Module 11 - Insect Conservation

Question 1

What is the goal of conservation biology?

Answer 1

To conserve threatened species and overall biodiversity

Question 2

Are insects really in decline?

Answer 2

YES
- over 730 endangered insect species
- more and more scientists have recognized that some insect populations and species are being lost at an alarming rate

Question 3

Why do we need insect conservation?

Answer 3

1. Humans have an obligation to prevent harm to as many species as possible that are ‘in our hands;
2. Insects play important roles in the maintenance of ecosystems
   - several species influence terrestrial habitats
   - pollinators
3. Predatory and herbivorous insects provide balance to an ecosystem
4. Insects provide an important food source for larger predatory organisms in an ecosystem

Question 4

Biomonitoring

Answer 4

Involves the assessment of ecosystem components, such as the types of habitats and species present
- this data is critical in conservation efforts
- insects used because they are widespread and sensitive to specific habitat requirements and respond quickly to enviro changes and are easy to sample
- helps up understand the impacts of natural and human-induced ecosystem changes on behaviour, diversity, and abundance of the target species, which in turn informs conservation efforts

Question 5

Habitat Loss

Answer 5

Industrial, agricultural, and urban human developments continue to expand and destroy many natural habitats rich in biodiversity (ex. forests, grasslands, aquatic ecosystems)
- Research projects such as the EMEND project are critical in helping us understand the impacts of activities and how to create more sustainable forest management practices

Question 6

Habitat Fragmentation

Answer 6

The process by which continuous natural habitats are broken into smaller patches, reducing the area of available habitat for organisms, and resulting in the physical isolation of populations.
- can result from natural phenomena but human-induced factors are even more widespread
- most severely impacts insects with poor dispersal capabilities

Question 7

Inbreeding depression

Answer 7

Occurs when populations become so highly inbred that the health of individuals drastically declines
- An issue that arises when small populations become separated
- Lack of genetic diversity means that problematic genes can become ever more present in the population
- Individuals may struggle to even find eachother to mate

Question 8

What 2 human-driven factors are the main causes of habitat fragmentation?

Answer 8

Agricultural development and urbanization
-increase in demand for food due to rising global human population = increase in amount of land devoted to agriculture
- highly modified landscapes, often monocultures, insects unable to survive or adapt
- industrial practices, such as creation of roads and survey lines

Urbanization: the movement of ppl from rural areas into towns and cities
- extensively modifies the landscape
- vehicle emissions, road salt, heat from buildings, light pollution all affect the surrounding habitat
- much of insect behaviour is dependent on circadian rhythm (a biological clock that directs behaviour and is primarily dictated by photoperiod); affected by light pollution; may be displaced from natural habitat and concentrated at artificial light source or repelled

Question 9

Since insects are small ectothermic animals, temperature has a heavy influence on multiple aspects of their biology. How so?

Answer 9

Temperature affects insect metabolic and developmental rates, the timing and level of insect activity as well as their overall survival
- Climate change affects insect biology, population distributions, and biodiversity

Question 10

Direct impacts of the changing climate on insect development and survival

Answer 10

1. warmer temps promote faster rates of development = faster life cycles = more generations in a year
2. metabolic activity increases = rate of food consumption will increase = rise in crop losses (not good w/ growing human pop)
3. temperature-size rule: dictates that ectothermic animals in warmer conditions develop faster, mature earlier, and yet are smaller at maturity than those developing in colder climates; may be due to physiological constraints on growth at higher temperatures; body size influence’s lifespan, home range, and reproductive capability
4. phenology
   - shifts in the timing of insect activity are detrimental if similar shifts are not occurring in the timing of other ecosystem events
   - or, climate change may induce a change in the phenology of the host plant without having the same impact on the insects; mismatch in timing of activity with resource availability = bad for insects with highly specific habitat requirements
5. insects that are habitat specialists or insects in tropical climates are at extreme risk
   - in tropical climates temps are near optimal; if temps rise they may exceed optimum (inverse is true in temperate regions)

Question 11

Temperature-size rule

Answer 11

dictates that ectothermic animals in warmer conditions develop faster, mature earlier, and yet are smaller at maturity than those developing in colder climates; may be due to physiological constraints on growth at higher temperatures

Question 12

Indirect impacts of climate change on species distributions

Answer 12

1. the species of plants that populate an ecosystem, as well as their growth and biology, can be determined by climate-driven environmental changes
   - changing temps, CO2 levels, and precipitation can alter plant traits such as chemistry, biomass, or seed production
   - change in range and distribution of plant species
   - insect herbivores affected by change in biology and distribution of host plants
2. insects respond to climate-driven pressures by shifting natural ranges
   - sometimes expand range, sometimes restrict; shift brings its own set of challenges
   - genetic isolation can lead to inbreeding depression
   - novel habitats may have sparse resources
   - use physiology-based models to predict the responses of insect populations to changes in climatic conditions

Question 13

Insect adaptations to climate change

Answer 13

Variance within a population, high numbers of offspring, and short generation times can allow rapid adaptive evolution
- this can allow some local insects to persist in a region despite climate change
- ex. Operophtera brumata (winter moth)

Question 14

Invasive species

Answer 14

Any organism with established populations in an area outside of their native range that causes harm in the new range
- threat to ecosystems; dramatic effects on the composition, structure, and fxn of native ecosystems through resource competition and trophic interactions
- negatively impact local biodiversity through exploitation of resources and rapid population growth due to a lack of natural enemies and coevolved host defenses in the new range
- economic costs for humans
- unintentionally transported to new places in a variety of ways
- in some cases, purposefully introduced into new habitat

Question 15

Impacts of Direct Harvesting of insects

Answer 15

• Another way humans negatively impact arthropod pops is through overexploitation
• We harvest wild insects for food, aesthetic purposes, scientific curiosity; leading cause of decline in some arthropod species
• Rarely the cause of insect decline alone, but in combination with other human-induced factors it can threaten populations

Question 16

Conservation Strategies

Answer 16

Step 1: prioritize the species on which to focus conservation efforts

Step 2: species is inventoried and monitored to track its population distribution and abundance

Step 3: management

Question 17

Conservation Strategy:
Step 1: Prioritization

Answer 17

Humans are limited to the resources we allocate towards conservation efforts; must PRIORITZE which species should be targeted by these efforts
- goal: to promote future biodiversity overall, and the identification of a conservation target allows us to effectively design conservation programs
- many species prioritized based on the concept of irreplaceability = measures the conservation value of a specific target, and can be determined in a few ways; important when resources are limited

Question 18

Irreplaceability

Answer 18

Measures the conservation value of a specific target, and can be determined in a few ways
- many species are PRIORITISED based on the concept of irreplaceability

First application of irreplaceability:
- prioritizes geographical regions severely impacted by climate and landscape changes; factoring in biodiversity hotspots
- drawbacks: unique or rare species are not emphasized, prioritization tactics may become unbalanced due to greater data available for species at risk in temperate regions
- in reality, most endangered species are found in the tropics simply bc of the higher biodiversity in these areas, but a lack of data may create the misleading impression that most endangered insects are found in temperate regions

Second application of irreplaceability:
- occurs at the species level
- species with limited numbers and geographic distribution have a higher level or irreplaceability compared to common species
- species with pops outside the conservation area becomes more replaceable
- allows us to account for measures such as taxonomic uniqueness, global rarity of the species in question, and unique phenomena

Question 19

Conservation Strategy:
Step 2: Inventory and Monitoring

Answer 19

• once target species for conservation is identified, next step is to INVENTORY at risk populations; pops tracked through variety of tools and methods
• insect populations difficult to quantify in biodiversity surveys due to small size
• MONITORING: the measurement of species abundance and distribution over time; tells us how a pop changes over time in response to different disturbances = we can extrapolate upon this data to make predictions about future of insect populations
• inventory and monitoring of at-risk pops done through regular BIODIVERSITY SURVEYS; invaluable data for conservation data; specimens either identified and counted out in the field or collected to be identified, catalogued, and quantified in the lab
• recently general public has become more involved in biodiversity monitoring via citizen science

Question 20

Why might it be challenging to monitor insect populations?

Answer 20

• insects are only active at certain times
• adult insects may only be present for a short period during the year
• pops often have large fluctuations, and regular changes in distribution, which can make data difficult to interpret
• important to accurately estimate pops bc overestimates of threat status can damage the credibility of ongoing conservation efforts

Question 21

Citizen science

Answer 21

Uses information provided by the general public in conservation research
- serves to educate the public on scientific processes, provides important data for researchers, and forms relationships btw citizens and scientific research
- valuable tool in the collection of data on insects that are easily identifiable
- tech advances has driven this farther
- however, limited by: ppl more likely to notice and report insects active in daytime, skewed by accessibility to locations, accurate identification, polymorphisms exhibited by many species, sexual dimorphism

Question 22

Conservation Strategy:
Step 3: Management

Answer 22

• final step in conservation
• complex interplays btw the ecosystem and its inhabitants mean that insect conservation involves the preservation of entire ecosystems rather than individual species
• habitat conservation through PARKS and RESERVES: sections of land designated to preserve biodiversity and natural ecosystem processes by minimizing human interference in the area
• connect habitats (separated due to fragmented landscape) with corridors that facilitate insect movement
• principles of insect conservation applied on smaller scale within urban enviros: parks, gardens, ponds

Question 23

In order for habitat preservation to effectively support a large number of species, the preserved landscape should be what?

Answer 23

Heterogeneous
- bc different species have different habitat requirements, and so a variety of habitats allows conservation efforts to support a broad diversity of species

Question 24

Challenges in Insect Conservation

Answer 24

1. Attitude of general public towards insects
   - many ppl think of insects as pests
   - public outreach and education is necessary to support local conservation efforts
   - conservation efforts can use charismatic species as FLAGSHIP SPECIES that evoke a positive public rxn and indirectly helps other less visually appealing insects = UMBRELLA EFFECT