congregata, are a common predator
Larvae can exhale small amounts of nicotine from the tobacco leaves they eat as a defense mechanism against wasps (Byron & Gillett-Kaufman)
Antibacterial proteins in the midgut of Manduca sexta during metamorphosis
Antibacterial proteins in the midgut of Manduca sexta during metamorphosis
Authors: Virginia Russell and Peter E. Dunn
Scientists want to determine the antibacterial defenses of the tobacco hornworm that are deployed by the midgut epithelial cells
Defenses are hemocyte phagocytosis of individual bacteria and the formation of large, multicellular hemocytic aggregates called nodules, which entrap large numbers of bacteria in an extracellular matrix (Russell and Dunn).
The presence of bacteria in the body cavity also induces the synthesis of a suite of antibacterial proteins which accumulate in the plasma (Russell and Dunn)
Larvae were treated with killed bacteria or bacterial peptidoglycan elicitors.
Causes the larvae to go into a “malaise syndrome” to prepare the midgut for antibacterial defenses (midgut will create lysozyme)
Concepts to Understand
Concepts to Understand
midgut epithelial cells- cells within the middle portion of an insect that act as a barrier between the gut lumen and the inside of the organism and absorbing nutrients
hemocyte phagocytosis- the process of engulfing various particles, such as bacteria, by blood cells
nodules- a growth or lump of cells
bacterial peptidoglycan elicitors- signal compound that provokes organisms to provide defense
malaise syndrome- a decrease in energy in preparation
lysozyme- protein present in many mucosal secretions, as well as the tissues of plants and animals
Data Analysis
Data Analysis
As seen with the spikes in the graph to the side, the introduction of these bacterial agents did help to cause an increase in lysozyme in the pupal midgut lumen
The peaks represent an absorption of light into the midgut. The amount of light absorbed represents the amount of lysozyme created by the tobacco hornworm within the midgut.
Based on this graph, it is able to be determined that adding bacteria to the midgut helps the tobacco hornworm produce more lysozyme than they would without the previous implementation of bacteria, leading to a higher growth rate
Conclusion
Conclusion
The introduction of killed bacteria or bacterial peptidoglycan elicitors to the tobacco hornworm larvae caused an increase in lysozyme in the pupal midgut lumen (Russell & Dunn)
By using light absorbance to determine the amount of lysozyme in the midgut of tobacco hornworm larvae, it showed that the hornworms produce enzymes and proteins to protect the body from bacteria (Russell & Dunn)
This study helped to determine what helps prevent bacterial infection during tobacco hornworm growth and development (Russell & Dunn)
References:
References:
Russell, V., Dunn, P. E. (1996). Antibacterial proteins in the midgut of Manduca sexta during metamorphosis. Journal of Insect Physiology, 42(1), 65–71. https://doi.org/10.1016/0022-1910(95)00083-6
Byron, M. A., Gillett-Kaufman, J. L. (n.d.). Tobacco hornworm, Manduca sexta (Linnaeus); tomato hornworm, manduca quinquemaculata (Haworth). Retrieved February 1, 2023, from https://entnemdept.ufl.edu/creatures/field/tobacco_hornworm.htm
Tobacco Hornworm | BioLogic Company. 2013 Sep 10. BioLogic Company | Producers of beneficial nematodes. [accessed 2023 Feb 8]. https://biologicco.com/blog/tobacco-hornworm/#:~:text=The%20moths%20mate%20and%20lay.
Marsden C. Hornworms. Wisconsin Horticulture. [accessed 2023 Feb 8]. https://hort.extension.wisc.edu/articles/hornworms/#:~:text=Tomato%20and%20tobacco%20hornworms%20feed.
Images courtesy of:
Images courtesy of:
Page updated
Google Sites
Report abuse