strategy in which a male will fly from one plant to another, then will walk around and strut. Once he encounters a female, the male will present vibrational signals to the female and if there is no response he will fly to another tree. If the female responds to these vibrations the male will approach the female and climb onto her side to initiate mating. Mechanical basis of the courtship call When performing their courtship call, the thorn bugs use the muscles in their abdomen to generate a continuous call that decreases in frequency as the tone gets longer, and high frequency clicks at periodic times in the call caused by the muscles pulling on the horn of the insect resulting in the clicks. Competition Because of the method of active mate searching in males, there is a significant difference in the mating ability of older males (25–33 days old) and younger males (19–25 days old) due to a loss of the ability to sustain flight and compete physically against other males. Older males are found only walking to search for females and their encounter rate is much lower than males that can fly from tree to tree. Though if a female has the choice between a younger and older male she will almost always pick the older male, the theories predict that this is because of their increased sexual advertisement and that they perform more overall courtships. Sex bias When a female plants her eggs on a branch, her clutch uses up a lot of that site's resources. Due to this, some clutches use up more resources than the host plant can provide, this can result in adults being much smaller than preferred. A female having a smaller body size, though can lay fewer eggs than a larger female, will not impact her overall reproductive fitness and will still be able to produce viable offspring. Males, on the other hand, have to compete with other males to reproduce so being smaller than average will affect his ability to mate and find food. These factors contribute to the altered sex ratio we see in U. crassicornis being a larger number of females in populations than males. Dispersal Once the young have matured to a point where they can leave the congregates, males will leave first averaging about 7 meters from the host plant, whereas females, who leave after the male