|MadSci Network: Other|
Determining if an insect (such as a ladybug) is a boy or a girl is not an easy thing to do! Other kinds of animals, such as some birds and humans, have markings or characteristics that we can use to determine gender (whether they are a boy or girl). Female (girl) birds often have very different external markings from male (boy) birds. Usually, many bird females have pale coloring, while males of many bird species have bright coloring. Some human males have hair on their faces (beards and mustaches!) that distinguish them from females. But ladybug males and females appear identical unless you examine their bodies VERY closely!
Generally the most reliable way to determine the gender of a ladybug is to look for its external reproductive structures. Specifically, you are looking for an ovipositor in females and an aedeagus in males. The females use an ovipositor to lay eggs, while the males use the aedeagus to fertilize the eggs with sperm. Unfortunately, these structures are not usually visible outside of the insect, and must be exposed by applying pressure to the abdomen, which is the last of three segments on an insect (the first is the head, the middle is the thorax (where the legs are), and the abdomen is the third section, furthest from the head). Unfortunately, handling the ladybugs and applying pressure to them can injure them. The ovipositor and aedeagus are often very difficult to recognize, even for experts!
I have included some images of a cricket ovipositor and a grasshopper aedeagus. They are difficult to see even when pointed out!
For more information about ladybugs, visit the following web sites:
Know Your Friends: Lady Beetles!
Natural History of Insects: UC Riverside Entomology
Entomology Notes: Michigan Entomological Society
I hope I've been of some help. Keep on exploring!
Sincerely Yours, Justin
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