Although opinions vary as to how effective mantises are at pest control, they are actually quite interesting creatures to raise and study, and are widely used in high school biology classes. The high demand for mantis egg cases, which can hold 50 to 200 eggs, has led to increased interest in collecting mantis egg cases, which garden supply companies are eager to purchase from dependable suppliers. Where we live in the mid-Atlantic region, there are healthy populations of the Chinese praying mantis, which can a make few hours’ time searching in the right places well worth the muddy boots and occasional scratches that accompany most walks in mantis country. [Mantis country is also tick country. –Ed.]
The Collector’s Experience
In our area, the mantises lay their egg cases a few weeks after the autumn equinox, making mid-Fall prime time for mantis egg hunting. Their preferred habitat is scrub vegetation with trees no more than about 10 feet high. A field in which vegetation is knee- to chest-high, with thickets of thorn bushes, dotted with occasional small trees, is a promising place for gathering egg cases. Mantises avoid woods, areas under cultivation, and any place where there is frequent human activity, although they can occur fairly close to busy roads and construction areas. In fact, we’ve found that areas that have been cleared for construction, and then left idle long enough for second-growth vegetation to take hold, or fields next to new developments that are awaiting further development, are prime areas for egg gathering (ironically, the recent slowdown in the housing industry has probably helped “preserve” — for now — a considerable area of mantis habitat). Of course, you should always get the landowner’s permission before searching for egg cases on private property.
To protect their egg cases against predators, mantises like to place them where they are hard to see and/or difficult to access. Some will strategically place their egg cases behind dead leaves that have not yet fallen, and will even work a piece of leaf into the construction of the egg case as camouflage. Other mantises will lay their egg cases at the base of stalks of goldenrod, concealing them both with the grass itself, and by proximity to the ground. When looking for mantis eggs, it’s always a good idea to examine carefully the ground around your feet as you move through a field.
Other mantises like to lay their eggs higher up in bushes or trees. You will find a number of egg cases on branches, often at about eye level as you walk through the fields. Bushes or trees with thorns are particularly popular with mantises — so dress accordingly. Cover as much as your skin as possible, and wear long underwear if it’s not too warm. We always wear work gloves, and clothes that can take a beating. Denim works well when it’s warmer, and when it’s colder, a rugged Carhartt, [Dickies], or Berne coat is an excellent choice for mantis country.
Mantises do a good job of attaching their egg cases firmly to whatever branch or bush they’re attaching them to, so a small clipper or even some heavy-duty scissors are a big help. Ideally, something small and light, with sharp blades, is best for reaching into hard-to-get places.
A healthy mantis population will deposit dozens, even hundreds of egg cases, in a particular field. Generally, you’ll find them in bunches of three or more close together. When you gather egg cases from a field, always leave some behind, to maintain the population for next year. If you see only single cases scattered through a field, someone else has probably been gathering there so it’s a good idea to move on.
Whether they are used for organic pest-control or educational purposes, mantises and their egg cases are valuable resources. Responsible harvesting maintains a supply of mantis egg cases, which are sold by numerous gardening and educational supply companies, for this purpose. Please remember, however, that excessive harvesting of this like any resource, can have a negative impact upon it. Gather responsibly!
About the Author: Etel Wheeler is an independent praying mantis egg case collector living and working in and around Harper’s Ferry, WV. Wheeler is one of our responsible collectors. Excepting the garment photo, article images courtesy of Etel Wheeler.