Cicada Killer - Sphecius speciosus


Sphecius speciosus have been found in every state east of the Great Divide, excluding Vermont and Michigan. Populations in the Western United States are shown to be smaller in size than the Eastern portion.  A 2010 study by Joseph Coelho et al, showed that Sphecius speciosus are frequently found at low elevations and were not found in high elevation areas such as the Appalachian and Rocky Mountain ranges. In the study they reported one possible explanation to avoiding high populations was due to lack cicadas to eat (Coelho et al., 2011).  Cicada killers can also be found in other parts of the world, including portions of Mexico and Canada (Holliday and Coehlo, 2006).

Eastern cicada killer females build underground nests by digging holes in the dry soil with little vegetation in the area.  Vegetation makes it more difficult to dig the nest and difficult for the female to enter and exit quickly (Coehlo et al., 2011).  Digging begins after mating and continues throughout the summer season.  While digging their mouth is used to break up the soil, which is next pushed under their body and propelled out of the hole by the hind legs.  After the hole has become too deep for this style to be effective, the female will turn around and use her forelimbs to carry or push the soil with her head.  The first section of a nest is a depth of approximately six to ten inches deep (Dambach and Good, 1940).  Once a chamber is dug, the female will place a cicada on the floor and lay an egg on top of it.  The chamber is then sealed off with dirt and another chamber is formed in front of it with the entrance facing the sun (Dambach and Good, 1940).  Soil type does not matter; however, tilled dry land is often used by Sphecius speciosus because of the speed and ease for digging.  Nests are located in the close proximity to trees that cicadas live in (Hastings et al., 2008).  Cicada killers are considered part of the subgroup of solitary wasps (National Geographic, 2013).  Wasps that make up the solitary group do not form colonies; however some scientists are looking into different forms of communication which may lead to females sharing portions of their nest for smaller periods of time (Coelho, 1998).

Coehlo et al. links Sphecius speciosus' population success to its ability to adapt to human development.  The 2011 study shows reports that nearly all of the organisms found were in some form of a humanly developed area. Most popular areas included peoples' yards and gardens (Coehlo et al., 2011).  Another study by Coehlo, on sexual size and flight behavior in cicada killers; shows evidence that being one of the larger Sphecius speciosus has perks.  This study showed that larger cicada killers were less likely to be forced out of their nests by an even larger female.   Along those same lines, larger cicada killers were able to displace smaller Sphecius speciosus from their homes in times of need (Coehlo, 1997).

One difference between wasp and bee homes is how they are made. Wasps build their nests either with scavenged materials or into existing structures such as the ground using their mouth pieces. Bees create their hives by secreting a substance from their bodies (National Geographic, 2013). Cicada killers do not hibernate to other locations. If the weather begins to get too cold for them they will enter a dormant state until conditions become warm again (Biokids, 2013).