Hormone system and Insect Development Flashcards
What are hormones?
chemical signals that are secreted into the circulatory system and communicate regulatory messages within the body
How are hormones moved through the body?
Hormones reach all parts of the body, but only target cells have receptors for that hormone
The endocrine system in insects is composed of two things, what are they and what are their function?
- neurosecretory cells (Involved in the production and release of chemical hormones
- Endocrine glands (secrete hormones)
Three types of hormones
- Prothoracic glands (source of ecdysteroids)
- Corpora allata (juvenile hormones)
- Corpora cardiaca (neuropeptide hormones)
There are two subclasses of pterygota, what are they?
- Exopterygota (wings develop outside the body)
- Endopterygota (wings develop inside the body)
Other main difference between the two subclasses?
Exopterygota have a simple metamorphosis (without pupal stage) whole Endopterygota have a complete metamorphosis which includes a pupal stage
How are they different from apterygota?
Apterygota have no metamorphosis, except for the size all larval stages closely resemble adults (wingless). These insects are defined as ametabolous and their development is called ametabolism.
3 stages of Exopterygota
- Egg
- Nymph
- Adult
4 Stages of Endopterygota
- Egg
- Larvae
- Pupa
- Adult
What do nymphs look like
Adults, the insects will stop molting once they have reached their adult size and by this time they will have grown wings
Molting and development are controlled by three hormones, what are they?
- Brain hormone PTTH (stimulates release of 20E from prothoraic glands)
- Juvenile Hormone (Retention of larval characteristics)
- 20E Promotes molting (in presence of Juvenile hormone, and promotes development (in absence of juvenile hormone)
