Eliminating harborage areas and food sources is half the battle in overcoming this venomous pest.
Possibly no other arachnid causes more panic than the venomous gladiator of the insect world, the scorpion. This nocturnal extermination machine is actually beneficial to humans because it can eliminate disease-carrying roaches and nuisance crickets. However, few people are willing to share their living space with these propitious creatures.
Scorpion biology teaches us that all scorpions remain protected during the daytime, emerging at night to defend their territory and hunt for prey. They ambush insects by grabbing them with chelae (pincers) and thrusting their telson (tail with a stinger at the end) over their back and into the prey. Venom is injected that kills or paralyzes the insect, enabling the scorpion to devour its victim.
Scorpion body fluids fluoresce under an ultraviolet (UV), or black light. This characteristic is very beneficial in learning about this creature. Either wavelength of UV light fluoresces the scorpion. The darker the night (no full moon) and elimination of other outdoor light sources, the increased effectiveness and range of the black light.
I have observed that scorpion territory size is contingent on the amount of harborage and food supply. Little or no harborage sites, with few insects, necessitates large territories for few scorpions because this environment is hostile. Areas with plentiful harborages and ample insects are locations hospitable to the scorpion, allowing small territories for large numbers of these predators.
Scorpion Control
I have learned three key factors in controlling scorpions. Here they are in order of importance:
- Eliminate their harborages.
- Eliminate their food supply.
- Apply pesticides as close to the peak period of scorpion activity as possible.
Eliminating harborage sites serves another purpose. It creates a hostile environment for other arthropods. Cockroaches and crickets can’t survive without harborage. Just by eliminating harborage areas alone, we can reduce populations of the scorpion and its food supply. Then, pesticide applications labeled for scorpions become more effective, not only against this predator, but against its food supply.
The following list reveals harborage locations.
- Dense ground cover provides harborage and also restricts pesticide penetration.
- Shrubs should be pruned to expose the trunk and ground around the plant.
- Remove leaf litter, mulch and other organic debris, including decorative bark chips.
- River rock should be eliminated. Decorative rock less than three-quarter-inch in diameter is permissible.
- Strip palm trees. After pruning the fronds, scorpions readily harbor down in the stubs. These stubs need to be removed.
- Trees with very rough or split bark. If possible, use trees with smooth bark as a substitute.
- Tall grass and weeds. Encourage customers to keep lawns mowed and weeded regularly.
- Holes and cracks in the ground should be filled. As clay soils expand and contract, large harborage areas are created, especially abutting concrete. Sand is a good material for this, because it won’t expand or contract.
- Don’t edge the lawn too deeply. Edgers set too deep can create big harborages.
- Seal under stucco walls. With a black light and a mirror, I have been able to find many scorpions up under these walls. Caution must be taken, however, to ensure that moisture doesn’t become a problem.
- Seal and weatherstrip around doors and thresholds. This is the No. 1 way that scorpions enter a structure. Incidentally, in my many years of black light sweeps, I have learned that attics are typically not scorpion harborage areas.
- Seal any gaps around utility penetrations into the structure.
- Seal hollow block fences. These fences have voluminous harborage areas, and this is where I find the most scorpions.
- Remove wood piles. If firewood is needed, it should be moved far from the house, and preferably stacked up off the ground.
- Eliminate clutter, which provides ample harborages.
- Eliminate insect food sources. Sanitary situations discourage insect populations, thereby, reducing any food supply for the scorpion.
Purchase a black light and search your worst scorpion accounts. You will learn much about this nuisance pest. Use the above ideas to create a hostile environment. The more problem areas corrected, the more effective your scorpion control will become. This translates into protected and happy clients.
Accurate Pest Control Technician Eric Lowe shows the scorpion harborage created in this palm tree, as well as in the river rock surrounding the tree.
John Beebe, an Accurate Pest Control technician, uses a black light on a wood pile to search for signs of scorpion harborage.
Properly pruned shrubs, with the ground and trunks exposed, lessens the chance of a scorpion population.
BY DONALD BOWLES
Donald Bowles is owner of Accurate Pest Control, Mesa, Ariz. He has been in the pest control industry for 37 years.