The biology of false wireworms and their adults (soil-inhabiting Tenebrionidae) (Coleoptera): a review

1980 ◽  
Vol 70 (3) ◽  
pp. 343-379 ◽  
Author(s):  
P. G. Allsopp
Keyword(s):  
Sex Chromosomes ◽  
Temporal Distribution ◽  
Basic Number ◽  
Life Cycles ◽  
Cultural Control ◽  
Pitfall Trapping ◽  
Important Species ◽  
Bacteria And Fungi ◽  
Definite Temperature ◽  
Direct Counts

AbstractSoil-dwelling tenebrionid larvae have developed in three evolutionary lines and are pests in all faunal regions. Description of and keys to most of the important species are available. However, revisional studies, on both adult and larval characters, are needed in many groups. The basic number of non-sex chromosomes appears to be 18, but the number and type of sex chromosomes are variable. Host ranges of both larvae and adults are usually extensive but usually only include plants. Development rates are related mainly to temperature, with life-cycles of one, two or three years. Larval development periods are rather long, and adults are long-lived. The number of instars is high, often above ten and frequently variable within a species. Sampling is best carried out by direct counts and pitfall trapping. In the species studied, mating follows a regular pattern and pheromones are involved. Species show definite temperature, moisture and soil-type preferences and these influence both spatial and temporal distribution. Recorded parasitoids include Diptera (mainly tachinids), Hymenoptera, mites, bacteria and fungi. Birds, carabids and a variety of other vertebrates are the main predators, but abdominal secretions and postural mechanisms provide some defence. Cultural control was formerly widely practised but has given way to chemical control.

Survey Results on Environmental Issues and Weed Science Research Priorities within the Corn Belt

1993 ◽  
Vol 7 (3) ◽  
pp. 763-770 ◽  
Author(s):  
Edward W. Stoller ◽  
Loyd M. Wax ◽  
David M. Alm
Keyword(s):  
Weed Control ◽  
Control Strategies ◽  
Research Priorities ◽  
Environmental Issues ◽  
Science Research ◽  
Life Cycles ◽  
Cultural Control ◽  
Corn Belt ◽  
Weed Species ◽  
Weed Science

A survey determined the views of individuals in seven groups comprising the weed science community in the corn belt (primarily in Illinois) for importance of 8 environmental and 14 crop production issues and 16 weed species in setting weed science research priorities for the next 3 to 5 yr. The survey also considered if funding of research to solve these environmental and production issues should be from the private or public sector. Velvetleaf, foxtail species, and common lambsquarters were considered the top three weed species by all respondents, and each of these weeds was among the five most important weeds within each of the seven survey groups. Improving ground and surface water quality were the foremost environmental issues for all respondents, but soybean growers listed herbicide carryover as their top environmental concern. Reducing herbicide residues in food and developing sustainable practices were given low preference by all groups. Sustainable growers rated reducing herbicide carryover and minimizing applicator exposure as their lowest priorities. Among all respondents, the top three production issues were improved weed control in conservation tillage, more economical weed control, and improved integrated control strategies. Studying the biology/life cycles of weeds was the third highest production priority of University and U.S. Department of Agriculture (USDA) weed scientists, but was the last choice when averaged over the aggregate survey group. Developing strategies for resistant weeds and herbicide-resistant crops were chemical dealers top two priorities. Industry representatives gave the former subject their highest rating and the latter their lowest rating. Crop consultants seemed to want decision aids, as they chose assessing weed loss/thresholds and developing weed control/economic models among their top three production issues. Both corn and soybean growers desired more economical weed control as a first choice, while sustainable growers wanted improved cultural control strategies. Corn and soybean growers ranked developing new herbicides among their top three choices, but this issue was the lowest choice of the sustainable growers. University, USDA, and industrial weed scientists suggested that their own organizations conduct the research on their highest priorities issues.

scholarly journals Late blight of potato and its management through the application of different fungicides and organic amendments: a review

2021 ◽  
Vol 4 (1) ◽  
pp. 301-320
Author(s):  
Injila Tiwari ◽  
Kabita Kumari Shah ◽  
Subina Tripathi ◽  
Bindu Modi ◽  
Sudeep Subedi ◽  
...  
Keyword(s):  
Disease Management ◽  
Late Blight ◽  
Organic Amendments ◽  
Preventive Measure ◽  
Life Cycles ◽  
Cultural Control ◽  
Crop Failure ◽  
Tropical Regions ◽  
Effective Interventions ◽  
Late Blight Of Potato

Late the blight  of  potato is  a  devastating  and  one of  the  economic diseases  of potato  and  other plants  belonging  to family Solanaceae. Late blight, caused by Phytophthora infestans, is one of the most threatening pathogenic diseases which not only results in direct crop losses but also cause farmers to embrace huge monetary expenses for disease control and preventive measure. It was first reported during the Irish Potato Famine, leading to massive starvation in Ireland and other parts of Europe during the middle of 19th century. Phytopthora harms the foliar portion in the field and also the tuber in the storage that can result in complete crop failure in potato. The pathogen has distinct survival mechanisms and two life cycles infection processes. The development of a sexual spore known as oospore includes two types of pairs, A1 and A2. The spores are introduced to good plants by wind and rain. Different methods for prevention of crops from late blight has been developed and used worldwide. An integrated disease management strategy includes successful control of this disease. Cultural control, chemical management, and advanced disease management are the most effective interventions. Integration of late blight control in tropical regions with abundant fungal inoculants in most months of the year was also seen as one of the best choices in disease management. This paper reviews the significance of late blight of potato and controlling strategies adopted for minimizing yield losses incurred by this disease by the application of synthetic fungicides and different organic amendments.

scholarly journals Extensive transcriptional changes in the aphid species Myzus cerasi under different host environments associated with detoxification genes

2018 ◽  
Author(s):  
Peter Thorpe ◽  
Carmen M. Escudero-Martinez ◽  
Sebastian Eves-van den Akker ◽  
Jorunn I.B. Bos
Keyword(s):  
Host Plant ◽  
Plant Species ◽  
Survival Rates ◽  
Aphid Species ◽  
Life Cycles ◽  
Controlled Environment ◽  
Primary Host ◽  
Important Species ◽  
Host Plant Species ◽  
Host Alternation

AbstractAphids are phloem-feeding insects that cause yield losses to crops globally. These insects feature complex life cycles, which in the case of many agriculturally important species involves the use of primary and secondary host plant species. Whilst host alternation between primary and secondary host can occur in the field depending on host availability and the environment, aphid populations maintained as laboratory stocks generally are kept under conditions that allow asexual reproduction by parthenogenesis on secondary hosts. Here, we used Myzus cerasi (black cherry aphid) to assess aphid transcriptional differences between populations collected from primary hosts in the field and those adapted to secondary hosts under controlled environment conditions. Adaptation experiments of M. cerasi collected from local cherry tress to reported secondary host species resulted in low survival rates. Moreover, aphids were unable to survive on secondary host Land cress, unless first adapted to another secondary host, cleavers. Transcriptome analyses of populations collected from primary host cherry in the field and the two secondary host plant species in a controlled environment showed extensive transcriptional plasticity to a change in host environment, with predominantly genes involved in redox reactions differentially regulated. Most of the differentially expressed genes across the M. cerasi populations from the different host environments were duplicated and we found evidence for differential exon usage. In contrast, we observed only limited transcriptional to a change in secondary host plant species.

scholarly journals Diversity and distribution of riffle beetle assemblages (Coleoptera, Elmidae) in montane rivers of Southern Brazil

2014 ◽  
Vol 14 (2) ◽  
Author(s):  
Bruna Marmitt Braun ◽  
Andrea Vanesa Batalla Salvarrey ◽  
Carla Bender Kotzian ◽  
Marcia Regina Spies ◽  
Mateus Marques Pires
Keyword(s):  
Temporal Distribution ◽  
High Water ◽  
Life Cycles ◽  
Rio Grande Do Sul ◽  
Beetle Assemblages ◽  
Tropical Areas ◽  
Spatio Temporal ◽  
Stream Depth ◽  
New Occurrences

The diversity and spatio-temporal distribution of Elmidae (Coleoptera) assemblages in montane rivers and streams of southernmost Brazil (Rio Grande do Sul state) were studied. Six genera were found, represented mostly by larval specimens. Austrolimnius and Macrelmis are new occurrences in the region. Assemblages’ genera composition and dominance were related to the presence of the macrophyte Podostemum. Also, water temperature and stream depth and velocity were the most important drivers related to the assemblages’ distribution. Richness and abundance were positively related to high water velocity and negatively to stream depth. Temporal patterns were detected especially in assemblage abundance, yet a slight pattern in richness was also observed. The seasonal structure was related to warm temperatures, but temporal distribution of Elmidae assemblages appears to be related to the dominant genera life cycles. The studied area shows an overall Elmidae richness similar to that found in some tropical areas and the role of mountainous environments in sustaining high rates of regional diversity in the Neotropics is stated.

The Control of Crematogaster Ants as a Means of controlling the Mealybugs transmitting the Swollen-shoot Virus Disease of Cacao in the Gold Coast

1956 ◽  
Vol 47 (2) ◽  
pp. 219-226 ◽  
Author(s):  
A. D. Hanna ◽  
E. Judenko ◽  
W. Heatherington
Keyword(s):  
Virus Disease ◽  
Active Material ◽  
Gold Coast ◽  
Important Species ◽  
Ant Nests ◽  
Large Populations ◽  
The Dead ◽  
Bacteria And Fungi ◽  
Wood Boring ◽  
Continuous Source

The most important species of Pseudoeoccid transmitting the swollen-shoot virus disease in the Gold Coast is Pseudococcus njalensis Laing. It is almost always attended by ants of the genus Crematogaster. These ants usually build their nests in the cavities and galleries that have already been excavated by wood-boring insects in the dead branches of cacao trees. The only apparent advantage of this association to the ants is to imbibe the honeydew secreted from the anal orifice of the mealybugs; if this is allowed to accumulate it becomes a medium for bacteria and fungi which seems to kill the mealybugs eventually.Attempts were made to break the link between the mealybugs and ants by spraying six cacao trees, not in contact with each other or any other trees, each with 3·5 litres of 0·2 per cent. DDT emulsion, twice at two-week intervals. All dead branches containing nests of ants were cut out, and a band of grease painted, on the trunk, one foot above the soil level to prevent the ants climbing up. Four weeks after the first application of spray, the population of mealybugs was brought down to 1·2 per cent, of its size before treatment. Unfortunately locating the ant nests, especially in the crevices and under the bark, is very difficult. Experiments were therefore carried out in which the trees were sprayed without previously eliminating all the sources of ants. The results were unsatisfactory, the size of the mealybug population, compared with that before treatment, after four, six and eight weeks was 16·9, 39·4 and 92·3 per cent., respectively, in the case of 0·2 per cent. DDT emulsion, and 11·6, 64·3 and 58·8 per cent., respectively, in the case of a treatment consisting of 3·5 litres per tree of a mixture of 0·2 per cent. DDT and 0·02 per cent, parathion active material. Cutting off the dead branches containing ant nests, followed by either painting the cut end of the dead branches with DDT (16·7 per cent, emulsion) or painting the trunk with a band of the same emulsion also gave poor results.The unsatisfactory results obtained by spraying are attributed to the fact i that only the ants that happen to be exposed are affected by the application of ithe insecticide; the immature stages inside the nests are not touched.The efficiency of dimefox when applied to the soil at 0·8 gm. active material per inch of tree girth was not increased when the ants had previously been partially eliminated.Treated cacao trees could not in practice be completely isolated from forest jtrees and climbers containing nests of Crematogaster ants and these provide a continuous source of large populations. It is, therefore, considered that the icomplete elimination of ants is not possible.It was also found that there is a relationship between the population of mealybugs and ants. Trees were usually free from mealybugs if no ants were found on them. The examination of isolated cacao trees with different sizes of dead branches containing nests of ants suggests that the number of mealybugs 38 in proportion to the size of the nests.

scholarly journals Novel Endochin-Like Quinolones Exhibit Potent In Vitro Activity against Plasmodium knowlesi but Do Not Synergize with Proguanil

2020 ◽  
Vol 64 (5) ◽  
Author(s):  
Donelly A. van Schalkwyk ◽  
Michael K. Riscoe ◽  
Sovitj Pou ◽  
Rolf W. Winter ◽  
Aaron Nilsen ◽  
...  
Keyword(s):  
Plasmodium Knowlesi ◽  
Ex Vivo ◽  
Life Cycles ◽  
The Novel ◽  
Important Species ◽  
Content Type ◽  
Ongoing Development ◽  
Multiple Species ◽  
Derivatives Of

ABSTRACT Quinolones, such as the antimalarial atovaquone, are inhibitors of the malarial mitochondrial cytochrome bc1 complex, a target critical to the survival of both liver- and blood-stage parasites, making these drugs useful as both prophylaxis and treatment. Recently, several derivatives of endochin have been optimized to produce novel quinolones that are active in vitro and in animal models. While these quinolones exhibit potent ex vivo activity against Plasmodium falciparum and Plasmodium vivax, their activity against the zoonotic agent Plasmodium knowlesi is unknown. We screened several of these novel endochin-like quinolones (ELQs) for their activity against P. knowlesi in vitro and compared this with their activity against P. falciparum tested under identical conditions. We demonstrated that ELQs are potent against P. knowlesi (50% effective concentration, <117 nM) and equally effective against P. falciparum. We then screened selected quinolones and partner drugs using a longer exposure (2.5 life cycles) and found that proguanil is 10-fold less potent against P. knowlesi than P. falciparum, while the quinolones demonstrate similar potency. Finally, we used isobologram analysis to compare combinations of the ELQs with either proguanil or atovaquone. We show that all quinolone combinations with proguanil are synergistic against P. falciparum. However, against P. knowlesi, no evidence of synergy between proguanil and the quinolones was found. Importantly, the combination of the novel quinolone ELQ-300 with atovaquone was synergistic against both species. Our data identify potentially important species differences in proguanil susceptibility and in the interaction of proguanil with quinolones and support the ongoing development of novel quinolones as potent antimalarials that target multiple species.

scholarly journals Karyotypic Studies in Ecotypes of Hippophaë rhamnoides L. from Romania

2010 ◽  
Vol 59 (1-6) ◽  
pp. 175-182 ◽  
Author(s):  
Elena Truţǎ ◽  
G. Cǎpraru ◽  
Ş. Surdu ◽  
M.-M. Zamfirache ◽  
Z. Olteanu ◽  
...  
Keyword(s):  
X Chromosome ◽  
Sex Chromosomes ◽  
Ploidy Level ◽  
Basic Number ◽  
Hippophae Rhamnoides ◽  
Small Tree ◽  
Hippophaë Rhamnoides ◽  
Physiological Variability ◽  
Male Sex ◽  
Hippophae Rhamnoïdes L

Abstract Sea buckthorn is a dioecious Eurasian shrub or small tree with large morphological, biochemical and physiological variability, evidenced by the great number of studies. Cytogenetically, uncertainties exist on species basic number, ploidy level, and sex chromosomes. In this study, detailed cytogenetic measurements were carried out on six Romanian ecotypes belonging to Hippophaë rhamnoides L. ssp. carpatica Rousi, in order to establish the features and the symmetry degree of karyotypes, to evidence the sex chromosomes, and to construct the idiogram. The ecotypes have 2n = 24 metacentric and submetacentric chromosomes. An intraspecific variation exists concerning the proportion of these two morphotypes. The karyotypes have similar symmetry patterns (R = 2.57-2.89; TF%= 38.54-42.70; AsI%= 57.99-61.41; A1=0.27-0.35; A2 = 0.26-0.36) and belong to 1B and 2B classes, being relatively high symmetric. Based on obtained results, we presume that the male sex chromosomes are heteromorphic, while in female plants are homomorphic. The Y chromosome is larger than X chromosome.

scholarly journals Keystone Species on New Zealand Offshore Islands: Ecological Relationships of Seabirds, Rats, Reptiles and Invertebrates on Cook Strait Islands

2021 ◽  
Author(s):  
◽  
Timothy J Markwell
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
C:N Ratio ◽  
Isotope Analysis ◽  
Keystone Species ◽  
Pitfall Trapping ◽  
Island Ecosystems ◽  
Important Species ◽  
Positive Effects ◽  
Lower Abundance

<p>The influence of seabirds and rats on island ecosystems was measured to assess the applicability of the keystone species concept for ecology and conservation. Pitfall trapping for lizards and small invertebrates, soil sampling and stable isotope analysis was used to assess the roles played by seabirds and rats on six islands in the Marlborough Sounds. Both abundance and ordinal richness of invertebrates were found to be greater on islands with seabirds than on seabird-free islands. Although lizard distribution was strongly influenced by species-specific habitat requirements, the greatest numbers of lizards recorded in this study were found on seabird-inhabited islands. Although significant differences were not found, the C:N ratio of soils in seabird colonies in this study and at other sites was lower than that at seabird-free sites. Nitrogen stable isotope analysis showed that a proportion of the diet of animals at a range of different levels throughout the island foodweb was derived from seabirds. Rats were found to negate many of the positive effects of seabirds. As well as significantly lower numbers of seabirds, islands with rats had lower abundance of lizards and lower abundance and diversity of mall invertebrates than rat-free islands. Although both seabirds and rats play important roles in island ecosystems, neither conformed to a definition of a keystone species. Theoretical and practical problems were found with the calculation of keystone status for different taxa. Given that important species cannot be shown to be keystones, and that calculation is technically difficult (and maybe impossible) the classification of seabirds, rats, or any other species as keystone is not likely to advance theoretical ecology or assist with conservation management. Attempts to define keystone species were found to be unsuccessful and abandonment of the term was advised.</p>

Biology, Ecology and Control of Soldier Flies Inopus Spp (Diptera, Stratiomyidae) - a Review

1988 ◽  
Vol 36 (6) ◽  
pp. 627 ◽  
Author(s):  
PG Allsopp ◽  
LN Robertson
Keyword(s):  
Sugar Cane ◽  
Population Biology ◽  
Host Plants ◽  
Control Strategies ◽  
Cultural Control ◽  
Important Species ◽  
Sampling Plans ◽  
Development Processes ◽  
And Control

The taxonomy and identification of the soldier flies, Inopus spp., their distribution, host plants, population biology and dynamics, and their chemical and cultural control are reviewed. Previous work has concentrated on I. rubriceps (Macquart), the most economically important species and a pest of sugar cane in Australia and pastures in New Zealand. Areas where further study is desirable include: the taxonomy and distribution of the genus; effects of host plants on development; processes involved in the inhibition of ratooning of sugar cane; detailed life-table studies on different host plants and different cultivars of sugar cane; damage and intervention thresholds and statistically based sampling plans for sugar cane; factors influencing pupation; the contribution of predation, parasitism and disease to mortality; control with insecticides other than organochlorines; the long-term need for insecticides; and control strategies other than insecticide treatments.

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