Tolerance of cryptic species of blue oat mites (Penthaleus spp.) and the redlegged earth mite (Halotydeus destructor) to pesticides

1999 ◽  
Vol 39 (5) ◽  
pp. 621 ◽  
Author(s):  
P. A. Umina ◽  
A. A. Hoffmann
Keyword(s):  
Cryptic Species ◽  
Control Strategies ◽  
Single Species ◽  
The Other ◽  
Control Problems ◽  
Halotydeus Destructor ◽  
Pest Outbreaks ◽  
Redlegged Earth Mite ◽  
Control Failure ◽  
Control Failures

Blue oat mites (Penthaleus spp.) and redlegged earth mites (Halotydeus destructor) are major pests of crops and pastures in southern Australia. Management of these mites has been complicated by the recent discovery of 3 cryptic parthenogenic species of Penthaleus, whereas prior research had assumed a single species. The response of the 3 Penthaleus species and H. destructor to commonly used pesticides (omethoate, methidathion, bifenthrin and endosulfan) was compared. Penthaleus falcatus was more tolerant of all pesticides than the other species, whereas H. destructor tended to be the most susceptible. The response of P. major was similar to that of an undescribed cryptic species (Penthaleus sp. x). Mites were sampled from 7 sites where control failures had been reported. Three of these failures were due to P. falcatus despite the fact that this species is relatively uncommon. This suggests that the high tolerance levels of P. falcatus relative to the other species may lead to control problems. Nevertheless, samples of P. falcatus from the control failure sites did not exhibit a higher level of tolerance than those from an unsprayed site. Clones of both P. falcatus and P. major differed in tolerance levels, suggesting some potential for the evolution of increased tolerance levels in mite populations. The results highlight the importance of determining species composition when devising control strategies for mite pest outbreaks.

scholarly journals Strategies for control of the redlegged earth mite in Australia

2008 ◽  
Vol 48 (12) ◽  
pp. 1506 ◽  
Author(s):  
T. J. Ridsdill-Smith ◽  
A. A. Hoffmann ◽  
G. P. Mangano ◽  
J. M. Gower ◽  
C. C. Pavri ◽  
...  
Keyword(s):  
Control Strategies ◽  
Field Trials ◽  
Effective Control ◽  
Synthetic Pyrethroids ◽  
Halotydeus Destructor ◽  
Mite Control ◽  
Redlegged Earth Mite ◽  
Single Well ◽  
Plant Seedlings ◽  
Control Package

The redlegged earth mite, Halotydeus destructor, continues to be an intractable pest causing damage to most crop and pasture species in southern Australia. H. destructor feed on all stages of plants, but particularly damage seedlings in autumn. Research has aimed to develop new controls based on a better understanding of the biology and ecology of this pest. Chemicals remain the key tool to control H. destructor, despite the recent appearance of resistance to synthetic pyrethroids. A control package, Timerite, has been developed by which a single well-timed spray in spring can prevent H. destructor from developing diapause eggs. Field trials show this strategy provides effective control of H. destructor the following autumn, and protects plant seedlings, although mite populations build up again during winter. Non-chemical control strategies include grazing, the use of tolerant plants such as cereals, resistant legume cultivars and avoiding rotations where favourable host plants are available in the year before growing susceptible crops such as canola. Natural enemies can assist in mite control, and their numbers can be enhanced by methods including increasing landscape features like shelterbelts. Interspecific competition can occur between H. destructor and other pest mites, but the extent to which these interactions influence the structure of pest communities under different management regimes remains to be investigated.

Responses and feeding damage of redlegged earthmite (Acarina: Penthaleidae) to seedlings of resistant and susceptible subterranean clover varieties

1995 ◽  
Vol 46 (5) ◽  
pp. 1091 ◽  
Author(s):  
TJ Ridsdill-Smith
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
The Other ◽  
Feeding Damage ◽  
Halotydeus Destructor ◽  
Pot Experiments ◽  
Resistant Varieties ◽  
Redlegged Earth Mite ◽  
Single Variety

Responses of redlegged earth mite (Halotydeus destructor) to seedlings of three resistant and four susceptible varieties of subterranean clover (Trifolium subterraneum) were measured after 7 or 14 days in pot experiments in the glasshouse. With a single variety/pot, mites on resistant varieties (DGI007, EP145SubD and Rutherglen B) produced 45% of the progeny that were produced by mites on the susceptible varieties (89838G, Dalkeith, Junee and 70088B). Number of stages completed and survival were little affected by varieties. Feeding damage (silvering of cotyledons) on resistant varieties averaged 45% of that on susceptible varieties with a single varietylpot. H. destructor fed less on resistant varieties in choice than in single variety experiments. On Junee and 89838G seedlings, feeding damage was similar to that on other susceptible varieties, but there were about half as many H. destructor progeny as on Dalkeith and 70088B. Mites laid more eggs on soil away from Junee plants, compared to the other three susceptible varieties. Different factors adversely affected the number of progeny produced on resistant varieties and on Junee.

No longer a west-side story – pesticide resistance discovered in the eastern range of a major Australian crop pest, Halotydeus destructor (Acari: Penthaleidae)

2018 ◽  
Vol 69 (2) ◽  
pp. 216 ◽  
Author(s):  
James L. Maino ◽  
Matthew Binns ◽  
Paul Umina
Keyword(s):  
Western Australia ◽  
Organophosphorus Pesticides ◽  
South Australia ◽  
Resistance Testing ◽  
Halotydeus Destructor ◽  
West Side Story ◽  
Redlegged Earth Mite ◽  
Important Pest ◽  
Control Failure ◽  
Upper South

The redlegged earth mite, Halotydeus destructor (Tucker) (Acari: Penthaleidae), is an important pest of pastures, broad-acre crops, and vegetables across southern Australia. Populations of H. destructor in Western Australia have been known to be resistant to pyrethroid and organophosphorus pesticides since 2006 and 2014, respectively. Resistant populations are currently widespread across Western Australia’s southern growing region but have, until now, remained undetected in the large south-eastern Australian range of H. destructor, despite ongoing resistance screening since 2006. Following reports of a field control failure in the Upper South East district in South Australia in 2016, resistance testing determined this South Australian population was resistant to pyrethroid and organophosphorus pesticides. The levels of resistance discovered were similar to resistant H. destructor populations in Western Australia, which are associated with chemical control failures. This work confirms for the first-time that pesticide resistant populations of H. destructor are no longer isolated to Western Australia.

scholarly journals Co-occurring cryptic species pose challenges for conservation: a case study of the African dwarf crocodile (Osteolaemusspp.) in Cameroon

Oryx ◽  
2014 ◽  
Vol 49 (4) ◽  
pp. 584-590 ◽  
Author(s):  
Nicole L. Smolensky
Keyword(s):  
Cryptic Species ◽  
Conservation Status ◽  
Taxonomic Revision ◽  
Single Species ◽  
Conservation Strategies ◽  
Encounter Rates ◽  
Distribution Maps ◽  
Species Complexes ◽  
Threatened Taxa ◽  
Population Structures

AbstractThe conservation status of threatened taxa may be obfuscated by the detection of cryptic species complexes, in both vertebrate and invertebrate species. African dwarf crocodiles (Osteolaemusspp.) are hunted throughout their range but their conservation status is unknown. Few population assessments have been carried out and there has been a taxonomic revision of the number of species in the genus. The similar morphologies ofOsteolaemus tetraspisandOsteolaemus osbornipose a challenge for conservation in Cameroon, where they are still managed as a single species. Nocturnal spotlight surveys were conducted in three regions during August–November 2010 and December 2011–February 2012 to provide population assessments ofO. tetraspisandO. osborniand raise awareness of the two species in Cameroon. The mean encounter rates ofO. tetraspisandO. osborniwere 1.02 ± SD 1.34 (65 individuals in 39 surveys) and 0.61 ± SD 0.38 (three in four surveys) crocodiles per km, respectively. TheO. tetraspispopulation comprised juveniles predominantly and had a male-biased sex ratio. The fewO. osbornidetected comprised both adults and juveniles. Both species are threatened in Cameroon, based on low encounter rates, young population structures and the threats of habitat loss and hunting pressure. This study provides distribution maps and serves as a baseline to quantify population trends and inform conservation strategies.

scholarly journals Spiribacter aquaticus Leon et al. 2017 is a later heterotypic synonym of Spiribacter roseus Leon et al. 2016. Reclassification of Halopeptonella vilamensis Menes et al. 2016 as Spiribacter vilamensis comb. nov.

2020 ◽  
Vol 70 (4) ◽  
pp. 2873-2878 ◽  
Author(s):  
María José León ◽  
Cristina Galisteo ◽  
Antonio Ventosa ◽  
Cristina Sánchez-Porro
Keyword(s):  
Type Species ◽  
Single Species ◽  
Amino Acid Identity ◽  
The Other ◽  
Phylogenomic Analysis ◽  
Content Type ◽  
Link Type ◽  
Average Amino Acid Identity ◽  
Single Genus ◽  
Type Strains

A comparative taxonomic study of Spiribacter and Halopeptonella species was carried out using a phylogenomic approach based on comparison of the core genome, orthologous average nucleotide identity (OrthoANIu), Genome-to-Genome Distance Calculator (GGDC) and average amino acid identity (AAI). Phylogenomic analysis based on 976 core translated gene sequences obtained from their genomes showed that Spiribacter aquaticus SP30T, S. curvatus UAH-SP71T, S. roseus SSL50T, S. salinus M19-40T and Halopeptonella vilamensis DSM 21056T formed a robust cluster, clearly separated from the remaining species of closely related taxa. AAI between H. vilamensis DSM 21056T and the species of the genus Spiribacter was ≥73.1 %, confirming that all these species belong to the same single genus. On the other hand, S. roseus SSL50T and S. aquaticus SP30T showed percentages of OrthoANIu and digital DNA–DNA hybridization of 98.4 % and 85.3 %, respectively, while these values among those strains and the type strains of the other species of Spiribacter and H. vilamensis DSM 21056T were ≤80.8 and 67.8 %, respectively. Overall, these data show that S. roseus SSL50T and S. aquaticus SP30T constitute a single species and thus that S. aquaticus SP30T should be considered as a later, heterotypic synonym of S. roseus SSL50T based on the rules for priority of names. We propose an emended description of S. roseus , including the features of S. aquaticus . We also propose the reclassification of H. vilamensis as Spiribacter vilamensis comb. nov.

A new species of Liophloeothrips (Thysanoptera, Phlaeothripidae) from leaf litter from Iran

Zootaxa ◽  
2019 ◽  
Vol 4571 (1) ◽  
pp. 138
Author(s):  
MAHSA HAKIMARA ◽  
KAMBIZ MINAEI ◽  
SABER SADEGHI ◽  
LAURENCE MOUND
Keyword(s):  
New Species ◽  
Leaf Litter ◽  
Type Species ◽  
Single Species ◽  
The Other ◽  
Single Female ◽  
Label Data ◽  
Fungal Hyphae ◽  
Plant Families ◽  
A New Species

Of the 16 species listed in the genus Liophloeothrips (ThripsWiki 2018), 13 are known only from India, and all of these are phytophagous with some inducing galls in various plant families (Tyagi & Kumar 2011). However, the biology of the type species, L. glaber, as well as that of the other two species, L. hungaricus and L. pulchrisetis, remains in doubt. Each of these three species is from Europe, with L. pulchrisetis known from a single female, L. glaber from two specimens, and hungaricus recorded from Hungary, Finland and Iran on a very few individuals (Minaei & Mound 2014). The record of L. hungaricus from Iran was published without any information concerning the locality, date of collection, or number of specimens (Mortazawiha 1995). However, Minaei and Mound (2014) pointed out that the slide label data of L. hungaricus specimens from Europe suggested that this species is associated with the bark of certain Salicaceae. Moreover, they indicated the possibility that the three names might actually represent a single species, although the male of L. glabrus has a sternal pore plate whereas this is apparently absent in hungaricus. Given the few known specimens, it is not possible to know if these thrips live under bark and feed on fungal hyphae, or if the few specimens collected were actually leaf-feeders that were sheltering under bark. In this paper, a new species of the genus is described from southern Iran, based on both sexes. These specimens were extracted from leaf litter using a Berlese funnel, thus again it is not possible to be certain if the species is part of the community of fungus-feeding litter thrips, or if the specimens were merely sheltering. 

Moving past sporadic eruptions, discursive killing, and running amok: recognizing the convergence of the serial and spree killer

2019 ◽  
Vol 9 (3) ◽  
pp. 138-146 ◽  
Author(s):  
Enzo Yaksic
Keyword(s):  
Control Strategies ◽  
Gun Control ◽  
The Other ◽  
Management Skills ◽  
Content Type ◽  
Limited Mobility ◽  
Rapid Sequence ◽  
Clear Delineation ◽  
Serial Murderers ◽  
Practical Implications

Purpose Rapid sequence homicide offenders (RSHOs), formerly spree killers, are an understudied population due to the confusion surrounding their classification in relation to serial murderers. The paper aims to discuss this issue. Design/methodology/approach An exploratory, comparative analysis of 56 RSHOs and 60 serial murderers was conducted on US-based data from 2014 to 2018 derived from the Consolidated Serial Homicide Offender Database to determine similarities and differences between the cohorts. Findings RSHOs and serial murderers are similar in that they often kill their victims using a singular method, have limited mobility, kill a similar number of victims both known and unknown to them and are both supremely motivated by domestic anger. There is an inverse relationship between serial murderers and RSHOs: as one group increases in prevalence the other decreases. Practical implications In order to divert men into more pro-social activities, attention must be dedicated to increasing mental health services that provide them with the tools to diffuse their hatred and couple that with effective gun control strategies and ways to enhance the compromised anger management skills of a generation of volatile men. Originality/value Academicians have been hesitant to juxtapose these offenders but based this conclusion on surface-level differences. A reimagining of these categorical structures is needed. The once clear delineation between these cohorts may continue to shrink and synchronize until one subsumes the other.

scholarly journals Correlation between stability and energy variations in control strategies for mobile base robot with manipulators subjected to external disturbances

2019 ◽  
Vol 16 (3) ◽  
pp. 172988141984465
Author(s):  
Changman Son
Keyword(s):  
Control Strategies ◽  
Control Problems ◽  
Robot System ◽  
External Disturbances ◽  
Comprehensive Comparison ◽  
Degree Of Control ◽  
Robot Tasks ◽  
And Control ◽  
Mobile Base ◽  
Load Mass

The correlation between stability and energy variations in control strategies for a mobile base robot with manipulators subjected to external disturbances is introduced. The correlation results can be used to stabilize and control problems when a mobile base robot is subjected to various types of external disturbances. This is because different robot system energy values display different stability distribution curves. Mobile base robot stability based on varying system’s energy is described. Two control strategies, computed force/torque and adaptive compensators, are applied to minimize uncertainties accompanied by the robot’s movements. The two compensators are then compared by simulating applied external disturbances, such as mobile base tipping motion and load mass changes on the robot end-effector. A comprehensive comparison with other methods is also described. The proposed technique is a useful tool in the maintenance of the degree of control and stability of the system and has various applications in the mobile robot tasks including choosing and placing operations, maneuvering around the workspace with protruding obstacles on sinuous shape paths, and manufacturing tasks.

The Influence of Aircraft Characteristics on A.T.C. Problems

1961 ◽  
Vol 65 (606) ◽  
pp. 418-423 ◽  
Author(s):  
B. N. Tomlinson
Keyword(s):  
Traffic Control ◽  
Air Traffic Control ◽  
Supersonic Jet ◽  
Air Traffic ◽  
The Other ◽  
Control Problems ◽  
Operating Characteristics ◽  
Transport Aircraft

To provide a basis for discussion of air traffic control problems some of the operating characteristics of long haul subsonic and supersonic jet transport aircraft are examined. Two trans-Atlantic aircraft are compared, one designed to cruise at 500 knots (Mach 0·85) and the other at 1,250 knots (Mach 2·2).

Cryptic species complexes in manipulative echinostomatid trematodes: when two become six

Parasitology ◽  
2008 ◽  
Vol 136 (2) ◽  
pp. 241-252 ◽  
Author(s):  
T. L. F. LEUNG ◽  
D. B. KEENEY ◽  
R. POULIN
Keyword(s):  
Cryptic Species ◽  
Phylogenetic Analyses ◽  
Morphological Characteristics ◽  
Single Species ◽  
Distinct Species ◽  
Molecular Data ◽  
Spatial Segregation ◽  
Small Scale ◽  
Intermediate Hosts ◽  
Species Complexes

SUMMARYRecent studies have shown that some digenean trematodes previously identified as single species due to the lack of distinguishing morphological characteristics actually consist of a number of genetically distinct cryptic species. We obtained mitochondrial 16S and nuclear ITS1 sequences for the redial stages of Acanthoparyphium sp. and Curtuteria australis collected from snails and whelks at various locations around Otago Peninsula, New Zealand. These two echinostomes are well-known host manipulators whose impact extends to the entire intertidal community. Using phylogenetic analyses, we found that Acanthoparyphium sp. is actually composed of at least 4 genetically distinct species, and that a cryptic species of Curtuteria occurs in addition to C. australis. Molecular data obtained for metacercariae dissected from cockle second intermediate hosts matched sequences obtained for Acanthoparyphium sp. A and C. australis rediae, respectively, but no other species. The various cryptic species of both Acanthoparyphium and Curtuteria also showed an extremely localized pattern of distribution: some species were either absent or very rare in Otago Harbour, but reached far higher prevalence in nearby sheltered inlets. This small-scale spatial segregation is unexpected as shorebird definitive hosts can disperse trematode eggs across wide geographical areas, which should result in a homogeneous mixing of the species on small geographical scales. Possible explanations for this spatial segregation of the species include sampling artefacts, local adaptation by first intermediate hosts, environmental conditions, and site fidelity of the definitive hosts.

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