BACKGROUND: The European earwig, Forficula auricularia(L.) (Dermaptera: Forficulidae), is regarded as an important beneficial in many orchard environments but has the potential to be a plant pest in other systems, including to grain crops. Due to its agricultural importance, the lifecycle of F. auriculariahas been widely studied in North America and Europe. However, much less is known in the southern hemisphere, including Australia where F. auriculariahas been present for over 170 years.

RESULTS: To elucidate the lifecycle of F. auricularia, we monitored five sites in grain-growing areas of southern Australia using two different trap types. Adults were found year-round, but most prevalent from late-spring to mid-winter. First instars were typically found from mid to late winter. Second, third and fourth instars occurred from winter through to late spring. The seasonal development of F. auriculariain Australia may be much earlier than observed in comparable North American studies. Degree day modelling highlights variation in development times across the active season for F. auricularia across our sites.

CONCLUSION: Forficula auriculariais well adapted to the Australian grain growing environments. The timing of egg hatching aligns closely with crop emergence, juveniles then develop alongside the crop, and adult development occurs by harvest time in late spring. These findings are important given that many of these crops (canola, lucerne, pulses) are vulnerable to attack by F. auricularia during emergence and development. They also suggest a phenotypic capacity of this species to adapt different phenology after introduction into a novel environment.

1.The Portuguese millipede, Ommatoiulus moreleti (Lucas, 1860), is increasingly a pest of grains crops in Australian agricultural ecosystems. With the rapid uptake of minimum-tillage practices, habitat quality has been enhanced for several species of soil dwelling invertebrates, in particular O. moreleti.

2.To understand the population dynamics of O. moreleti in Australian grains crops, populations were sampled at multiple sites for more than 2 years using pitfall traps and cardboard roll traps. Specimens were dissected to investigate reproductive status and developmental stage.

3.Millipede trapping rates varied between sites and across the year, and tended to be lower when soil water content (m3/m3) was high. Both sexes were active year round, however females were relatively more abundant when ground temperatures were higher.

4.Males in a copulatory state and females with mature eggs were collected year round although females lacking mature eggs were more common when ground temperatures were higher and the soil was drier, and female egg load was higher under cooler conditions. Females at a stadium 9 or later carried mature eggs and copulatory males tended to be from stadium 8 or later. Different developmental stages could be recovered at all times of the year.

5.These findings indicate persistent populations of O. moreleti across fields throughout the year, with a key breeding period in autumn but likely opportunistic breeding all year. Control of millipedes will need to focus on increasing the impact of biological agents, decreasing suitable habitat for millipede breeding and intensive control at susceptible crop periods.

Diuraphis noxia, Russian wheat aphid (Hemiptera: Aphididae), established in Australia since 2016, is dependent on grasses (Poales: Poaceae) to persist in the low-rainfall Australian wheat belt, where no crops are present during summer. To identify grasses as D. noxia hosts in Australia, plants were tested in greenhouse conditions as either whole plants collected from roadsides or grown from collected seed in 2017 and 2018. To determine actual field refugia, direct grass sampling and Berlese extraction of aphids were conducted from October 2018 to May 2020 throughout Southern Australia (2,285 samples). One hundred and twentysix grass species were collected, 54 showed presence of D. noxia, of which 24 were considered host plants, including 16 species (9 Australian natives) not recorded as host plants previously. Hordeum leporinum (Link) Arcang. Poales:Poaceae and several Bromus species (Poales: Poaceae) showed the highest D. noxia detection frequency and aphid numbers, but these introduced grass species are not summer active in most of South Australia. The native Enneapogon nigricans (Poales: Poaceae) (R.Br.) is the most important summer refuge species because of its widespread distribution, summer growth, and an intermediate level of positive detections with low D. noxia populations. The late summer represents the main bottleneck for D. noxia with very few hosts available and very low D. noxia detections overall. Late summer rainfall (February) seems essential to have the main host grasses germinate for D. noxia populations to build up and potentially invade crops sown in autumn.

New information is presented on previously introduced aphid parasitoids using the newly arrived Russian wheat aphid (RWA), Diuraphis noxia Kurdjumov 1913 (Hemiptera: Aphididae) in South Australia including species diversity and relative abundance, population dynamics and regional differences in communities. In total, eight species of primary braconids (Hymenoptera) were identified from D. noxia: Aphidius colemani Viereck, 1912 A. platensis Bre`thes 1913, A. ervi Haliday 1834 (Hymenoptera: Braconidae), A. rhopalosiphi De Stefani Perez, 1902, A. salicis Haliday, 1834, A. smithi Sharma and Subba Rao, 1959, Diaeretiella rapae (McIntosh, 1855) and Lysiphlebus testaceipes (Cresson, 1880). The predominant parasitoids of D. noxia were D. rapae, A. colemani and A. platensis which was consistent across regions. This study indicates the pre-emptive importation of biological control agents (generalist parasitoid wasps) contributed to limiting an invasive pest. Data presented provides a baseline for further research on parasitoid species to reduce D. noxia, a new pest species in Australian cereal ecosystems.

Globally, dung beetles are recognised as important ecosystem engineers due to their ability to bury large amounts of animal dung. In Australia, the native dung beetle fauna do not have the capability to process introduced cattle dung consistently, resulting in a breeding medium for nuisance fly species and nematodes. This unprocessed livestock dung smothers the pasture, reducing the availability of viable pasture for rearing livestock. Communities of exotic dung beetles were successfully established in Australia between 1960-2020, with the primary aim to process large quantities of cattle dung. Since establishment, very limited work has investigated their current distribution across agricultural landscapes and, how they respond both spatially and temporally to different livestock management practices.

The aim of this dissertation was to investigate how dung quality influences the community structure and population dynamics of northern NSW dung beetles. It primarily investigated the introduced dung beetle community in northern NSW, Australia, identify key abiotic factors for colonization and reproduction, and any reciprocal effects, and provide a targeted assessment of the response of introduced dung beetle species to cattle dung derived from different pasture types. The dissertation is structured around an introduction and literature review (Chapter 1), four data chapters and a synthesis chapter (Chapter 6). Also included are appendices that provide a publication and data collected during the thesis. The dissertation addressed four objectives which are the basis of the research chapters: Objective 1 (Chapter 2) to establish the main abiotic factors driving the introduced dung beetle community in northern NSW. Objective 2 (Chapter 3) to establish how pasture species, and combinations, influence dung quality and dung beetle reproduction and progeny traits. Objective 3 (Chapter 4) to determine how pasture species/combinations influence the field colonisation and burial of dung by the dung beetle community on the New England Tablelands. Objective 4 (Chapter 5) to establish how the dung beetle Onthophagus binodis interacts with dung pH and the reproductive consequences of this interaction.

The dung beetle communities of northern NSW (Chapter 2) were sampled by a national citizen science project, and identified that the communities strongly varied spatially across locations, and that mean monthly minimum temperature positively influenced the abundance and species richness of dung beetles at all sites. Sixteen introduced and eight native dung beetle species were identified with Labarrus lividus (42%) being the most prevalent followed by Euoniticellus intermedius (16.2%). Paracoprids were the dominant functional guild across northern NSW. It is concerning that the dung beetle communities of northern NSW were dominated by a single or few species, by which to provide the majority of the ecosystem services in livestock dominated landscapes.

The influence of pasture type (Chapter 3) on cattle dung quality was investigated across three dominant temperate dung beetle species (Euoniticellus africanus, E. intermedius and Onthophagus binodis) under controlled conditions to determine the impact on brood production and phenological changes in progeny. The dung of cattle grazed on three pasture types (improved native, forage oat & rye/clover pasture – dung type) were collected and quantified. Pasture type influenced the chemical parameters of dung quality, with nitrogen likely an important parameter for determining progeny size. Rye/clover derived dung had the highest nitrogen content and produced the largest (longer total length and wider pronotums) progeny of female E. intermedius, and both males and females of O. binodis.

An Australian dung beetle community study (Chapter 4) in the field was conducted to determine the colonization (abundance and species richness) and subsequent burial of three different dung types. Three dung types were accessible to the temperate dung beetle community on the New England Tablelands for 24 hours every month for twelve months. Across the three pasture types, 13 species of dung beetle were trapped from 11,174 specimens, with Onthophagus binodis (49.7%), Aphodius fimetarius (24.4%) and L. lividus (17.1%) having the highest abundances. Abundance and species richness were influenced by month and local landscape, with weak evidence (p=0.1-0.05), that abundance was influenced by pasture types, whereas dung burial (organic matter) was strongly influenced (p = 0.0001) by month and pasture type. How a more diverse community responds to different dung conditions requires further investigation.

Previous investigations determined that cattle dung pH was a likely contributing factor to dung beetle colonization and reproductive success. The influence of cattle dung pH on dung beetle reproduction was investigated using the dominant temperate dung beetle species Onthophagus binodis (Chapter 5). A single previous study (Dadour and Cook 1996 Environmental Entomology 25) hypothesised that O. binodis could not reproduce in cattle dung below 6.3, such as that produced by grain fed cattle dung. To test this, beetles were reared in dung with artificially manipulated pH (7.3, 7.0, 6.0 and 5.0), and their broods and progeny were assessed. The pH of cattle dung influenced development time, ellipsoid volume of brood balls, and offspring width and length. Notably, O. binodis offspring were larger from pH 6.0 dung compared to the other pH treatments. The results indicate that dung pH is a key driver of brood success refuting the earlier study.

The research outlined in this dissertation provides a valuable understanding of the current distribution of introduced dung beetle species in northern NSW, and particularly the role of cattle diet in resultant dung quality, and subsequent dung beetle colonisation and reproductive success. Researchers, livestock producers, landcare groups and best practice management for dung beetle research will all benefit from the information presented within this dissertation. This dissertation expands the current knowledge of dietary impacts on dung beetles within Australia on three common pasture types. The thesis provides novel findings of the tolerance of O. binodis to cattle dung pH which highlights that past research has made assumptions without investigating further. Additionally, the ecology of dung beetles to different pasture types improves the understanding the fragility of the ecosystem services of the New England Tablelands while helping within applied management by encouraging higher nitrogen forages to improve dung beetle reproduction and colonisation.

The diel activity of dung beetles is poorly understood in Australia. Understanding diel activity is fundamental to understanding the ecology and management of these insects. The diel activity is typically measured using ground-based pitfall traps, which require manual changing. Here we showcase a time sorting pitfall trap (TSPT) that allows for automated time sorted sampling of dung beetle communities to help investigate diel activity and determine abiotic triggers of diel activity. Testing was undertaken to determine the following: 1) Can the TSPT capture dung beetles at eight (3-hr interval) time points throughout a 24-hr period? 2) How efficiently can the TSPT capture dung beetles compared to a ground-based pan trap? 3) How does the height of the TSPT (standing vs. buried) affect the species diversity and abundance? We found that the TSPT successfully captured dung beetles at different time intervals, providing an assessment of beetle activity. We provide examples from two locally abundant dung beetles species, Labarrus lividus (Olivier, 1789) (Aphodiinae) and Onthophagus binodis (Thunberg, 1818) (Scarabaeinae). The height of the TSPT negatively influenced species diversity and abundance compared to ground-based pan traps. When we compared the results of pan traps and the equivalent of a buried TSPT (TSPT lid with pan trap underneath set at ground height), no difference was detected in overall species diversity, yet abundance was still reduced. When the height of the TSPT was reduced, only 20% of the abundance was captured compared to the ground pan trap. Overall, the TSPT worked for the intended purpose of measuring diel activity though it should be buried or have its height reduced to improve capture rate.

Dermaptera (earwigs) from the Anisolabididae family may be important for pest control but their taxonomy and status in Australia is poorly studied. Here we used taxonomic information to assess the diversity of southern Australian Anisolabididae and then applied cox1 barcodes as well as additional gene fragments (mitochondrial and nuclear) to corroborate classification and assess the monophyly of the putative genera. Anisolabididae morphospecies fell into two genera, Anisolabis Fieber and Gonolabis Burr, based on paramere morphology. Combinations of paramere and forceps morphology distinguished seven morphospecies, which were further supported by morphometric analyses. The morphospecies were corroborated by barcode data" all showed within-species genetic distance < 4% and between-species genetic distance > 10%. Molecular phylogenies did not support monophyly of putative genera nor clades based on paramere shape, instead pointing to regional clades distinguishable by forceps morphology. This apparent endemism needs to be further tested by sampling of earwig diversity outside of agricultural production regions but points to a unique regional insect fauna potentially important in pest control.

The Russian wheat aphid (Diuraphis noxia [Kurdjumov, Hemiptera: Aphididae], RWA) was first detected in Australia in 2016 and is threatening an annual cereal industry valued at nearly 10 billion AUD per annum. Considerable uncertainty surrounds the economic risk of D. noxia to Australian cereals, which limits cost-effective farm management decisions. Through a series of inoculated and non-inoculated field trials in 2018 and 2019 in south-eastern Australia, we generated a range of D. noxia pressure metrics under different growing conditions for barley, wheat, and durum wheat. Relative yield loss was best explained by the 'percentage of tillers with D. noxia' (%TwRWA) with 0.28% yield loss per percent of tillers with D. noxia, which is significantly lower than 0.46–0.48% for susceptible winter wheat varieties in dryland conditions in the United States. Highest infestation levels were typically reached around GS40–50. To develop an action threshold, we calculated the rate of increase in the %TwRWA through time at 0.021% per day per %TwRWA (with little variation across sites). This allowed prediction of the expected maximum %TwRWA based on observations post tillering (GS30) and the expected duration before GS50 is reached. For earlier growth stages (

Both indigenous and introduced Australian dung beetles (Coleoptera: Scarabaeoidea) play an important role in agricultural systems. Temperate grasslands in Australia are expected to have some of the greatest increases in temperature and reduction in precipitation due to climate change which may directly threaten dung beetles. Several biotic and abiotic factors affect the development of larvae and fitness of young dung beetles. To understand if dung beetles can continue to provide ecosystem services across temperate Australia under changing management and climate, we review what is known about their life history traits that will facilitate their adaption.

We believe dung beetles will continue to provide valuable ecosystem services and have potential to aid in adapting and alleviating the impacts on crops and pastures from reduced and sporadic rainfall. However, the level of function, may be impeded due to climatic stress and a loss of diversity with thermal specialists and some indigenous species, expected to be displaced into narrower ranges. An increase in feeding competition from thermal generalists and introduced species will likely implement this movement. The evidence from naturalised introduced species indicate behavioural adaptations and/or phenotypic plasticity suggest some species will continuing to provide services that improve pasture production despite changes to climate. Ongoing monitoring of phenological shifts will inform adaptive management of this vital group.

The Russian wheat aphid,Diuraphis noxia(Mordvilko ex Kurdjumov), is one of the world's most economically important pests of grain crops and has been recorded from at least 140 grass species within Poaceae. It has rapidly dispersed from its native origin of Central Asia into most major grain-producing regions of the world including Africa, Asia, Europe, the Middle East, North America and South America.Diuraphis noxia was first found in Australia in a wheat crop in the mid-north of South Australia in May 2016. Since then,D. noxia has been recorded throughout grain-growing regions of South Australia, Victoria, New South Wales and Tasmania. The distribution will continue to expand, with climatic suitability modelling suggesting D. noxia can persist in all key grain regions, including large parts of Western Australia and Queensland. Australian populations of D. noxia appear to be anholocyclic, with no sexual stages being observed. The aphids can reproduce year round as long as host plants are available. Australian farmers have generally adopted prophylactic insecticide seed treatments and/or foliar sprays to manage D. noxia. Research is required to fully understand yield impacts, host preferences and host plant resistance associated with D. noxia. Cultural control through managing alternate host plants over summer, agro-nomic crop management, biological control and developments in host plant resistance should provide considerable future benefits.