Abdomen Flashcards
Main roles of the abdomen?
Food storage, digestion, reproduction
How many segments in the abdomen?
11
In more advanced insects are there usually more or less segments?
Less
A dorsal and a ventral part (sclerites) joined laterally by a…
Pleural Membrane
How do the segments all the insect to expand and contract?
The front margins of each segment often “telescope” into the sclerites of the preceding segment
In most insects is the junctions between the thorax and abdomen broad or skinny?
Most of the cases it is broad, in wasp like insects it can be very narrow and skinny
What are cerci?
They are a pair of many-segmented appendages at the tip of the abdomen in many primitive species
What is the function of the cerci?
They can be used for sensory functions and/or are used to predate/defend
what is included in the anal-genital part of the abdomen of adult female insects?
External structures used for oviposition
The ovipositor can be modified in some insects, which insects and how is it modified?
In bees, ants, and predatory wasps the ovipositor can be modified into a defensive structure called a sting (stinger) and is only found in females
What is the function of the external genitalia for male species?
They are used for transferring spermatozoa to the female and often involve structures that grasp and hold the partner during mating. It is usually enclosed in a tube like structure that enters the females body
Are most insects, sexual, asexual, or bisexual?
Most insects, but not all are bisexual meaning that one egg from a female and one sperm from a male fuse
What is parthenogenesis?
It is a form of sexual reproduction in which new individuals develop from unfertilized eggs
Are some of these species able to alternate between bisexual and parthenogenetic reproduction?
Yes, bees are a good example of this. Others can be exclusively parthenogenetic where no males ever occur
Talk about the reproductive differences between more advanced and more primitive insect species
More primitive species can reproduce via no contact, while more advanced species exhibit internal fertilization
