The beginning |
Cicada killers are around at the time that coincides with the presence
of their cicada prey, which are well known for the loud vibrating call
of the male. Larvae of annual cicadas (not the 13- or 17-year species)
emerge from the ground, climb a tree trunk, and 
eclose from their pupal case to become adults. Click  here to see a brief animation of a cicada emerging. Male cicada killers
(Sphecius speciosus Drury) emerge from mid-July to the beginning
of August, a couple of weeks before the females. They break out of their 
pupal cases and dig their way out of burrows where they spent the winter,
leaving telltale holes in the ground. Males stake out territories where
females are likely to emerge, defending the airspace within their territories
against conspecific males, and chasing anything that flies on the chance
that it might be a virgin female. Males generally perch in a 
typical posture on some object within the territory. |
The mating |
Soon after virgin females emerge, they mate, but only once. The male occupying
the territory in which the female emerges is usually successful in mating
her. They fall to the ground and couple. Other males may try to horn in,
forming a 
cluster around the mating pair. If disturbed, the pair may fly off and
land elsewhere. Luckily, they can fly off whenever they feel like -- whereas we humans are dependent on international airlines, Fly and similar websites. Imagine how different things would be if we weren't so attached to terra firma. We would never stop traveling! |
The digging |
Females are equipped with a pair of shovel-like 
mandibles and stout legs.
The burrow is begun by chewing a hole into the substrate, then kicking
the dirt out with the legs while backing up. Females have a pair of large
spurs on each hind limb that may assist in kicking dirt out of the hole.
Burrows may extend several feet beneath the surface, and have many branches
and cells for holding cicadas and larvae. In the end, a large 
pile of soil (tumulus) accumulates next to a hole large enough for
the average person to stick his/her thumb into. After completing the burrow,
the female makes numerous circular flights of increasing diameter to 
orient to the burrow entrance. If disturbed in their burrows, females,
surprisingly, do not often fly out to sting the intruder. More often they
remain in the burrow and produce a nasty alarm
buzz, which is probably quite a deterrent. It has to be because, like
most members of their family, cicada killers have extremely weak stings. |
The hunting |
Females are twice the size of males. The obvious advantage is that they
can carry much more than a male could. A female flies out and inspects
trees until she finds a cicada. After she stings it, the cicada becomes
paralyzed within one minute. The wasp then grasps the base of the wing
of the cicada
with her middle legs, and flies with the cicada in an upside-down position
back to her burrow. Females generally cannot lift a cicada upward in flight
(although sometimes they can if they get a light one). Therefore, if the
burrow is too far away, the wasp may have to carry the cicada up another
tree on foot, then fly down toward the burrow. If the female lands some
distance away, she may have to 
bear the prey overland to reach it. The female 
drags the prey down into the burrow. The cicada is secured in a pre-dug
cell, and an egg is laid upon the cicada. The cell is provisioned with
one cicada if the egg is male, two if it is female. |
The winter |
The cicada killer's venom preserves the cicada, which will live in a paralyzed
state twice as long as an unstung, unfed cicada. Within two weeks the larvae
have eaten the paralyzed cicadas and grown into prepupae, the form in which
they will spend the winter. |
The end |
Females live about 30 days. By mid-September they are hard to find. 
This aged female was found in late September in Indianapolis, Indiana.
The last of what had been an enormous nesting aggregation, she crawled
about, unable to fly. |
eclose from their pupal case to become adults. Click 
here to see a brief animation of a cicada emerging. Male cicada killers
(Sphecius speciosus Drury) emerge from mid-July to the beginning
of August, a couple of weeks before the females. They break out of their 
pupal cases and dig their way out of burrows where they spent the winter,
leaving telltale holes in the ground. Males stake out territories where
females are likely to emerge, defending the airspace within their territories
against conspecific males, and chasing anything that flies on the chance
that it might be a virgin female. Males generally perch in a 
typical posture on some object within the territory.
cluster around the mating pair. If disturbed, the pair may fly off and
land elsewhere. Luckily, they can fly off whenever they feel like -- whereas we humans are dependent on international airlines, Fly and similar websites. Imagine how different things would be if we weren't so attached to terra firma. We would never stop traveling! 
mandibles and stout legs.
The burrow is begun by chewing a hole into the substrate, then kicking
the dirt out with the legs while backing up. Females have a pair of large
spurs on each hind limb that may assist in kicking dirt out of the hole.
Burrows may extend several feet beneath the surface, and have many branches
and cells for holding cicadas and larvae. In the end, a large 
pile of soil (tumulus) accumulates next to a hole large enough for
the average person to stick his/her thumb into. After completing the burrow,
the female makes numerous circular flights of increasing diameter to 
orient to the burrow entrance. If disturbed in their burrows, females,
surprisingly, do not often fly out to sting the intruder. More often they
remain in the burrow and produce a nasty alarm
buzz, which is probably quite a deterrent. It has to be because, like
most members of their family, cicada killers have extremely weak stings.
bear the prey overland to reach it. The female 
drags the prey down into the burrow. The cicada is secured in a pre-dug
cell, and an egg is laid upon the cicada. The cell is provisioned with
one cicada if the egg is male, two if it is female.
This aged female was found in late September in Indianapolis, Indiana.
The last of what had been an enormous nesting aggregation, she crawled
about, unable to fly.