L6 Ecdysis Flashcards
What is ecdysis
Shedding of the cuticle
What are 5 functions of ecdysis
Allow insect to grow
Replace mouthparts (mantids and plant feeders)
Replace or extend lining of trachea (need more oxygen)
Restore waterproofing
Shed pathogens (fungal spores)
give 3 disadvantages of ecdysis
slow
dangerous - insect vulnerable to predation while cuticle hardens
energetically expensive - made of protein and sclerotised cuticle cannot be reused
what does pharate mean
the stage when an insect is actively constructing a new cuticle
what does teneral mean
the stage when an insect has not yet hardened and darkened - it is soft and colourless
give an example of an insect which exhibits mass emergence controlled by environmental cues
dragonflies emerge at 8-9pm
how many holometabolic orders are there and what proportion of insects do they represent
10
86%
what are 2 benefits of metamorphosis
life cycle compartmentalisation -larval form can be optimised for growth and feeding without compromising the form of the adult
can exploit different environmental resources and occupy different habitats
what is the role of juvenile hormone at each moult
high juvenile hormone inhibits genes that cause development into an adult
where is the juvenile hormone secreted from
corpora allata
what is responsible for stopping the corpora allata from producing juvenile hormone at the final larval instar
medial nerve
what occurs is juvenile hormone levels drop
triggers release of PTTH and beginning of moult
what is the role of juvenile hormone in adult insects
assist in sexual maturity
what affect does juvenile hormone have on each of the sexes
females - stimulates yolk production
males - stimulates accessory glands to produce proteins needed for seminal fluid and spermatophore case
what happens in juvenile hormone is not produced in an adult insect
adult remains sexually sterile
