What’s This Bug? The Lord Howe Island Stick Insect.

Lord Howe Island

This is the Lord Howe Island Stick Insect (Dryococelus australis), or LHISI, also known as Land Lobster, Walking Sausage, Tree Lobster and Lord Howe Island Phasmid (phasmids are insects that eat leaves and resemble sticks or leaves). It is considered to be the rarest insect in the world and is native to a small island off the coast of Australia . This is a big (up to 8 “ in length) and sturdy oblong-shaped insect with no wings. Females are considerably bigger than males and lay their eggs while hanging upside down from trees. Unlike most insects, the LHISI form mating pairs (this video shows all life stages and mating behavior). But these qualities and behaviors are not the most unusual things about them – that would be their whole back story.

The story of these insects would make an excellent movie – it has exotic locales, mad scientists, fortune hunters, explorers, bad guys and heroes and, in the end, the underdog wins. It’s also a master class in geographically isolated habitats and evolution therein and, inevitably,  the careless destruction of such environments. For these insects, though, it’s ultimately a story of triumph and rebirth that shows what can be done when caring and motivated people work to repair the damage done by their uncaring and unmotivated predecessors.

The story really begins seven million years ago when Lord Howe Island was created by a volcanic eruption. Then it apparently sat there creating its own unique ecosystem until, in 1788, a British ship carrying convicts between penal colonies in modern-day Sydney and Tasmania stumbled across the island (it bears noting that they were clearly lost). Despite careful study, no evidence has been found that aboriginal or native Pacific Islanders had ever been there before these lost Brits, so the environment was pristine. 

In the years after its discovery by the British, it became a stopping point for whaling ships. The first permanent colony was formed in 1834, but the population was down to 11 people by 1849. When the Australian Gold Rush struck in 1851 the island again had a population surge as ships carrying would-be miners would put in port there. By the 1860’s, the rush was over and the only ones who were interested in this far, far off place were scientists. Charles Darwin had published his seminal study of evolution, On the Origin of Species, in 1859 and it sparked a rush of scientists seeking their own discoveries. 

Ships carrying gold miners, 1850s

All this human activity created many ecological disasters on the island and the story of the LHISI perfectly illustrates the arch of destruction. This insect was first described by Xavier Montrouzier in 1855 (he was a few years ahead of the Darwin cult). At that time, the insects were all over the island and commonly used as fishing bait. And then came the rats. Unwanted passengers on ships all over the 

world throughout time, they have caused (and are continuing to) cause environmental devastation wherever they are. On Lord Howe Island , they

began being a presence in the late 1800s, but the real trouble started in 1918 when the SS Makambo went aground off the coast. Rats left that nearly-sinking ship and proceeded to enjoy the buffet of delicacies that Lord Howe had to offer. They wiped out many species of birds and fauna and raided the islander’s crops. And, of course, they gorged themselves on the delicious Walking Sausages. So much so that they were extinct on Lord Howe by 1920.

Ball's Pyramid with Lord Howe Island in the distance

In 2001, even though they’d been on the extinct list for 81 years, a group of Australian researchers decided to check out a nearby rock outcropping off Lord Howe’s coast called Ball’s Pyramid.  It’s the remnants of a volcano, known as a sea stack, sea spire or volcanic stack, and it’s the tallest in the world at over 1800 feet.  And, as described in this video, it looks like the lair of a super-villain. Over the years there had been a handful of climbers to the pyramid who’d found dead insects, so the scientists decided to venture out there and check it out to see there were any live LHISI. 

But they were limited to those areas that required no specialized climbing skills or gear, which greatly limited the search area but still encompassed most of its vegetation. They scrambled around in the day and found frass and eggs, but no adults. Thanks to the original scientists who’d carefully studied the LHISI on its home island, these modern insect hunters knew it was nocturnal, so they returned at night. Moving around carefully with only flashlights to light their way, they discovered a small colony of 24 adults feeding on and living under a single bush (Melaleuca howeana - found only on the pyramid and Lord Howe). How these insects made it across 14 miles of tempestuous ocean is still a mystery.

At Melbourne Zoo

The scientists chose two breeding pairs to bring back to Australia and left the others undisturbed. One of the females became ill, but the incredible staff at Melbourne Zoo were able to nurse her back to health. As of 2019, 14,000 individuals have been bred from these two pairs (learn more here). Meanwhile, steps have been taken to protect the population on inhospitable Ball’s Pyramid (more details here), which is part of the Lord Howe Island Permanent Park Preserve. These islands, and the sea around them, have also been declared a UNESCIO World Heritage Site. In the grand scheme of things, the LHISI is already a win for conservationists but the ultimate goal is to return them to their true home on the island. Australia has spent many years and millions of dollars to eradicate the rats and once it’s determined that they are truly gone, the insects will be reintroduced. That will be a truly triumphant day for these rare insects and the people who care for them.

Take Care.

Submitted by Pam

The World of Biorational Controls

It wasn’t that many years ago that organic and natural pesticides were virtually non-existent in the retail sphere, so home gardeners, hobby farmers and the like had to make difficult decisions about the products they used. Thankfully, that’s changed greatly and nowadays we have a world of biorational controls to choose from.

There’s no hard and fast definition of biorational controls; the term covers products that have a reduced risk to living things and have little to no impact on the environment. This characterization is especially important when discussing pest control, fungicides and herbicides – all of which have an over-representation of toxic products on the market. Biopesticides (biological pesticides) and biofungicides (biological fungicides), certain minerals, botanical extracts, herbicides and soaps all fall within the biorational parameters. 

Biopesticides/Biofungicides 

Beauvaria bassiana at work

This is arguably the category that’s seen the most innovation in the last 10 years or so. There are many types of biopesticides these days, including:

• Insecticides that use entomopathogenic fungi to kill specific groups of insects, like Beauvaria bassiana which infects a wide range of insects with deadly white muscardine disease and Isaria fumosorosea Apopka Strain 97 that kills mites and soft-bodied insects.

• Insecticides that use targeted strains of bacteria to kill specific insects, like Bacillus thuringiensis israelensis (Bti) that kills mosquito larvae, and Bacillus thuringiensis kurstaki (Btk), which kills Lepidoptera caterpillars.

• Insecticides that come from plant-derived oils and their extracts like Neem Oil and

Pyrethrins. Neem comes from the Neem tree, a native to the Indian subcontinent; it will kill soft-bodied insects and is also useful as a deterrent or repellent. Pyrethrins come from the Chrysanthemum cinerarifolium, a daisy, and can be used to control both soft-bodied and hard-shelled insects.

Biofungicides also use a variety of beneficial microorganisms to control plant pathogens like powdery mildew and botrytis. They work in multiple ways, but generally speaking they overpower the pathogens and out-compete them for resources. The ingredients in some common biofungicides include:

Bacillus subtilis

• Bacillus amyloliquefaciens strain D747, a naturally occurring soil bacteria

• Bacillus subtilis – a bacteria found in the soil and the gastrointestinal tract of certain animals

• Trichoderma – This is a group of soil-dwelling fungi of which certain strains have been developed for maximum efficacy in the plant world. 

• Inorganic compounds like potassium bicarbonate, the active ingredient in Milstop 

• Botanical oils like the Thyme Oil in Thymox Control Organic.

These are deeply researched and complex products that are, nevertheless, easy to use and readily available to any size grower. I strongly encourage you to dig deeper into these categories; there are many products than I have pointed out and there is much more information on each product page. 

Biopesticides and biofungicides are excellent choices for IPM program and because they often only affect targeted pests, using them reduces the effects to non-target organisms. These products also cut down the danger of residual pollution and eliminate the problem of pesticide/fungicide resistance. They are also cost-effective overall as they reduce the need, and thus the cost, of conventional products.

Minerals

Rice Terraces in Southern China

Mineral-based biorational controls are often products that have been around for a long time but are getting new respect as the interest in safe and natural solutions grow. For example, the use of kaolin clay for pest control dates back over 2,000 years. It works as a crop protectant and will also repel pests, cause irritation and confusion, and create an obstacle for feeding and egg-laying. The popularity of the kaolin clay product we carry, Surround WP, shows that modern consumers still see the value in this biorational mineral. Diatomaceous Earth (DE) has been used in China for 4,000 years. DE comes from the fossilized shells of microorganisms known as diatoms that has been crushed into a fine dust. It has innumerable microscopic sharp edges that cling to insects as they pass through it and mortally wound them by cutting up their exoskeletons. It will also absorb the waxy cuticle around the insect, which causes it to dehydrate and die in as little as 48 hours.

Botanical Extracts

Talk about a product line that has exploded in the last few decades! Using botanical oils for pest control is another case of an ancient-but-still-excellent method. Mineral biorationals  may have changed very little over millennia,  but oils have enjoyed a renaissance as newer, more target-specific and user-friendly formulas have been developed. Botanicals can now be found in pesticides, fungicides, bactericides and repellents. For more information on some of the most commonly used botanical extracts, check out my blog on the subject here. Happily, the use of botanicals is becoming main-stream; they’re easy on the environment in general and their use falls well within the principles of IPM.

        Herbicides

We have come a long way from spraying highly-toxic herbicides like DDT all over everything. Nowadays most people understand the need to keep weed control products, not just weeds, in check.  Biorational herbicides use a wide variety of ingredients to great effect. We carry herbicides that use corn gluten meal, botanical oils, iron, barrier controls, d-limonene (citrus oil), ammonium nonanoate (BioSafe Weed & Grass Killer) and citric acid. Biorational herbicides will not produce the quick knockdown of weeds that the toxic sprays can, but they are still highly effective for the patient and conscientious consumer.

           Soaps

Biorational insecticidal soaps are another product line that reflect the modernization and upgrade of an old school DIY form of pest control. Insecticidal soaps these days are potassium salts of fatty acids and are used to control soft-bodied insects and some path pathogens. One of our customer-favorite soaps is M-Pede, which, in addition to its insecticidal properties, is labeled as a curative control for powdery mildew.

As far as our pest control products go here at ARBICO, we have very few that cannot be classified as  biorational (traps come to mind). There are still some hard-to-kill pests that we struggle to find biorational controls for, but we are committed to finding as many as we possibly can and presenting them to you as soon as we do.

Submitted by Pam