Toxicity in Cuscuta reflexa Sucrose Content Decreases In Shoot Tips Upon Trehalose Feeding Trehalose

Trehalose, an {alpha},{alpha}-diglucoside, induced a rapid blackening and death of shoot tips of Cuscuta reflexa (dodder) cultured in vitro. The onset of toxic symptom was delayed if any of the several sugars which support the in vitro growth of Cuscuta was supplied with trehalose. The rate of trehalose uptake or its accumulation in the tissue was not affected by sugar cofeeding. The levels of total and reducing sugars declined appreciably in the trehalose-fed shoot tip explants compared to control tissue cultured in absence of a carbon source. This was not due to an increased rate of respiration of the trehalose-treated tissue. In shoot tips cultured in presence of both trehalose and sucrose, the decline in total and reducing sugars was curtailed. There was a marked fall in the level of sucrose; and invertase activity was higher in trehalose-fed shoot tips. The incorporation of label from [14C]glucose into sucrose in the shoot tip explant was reduced as early as 12 h of trehalose feeding. The results suggest that increased utilization of sucrose as well as an inhibition of its synthesis contribute to the drastic fall in the sucrose content upon trehalose feeding

Localization of feeding of Anomalococcus indicus (Hemiptera: Lecanodiaspididae) and supplementary biological notes: Towards the biological management of the invasive tree Vachellia nilotica indica (Fabales: Mimosoideae) in North-Eastern Australia

. Management of the invasive Vachellia nilotica indica infesting tropical grasslands of Northern Australia has remained unsuccessful to date. Presently Anomalococcus indicus is considered a potential agent in the biological management of V. n. indica. Whereas generic biological details of A. indicus have been known, their feeding activity and details of their mouthparts and the sensory structures that are associated with their feeding action are not known. This paper provides details of those gaps. Nymphal instars I and II feed on cortical-parenchyma cells of young stems of V. n. indica, whereas nymphal instars III and adult females feed on phloem elements of older shoots. Nymphal instars and adults (females) trigger stress symptoms in the feeding tissue with cells bearing enlarged and disfigured nuclei, cytoplasmic shrinkage, cytoplasmic trabeculae, abnormal protuberances and uneven cell wall thickening, unusual cell membrane proliferation, and exhausted and necrosed cells. Continuous nutrient extraction by A. indicus can cause stem death. We provide evidence that A. indicus, by virtue of its continuous feeding activity and intense population build up, can be an effective biological-management agent to regulate populations of V. n. indica in infested areas. © 2014 © 2014 Société entomologique de France.

A new gall midge of the genus Dentifibula (Diptera: Cecidomyiidae), a predator of the scale insect Aulacaspis australis feeding on mangrove Bruguiera gymnorrhiza

Dentifibula nigroapicalisKolesik sp. nov., a new species of gall midge, is described whose larvae were found preying on the mangrove scale insect Aulacaspis australisBrimblecombe (Hemiptera: Coccoidea: Diaspididae). The mangrove scale was feeding on leaves of the mangrove Bruguiera gymnorrhiza (Rhizophoraceae) in Queensland. The new species is the first DentifibulaFelt known from Australia. © 2013 Australian Entomological Society.

Fungus-feeding thrips from Australia in the worldwide genus Hoplandrothrips (Thysanoptera, Phlaeothripinae)

From Australia, 16 species of Hoplandrothrips are here recorded, of which 11 are newly described. An illustrated key is provided to 15 species, but Phloeothrips leai Karny cannot at present be recognised from its description. The generic relationships between Hoplandrothrips, Hoplothrips and some other Phlaeothripinae that live on freshly dead branches are briefly discussed.

Rhipicephalus (Boophilus) microplus tick in vitro feeding methods for functional (dsRNA) and vaccine candidate (antibody) screening

Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) ticks cause economic losses for cattle industries throughout tropical and subtropical regions of the world estimated at $US2.5 billion annually. Lack of access to efficacious long-lasting vaccination regimes and increases in tick acaricide resistance have led to the investigation of targets for the development of novel tick vaccines and treatments. In vitro tick feeding has been used for many tick species to study the effect of new acaricides on the transmission of tick-borne pathogens. Few studies have reported the use of in vitro feeding for functional genomic studies using RNA interference and/or the effect of specific anti-tick antibodies. In particular, in vitro feeding reports for the cattle tick are limited due to its relatively short hypostome. Previously published methods were further modified to broaden optimal tick sizes/weights, feeding sources including bovine and ovine serum, optimisation of commercially available blood anti-coagulant tubes, and IgG concentrations for effective antibody delivery. Ticks are fed overnight and monitored for ∼5–6 weeks to determine egg output and success of larval emergence using a humidified incubator. Lithium-heparin blood tubes provided the most reliable anti-coagulant for bovine blood feeding compared with commercial citrated (CPDA) and EDTA tubes. Although >30 mg semi-engorged ticks fed more reliably, ticks as small as 15 mg also fed to repletion to lay viable eggs. Ticks which gained less than ∼10 mg during in vitro feeding typically did not lay eggs. One mg/ml IgG from Bm86-vaccinated cattle produced a potent anti-tick effect in vitro (83% efficacy) similar to that observed in vivo. Alternatively, feeding of dsRNA targeting Bm86 did not demonstrate anti-tick effects (11% efficacy) compared with the potent effects of ubiquitin dsRNA. This study optimises R. microplus tick in vitro feeding methods which support the development of cattle tick vaccines and treatments.

Reproductive interference between honey bee species in artificial sympatry

Reproductive isolation between closely related species is often incomplete. The Western honey bee, Apis mellifera, and the Eastern hive bee, A. cerana have been allopatric for millions of years, but are nonetheless similar in morphology and behaviour. During the last century the two species were brought into contact anthropogenically, providing potential opportunities for interspecific matings. Hybrids between A. mellifera and A. cerana are inviable, so natural interspecific matings are of concern because they may reduce the viability of A. cerana and A. mellifera populations – two of the world's most important pollinators. We examined the mating behaviour of A. mellifera and A. cerana queens and drones from Caoba Basin, China and Cairns, Australia. Drone mating flight times overlap in both areas. Analysis of the spermathecal contents of queens with species-specific genetic markers indicated that in Caoba Basin, 14% of A. mellifera queens mated with at least one A. cerana male, but we detected no A. cerana queens that had mated with A. mellifera males. Similarly, in Cairns, no A. cerana queens carried A. mellifera sperm, but one third of A. mellifera queens had mated with at least one A. cerana male. No hybrid embryos were detected in eggs laid by interspecifically-mated A. mellifera queens in either location. However A. mellifera queens artificially inseminated with A. cerana sperm produced inviable hybrid eggs, or unfertilised drones. This suggests that reproductive interference will impact the viability of honey bee populations wherever A. cerana and A. mellifera are in contact. This article is protected by copyright. All rights reserved.

Fungus-feeding phlaeothripine Thysanoptera in the genus Holothrips from Australia and New Caledonia, with a structurally similar new genus, Holoengythrips

Ten species of Holothrips, including seven new species, are recognized from Australia, with one further new species from New Caledonia. A new genus, Holoengythrips, is described from Australia, with nine new species that look similar to Holothrips species in having elongate maxillary stylets that are close together medially for the full length of the head. In contrast to species of Holothrips, the species of Holoengythrips are strongly sexually dimorphic, with antennal segment VIII separated from VII and the maxillary stylets more slender, and the males have a pore plate on the eighth sternite. Holoengythrips is therefore considered to be more closely related to Hoplandrothrips.

The minute, fungus-feeding species of Sophiothrips (Thysanoptera, Phlaeothripinae) from Australia and New Zealand

Five new species of Sophiothrips are described from mainland Australia, of which one is widespread in the eastern part of the continent, with a second widespread across the northern tropical zone. These species appear to be members of the breviceps species-group from the Old World tropics. One of these five is particularly unusual within the genus in that the maxillary stylets are retracted into the head anterior to the postoccipital ridge. A sixth new species is described from Australia that is known only from Norfolk Island, but this is closely related to two species that are endemic to New Zealand. A key is provided to the nine species recognised.

Comparison of the pregnancy rates and costs per calf born after fixed-time artificial insemination or artificial insemination after estrus detection in Bos indicus heifers

This study compared pregnancy rates (PRs) and costs per calf born after fixed-time artificial insemination (FTAI) or AI after estrus detection (i.e., estrus detection and AI, EDAI), before and after a single PGF2α treatment in Bos indicus (Brahman-cross) heifers. On Day 0, the body weight, body condition score, and presence of a CL (46% of heifers) were determined. The heifers were then alternately allocated to one of two FTAI groups (FTAI-1, n = 139) and (FTAI-2, n = 141) and an EDAI group (n = 273). Heifers in the FTAI groups received an intravaginal progesterone-releasing device (IPRD; 0.78 g of progesterone) and 1 mg of estradiol benzoate intramuscularly (im) on Day 0. Eight days later, the IPRD was removed and heifers received 500 μg of PGF2α and 300 IU of eCG im; 24 hours later, they received 1 mg estradiol benzoate im and were submitted to FTAI 30 to 34 hours later (54 and 58 hours after IPRD removal). Heifers in the FTAI-2 group started treatment 8 days after those in the FTAI-1 group. Heifers in the EDAI group were inseminated approximately 12 hours after the detection of estrus between Days 4 and 9 at which time the heifers that had not been detected in estrus received 500 μg of PGF2α im and EDAI continued until Day 13. Heifers in the FTAI groups had a higher overall PR (proportion pregnant as per the entire group) than the EDAI group (34.6% vs. 23.2%; P = 0.003), however, conception rate (PR of heifers submitted for AI) tended to favor the estrus detection group (34.6% vs. 44.1%; P = 0.059). The cost per AI calf born was estimated to be $267.67 and $291.37 for the FTAI and EDAI groups, respectively. It was concluded that in Brahman heifers typical of those annually mated in northern Australia FTAI compared with EDAI increases the number of heifers pregnant and reduces the cost per calf born.

Baseline and greenhouse-gas emissions in extensive livestock enterprises, with a case study of feeding lipid to beef cattle

For accurate calculation of reductions in greenhouse-gas (GHG) emissions, methodologies under the Australian Government's Carbon Farming Initiative (CFI) depend on a valid assessment of the baseline and project emissions. Life-cycle assessments (LCAs) clearly show that enteric methane emitted from the rumen of cattle and sheep is the major source of GHG emissions from livestock enterprises. Where a historic baseline for a CFI methodology for livestock is required, the use of simulated data for cow-calf enterprises at six sites in southern Australia demonstrated that a 5-year rolling emission average will provide an acceptable trade off in terms of accuracy and stability, but this is a much shorter time period than typically used for LCA. For many CFI livestock methodologies, comparative or pair-wise baselines are potentially more appropriate than historic baselines. A case study of lipid supplementation of beef cows over winter is presented. The case study of a control herd of 250 cows used a comparative baseline derived from simple data on livestock numbers and class of livestock to quantify the emission abatement. Compared with the control herd, lipid supplementation to cows over winter increased livestock productivity, total livestock production and enterprise GHG emissions from 990 t CO2-e to 1022 t CO2-e. Energy embodied in the supplement and extra diesel used in transporting the supplement diminished the enteric-methane abatement benefit of lipid supplementation. Reducing the cow herd to 238 cows maintained the level of livestock production of the control herd and reduced enterprise emissions to 938 t CO2-e, but was not cost effective under the assumptions of this case study.

Resting sites, edge effects and dispersion of a polyphagous Bactrocera fruit fly within crops of different architecture

The spot or strip application of poisoned protein bait is a lure-and-kill technique used for the management of fruit flies. Knowledge of where flies occur in the crop environment is an important part of maximizing the efficacy of this tool. Bactrocera tryoni is a polyphagous pest of horticulture for which very little is known about its distribution within crops. With particular reference to edge effects, we monitored the abundance of B. tryoni in two crops of different architecture; strawberry and apple. In strawberries, we found more flies on the crop edge early in the fruiting season, which lessened gradually and eventually disappeared as the season progressed. In apple orchards, no such edge effect was observed and flies were found equally throughout the orchard. We postulated these differences may be due to differences in crop height (high vs. short) and/or crop canopy architecture (opened and branched in apple, dense and closed in strawberry). In a field cage trial, we tested these predictions using artificial plants of different height and canopy condition. Height and canopy structure type had no significant effects on fly oviposition and protein feeding, but the 'apple' type canopy significantly influenced resting. We thus postulate that there was an edge effect in strawberry because the crop was not providing resting sites and flies were doing so in vegetation around the field margins. The finding that B. tryoni shows different resting site preferences based on plant architecture offers the potential for strategic manipulation of the fly through specific border or inter-row plantings. © 2013 Blackwell Verlag GmbH.

Application of Artificial Viscosity in Establishing Supercritical Solutions to the Transonic Integra

The nonlinear singular integral equation of transonic flow is examined in the free-stream Mach number range where only solutions with shocks are known to exist. It is shown that, by the addition of an artificial viscosity term to the integral equation, even the direct iterative scheme, with the linear solution as the initial iterate, leads to convergence. Detailed tables indicating how the solution varies with changes in the parameters of the artificial viscosity term are also given. In the best cases (when the artificial viscosity is smallest), the solutions compare well with known results, their characteristic feature being the representation of the shock by steep gradients rather than by abrupt discontinuities. However, 'sharp-shock solutions' have also been obtained by the implementation of a quadratic iterative scheme with the 'artificial viscosity solution' as the initial iterate; the converged solution with a sharp shock is obtained with only a few more iterates. Finally, a review is given of various shock-capturing and shock-fitting schemes for the transonic flow equations in general, and for the transonic integral equation in particular, frequent comparisons being made with the approach of this paper.

The leaf-feeding geometrid Isturgia disputaria (Guenee)-A potential biological control agent for prickly acacia, Vachellia nilotica subsp. indica (Benth.) Kyal. & Boatwr. (Mimosaceae) in Australia

Prickly acacia (Vachellia nilotica subsp. indica), a native multipurpose tree in India, is a weed of National significance, and a target for biological control in Australia. Based on plant genetic and climatic similarities, native range surveys for identifying potential biological control agents for prickly acacia were conducted in India during 2008-2011. In the survey leaf-feeding geometrid, Isturgia disputaria Guenee (syn. Tephrina pulinda), widespread in Tamil Nadu and Karnataka States, was prioritized as a potential biological control agent based on field host range, damage potential and no choice test on non target plant species. Though the field host range study exhibited that V. nilotica ssp. indica and V. nilotica ssp. tomentosa were the primary hosts for successful development of the insect, I. disputaria, replicated no - choice larval feeding and development tests conducted on cut foliage and live plants of nine non-target acacia test plant species in India revealed the larval feeding and development on three of the nine non-target acacia species, V. tortilis, V. planiferons and V. leucophloea in addition to the V. nilotica ssp. indica and V. nilotica ssp. tomentosa. However, the proportion of larvae developing into adults was higher on V. nilotica subsp. indica and V. nilotica subsp. tomentosa, with 90% and 80% of the larvae completing development, respectively. In contrast, the larval mortality was higher on V. tortilis (70%), V. leucophloea (90%) and V. planiferons (70%). The no-choice test results support the earlier host specificity test results of I. disputaria from Pakistan, Kenya and under quarantine in Australia. Contrasting results between field host range and host use pattern under no-choice conditions are discussed.

A field investigation of a modified intravaginal progesterone releasing device and oestradiol benzoate based ovulation synchronisation protocol designed for fixed-time artificial insemination of Brahman heifers

Pregnancy rates (PR) to fixed-time AI (FTAI) in Brahman heifers were compared after treatment with a traditional oestradiol-based protocol (OPO-8) or a modified protocol (OPO-6) where the duration of intravaginal progesterone releasing device (IPRD) was reduced from 8 to 6 days, and the interval from IPRD removal to oestradiol benzoate (ODB) was increased from 24 to 36 h. Rising 2 yo heifers on Farm A: (n = 238 and n = 215; two consecutive days AI); B (n = 271); and C (n = 393) were allocated to OPO-8 or OPO-6. An IPRD was inserted and 1 mg ODB i.m. on Day 0 for OPO-8 heifers and Day 2 for OPO-6 heifers. On Day 8, the IPRD was removed and 500 μg cloprostenol i.m. At 24 h, for OPO-8 heifers, and 36 h, for OPO-6 heifers, post IPRD removal all heifers received 1 mg ODB i.m. FTAI was conducted at 54 and 72 h post IPRD removal for OPO-8 and OPO-6 heifers. At Farm A, OPO-6 heifers, AI on the second day, the PR was 52.4 to FTAI (P = 0.024) compared to 36.8 for OPO-8 heifers. However, no differences were found between OPO-8 and OPO-6 protocols at Farm A (first day of AI) (39.9 vs. 35.7), or Farms B (26.2 vs. 35.4) and C (43.2 vs. 40.3). Presence of a corpus luteum at IPRD insertion affected PR to FTAI (43.9 vs. 28.8; P < 0.001). This study has shown that the modified ovulation synchronisation protocol OPO-6 may be a viable alternative to the OPO-8 protocol for FTAI in B. indicus heifers.

Lighting the way: Towards reducing misorientation of olive ridley hatchlings due to artificial lighting at Rushikulya, India

Sea-finding behavior in sea turtle hatchlings is modified by the visual cues provided by artificial beach front lighting. The consequent landward movement of hatchlings in response to coastal electric lighting reduces their survival rates. We assessed the potential impact of coastal lighting at Rushikulya, an important mass nesting site of the olive ridley sea turtle (Lepidochelys olivacea) in the Indian Ocean region. We examined the response of hatchlings to light characteristics in an experimental setup, as well as to the existing lighting regimes along the beach, using arena trials. Previous studies on other species indicate preferential orientation towards low wavelength and high intensity light. Our study confirms these preferences among hatchlings from the Indian Ocean population of olive ridleys. In addition we also found that wavelength and intensity could have an interactive effect upon hatchling orientation. Hatchlings at the study site respond both to visible point sources of light and to sheer glows of light. Though beach plantations of introduced Casuarina equisetifolia are generally considered to have negative impacts on sea turtle nesting beaches, we found that they acted as an effective light barrier when planted about 50 m away from the high tide line. We developed a model of the expected impact of artificial lighting on hatchling orientation during mass hatching events of previous years, and predict as much as 50% misorientation in some years. We also developed a map representing the misorientation of hatchlings due to artificial lighting based on arena trials in different regions of the beach. The results of the study helped identify focal areas for light management on the beach, which could be critical for the survival of this population.