Information, Even If You Don’t Want It: Integrated Pest Management

One of the issues with which we struggle at the Triffid Ranch is a bit of a logical leap in what carnivorous plants can do. Based on phone calls, emails, letters, and incessant queries at shows and events, the logic starts with the given “Carnivorous plants attract, capture, and digest insect and other animal prey” and veers Immediately into “carnivorous plants will take care of my bug problem.” This leads to calls and queries. “My house abuts a stream, and the stream attracts mosquitoes. I need a pitcher plant to eat all of the mosquitoes.”  “My kids leave the door open all day, and we need a Venus flytrap to eat all of the flies they let in.” “My roommate won’t take out the garbage, so I need a flytrap to eat the flies on the garbage.” Sometimes this goes to extremes: “I saw ants at the end of the driveway, and I want to build a berm around my house and cover it with flytraps to get the ants.” Or my personal favorite and a reason why I refuse to return to one show at which I displayed plants in 2013, “Cool! Got anything that will eat bedbugs?”

To all of these, I try to explain, over and over, that while you can get great satisfaction in watching a Cape sundew digest mosquitoes, and even add Battle Boy sound effects to liven things up, one plant or even a thousand won’t get rid of every insect in your time zone. It’s not even a matter of picking wildly inappropriate plants, such as the people who ask repeatedly about using Venus flytraps to control fleas. (The simple answer: they won’t. Even sticky-trap carnivores such as sundews and butterworts may catch fleas, but they won’t break the life cycle.)  Besides, as entomologist and brilliant bug blogger Gwen Pearson notes, you’ll never bug-proof. your house. We lost the war against bugs, spiders, and other exoskeletal creepies about 400 million years ago, and barring a mass extinction that wipes out every arthropod (up to and including the millions of skin mites that eat dead skin cells on your body), we stand no chance of changing that.

That said, while wiping out pests is a lost cause, it’s possible to keep their depredations down to a dull roar. That’s the basic idea behind the concept of integrated pest management, which attempts to minimize horticultural chemical use by understand that complete annihilation is impossible, but cutting populations down to a dull roar isn’t. 

For example, one of the more pernicious pests in most households this time of the year is a recent invader, having only been documented in large numbers since 2004. Since then, the shelf elf has been found in living rooms and bedrooms across the United States and Canada, never appearing in the same place twice during the holiday season, and resisting all attempts at capture or restraint. Not only will they return each year, but they have a propensity for breeding out of control, and all efforts at spaying and neutering have been complete failures. They also have a distinctive hive mind, reporting back to a central dominant individual known as a sinterklaas, thereby making efforts to collapse the hive structure nearly impossible. Recent reports suggest that they’re able to communicate with the sinterklaas from considerable distances, but whether this is by telepathy, by Extra Low Frequency vibrations through earth and water, or by pheromones or other vaporous output is unknown. What IS known is that they seem to be especially astute at viewing and modifying the behavior of children, merely by watching and waiting, and the intimation of a reward in exchange for those behavioral changes. Also unknown is the reason for initiating the behavior changes, but research suggests a model comparable to that of the pathogen Toxoplasma.

Thankfully, there are ways to deal with this menace using IPM, so let’s fire up the appropriate soundtrack and get going,.

The first and most obvious control, chemical, is problematic for multiple reasons. In fact, that problematic nature is why integrated pest management was founded in the first place, because the overuse of pesticides was becoming a significant issue in both farmlands and in residential areas. As a last resort, chemical repellents and poisons have their place, but be warned that most of the effective options for invasive elves also have negative effects on the human population. Butyric acid in aromatherapy bottles works sporadically as a repellent, but the enterprising and cost-conscious homeowner should consider making a custom mix of 75 percent potassium nitrate, 15 percent sulfur, and 10 percent charcoal, or an equal weight of gasoline and polystyrene foam. When ignited, both have an effect on local elf populations: when mixed up in sufficiently large quantities, the effects may be seen from low Earth orbit.

The second control, mechanical, applies to most traps, grinders, zappers, or pitfalls. Repeated vivisections of shelf elves reveals no vital organs or internal structure particularly susceptible to anything other than overwhelming force, and documented sightings exist of shelf elves recovering and attacking immediately after crushing or flattening that would kill most Earthly life. With this in mind, further research continues with finding all-inclusive mechanical controls that can anticipate and neutralize shelf elves before the sinterklaas can give them new orders. The choice of mechanical control is up to the one applying it: from personal experience, while American, Chinese, and Australian controls are have their advantages, Russian controls are low-maintenance, exceeingly durable in multiple environments, and extremely effective.

This leaves the obvious and logical choice: biological controls. Since shelf elf study really only started a decade ago, many “facts” about their behavior, reproduction, natural history, and evolutionary history are little more than assumptions, and are forcefully disputed. One of the most disputed involves predators in their original environment before coming in contact with humans. Due to their lack of internal structure, which leads some palaeontologists to make comparisons to the extinct Ediacara faunas of the Vendian Era (Crusher, Franklin, & Shaw, 2010), nothing other than highly contentious fragments exist in the fossil record, and genome sequencing has been stymied by a complete lack of sequenceable DNA (Banner, 2011; Richards, 2012; Hoshi, 2012). One thing is certain, though: in multiple tests in captivity, a wide variety of predators actively attract, capture, consume, and digest shelf elves (Logan, West, & Furter, 2015). No widespread field tests on predator selection have been done to date, and the understandable concern is that any effective introduced predator may itself become an invasive species, as demonstrated with the introduction of the cane toad (Bufo marinus) in Australia (Benway, 1959; Duke, 1971).

One very promising avenue of biological control involves the use of exoparasites, which utilize host organisms during stages of their life cycle. Again, the largest concern involves whether the exoparasite stays with one host or utilizes multiple host species. An equally vital concern, based on recent studies, is whether shelf elves will evolve changes in structure or behavior to bypass parasitism, causing the exoparasite to seek out new host species or become extinct. Using cicadas as a model, extreme predation or parasitism may cause shelf elves to spread out infestations over multiple years, in an attempt to keep parasites from depending upon them every holiday season. Alternately, shelf elf emergence may start earlier in the year: reports of shelf elves being spotted as early as July may be examples of this new behavior.

Due to the challenge of the shelf elf life cycle, with large populations accumulating only in the month of December, the secret may be in finding a combination parasite/predator. A predator that subsists through the rest of the year either in hibernation or on the occasional early emergence, only to reproduce during the height of the shelf elf cycle, may be the only effective way to get populations into something approximating control.

In some cases, while biological controls may seem to be the best option, the available biological controls may be organisms that may themselves become pests under the right conditions: for instance, Asian ladybugs becoming pests in vineyards when they feed on ripening grapes and taint the resultant wine. Sometimes the best option is to use several types of control organisms, especially when needing to ensure that one species doesn’t become a threat with increased numbers.

Finally, one remaining option is now available due to advances in technology. A possible alternative to wiping out the shelf elf may involve introducing organisms that outcompete it for available resources, such as food or nesting sites. In many areas, the beneficial Bench Mensch has made inroads into shelf elf habitat, but future control may involve a combination of mechanical and biological controls. A competitor that can remain in hibernation for years or even centuries between shelf elf infestations, with an active resistance to retaliation, and a built-in weakness should it become a pest: the future is here.