Spined Soldier Bug Vol. 9, No. 26
Podisus maculiventris
Order: Hemiptera
Family: Pentatomidae
Not all stink bugs are pests. Spined soldier bugs are predators of caterpillars, as well as many other insects. They can’t run down an adult grasshopper, but they can easily catch caterpillars and other slow-moving insects. Spined soldier bugs can successfully tackle prey that is considerably larger than themselves, especially if the prey insect is molting or in some other vulnerable state. They also feed on plant sap, causing no significant damage, but get most of their nutrition from their insect prey. Both nymphs and adults are predatory. Notice there is a nymph freeloading on the caterpillar that was captured by the adult in the photo.
These are generalist predators that occur in a wide range of settings, ranging from home gardens and landscapes to weedy roadsides to fields of soybeans and other row crops. Sometimes they are numerous enough to contribute significantly to biological control of loopers and other caterpillar pests in agricultural crops.
Spined soldier bugs are named for those two spines they have on either side of their thorax, but some plant-feeding stink bugs have similar spines. Examples of other predatory stink bugs in the Southeast include Florida predatory stink bugs, anchor bugs, and giant strongnosed stink bugs.
Compared to the eggs of other stink bugs, spined soldier bug eggs are distinctive and easy to identify. When first deposited the eggs are white, but as they age, they assume a uniform metallic color, ranging from silver to gold, and each egg is topped with a halo or ring of small spines. Eggs are deposited in small masses of one to three dozen.
One of the more interesting things about spined soldier bugs is what can happen to the eggs after they are deposited. Of course, many hatch into tiny stink bug nymphs after an incubation period of about five to eight days and become adults in another four weeks or so. But spined soldier bug eggs are also parasitized by tiny wasps. Telenomus podisii is one such wasp. These gnat-sized wasps also parasitize the eggs of some plant-feeding stink bugs. Parasitized eggs don’t hatch into stink bug nymphs, they hatch into adult wasps.
Spined soldier bug eggs are also parasitized by Telenomus clavatus, which is more particular about its host, and will only parasitize spined solder bug eggs. Spined solder bug eggs are hard to find out in the environment, and they are only suitable for parasitism for a short time after they are deposited. But the little T. clavatus wasps have a clever means of not only finding the right egg masses, but of being there at the right time. They simply find an adult female spined soldier bug and ride on her back until she lays eggs. Then they hop off and deposit eggs of their own.
This phenomenon of one animal riding on another is known as phorsey (easy to remember because it rhymes with horsey). Some wingless arthropods routinely exhibit phoretic behavior by hitching rides on other more mobile insects as a means of dispersal. For example, pseudoscorpions hitch rides on bees, flies and other insects by grasping them by the leg with their claws, and many non-parasitic mites hitch rides on flying insects.
Blake Layton, Extension Entomology Specialist, Mississippi State University Extension Service.
The information given here is for educational purposes only. Always read and follow current label directions. Specific commercial products are mentioned as examples only and reference to specific products or trade names is made with the understanding that no discrimination is intended to other products that may also be suitable and appropriately labeled.
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