About a 180 species of insects are vulnerable or endangered due to the spread of invasive species. Invasive species are organisms that have established populations in an area outside of their traditional range which cause harm in the new range. Invasive species can negatively affect local biodiversity and ecosystem health, by changing the composition, structure, and function of natural ecosystems through resource competition or predation. Invasive species often outcompete native populations through exploitation of resources and a lack of established natural enemies. Additionally, plant hosts or animal prey lack adaptations to tolerate the presence of invasive enemies. The impact of invasive species on crop loss and mitigation measures, is estimated to be more than $30 billion in the United States every year. Insects can invade new places in a variety of ways. People can contribute unwittingly to the spread of invasive species through something as simple as the movement of firewood to a new location. Invasive species can be introduced by the distribution of ornamental trees and flowers among nurseries and gardens, and the global food trade has facilitated the movement of over a thousands species of arthropod pests that are a threat to agriculture. In most countries, incoming shipments of live plants or food are checked for potential invasive pests, but there are practical limitations to how much inventory can be inspected, and sometimes there are no outward signs of the invasive insect. Range expansion in the establishment of insect pests in all regions where the climate is suitable, seems to be a likely eventual outcome of increased global trade. Ants are a good example of an insect group that has invaded almost every continent on Earth. More than a 150 ants species have hitchhiked with humans to new habitats across the world. Invasive yellow crazy ants are a major threat to the well-known red crabs of Christmas Island. The mass migration of red crabs across the island is a phenomenon enjoyed by tourists and locals like. The yellow crazy ants were introduced to Christmas Island by boat, from a shipment of produce or construction materials sometime between 1915 and 1930. The ants attack the crabs with formic acid which blinds and kills them. The ants then consume the crabs from the inside out. The crabs have no defense against the ants and their populations have been severely impacted by these invasive insects. In the United States and Canada, invasive fire ants have caused considerable damage to agriculture and urban landscapes. The hardened mounds formed by their colonies reduce available pastureland for grazing and can even damage field equipment. Fire ants also feed on seeds of field crops, such as corn or wheat, before they have a chance to germinate. In addition, the aggressive nature of the ants can make it difficult for workers to hand-pick crops and can even make them a nuisance to humans and animals. Fire ants have also impacted native fauna, including populations of native ants and other arthropods. While fire ants have caused ecosystem damage and are a nuisance to people through their painful things, other insects are more important in terms of economic damage. The spotted lanternfly despite its striking appearance, has the potential to become one of the most devastating invasive pests in North America. It has an incredibly wide host range of over 70 plant species that make it a threat to vineyards, fruit orchards, and the forestry industry. The spotted lanternfly was first detected in Pennsylvania in 2014, likely after stowing away in commercial products or packaging. It is now established in the region and substantial populations result in large-scale defoliation of crop plants and rain like mists of honeydew in the air beneath the host plants. Honeydew is the sugary secretion produced by hemipterans that feed on plant sap, which can promote mould growth on and around host plants. spotted lanternflies have a high fecundity that contributes to their pest status. Females lay almost 200 egg masses in their lifetime, each of which can contain more than 30 individual eggs. The inconspicuous egg masses are laid on host plants, but can also be laid on construction material and even cars which means the egg masses can be unwittingly transported by people. The spotted lanternfly has continued to make the news in years since its arrival in the US, with quarantines enforced in numerous counties surrounding the area of introduction. Grape producers have already started to see the pest's impact on yield and inspection of all wood products can put a substantial strain on the forest industry. The pest has attracted the attention of government agencies and researchers, with millions of dollars put towards research, monitoring, and treating spotted lanternfly in Pennsylvania in 2018 alone. A different invasive insect, the spotted wing fruit fly, Drosophila Suzukii, has become the scourge of berry production in North America and in some parts of Europe. Most fruit flies are considered nuisance pests of overripe and spoiled fruits. Females of the spotted wing drosophila however, have a serrated ovipositor that can cut into young fruit so that the fly can lay eggs inside of ripening berries. Developing larvae are present in the berries at the time of harvest, which results in poor quality fruit and his disconcerting for producers and consumers alike. Since the fly can have as many as 13 generations per year, late maturing berry varieties can be subject to enormous pest pressure. One year after detection in Coastal California in 2008, the spotted wing drosophila had already spread North to British Columbia in Canada over a 1,000 kilometers away. Today, the spotted wing drosophila has invaded almost all regions of the United States and most of Southern Canada, as well as several countries in Western Europe. The flies has spread rapidly, partly due to the fact that there are no natural enemies, native or introduced, to reduce populations of these insects. The ecological impact of invasive species on natural ecosystems is just as great as their effect in managed ecosystems. Recent research has shown that the establishment of an invasive forest pests, the hemlock woolly adelgid in Eastern Hemlock Forests in the US, has caused a complete change in the community composition of forest-dwelling birds. The hemlock woolly adelgid is a hemipteran that feeds with piercing-sucking mouthparts on hemlock trees which causes the trees to lose their needles and eventually die. This reduces the habitat quality for forest dwelling birds and reduces populations of birds that are forest specialists. At the same time, the dead trees on the landscape allow more light to penetrate the forest canopy, which promotes the growth of understory vegetation. This change in vegetation provides habitat for different bird species. The damage caused by the hemlock woolly adelgid results in a change in the bird community through both direct and indirect effects on the ecosystem. The hemlock woolly adelgid has invaded more than 90 percent of the range of eastern hemlock, causing impacts far across the tree's range. Sometimes species are introduced into a new area on purpose, although there may be unintended consequences if thorough research is not performed prior to release. In the early 20th century, the parasitoid fly Compsilura concinnata was deliberately introduced into the United States for classical biological control of the significant forest defoliator, the gypsy moth. Its introduction has resulted in the unintentional attack of more than 200 types of native insects. Populations of some giant silkworm moths have been reduced up to 80 percent due to parasitism by these flies. The magnitude of potential damage from these introduced control agents, is often unrecoverable, so extensive screening must be done before an organism can be imported as a biological control agent. We have introduced a bit about invasive species, our next speaker is an Assistant Professor at MacEwan University in Edmonton and will tell us more about this topic. My name is Leah Flaherty, I'm an Assistant Professor of Biological Sciences at MacEwan University. My research is focused on improving the tools that are available for early detection of bark and wood-boring beetles specifically. So I'm not monitoring specific species per se, but rather conducting research that helps us monitor. Bark and wood-boring beetles are especially problematic as exotic and potentially invasive species because of their rather cryptic development. So they spend a portion of their lifecycle under the bark or inside the wood of trees, which makes them difficult to detect or intercept in international ports of trade. Bark and wood-boring beetles can be monitored using a variety of different trap types. Most of them are in the category of being a flight intercept trap of some sort. It'll depend a bit on the regulatory or the monitoring agency as well as on the specific species or group of species that are being monitored. But a 12 funnel Lindgren trap like the one you see here are really commonly used to monitor bark and wood-boring beetles. But the idea being here that an insect would essentially just be flying, intercept the trap, and would fall down the funnels into the eventual collection cup at the bottom. Very importantly, you can see here that there's a number of lures or baits hung on the trap. So for monitoring bark and wood-boring beetles, it's really common to use host volatiles. So these are chemicals that smell like usually sick or stressed trees. So for bark and wood-boring beetles specifically, solid wood packaging material that's used in international trade is one of the biggest culprits. However, once they've arrived, one of the biggest problems in terms of spreading those invasive species is the movement of firewood for recreational purposes. So that's one of the big recommendations in terms of what everyday people can do to stop the spread of invasive species, is to not move firewood and to buy your firewood on-site all the time. So invasive species have significant and diverse ecological as well as social and economic impacts that are really going to depend on the specific species or taxa that you're talking about. So one of the big ones is biodiversity loss. So when invasive species come in, what makes them invasive is their ability to take over an area and often to choke out native species. Bark and wood-boring beetles specifically damage the ecosystem by often killing trees or weakening them, making them more susceptible to other insects or diseases that might eventually kill them. So that ultimately can lead to things like habitat destruction which has cascading effects to other members of the ecosystem. Canada, like every other place around the world is certainly faced with a number of problematic invasive species. In terms of insects right now one of the most problematic species is emerald ash borer. So this species was introduced from Asia to North America in the Great Lakes region in the US in the early 2000s, and has subsequently spread significantly throughout the Northeast and now Southeast US and is also in Canada as well. Be aware, educate yourself on the invasive species that are in your area as well as an area that you might travel to. So unfortunately, that means becoming aware of quite a number of different species, but oftentimes there are important regulations that will apply to certain activities that you might engage in. So for example, knowing the regulations around fishing with regards to live bait, when you can use live bait and when you can't in terms of different lakes as well as what live bait you can use and what life bait you can't, or knowing if you're in a regulated area where it's actually restricted to move firewood or even better don't move firewood at all. But generally being aware of the problems in an area or an area that you're traveling to, it is really important. Even something so simple as going for a hike in Edmonton river valley, for example, there's likely going to be garlic mustard seeds in some of the areas where you're hiking. So things like if you know you're hiking in an area with garlic mustard, we recommend that you wash your boots after hiking in an area like that. So being aware is really the first step to prevent contributing to the problem. Over-exploitation by humans is another challenge faced by some arthropods. Wild insects and other arthropods may be harvested for multiple reasons; for use as food, aesthetic purposes, or simply scientific curiosity. For example, many species of tarantulas are kept as pets. Two commonly kept species, the Mexican red rump and the curlyhair tarantula are highly desirable because of their beautiful coloration and docile nature. These species are now endangered due to over-collection for the pet trade. Some insects are threatened in part from over-harvesting for medicinal purposes. This has occurred with the weaver ant, which has many common uses in traditional Chinese medicine. Others may be threatened from overharvest as a food source for humans. Human history is full of examples of animals being hunted to extinction, and in recent years similar impacts have been seen in some insect populations. While insects can be valuable and sustainable food sources due to their high reproductive capacity, we must still exercise caution when harvesting from wild populations. Poor harvesting practices can reduce insect populations. Many insects are harvested as juveniles, so over-harvesting may not leave enough adults in the population to produce the next generation. High market prices can increase harvesting efforts and exert an additional degree of pressure on these insect populations. Insects are threatened due to over-exoploitation in a few regions around the world, including Mexico, China, and parts of Africa. Over-exploitation of insects by humans is not a common occurrence though. Other factors like habitat loss or degradation amplify the effect of over-exploitation and can result in insect decline. In general, these factors have a much more significant contribution to insect declines than over-harvesting. Harvest of insect species that are in decline should be carefully monitored and regulated to prevent local extinction. Many countries like the United Kingdom have regulations that prohibit or limit the collection of endangered insect species. At the international level, the Convention on Biological Diversity and the Convention on International Trade in Endangered Species, or CITES aim to improve sustainable use of plant and animal species and protect species threatened by international trade. Human activities can have dramatic effects on insect diversity. Human-mediated spread of invasive species, both accidental and intentional, serves to further disturb ecosystems already stressed by landscape and climate changes. Harvesting insects may inflict additional pressures on populations that are already in decline from the impacts of negative human-induced disturbances. Effective conservation programs are designed to mitigate the loss of insect diversity. In the next video, we will learn about some of the processes and approaches involved in insect biodiversity conservation.
