Omus californicus- California Night-stalking Tiger Beetle


 Form and Function

    Throughout time and evolution there is a lot of ways Omus californicus or the California Night-stalking Tiger Beetle adapted its form and function to best suit the environment. To begin, they are small creatures overall averaging from 15 to 21 millimeters long (Wirth et al. 2005). This is fairly large for an insect, and there are few bugs that are larger within the same habitat so the Tiger Beetle fears bigger predators.  Because they are large beetles they have been known to be one of the fastest land dwelling arthropods on the planet (Kamoun and Hogenhut 1996). This speed helps them to capture prey increasing food supplies and survival; this speed also helps tiger beetles to evade predators.   

    Omus californicus also has many other ways or mechanisms that help it survive and thrive in the habitat, including body color and size, fleeing response to sound, chemical defenses, group mentality, and sometimes flight (Schmidt 2013). Flight, though is not found in the genus Omus of Beetles is found in all other genera (Wirth at el. 2005). All of these mechanisms have evolved through time, in response to certain predators. The color of their body plays a huge roll in the survival of the California Night-stalking Tiger Beetle. Since all of their active life is spent at night on the ground in leaf litter, being the color black or extremely dark brown helps to blend into the background (Wirth at el. 2005).  Being relatively small aids in the ability to hide in small places under dead trees and leaf litter. Another thing that helps Tiger Beetles survive in the environment is their acute sense of hearing and the ability to flee quickly once something is heard. This also helps them avoid predators by not letting them sneak up on them

   Omus californicus Like a lot of smaller bugs, the California Night-stalking Tiger Beetle has developed a chemical defense, which releases toxins from a special pygidial gland. There are three main chemicals that were found to be used by Tiger Beetles: they are mandelonitile, hydrogen cyanide, and benzaldehyde. The main chemical found throughout the tiger beetles is the benzaldehyde (Blum at el. 1981).  Benzaldehyde is an almond smelling scented aldehyde that is sprayed out into the air to block the chemoreceptors found in the antennas of other predatorily invertebrates (Kelley and Schilling 1998). By blocking the chemoreceptors, it makes it hard for the predator to locate the Tiger Beetle. The use of hydrogen cyanide is used to help defend it from vertebrae predators because it will make them sick if they eat the beetle when the chemical is released. To survive in their environment, it helps them to have a group mentality and stay in the group. This helps when there are predators near by because they will all be able to let off their chemical defenses. When they all release these chemicals, it will be more noticeable for predators in the area and make it less likely for them to find them with the chemoreceptors or have the want to eat them. 
    As young, they even have some functions that help them attain food. When they eat, they simply lay on the edge of the parent’s turrets which attract prey to the entrance so the larva can eat (Schmidt 2013).  The larva catches the bugs like flies and spiders at the entrance of the cave with their mouth. They have hooks on their abdomen that keep them hooked in the mouth of the cave. This hook allows them stay in the cave so they cannot be dragged out and consumed themselves (Schmidt 2013).  These are just a few examples as to how the extremely fascinating California Night-stalking Tiger Beetle evades predators and attacks prey; an organism that has all these great functions to help it survive in the wild.  




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