I just read a curious book by Jonathan Balcombe + a couple photos I took of their curious visitations, below.
Some juicy tidbits:
• For each human on Earth, there are 17 million flies.
• A particular fly, the mosquito, has killed half of humanity (over 50 billion people).
• They are super fly:
– Their wings can beat at an audible 1 kHz, well in excess of neuronal firing rates.
– They can adjust the wing song to woo mates, and the volume to account for distance.
– They have a gearbox and clutch at the base of each wing, like in a car, to adjust wingbeat height, and a runt-wing that acts as an adjustable anti-phase gyroscope
– They can hover, fly backwards and land upside down
– They have the most powerful flight muscles of any animal (per gm)
– They flew 150 million years before any other animal
– First animal in space (fruit flies in flight, 1947)
• They taste with their feet (and you know they have six of them!)
• Fly eyes have hundreds of hexagonal facet sensors, with integrated vision at the brain (like our field of view from two eyes) with dedicated neuronal circuits for facet prioritization, object tracking, optical flow across facets, and motion parallax for foreground/background distinction. Three independent sensors on the top of the head calibrate overall light intensity, allowing rapid detection of an incoming slap (and engaging evasive flight within 0.1 seconds). With eyes fixed to their head, they saccade their bodies in flight the way we do with our eyes, providing a series of image stabilized moments in motion.
• Flies are the primary pollinators in certain artic and alpine environments, and they may have been the first pollinators 97 million years ago when flowering plant diversity first bloomed.
-We depend on them in our food webs as well, a bumper crop for many other animals. The total mass of insects on Earth is falling 2.5%/year, a rate that is 8x other animals.
• The fruit fly is the most studied animal on Earth
– They have 135K neurons, with dopamine and serotonin, long-term memory and sleep, and can probably feel pain
– Largest contributor to the understanding of genetics, with rapid generation cycles.
– Some GMO variant names: “Ken and Barbie” lack external genitalia. “Cheap Date” is especially susceptible to alcohol. The short-lived “Tin Man” lacks a heart.
– To study evolution in action, one lineage of fruit fly has been kept in constant darkness since 1954. This lineage has lived and reproduced in the dark for over 1,500 generations. Differentiation of reproductive fitness has already occurred.
• Getting their freak on:
– Lovebugs copulate for a continuous 56 hours, flying in unison up to 1,500 ft.
– Sex-deprived flies turn to alcohol
– One male fly has a penis as long as his body
– A small fly holds the record for the longest sperm of any animal of any size — over 6cm long! Not a typo.
– Females have co-evolved matching receptacles, even sporting sperm sorting pouches for selecting from multiple donors.
• The baby maggots are pretty amazing too:
– An example: the scuttle flies drop a single egg on the thorax of their target ant. The maggot wiggles into the head of the ant, carefully munching on the big mandible muscles, but avoiding the brain for two weeks. Then it releases an enzyme that dissolves the membrane that holds the ant’s head to the body. The head falls off and provides a protective shell for the growing larva.
– Maggots are carrion and dung recyclers. In places where dogs and vultures are scarce, they consume most of a carcass. Without flies, we would be awash in organic waste. Billions are grown for composting and industrial protein production.
– Flies can smell a dead body from 40 miles away, and they arrive with such predictable rapidity, that they are used in forensics to date the time of death to one hour of accuracy. The colonizing larvae can even squeeze through the gaps in closed zipper teeth or suitcases holding murder victims.
– Tsetse fly larva are ¾ the length of the mother at birth
• Almost all of us eat insects every day. 25% of humanity eats insects intentionally.
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