Broiler farming practices using new or re-used bedding, inclusive of free-range, have no impact on Campylobacter levels, species diversity, Campylobacter community profiles and Campylobacter bacteriophages.

A multi-stage option to address food-safety can be produced by a clearer understanding of Campylobacter's persistence through the broiler production chain, its environmental niche and its interaction with bacteriophages. This study addressed Campylobacter levels, species, genotype, bacteriophage composition/ levels in caeca, litter, soil and carcasses across commercial broiler farming practices to inform on-farm management, including interventions. Broilers were sequentially collected as per company slaughter schedules over two-years from 17 farms, which represented four commercially adopted farming practices, prior to the final bird removal (days 39-53). The practices were conventional full clean-out, conventional litter re-use, free-range-full cleanout and free-range-litter re-use. Caeca, litter and soil collected on-farm, and representative carcases collected at the processing plant, were tested for Campylobacter levels, species dominance and Campylobacter bacteriophages. General community profiling via denaturing gradient gel electrophoresis of the flaA gene was used to establish the population relationships between various farming practices on representative Campylobacter isolates. The farming practice choices did not influence the high caeca Campylobacter levels (log 7.5 to log 8.5 CFU/g), the carcass levels (log 2.5 to log 3.2 CFU/carcass), the C. jejuni/C. coli dominance and the on-farm bacteriophage presence/levels. A principal coordinate analysis of the flaA distribution for farm and litter practices showed strong separation but no obvious farming practice related grouping of Campylobacter. Bacteriophages originated from select farms, were not practice-dependent, and were detected in the environment (litter) only if present in the birds (caeca). This multifaceted study showed no influence of farming practices on on-farm Campylobacter dynamics. The significance of this study means that a unified on-farm risk-management could be adopted irrespective of commercial practice choices to collectively address caeca Campylobacter levels, as well as the potential to include Campylobacter bacteriophage biocontrol. The impact of this study means that there are no constraints in re-using bedding or adopting free-range farming, thus contributing to environmentally sustainable (re-use) and emerging (free-range) broiler farming choices.

Spatial Distribution and Flight Patterns of Two Grain Storage Insect Pests, Rhyzopertha dominica (Bostrichidae) and Tribolium castaneum (Tenebrionidae): Implications for Pest Management.

The lesser grain borer, Rhyzopertha dominica, and the rust red flour beetle, Tribolium castaneum, are two major beetle pests commonly found infesting stored products worldwide. Both species can cause severe economic damage and their management is complicated by their potential to develop resistance to several of the limited chemical options available. However, pest management strategies can be improved by understanding the ecology of the pest insect. To determine the spatiotemporal activity of R. dominica and T. castaneum, we conducted a trapping study over two years in a temperate region of south-eastern Australia, with traps located near grain storages and fields. We captured higher numbers of R. dominica than T. castaneum, and both species were more prevalent in traps located close to grain storages. Similar and consistent seasonal patterns were displayed by both species with activity ceasing during the winter (June-August) months. We found linear correlations between maximum daily temperatures and trap catches, and minimum threshold temperatures for flight activity were 14.5 °C and 15.6 °C for R. dominica and T. castaneum, respectively. The results are discussed in relation to the ecology of these pests along with their implications for pest management.

Comparative Trap Catches of Male Bactrocera, Dacus, and Zeugodacus Fruit Flies (Diptera: Tephritidae) With Four Floral Phenylbutanoid Lures (Anisyl Acetone, Cue-Lure, Raspberry Ketone, and Zingerone) in Queensland, Australia.

The male fruit fly attractants, cue-lure (CL) and raspberry ketone (RK), are important in pest management. These volatile phenylbutanoids occur in daciniphilous Bulbophyllum Thouar (Orchidaceae: Asparagales) orchids, along with zingerone (ZN) and anisyl acetone (AA). While these four compounds attract a similar range of species, their relative attractiveness to multiple species is unknown. We field tested these compounds in two fruit fly speciose locations in north Queensland, Australia (Lockhart and Cairns) for 8 wk. Of 16 species trapped in significant numbers, 14 were trapped with CL and RK, all in significantly greater numbers with CL traps than RK traps (at least in higher population locations). This included the pest species Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) (CL catches ca. 5× > RK), Bactrocera neohumeralis (Hardy) (Diptera: Tephritidae) and Bactrocera bryoniae (Tryon) (Diptera: Tephritidae) (CL catches ca. 3× > RK), and Bactrocera frauenfeldi (Schiner) (Diptera: Tephritidae) (in Cairns-CL catches ca. 1.6× > RK). Seven species were trapped with AA, and all were also caught in CL and RK traps in significantly greater numbers, with the exception of B. frauenfeldi. For this species, catches were not statistically different with CL, RK, and AA in Lockhart, and RK and AA in Cairns. Seven species were trapped with ZN, two at this lure only, and the remainder also with CL or RK but in significantly greater numbers. This is the first quantitative comparison of the relative attractiveness of CL, RK, AA, and ZN against multiple species, and supports the long-held but untested assumption that CL is broadly more attractive lure than RK.

Bacteriophages to Control Campylobacter in Commercially Farmed Broiler Chickens, in Australia.

This study describes the development and use of bacteriophage cocktails to control Campylobacter in broiler chickens, in a commercial setting, in Queensland Australia, following the birds from farm to the processing plant. The components of the bacteriophage cocktails were selected to be effective against the maximum number of Campylobacter jejuni and Campylobacter coli isolates encountered on SE Queensland farms. Farms were identified that had suitable Campylobacter target populations and phage were undetectable 1 week prior to the intended treatment. Cocktails of phages were administered at 47 days of age. Groups of study birds were slaughtered the following day, on-farm, at the end of flock transport to the plant, and at processing (approximately 28 h post-treatment). On Farm A, the phage treatment significantly reduced Campylobacter levels in the ceca at the farm in the range of 1-3 log10 CFU/g (p = 0.007), compared to mock treated controls. However, individual birds sampled on farm (1/10) or following transport (2/10) exhibited high cecal Campylobacter counts with low phage titers, suggesting that treatment periods > 24 h may be required to ensure phage replication for effective biocontrol in vivo. At the time of the trial the control birds in Farm B were phage positive despite having been negative one week earlier. There was no significant difference in the cecal Campylobacter counts between the treatment and control groups following treatment but a fall of 1.7 log10 CFU/g was observed from that determined from birds collected the previous week (p = 0.0004). Campylobacter isolates from both farms retained sensitivity to the treatment phages. These trials demonstrated bacteriophages sourced from Queensland farms have the potential to reduce intestinal Campylobacter levels in market ready broiler chickens.

Maximizing Lucerne (Medicago sativa) Pasture Intake of Dairy Cows: 1-the Effect of Pre-Grazing Pasture Height and Mixed Ration Level.

The effect of lucerne (Medicago sativa L.) pre-grazing pasture height on pasture intake and milk production was investigated in a sub-tropical partial mixed ration (PMR) dairy system in south-east Queensland, Australia. The experiment involved a 26-day adaptation period followed by an eight-day measurement period during April and May 2018. Twenty-four multiparous Holstein-Friesian dairy cows were offered a mixed ration at either 7 (low) or 14 (high) kg dry matter (DM)/cow/day and allocated pastures at pre-grazing heights ranging from 23 to 39 cm. The targeted pasture intake was 14 and 7 kg DM/cow/day for cows offered the low and high mixed ration allowances respectively, with a total intake target of 21 kg DM/cow/day. Pasture structure did not limit pasture intake as the all groups left at least 12% of the allocated area ungrazed, and therefore could selectively graze pasture. There was no significant difference in intake between mixed ration levels, however intake had a positive linear relationship with pre-grazing pasture height. For every one cm increase in pasture height, intake increased by 0.3 kg DM/cow/day. Using a grazing strategy that ensures the some pasture remains ungrazed and the pre-grazing height of lucerne is approximately 39 cm above ground level will maximise pasture intake in sub-tropical PMR dairy systems.

Maximising Lucerne (Medicago sativa) Pasture Intake of Dairy Cows: 2-the Effect of Post-Grazing Pasture Height and Mixed Ration Level.

The effects of lucerne (Medicago sativa) post-grazing residual pasture height on pasture utilisation (vertical and horizontal), pasture intake and animal production were investigated in a sub-tropical partial mixed ration dairy system. The study took place at the Gatton Research Dairy, Southeast Queensland (-27.552, 152.333), with a 26-day adaptation period followed by two 8-day measurement periods during August and September 2018. A quantity of 30 multiparous Holstein-Friesian dairy cows were offered two levels of mixed ration, 7 and 14 kg dry matter (DM)/cow/day for low and high levels respectively, and five levels of pasture allocation, to achieve decreasing residual pasture heights. Pasture allocations measured from 5 cm above ground level for the low mixed ration groups averaged 12.7, 15.9, 19.8, 35.3 and 49.2 kg DM/cow/day, and for the high mixed ration groups averaged 5.0, 8.3, 10.3, 18.6, and 25.2 kg DM/cow/day, respectively. As pasture allocation decreased, cows were forced to graze further down into the pasture sward, and therefore residual pasture height declined. Total intake (kg DM/cow/day) declined as residual pasture height (expressed as % of the initial height) declined, irrespective of mixed ration level, decreasing by 0.5 kg DM/cow/day for every 10% decrease in residual pasture height. Low total intakes were associated with high non-esterified fatty acid (NEFA) levels in plasma, indicating mobilisation of fat tissue to maintain milk production. In the high allocation treatments, an area of pasture remained ungrazed and cows were only grazing the top leafy stratum where pasture intake rate and intake were highest. Therefore, to maximise intake in sub-tropical partial mixed ration (PMR) systems, lucerne pasture should be allocated so that cows are always grazing the top leafy stratum. This can be achieved by ensuring the pasture around faecal patches remains ungrazed.

Isoeugenol, a More Attractive Male Lure for the Cue-Lure-Responsive Pest Fruit Fly Bactrocera curvipennis (Diptera: Tephritidae: Dacinae), and New Records of Species Responding to Zingerone in New Caledonia.

Bactrocera curvipennis (Froggatt) is a polyphagous pest fruit fly endemic to New Caledonia that is weakly attracted to the male lure cue-lure (CL). Effective male lures are important for the monitoring and management of numerous pest species of Dacinae fruit flies. However, if a species is weakly responsive to these lures its detection and control is difficult. Recently in Oceania and Asia, more attractive male lures (isoeugenol, methyl-isoeugenol, dihydroeugenol, and zingerone) were identified for several weakly CL- and methyl eugenol (ME)-responsive species. To determine if these lures may be more attractive to B. curvipennis, we field tested them in comparison to CL and ME in New Caledonia. Bactrocera curvipennis catch with isoeugenol-baited traps (mean 20.3 ± 3.0) was 15 times greater than with CL (1.3 ± 0.8) and catch with dihydroeugenol (5.7 ± 1.6) was four times greater than with CL. This is the first record of B. curvipennis responding to these lures. It was also the only species that responded to isoeugenol in this study. Bactrocera fulvifacies (Perkins) (Diptera: Tephritidae), a rarely encountered species 'nonresponsive' to male lures, was attracted to zingerone with its trap catch (2,574 flies) approaching that of Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) at CL (2,724 flies). Another nonresponsive species, Dacus aneuvittatus (Drew) (Diptera: Tephritidae), was also trapped by zingerone-baited traps. This is the first record of these species responding to a male lure. The significantly greater response of B. curvipennis to isoeugenol would make it a considerably more effective attractant for use in surveillance and control programs.

Combining Cue-Lure and Methyl Eugenol in Traps Significantly Decreases Catches of Most Bactrocera, Zeugodacus and Dacus Species (Diptera: Tephritidae: Dacinae) in Australia and Papua New Guinea.

Male fruit fly attractants, cue-lure (CL) and methyl eugenol (ME), are important in the monitoring and control of pest fruit fly species. Species respond to CL or ME but not both, and there are conflicting reports on whether combining CL (or its hydroxy analogue raspberry ketone) and ME decreases their attractiveness to different species. Fruit fly monitoring programs expend significant effort using separate CL and ME traps and avoiding lure cross-contamination, and combining the two lures in one trap would create substantial savings. To determine if combining lures has an inhibitory effect on trap catch, CL and ME wicks placed in the same Steiner trap were field tested in comparison to CL alone and ME alone in Australia and Papua New Guinea (PNG). In Australia, 24 out of 27 species trapped were significantly more attracted to CL or ME alone than the combination ME/CL lure, including the pests Bactrocera bryoniae (Tryon), B. frauenfeldi (Schiner), B. kraussi (Hardy), B. neohumeralis (Hardy), B. tryoni (Froggatt) (CL-responsive), and B. musae (Tryon) (ME-responsive). In PNG, 13 out of 16 species trapped were significantly more attracted to CL or ME alone than the ME/CL combination, including the pests B. bryoniae, B. frauenfeldi, B. neohumeralis, B. trivialis (Drew), Zeugodacus cucurbitae (Coquillett) (CL-responsive) and B. dorsalis (Hendel), B. musae, and B. umbrosa (Fabricius) (ME-responsive). This study shows that combining CL and ME in the one trap in equal parts significantly reduces catches of most species of Dacini fruit flies in Australia and PNG.

Methyl-isoeugenol, a Highly Attractive Male Lure for the Cucurbit Flower Pest Zeugodacus diversus (Coquillett) (syn. Bactrocera diversa) (Diptera: Tephritidae: Dacinae).

Effective male fruit fly attractants, such as cue lure (CL) and methyl eugenol (ME), are important in the monitoring and management of pest species through lure and kill techniques of trapping and male annihilation. However, some species are only weakly responsive to these lures, making their detection and control difficult. Zeugodacus diversus (Coquillett), a pest of cucurbit flowers in Asia, is weakly attracted to ME. Recently in Australia and Papua New Guinea, the eugenol analogues isoeugenol, methyl-isoeugenol, and dihydroeugenol were found to be effective attractants for species with a weak response to ME and CL, as well as several nonresponsive species. Additionally, studies from the early 1900s indicated that Z. diversus was attracted to isoeugenol. To determine if these eugenol analogues may be more effective attractants for Z. diversus, we field tested them in Bangladesh in comparison to ME, as well as CL and zingerone. Z. diversus was significantly more attracted to all three eugenol analogues than ME, with it most attracted to methyl-isoeugenol. Its attraction to methyl-isoeugenol was 49 times greater than its attraction to ME (respective means 23.58 flies/trap/day (FTD) and 0.48 FTD). Z. diversus was also consistently trapped at methyl-isoeugenol at all trap clearances including when populations were low, whereas it was only trapped at ME at 6 out of the 13 clearances. This study demonstrates that methyl-isoeugenol is a highly attractive lure for Z. diversus and would be a valuable inclusion as an attractant in monitoring and male annihilation programs.