Living With Scent Glands

Insects secrete a variety of substances for purposes of communication and defense. Sometimes the best defense is communicating with the enemy. Insects may be inedible or unappetizing to predators. However, if a predator must bite the insect to discover its foul properties, the insect might not survive the attack. One function of insect glands is to present a potential predator with a “taste” of the defensive chemical prior to the predator taking a bite. Glands are one way that an insect can advertise its unpalatability.

The milkweed bug, Oncopeltus fasciatus, feeds on milkweeds that contain toxic cardenolides. These cardenolides can cause regurgitation in vertebrates and disrupt normal heart rhythm. The milkweed bugs sequester these toxins as defense against predators. The male and female adult milkweed bugs have scent glands on the thorax that secrete a variety of substances including cardenolides. As a defense, predators encountering the cardenolides may be more inclined to pass on attacking a milkweed bug.

Scent glands on the thorax of the milkweed bug.  Inset:  enlargement of the scent gland and the scent canal

Scent glands on the thorax of the milkweed bug.
Inset: enlargement of the scent gland and the scent canal

About jjneal

Jonathan Neal is an Associate Professor of Entomology at Purdue University and author of the textbook, Living With Insects (2010). This blog is a forum to communicate about the intersection of insects with people and policy. This is a personal blog. The opinions and materials posted here are those of the author and are in no way connected with those of my employer.
This entry was posted in behavior, Biomaterials, by jjneal, Environment. Bookmark the permalink.

1 Response to Living With Scent Glands

  1. Bianca says:

    Hi, its pleasant article about media print, we all know
    media is a fantastic source of facts.

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