The following is a guest post by Emma DesPland

Last week the CBC contacted me about an “infestation” of caterpillars near a local sports and community centre, citing parents’ concern that these could be dangerous for their children.

I was surprised.

The pine (Thaumetopoea pityocampa) and oak (T. processionea) processionary caterpillars do have a genuine claim to being a public health hazard: the later instars are covered with barbed setae containing an urticating toxin. These setae break off readily on contact and can even become airborne: if they lodge in the skin, they can cause a rash, but if they contact the eyes or throat the allergic response can be more serious.

Both are Mediterranean species that are expanding their range and causing concern in Northern Europe among people without prior experience.  Neither has been reported in North America.

There are several species of hairy caterpillars in Quebec: Eastern tent caterpillars, forest tent caterpillars, gypsy moth and woolly bears among the most common.   None have the allergenic properties of processionary caterpillars.

So what were these caterpillars invading the community centre? Forest tent caterpillars (Malacosoma disstria) and gypsy moth (Lymantria dispar).  Neither has any history of causing allergies or any other health consequences, except for possibly causing abortions in mares who eat large numbers of them.

Gypsy moth caterpillar, one of the species found in the community centre. Photo by Brad Smith, used under terms of a Creative Commons BY-NC 2.0 Licence.

I have handled forest tent caterpillars for years, as have many other researchers, the students in my lab as well as my own children. We have also given hands-on science exhibits, in which countless other children have handled them. Fitzgerald’s classic 1995 book The Tent Caterpillars contains a chapter on “Maintaining Colonies and Suggestions for Classroom Activities”.  No-one to my knowledge has had an allergic reaction.

Does this mean that it is impossible that someone be allergic to the hairs on these caterpillars? Of course not, allergies are very diverse, widespread, complex and poorly understood.  Some people are allergic to laundry detergent, others to strawberries.

Are there any benefits to be gained by children handling caterpillars? First, it’s hard to stop them.  Children are curious and intrigued by the world around them, and caterpillars are ideal experimental subjects: they move and do interesting things, but not too fast.  They can be herded and driven across bridges, housed in jars and passed from one finger to the next, but never entirely controlled as they generally manage to escape somehow.  This kind of non-directed, curiosity-driven play is just the sort that develops scientific thinking. In addition, spending time with nature calms people, children and adults alike, and helps them recover from stress. Finally, conservation ethics – a feeling that the natural word is precious and deserves protection for its own sake – develops in childhood, through non-directed play in nature.  A type of play that is becoming less and less accessible for an increasing number of city-dwelling children.

Instilling fear of the natural world – fear of even something as cute, slightly ridiculous and totally innocuous-looking as a fuzzy caterpillar – cannot be a good way to go,  in a world that increasingly needs calm, unstressed people with conservation ethics.

Cobblestone Tiger Beetle. Photo by Stephen Krotzer, used with permission.

by Mischa Giasson

In 2008, l was asked to participate in a mark-release-recapture survey on the shores of Grand Lake, New Brunswick. My dad and I joined Fredericton entomologist Reggie Webster on a boat to visit three small sites among the rocky beaches surrounding the lake. We were searching for a rare, recently locally discovered beetle that is found nowhere else in Canada: the Cobblestone Tiger Beetle. This experience was the first of many that lead me to the realisation that a career in entomology was an option, fueled by my life-long fascination with insects (and other creepy-crawlies).

The Cobblestone Tiger beetle (Cicindela marginipennis) is an insect in the sub-family Cicindellidae (Coleoptera: Carabidae). This small, pretty beetle is listed as Endangered and placed in Schedule 1 of the Species at Risk Act (SARA), which means that the species has been deemed at risk and that there has been development and implementation of protective and recovery measures.

There is no doubt that Tiger Beetles live up to their namesake as extremely beautiful, but equally deadly predators. These beetles run down their prey by sprinting in short, quick bursts. In fact, they run at such high speeds that they temporarily go blind! One species has been recorded moving at 9 km/hr, which is almost 54 times its body length per second. Their antennae are used to prevent any collisions while sprinting and they have a very short reaction time, but they must make frequent stops to take in their surroundings and make sure they’re on the right track.

Both the adults and larvae are predators, the larvae employing a sit-and-wait approach: they wait in ambush from small vertical burrows in the ground, striking out at lightning speed to catch any prey that passes nearby. Prey consists of other insects as well as spiders, which stand no chance against the huge mandibles of the Tiger Beetle. The Cobblestone Tiger Beetle can be distinguished from other Tiger Beetles by the smooth, continuous cream-coloured border along the outer edges of the elytra and by a bright orange/red abdomen that is visible when the beetle is in flight. Their overall colour is most often a dark chocolatey brown, but some metallic blue and green individuals have been observed in the New Brunswick populations.

Cobblestone Tiger Beetle. Photo by Stephen Krotzer, used with permission.

The Cobblestone Tiger Beetle gets its name from its choice in habitat. The eight sites in New Brunswick where it can be found are all cobblestone beaches. This beetle is also found along major river systems in the United States, from Mississippi to Alabama and from Indiana through to New England. Populations are quite small, few and far between. The Canadian population was discovered in 2003 by Dwayne Sabine and is the only known population to also inhabit lakeshore sites, likely due to the riverine characteristics of Grand Lake. There are three known sites on Grand Lake, while the other five are on the shores of small islands in the Saint John River between Woodstock and Bath. These cobblestone habitats are unique to areas with yearly spring flooding which keeps the vegetation from spreading along the beach, maintaining the flat areas of gravel and sand between the stones which are necessary for the larvae to make their burrows. Not much is known of the Cobblestone Tiger Beetle’s specific life history, but it is assumed to be similar to that of other tiger beetle species. The beetles have a two-year life cycle: eggs are laid individually in the sand, where the larvae will hatch and make burrows. The larvae overwinter in their burrows, somehow surviving the spring floods and emerging as adults in June.

Cobblestone Tiger Beetle. Photo by Stephen Krotzer, used with permission.

Due to their specific habitat requirements, Cobblestone Tiger Beetles are very vulnerable to environmental changes and disturbances. The biggest threat is habitat damage. In New Brunswick, the installation of the Mactaquac dam destroyed many suitable habitats both upstream and downstream. The small beetle populations are also quite vulnerable to over-collection by scientists and insect enthusiasts. The current concerns involve the use of off-road vehicles, as this leads to the alteration of suitable habitat and often directly leads to the death of many larvae present on the beaches. This threat applies mostly to the shores of Grand Lake, where there is increasing development and use of the beaches. The protective measures implemented include developing a stewardship plan, educating the local communities and encouraging their support and participation in the conservation of this special beetle. Decreasing human disturbance is the most important factor in ensuring the survival in our province of the already very small populations of the Cobblestone Tiger Beetle.

References

https://www.registrelep-sararegistry.gc.ca/virtual_sara/files/plans/rs_cobblestone_tiger_beetle_e_final.pdf

http://www.sararegistry.gc.ca/species/speciesDetails_e.cfm?sid=1031

Zurek, D. B., & Gilbert, C. (2014). Static antennae act as locomotory guides that compensate for visual motion blur in a diurnal, keen-eyed predator. Proceedings of the Royal Society of London B: Biological Sciences. 281(1779): 20133072.

Fig. 1. Skillet Clubtail dragonfly adult; notice the distinctive “skillet” on tail. Photo Credit: David Marvin. Used under a Creative Commons BY-NC-ND 2.0 licence. 

By Melody McLean

What if I told you that as a New Brunswicker, there are animals in danger of going extinct in your own backyard? Saying that, you’re probably thinking of a cute, fuzzy, little animal with big, sad eyes being displaced from its home.  Well, that’s not what I’m referring to. I’m talking about the Skillet Clubtail Dragonfly (Gomphus ventricosus), belonging to the insect order Odonata. This dragonfly currently has no status under the Species at Risk Act (SARA), but was the only arthropod classified in the 2010 COSEWIC (Committee On the Status of Endangered Wildlife In Canada) report as being endangered. Simply put, if we don’t do something, they could become extirpated[i] from Canada or even extinct.  When we hear about insects in our province, we often associate them with being pests, like spruce budworm, aphids, or disease spreading agents like mosquitos. But what we don’t often realize is that not all animals at risk of extinction are cute and fluffy. I’m here to shed some light on an underdog of the animal world, who could use a little help from us.

Insects-we can’t live with them; we can’t live without them.

  What you may not know is just how thankful we (myself included) should be for insects. They clean up after us, help to provide us with rich soil for our gardens, indirectly provide us with fresh food thanks to their pollination efforts; some, like dragonflies, even keep other insects from bugging us¾like our own personal pest control.

The Skillet Clubtail dragonfly is strikingly beautiful, with green, yellow, black and brown markings running along its thorax and abdomen; transparent wings; big dark green eyes; and a distinctive circular flare, resembling a skillet, at the tip of its tail (Fig. 1).

The Biology behind the Insect

The Skillet Clubtail’s  life cycle and biology is very similar to that of other dragonflies. The female lays her eggs by dipping her abdomen into the water to release them. Growing and developing, the shallowly burrowed nymphs take at least 2 years (possibly more) to develop before emerging. If conditions are right, usually in the latter 2 weeks of June, the dragonfly nymphs will find a “settle point” where the water is calm; they’ll climb up onto nearby vegetation to emerge synchronously[ii] as adults. Although the nymphs spend the majority of their lives in the water, the adults spend most of their lives around brush, fields, bogs and in the nearby canopy to forage for other insects.

Home of the Skillet Clubtail

 This stunning dragonfly is restricted to North America. In Canada, it is currently found only in a few select places along the Saint John River, specifically in the Fredericton region of New Brunswick.  Over 60 years ago, the Skillet Clubtail could be found in a few other locations in Canada, including Ontario, Nova Scotia and Quebec. But since there have been no recent sightings there, New Brunswick may be the last known Canadian location. The United States is running into similar problems with this insect too.  It was once found in Pennsylvania and New York but is likely extirpated from both of those areas. The U.S. range extends along the Red River Basin, running from Mississippi, Tennessee, Minnesota, to the northeastern limit in New Hampshire and Maine.

Habitat: Very Important

 This insect is in need of a specific and rare habitat type: a clean, large, slowly running body of water, with fine sediments and substrate, such as clay, silt, or sand, with nearby forested areas for cover. Many of these habitats are only found when the waters run through an area of rich soils, at a low gradient[iii].

99 Problems

 This is where problems arise, as the Skillet Clubtail’s habitat is often prime agricultural land, where possible pollution in the river can occur, and nutrient run-off becomes a concern. Keep in mind, agriculture runoff from fertilizers, pesticides, and herbicides, are not the only culprits behind river pollution. Accidental and illegal dumping, and everyday toxins such as oil, grease, road salt, contaminants from vehicle exhaust, lawn and garden chemicals, and other harmful substances, all have a tendency to wash off lawns and roadways down to rivers and waterways. This is especially relevant here in Fredericton as the Saint John River is considered to have “marginal” water quality. As this city is literally built on a hill, all that urban runoff must go somewhere.

Although pollution is likely a major factor to this species decline, there is also the problem of sea level rise. As the sea level rises, saline water travels further up stream into the rivers, changing the chemistry of the water. This is likely to impact freshwater aquatic wildlife, as most aquatic species cannot adapt to such rapid change in their habitat. Because the farthest population is just 5 km away from the saline water limit, this is a real possibility. It’s been discussed that the Skillet Clubtail populations further upstream on the Canaan River and Salmon River could be safe from saline influence. However it has also been speculated that the main Saint John River population acts as a metapopulation, supporting the other two populations by providing immigrating individuals to them.

It’s good to note that this species needs the surrounding forest, included in its habitat. Even though mass cuttings of forests in these locations are unlikely to happen right now, we should still keep in mind deforestation has the potential to affect not only the Skillet Clubtail dragonfly, but many other species as well.

Why should you care?

Maybe you’ve gotten through this whole article and decided that you don’t care about the Skillet Clubtail Dragonfly. That’s fine. But think of it this way: the things that are likely affecting this particular dragonfly should be of broader concern to us. Chemical runoff, deforestation, general pollution and rise in sea level don’t just affect this one dragonfly species; they affect everything living that comes in contact with them, including us. The best way to finding a solution to a problem is by better understanding it through increasing our knowledge.  Don’t be ignorant of the events happening in your community and environment. Take notice and do something about any detrimental events, like pollution, in your area. Dragonflies and other aquatic insects are great indicators of stream and river health, and not much is known about this particular dragonfly. So if you spot the Skillet Clubtail dragonfly, send your recordings and findings to your local Entomological Society. Many little changes have the potential to lead to one big change.

[i]  Extirpated: a species that was once found in an area but is no longer found there. This is different from extinction because you can still find that particular species of animal in other areas of the country or world, therefore not totally extinct just extirpated.

[ii] They all emerge at once over a short period of time.

[iii] Low gradient streams are associated with flattened stream beds, with slow moving water and gradual, less steep slopes of surrounding valley