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Giant Mesquite Bug (Thasus spp.)

Detailing the identifying qualities of the Giant Mesquite Bug, including physical features and territorial reach.

 Updated: 8/1/2017; Authored By Staff Writer; Content ¬©

  Giant Mesquite Bug  
Picture of Giant-Mesquite-Bug

Giant Mesquite Bugs are at home in the Southwest, where their favorite plant grows in the Sonoran desert chapparal.

The Giant Mesquite Bug is very large and conspicuous. This gives it an advantage over possible insect predators, but it also makes it easier for birds and lizards to find and eat them. They are usually found hanging around on Mesquite trees, whose wood is often used by people to smoke meats or barbecue. This native plant is a food source for the insect.

Young, larval Giant Mesquite Bugs from the species neocalifornicus differ greatly in their appearance compared to the more mature form. This species is found mostly in the U.S.. They are usually found in large groups, clustered on a mesquite. They feed on the juices pulled out of its softer plant parts like new leaves, seed pods and young stems. Their coloration is quite bold. They are bright red with many vivid white horizontal lines along their backs. Along the 'spine' is a series of white dots with a few black rings in between them. Their legs have red and black bands. Females have flattened discs near the tips of their antennae. They emit a chemical that smells and is meant to deter predators from eating them.

Adults look darker, longer and have a triangular block of yellowish white lines crossing over their elytra. They may look dark brown or olive green with bright red bands on their black legs. Their sides are also red. They, too, can emit a chemical deterrent that has a noxious odor, but the make-up of it changes once they mature. It is thought that the chemical secretion morphs in order to be more beneficial against the different predators the bug encounters at particular life stages.

Picture of the Giant Mesquite Bug
Picture of the Giant Mesquite Bug

Giant Mesquite Bug Information

Category: True Bug
Common Name: Giant Mesquite Bug
Scientific Name: Thasus spp.

Taxonomy Hierarchy

 Arrow graphic Kingdom: Animalia
  Arrow graphic Phylum: Arthropoda
   Arrow graphic Class: Insecta
    Arrow graphic Order: Hemiptera
     Arrow graphic Family: Coreidae
      Arrow graphic Genus: Thasus
       Arrow graphic Species: spp.

Size, Identifying Tags and Territorial Reach

Size (Adult, Length): Size (Adult, Length): 15 mm to 40 mm (0.585 inches to 1.56 inches)
Identifying Colors: brown, white, black, orange, red, green
Additional Descriptors: flying, large, lines, long

North American Territorial Reach (Though Not Limited To): Arizona; New Mexico; Mexico

A Note About Territorial Reach: Keep in mind that an insect's reach is not limited by lines drawn on a map and therefore species may appear in areas, regions and/or states beyond those listed above. Insects are driven by environmental factors, food supplies and mating patterns and do not nescessarily work within hard-and-fast territorial lines like we humans do.

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