Termites of Iranian Date Palm Orchards And Their Spatial and Temporal Distribution

This study was conducted during 2013-2014 to determine the dominant species and behavior of termites foraging in date palm orchards in Khuzestan province, Iran. Starting in early March, the ‘cluster random sampling’ method was used within sixty-five sampling plots. Termite species were sampled by breaking open mud tubing and collecting different castes, then bringing them to the laboratory for identification using scientific keys. Glass microscope slides of different body parts, especially the labium, maxillae, palps, mandibles, labrum, and clypeus. The Simpson Diversity Index was used to determine the level of dominance. Results showed three species of termites, Microcerotermes diversus Silvestri, Microcerotermes buettikeri Chhotani and Bose and Amitermes vilis Hagen, all family Termitidae, are active in Khuzestan date palm plantations. Microcerotermes diversus was dominant with a correlation coefficient 0.997 and 8.87, respectively.  Seasonal population fluctuations of workers, nymphs, soldiers and winged castes had two, four, four and four peaks, respectively, over the years.  According to Kriging map spatial distribution, four geographic severity groupings for M. diversus can be considered.  These groups include low, medium, and high risk, and hotspot infestation geographic regions, with severity indices of 2.3 to 3.96, 3.97 to 4.82, 4.83 to 5.68, and 5.96 to 6.53, respectively

Intraspecific Aggressive Behavior of the Subterranean Termite Microcerotermes diversus Silvestri (Isoptera: Termitidae)

Considerando que todos os textos jornalísticos são narrativas e que a personagem é uma das categorias centrais do texto narrativo, o presente trabalho pretende, através do cruzamento entre os Estudos Narrativos e as Ciências da Comunicação, contribuir para o estudo da personagem em narrativas jornalísticas digitais. Para tal, recorre-se ao confronto entre a bibliografia e um estudo de caso, com um corpus constituído por três séries de reportagens digitais, de três órgãos de comunicação social portugueses: Público, Expresso e Rádio Renascença. Num primeiro momento, apresentamos o estado da arte, em que é feita a primeira abordagem ao tema do trabalho, articulando a teoria da personagem com as questões relacionadas com o ambiente digital. De seguida, é teorizada a personagem na narrativa jornalística, com base nas teorias construtivistas do jornalismo e na adaptação das teorias sobre a personagem ficcional, definindo-se aí que “a personagem jornalística é qualquer figura – individual ou coletiva – constante de uma narrativa jornalística, ao serviço de objetivos informativos e comunicacionais, construída de acordo com uma seleção de caraterísticas de uma pessoa com existência empírica”. Posteriormente, a narrativa e, mais precisamente, a reportagem, é caraterizada em ambiente digital, identificando-se o que é que a personagem pode ganhar ao ser construída nesse contexto, tirando partido, essencialmente, das caraterísticas inerentes a esse meio: hipertextualidade, não-linearidade, interatividade, convergência, multiplataforma, transmedialidade, imersão e multimodalidade. Antes de se concluir, são apresentados os resultados do estudo de caso, bem como o modelo de análise de personagens jornalísticas criado para analisar o corpus, que cruza os modelos de análise de personagens ficcionais com as técnicas de análise dos media, nomeadamente a análise de conteúdo e a análise do discurso

Laboratory Evaluation of Flurox, a Chitin Synthesis Inhibitor, on the Termite, Microcerotermes diversus

Microcerotermes diversus (Silvestri) (Isoptera: Termitidae) is the most economically destructive termite in structures in southwest Iran. One sustainable control strategy that usually helps to reduce subterranean termite damage in buildings, is the use of insect growth regualtors in a suitable bait matrix that are safe to the user and the environment. In the laboratory assays described here, the delayed toxicity of Flurox, a chitin synthesis inhibitor, to M. diversus was evaluated under force-feeding and choice trials. Flurox induced worker and nymph mortality and incomplete ecdysis in nymphs of M. diversus under no-choice and two-choice feeding tests. These adverse effects may cause disruption of the caste balance in M. diversus, leading to the collapse of the colony. These assays determined concentrations of Flurox that can be used in bait formulations

Application of Bait Treated with the Entomopathogenic Fungus Metarhizium anisopliae (Metsch.) Sorokin for the Control of Microcerotermes diversus Silv.

Microcerotermes diversus Silvestri (Isoptera, Termitidae) is considered to be the most destructive termite in Khuzestan province (Iran), and its control by conventional methods is often difficult. Biological control using entomopathogenic fungi could be an alternative management strategy. Performance of a bait matrix treated with the entomopathogenic fungus Metarhizium anisopliae (Metsch.) Sorokin, Strain Saravan (DEMI 001), against M. diversus was evaluated in this paper. The highest rate of mortality occurred at concentrations of 3.7 × 107 and 3.5 × 108 (conidia per mL). There was no significant difference between treatments, in the rate of feeding on the bait. The fungal pathogen was not repellent to the target termite over the conidial concentrations used. The current results suggest potential of such bait system in controlling termite. However the effectiveness of M. anisopliae as a component of integrated pest management for M. diversus still needs to be proven under field conditions

Evaluation of cellulose substrates treated with Metarhizium anisopliae (Metschnikoff) Sorokin as a biological control agent against the termite Microcerotermes diversus Silvestri (Isoptera: Termitidae)

This article is the first report on the promising effect of an entomopathogenic fungus, <em>Metarhizium anisopliae</em> (Metschnikoff) Sorokin to control populations of <em>Microcerotermes diversus </em>Silvestri. Biological control is an alternative to the long-term usage of chemical pesticides.<em> M. anisopliae</em>, the causal agent of green muscardine disease of insects, is an important fungus in biological control of insect pests. Bait systems can eliminate entire colonies of subterranean termites. Baiting reduces adverse environmental impacts caused by organochlorine and organophosphate pesticides in the control of termites and creates sustainable protection of buildings against their invasion. Treated-sawdust bait was applied by two methods: a) combination of treated sawdust and untreated filter paper, and b) combination of treated sawdust and untreated sawdust. When combinations of treated sawdust and untreated sawdust were used, LC50 and LC90 were 8.4&times;106 and 3.9&times;107 (spore/ml), respectively. With the use of improved bait formula and more virulent strains, we hope to achieve better control of termite colonies and enable pathogens to become a useful element in the Integrated Pest Management system

Differentiation of Five Species of Megachile (Hymenoptera: Megachilidae), based on Wing Shape

In the present work we used landmark-based geometric morphometrics to compare the wing shapes of five species of Megachile (belonging to three subgenera) to confirm whether this technique may be used reliably for differentiation of this group. Analyses of wing shape by the use of principal component analysis (PCA), and canonical variate analysis (CVA) led to a clear differentiation among species. We found a close phenotypic similarity in wing shape between M. albisecta (belonging to the subgenus Creightonella) and M. picicornis (belonging to the subgenus Eutricharaea). According to the results of UPGMA, a higher degree of divergence between M. farinosa (belonging to the subgenus Pseudomegachile) and species belonging to other subgenera, was detected. The results of a cross-validation test indicated that geometric morphometrics is an effective technique to use for distinguishing between Megachile species. The reliability rate of this technique was between 85.71-100%. Using only two submarginal cell landmarks for generating shape variables, the cross-validation test correctly assigned individuals to their respective species, with a 92.85-100% reliability rate. Significant differences in wing size were obtained among the analysed species

Horizontal Transmission of the Entomopathogen Fungus Metarhizium anisopliae in Microcerotermes diversus Groups

An experiment was carried out in order to investigate fungal conidia transmission of Metarhizium anisopliae (Metschnikoff) Sorokin from vector (donor) to healthy Microcerotermes diversus Silvestri (Iso.: Termitidae) and determine the best donor/concentration ratio for transmission. After preliminary trials, concentrations of 3.1 × 104, 3.9 × 105, 3.2 × 106 and 3.5 × 108 conidia mL−1 were selected for testing. The experiment was performed at three donor : Recipient ratios of 10, 30 and 50%. The highest mortality of recipient workers was observed after 14 days at the concentration of 3.5 × 108 conidia mL−1 and donor ratio of 50%. The mortality of recipient workers was less than 20% at all concentrations at a donor ratio of 10%. Our observations indicate social behavior of M. diversus, such as grooming, can be effective in promoting epizootic outbreaks in a colony. While the current results suggest good potential for efficacy, the use of M. anisopliae as a component of integrated pest management of M. diversus still needs to be proven under field conditions

Population Growth Parameters of <i>Helicoverpa armigera</i> (Hübner) on Various Legume Seeds Reveal Potential Tolerance Traits

Helicoverpa armigera (Hübner) is a key polyphagous pest with global spread that causes economic damage to agricultural crops. It is commonly managed by synthetic insecticides, which can cause negative impacts on the environment and human health, as well as toxicity to natural enemies. Hence, investigations into alternative pest management approaches such as the use of resistant host plant cultivars against H. armigera is important. In this study, the effects of various legume seeds based on meridic diets were evaluated using biology and population growth parameters of H. armigera under laboratory conditions. The results indicated that the shortest developmental time and pupal incubation periods occurred on white kidney bean Dehghan, while the longest periods occurred on broad bean Mahta. The intrinsic rate of population increase (r) was highest when H. armigera was reared on white kidney bean Dehghan and cowpea Arabi, and the lowest when reared on broad bean Mahta and common bean Khomein. Furthermore, the highest net reproductive rate (R0) occurred on white kidney bean Dehghan and the lowest on common bean Khomein. Cluster analysis revealed that white kidney bean Dehghan and cowpea Arabi were the most susceptible hosts, while common bean Khomein, and broad beans Feyz and Mahta were the poorest and perhaps least susceptible hosts for population growth of H. armigera. Our results suggest that the selective use of certain bean cultivars as potential sources of antibiosis against this pest may be useful as part of an integrated management program

Historical biogeography of Reticulitermes termites (Isoptera: Rhinotermitidae) inferred from analyses of mitochondrial and nuclear loci

International audienceTermites of the genus Reticulitermes are ecologically and economically important wood-feeding socialinsects that are widespread in the Holarctic region. Despite their importance, no study has yet attemptedto reconstruct a global time-scaled phylogeny of Reticulitermes termites. In this study, we sequencedmitochondrial (2096 bp) and nuclear (829 bp) loci from 61 Reticulitermes specimens, collected acrossthe genus’ entire range, and one specimen of Coptotermes formosanus, which served as an outgroup.Bayesian and Maximum likelihood analyses conducted on the mitochondrial and nuclear sequencessupport the existence of four main lineages that span four global geographical regions: North America(NA lineage), western Europe (WE lineage), a region including eastern Europe and western Asia(EA +WA lineage), and eastern Asia (EA lineage). The mitochondrial data allowed us to clarify the phylogeneticrelationships among these lineages. They were also used to infer a chronogram that was timescaled based on age estimates for termite fossils (including the oldest Reticulitermes fossils, which dateback to the late Eocene–early Oligocene). Our results support the hypothesis that the extantReticulitermes lineage first differentiated in North America. The first divergence event in the ancestral lineageof Reticulitermes occurred in the early Miocene and separated the Nearctic lineages (i.e., the NA lineages)from the Palearctic lineages (i.e., WE, EE + WA, and EA lineages). Our analyses revealed that themain lineages of Reticulitermes diversified because of vicariance and migration events, which were probablyinduced by major paleogeographic and paleoclimatic changes that occurred during the Cenozoic era.This is the first global and comprehensive phylogenetic study of Reticulitermes termites, and it provides acrucial foundation for studying the evolution of phenotypic and life-history traits in Reticulitermes. Forinstance, the phylogeny we obtained suggested that ‘asexual queen succession’, a unique reproductivesystem, independently evolved at least three times during the diversification of the genus