Creating an insectary for Australian native insects

Introduction

Australia is home to a diverse range of native insects that play a crucial role in ecosystems by pollinating plants, decomposing organic matter, and controlling pest populations. However, habitat destruction, climate change, and pesticide use threaten many of these vital species (CSIRO 2021). Establishing an insectary—a designed habitat that supports native insects—can help preserve and encourage biodiversity in gardens, farms and urban spaces. This article explores how to create an insectary for Australian native insects and the benefits for the environment.

The role of native insects

Native insects contribute significantly to ecosystem health (Australian Museum, 2020). Key groups include:

·         Pollinators. Native bees, butterflies, and beetles help fertilise flowers, which are essential for fruit and seed production (Neff and Simpson, 2018).

·         Decomposers. Dung beetles, termites and certain flies break down organic material, recycling nutrients back into the soil (Halcroft et al., 2013).

·         Predators. Ladybirds, lacewings and parasitic wasps control pest populations naturally (Smith et al., 2020).

·         Seed dispersers. Ants assist in spreading native plant species (Department of Environment 2022).

How to create an insectary

1. Choose a suitable location. Select a site that receives a mix of sunlight and shade. Native insects thrive in areas with diverse microclimates, including gardens, bushland, and urban green spaces (CSIRO, 2023).

2. Select native plants. Incorporate diverse native flowering plants which provide nectar and pollen throughout the year. Suitable plants include:

o   Eucalyptus is used for nectar-feeding insects (Rayment, 2017).

o   Callistemon (bottlebrush) to attract native bees and butterflies (Australian Native Plants Society, 2022).

o   Leptospermum (Tea tree) to provide food for pollinators (Tew et al., 2021).

o   Grevillea, which supports insects and birds (Department of Environment, 2022).

o   Grasses, which shelter insects and small birds.

3. Provide shelter and nesting sites.

o   Install bee hotels with drilled wood blocks or bamboo to support solitary native bees (Neff & Simpson, 2018).

o   Leave logs, leaf litter and rocks to create natural shelters for beetles, ants and other insects (Australian Museum, 2020).

o   Grow dense shrubs to provide hiding spots for insects from predators and extreme weather (Smith et al., 2020).

4. Provide a water source.

o   A shallow dish with pebbles and freshwater provides hydration for insects (Halcroft et al., 2013).

o   Damp muddy areas help native bees build nests (Neff & Simpson, 2018).

5. Avoid pesticides and chemicals.

o   Use natural pest control methods, such as companion planting and encouraging predatory insects (CSIRO, 2021).

o   Use organic gardening practices to protect insect populations from harmful chemicals (Department of Environment, 2022).

6. Encourage a diverse habitat.

o   Plant species with different heights, textures and flowering times to support various insects (Tew et al., 2021).

o   Incorporate grasses, ground covers and climbing plants for layered insect habitats (Australian Entomology Society, 2019).

7. Monitor and maintain the insectary.

o   Regularly observe insect activity to ensure the habitat remains functional (Smith et al., 2020).

o   Prune plants selectively to maintain diversity while keeping shelter areas intact (Neff & Simpson, 2018).

o   Record sightings of different insect species to track biodiversity improvements (Halcroft et al., 2013).

Creating distinct habitats for Australian insects.

Different insect species thrive in distinct habitats. Varied microhabitats support diverse native insects. Understanding different habitats can help get your eye into what you can build at home. Here are several habitat ideas:

1. Woodland habitat

o   Best for: Beetles, ants and native bees.

o   How to create: Leave fallen logs, bark, and leaf litter to mimic natural woodland floors, such as plant trees such as eucalyptus and acacia (wattle) (Rayment, 2017).

2. Meadow and grassland habitat

o   Best for: Butterflies, moths and grasshoppers.

o   How to create: Grow native grasses and wildflowers such as kangaroo grass and everlastings. Avoid mowing too frequently (Tew et al., 2021).

3. Wetland habitat

o   Best for: Dragonflies, mosquitoes and water beetles.

o   How to create: Establish shallow ponds with native aquatic plants such as sedges and rushes. Include partially submerged logs for resting spots (Department of Environment, 2022).

4. Sandy or rocky habitat

o   Best for: Solitary native bees and ants.

o   How to create: Provide exposed sandy areas for ground-nesting bees. Arrange flat rocks and deadwood for sun-basking insects (Australian Entomology Society, 2019).

Benefits of an insectary:

·         Enhances pollination. Boosts fruit and vegetable production in gardens and Farms (Neff & Simpson, 2018).

·         Natural pest control. Reduces the need for chemical pesticides by promoting predator insects (Smith et al., 2020).

·         Soil health improvement. Decomposing insects contribute to nutrient recycling (Harcroft et al., 2013).

·         Biodiversity conservation. Provides refuge for threatened native insect Species (CSIRO, 2013).

·         Educational opportunities. Encourages community awareness and appreciation of insect ecology (Australian Museum, 2020).

Grasses

This article, "6 of the best native grasses to plant in your yard" lists

low-maintenance Australian native grasses that are beneficial for gardens. Here

are some of the grasses featured:

1.      Weeping rice-grass (Microlaena stipoides). Ideal for lawns, especially in cool, semi-shady areas like the Adelaide Hills. Once established, it requires minimal watering and tolerates light foot traffic.

2.      Kangaroo grass (Themeda triandra). Features leaves up to 50 cm long that transition from green to red as they mature. It attracts butterflies and beneficial insects, thrives in drought conditions but is sensitive to frost and heavy grazing.

3.      Brush wiregrass (Aristida behriana). Grows to about 20 cm tall with distinctive flower heads resembling green witches' brooms that mature to a cream colour. It flowers year-round and is highly drought-tolerant.

4.      Windmill grass (Chloris truncata): Named for its windmill-like flowers, this grass reaches about 40 cm in height. It is suitable for low-traffic lawn areas in drier regions and responds well to occasional summer rains.

5.      Bottlebrush grass (Enneapogon nigricans). Known for its unique seed heads that resemble bottlebrushes, it grows to about 30 cm tall. This grass can withstand drought but is less tolerant of frost.

6.      White top or wallaby grass (Rytidosperma species). This grass also attracts beneficial insects to the garden and is also noted for its interesting seed appearance,

Incorporating native grasses can enhance garden aesthetics, support local wildlife and reduce maintenance efforts. See:

https://www.environment.sa.gov.au/goodliving/posts/2017/11/australian-nativegrasses

References

Australian Entomology Society. (2019). Insect conservation in urban landscapes.

Australian Museum. (2020). Native insects of Australia: Ecology and habitat needs.

Australian Native Plants Society. (2022). Gardening with Australian native plants.

CSIRO. (2021). Native bee populations and habitat conservation.

CSIRO. (2023). Managing urban green spaces for biodiversity.

Department of Environment. (2022). Wildlife-friendly garden design.

Halcroft, M., et al. (2013). The nesting behaviour of Australian native bees.

Neff, J., & Simpson, B. (2018). Pollinator habitats and their ecological importance.

Rayment, T. (2017). The Australian bee guide.

Smith, L., et al. (2020). Enhancing insect populations through artificial habitats.

Tew, N., et al. (2021). The role of microhabitats in insect conservation.