Thuringiensis Isolates Research Articles

Bacillus thuringiensis isolates from Egyptian soils and their potential activity against lepidopterous insects

This study aims to search for indigenous Bacillus thuringiensis (Bt) strains from the soils of different locations representing 11 Egyptian governorates. A total of 2671 colonies from 93 soil samples were examined. The total number of Bt positive soil samples was 40/93 i.e. 43.01%. The results indicate that the percentage of the occurrence of Bt in these samples was 3.818%. The Egyptian soil showed to be rich in Bt. The evaluation of the potential activity of 40 positive soil isolates against Spodoptera littoralis and Helicoverpa (=Heliothis) armigera was carried out. Subsequently, LC50 and LC90 values and the potency of the Bt isolates were determined when applied against the target insects with reference to three standard preparations.

Characterisation of Bacillus thuringiensis mutant highly producing melanin pigment and active against potato tuber moth

The bacteria Bacillus thuringiensis mutant is highly producing melanin pigment with increased ultra violet resistance and insecticidal activity against the potato tuber moth Phthorimaea operculella (Zeller). The results showed that the high decrease of crystal protein formation rate ranged from 100% (B.t.EMS-M2 and B.t.EMS-M6) to 91.82% (B.t.EMS-M9). The EMS–UV-induced mutants (B.t.EMS–UV-2h-1, B.t. EMS–UV-2h-2, B.t.EMS–UV-2h-3, B.t.EMS–UV-2h-5, B.t.EMS–UV-4h-1, B.t.EMS–UV-4h-3 and B.t.EMS–UV-6h-2) showed 100% decrease in the crystal protein formation. Results also showed that the growth rate of B. thuringiensis isolates was detected by measuring the light absorption of culture broth (BP media at pH 8) at the wavelength of 600 nm. The absorbance values of the standard melanin were 2.055 and 0.134 at wavelengths of 226.5 and 602 nm, respectively. This means that the maximum absorbance at wavelength was 226.5 nm, this result is similar to that of the synthetic melanin which has the absorbance of 226 nm. Our experiments detected that the pigment extracted from the mutant isolate B.t.EMS-M3 (EMS-induced mutant) gave the maximum value of absorbance (2.615) at wavelength of 227.5 nm that was similar to standard melanin which gave absorbance value about 2.055 at a wavelength of 226.5 nm. This may be due to the genetic alterations that happened to the mutant isolates due to the mutation by EMS or/and UV irradiation.

Characterization of Insecticidal Genes of Bacillus thuringiensis Strains Isolated from Arid Environments

This study aimed at characterizing the insecticidal genes of eight Bacillus thuringiensis isolates that were recovered from the local environment of western Saudi Arabia. The screening for the presence of lepidopteran-specific cry1A family and vip3A genes, dipteran-specific cry4 family and coleopteran-specific cry3A, vip1A and vip2A genes, was carried out by PCR. All eight isolates produced PCR products that confirmed the presence of cry1Aa, cry1Ab, cry1Ac, cry4A, cry4B genes, but not cry3A, vip1A and vip2A genes. However, three isolates only were found to carry vip3A genes as revealed by PCR. The observation of cry1 and cry4 genes suggests that these eight isolates may have dual activity against Lepidoptera and Diptera species, while three isolates possessed vip3 genes in addition to cry1 and cry4 which suggests that these three isolates have toxic crystals and vegetative proteins. The results of this study are interesting in the sense that they may help developing new strategies for controlling insects of economic and medical importance in Saudi Arabia, using B. thuringiensis strains that naturally exist in the local environment instead of the current control strategies that are based solely on chemical insecticides.

GC/MS Method for Positive Detection of Bacillus anthracis Endospores

A simple method was developed for detection of Bacillus anthracis (BA) endospores and for differentiation of them from other species in the Bacillus cereus group. Chemical profiles that include lipids (i.e., fatty acids), carbohydrates (i.e., sugars), and the spore-specific biomarker, dipicolinic acid, were generated by one-step thermochemolysis (TCM) at 140 °C in 5 min to provide specific biomarker signatures. Anthrose, which is a biomarker characteristic of the B. cereus group of bacteria, was determined from a fragment produced by TCM. Surprisingly, several virulent BA strains contained very low levels of anthrose, which confounded their detection. A statistical discrimination algorithm was constructed using a combination of biomarkers, which was robust against different growth conditions (medium and temperature). Fifteen endospore-forming Bacillus species were confirmed in a statistically designed test (~90%) using the algorithm, including six BA strains (four virulent isolates), five B. thuringiensis (BT) isolates, and one isolate each for B. cereus (BC), B. mycoides (BM), B. atrophaeus (BG), and B. subtilis (BS). The detection limit for B. anthracis was found to be 50,000 endospores, on the basis of the GC/MS detection limits for 3-methyl-2-butenoic acid methyl ester, which is the biomarker derived from TCM of anthrose.

Bacillus thuringiensis isolates from Korean forest environments

We investigated the distribution, toxicity, morphology, and protein profiles of Bacillus thuringiensis isolates from forests in Korea to isolate naturally occurring novel B. thuringiensis. A total of 170 B. thuringiensis isolates were obtained from 832 samples producing spore and parasporal inclusion bodies. In toxicity tests for lepidopteran, dipteran, and coleopteran insects, 57.6% isolates were toxic only to Lepidoptera, 5.3% were toxic only to Diptera, and 24.1% were toxic to both Diptera and Lepidoptera. The remaining collections (13.0%) were not toxic to the tested insects. The shapes of the parasporal crystals produced in B. thuringiensis isolates were bipyramidal, spherical, ovoid, or irregular. As their toxicities varied with parasporal crystal shape, B. thuringiensis isolates possessing bipyramidal or irregular parasporal crystals were largely toxic to lepidopteran species whereas those producing spherical parasporal crystals were mainly toxic to dipteran species. B. thuringiensis toxic to both dipteran and lepidopteran insects contained 130- and 70-kDa parasporal crystals, whereas B. thuringiensis toxic to lepidopteran insects expressed 130-kDa parasporal crystals. The results suggest that forest areas in Korea are a rich source of B. thuringiensis and need to be further explored to discover novel B. thuringiensis isolates.

Molecular typing of native <i>Bacillus thuringiensis</i> isolates from diverse habitats in India using REP-PCR and ERIC-PCR analysis

Bacillus thuringiensis is a bacterium of great agronomic and scientific interest. The subspecies of this bacterium colonize and kill a large variety of host insects and even nematodes, but each strain does so with a high degree of specificity. Therefore molecular typing and diversity analysis of B. thuringiensis has enormous importance for discrimination of strains isolated from different sources. In this study, 113 native B. thuringiensis isolates collected from diverse habitats and locations in India and 27 B. thuringiensis type strains obtained from the Bacillus Genetic Stock Centre (BGSC), Ohio State University, USA and used as reference, were analyzed for molecular typing. Genotypic data of 140 B. thuringiensis isolates and type strains was generated by using REP-PCR and ERIC-PCR primers and unweighted pair group method with arithmetic mean (UPGMA) analysis using NTSYSpc2.2 and grouped into 4 main clusters. All the groups have isolates from diverse origins. No group was found to represent any specific origin or location. The observed patterns of REP-PCR and ERIC-PCR pattern were discriminatory enough to reveal differences in the B. thuringiensis isolates and reference strains. The resolution power and marker index of the ERIC-PCR (RP 9.39, MI 6.34) was found to be higher than that of the REP-PCR (RP 6.20, MI 4.48). The REP-PCR and ERIC-PCR markers have been found to be useful for discrimination of B. thuringiensis isolates and reference strains. ERIC-PCR was the more informative of the two techniques. This study showed that the B. thuringiensis isolates collected from diverse habitats in India had a high degree of genetic diversity.

A study on the characterization and pathogenicity of bacteria from Lymantria dispar L. (Lepidoptera: Lymantriidae)

Gypsy moth, Lymantria dispar L. (Lepidoptera: Lymantriidae), is one of the most serious pests affecting fruit, forest, industrial, and foliage plants worldwide. The aim of this study was to isolate and characterize pathogenic bacteria from this pest and determine their pathogenicity. L. dispar larvae were collected from various populations in the forest areas of the Black Sea region of Turkey in May and June of 2008 and 2009, and 9 culturable bacterial isolates were obtained from these larvae. Morphological and physiological characteristics of bacterial isolates were determined by conventional and routine techniques, and biochemical properties and metabolic enzyme profiles were revealed using API20E and Phoenix 1000A panel test systems. Additionally, a 16S rRNA gene sequence analysis was performed to identify the isolates at the molecular level and to query against the NCBI genetic database. Consequently, 7 of the bacterial isolates were determined and characterized at the species level while the rest were characterized at the genus level. From the results of all tests, the isolates were identified as Pantotea agglomerans (Lyd1), Klebsiella sp. (Lyd2), Acinetobacter calcoaceticus (Lyd3), Serratia marcescens (Lyd4), Erwinia sp. (Lyd5), Bacillus thuringiensis (Lyd6), B. thuringiensis (Lyd7), B. thuringiensis (Lyd8), and B. thuringiensis (Lyd9). Of all bacterial isolates tested for insecticidal activity, 2 of the B. thuringiensis isolates (Lyd6 and Lyd9) were found to cause the highest insecticidal activity (90%) within 10 days of application. Furthermore, 100% insecticidal activity was observed with a crystal-spore mixture of the same isolates against Lymantria dispar larvae within 10 days.

Caracterização de novos isolados de Bacillus thuringiensis para o controle de importantes insetos-praga da agricultura

A bactéria Bacillus thuringiensis Berliner produz um corpo de inclusão paraesporal (cristal) de natureza proteica, formado durante a esporulação, que atua de forma eficiente no controle de insetos-praga de culturas economicamente importantes. Esse cristal é constituído de proteínas Cry, que são codificadas pelos genes cry; um isolado pode ser caracterizado pelo conteúdo de genes cry que apresenta. Visando caracterizar novos isolados no combate de insetos-praga pertencentes às ordens Lepidoptera e Coleoptera, 76 isolados bacterianos foram analisados molecularmente e tiveram seu potencial de controle avaliado por meio de bioensaios com larvas de Spodoptera frugiperda (J.E. Smith), Sphenophorus levis Vaurie e Tenebrio molitor Linnaeus. As análises moleculares indicaram 11 isolados (14,5% da coleção), contendo genes lepidóptero-específicos e 17 (22,37%) com genes coleóptero-específicos. As análises de patogenicidade revelaram dois isolados com alto potencial de controle para lagartas de S. frugiperda, um para larvas de S. levis e seis prejudiciais ao desenvolvimento das larvas de T. molitor. Esses isolados de B. thuringiensis podem ser promissores no controle biológico das referidas pragas.

Molecular characterisation of Bacillus thuringiensis isolates from the Egyptian soils

Molecular characterisation of nine different Bacillus thuringiensis isolates from the soil of different Egyptian governorates and with varying activities against some lepidopterous insects was carried out using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), polymerase chain reaction (PCR) and randomly amplified polymorphic DNA (RAPD)-PCR analysis. Molecular weights of the major components of the crystal proteins of the tested strains revealed that those strains with bands 39 and 141 KDa would be possibly potent against the cotton leafworm Spodoptera littoralis (Biosduval) (Lepidoptera: Noctuidae), those with bands 39–73 and 104–178 KDa showed toxicity against the American bollworm Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) and those with bands 25–3 and 135 KDa may be toxic to the pink bollworm Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae). PCR analysis indicates that the frequency of the cry 1 genes predominated 72.41% of isolates amplifying cry 1 gene. DNA fingerprinting-based randomly amplified polymorphic DNA (RAPD) techniques proved to be a reliable method for identification of different B. thuringiensis strains at the DNA level.

Cloning and expression of novel coleopteran active cry genes from native Bacillus thuringiensis isolates

Cloning and expression of novel coleopteran active cry genes from native Bacillus thuringiensis isolates

Characterization of Bacillus thuringiensis isolates with potential for control of Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae)

Aedes aegypti (Linnaeus) is the vector of dengue virus in Brazil. Bioinsecticides based on Bacillus thuringiensis have shown satisfactory results in the control of Diptera, due to the production of proteins called Cry and Cyt. The aim of the present study was to select B. thuringiensis isolates carrying the cry and cyt genes, which are efficient in the control of Ae. aegypti. A collection of 27 isolates of B. thuringiensis, derived from various regions in Brazil, was evaluated using selective bioassays against A. aegypti larvae. Of the 27 isolates, five showed 100% larval mortality at a concentration of 0.05ppm and the toxicity of these isolates in quantitative bioassays did not differ significantly at temperatures of 15, 25 and 35°C. In addition, these isolates showed statistical differences for the LC50 values only above pH 9, which indicates a maintenance in insecticide potential in a wide range of alkaline pH values. This result is promising, considering that waste treatment reservoirs generally show an acid pH and higher temperatures. These isolates were also evaluated by PCR using specific primers for the genes cry4A, cry4B, cry10A, cry11, cyt1 and cyt2. The analyses demonstrated that all the five isolates showed amplification products for all the studied genes showing four different Cry proteins, besides Cyt proteins. The obtained results of bioassays and PCR demonstrates the great potential for the use of these isolates in controlling populations of Ae. Aegypti and perhaps other species of mosquitoes in a wide range of environments.

EKSPLORASI BAKTERI ENTOMOPATOGENIK PENGENDALI HAMA Plutella xylostella DAN Spodoptera Sp. PADA TANAMAN KUBIS BUNGA DAN BROKOLI

ABSTRACT The research aimed to explore potential entomopathogenic bacteria as biological control agent for insect pest of P. xylostella and Spodoptera sp. in cabbage and broccoli. The indigenous bacteria were explored by taking 103 samples from location around North Sulawesi. Bacteria were selectively isolated by using Ohba and Aizawa method and then identified based on morphology. Subsequently the isolates were screened by their potency to kill test insect of P. xylostella and Spodoptera sp. The isolates were able to kill ≥ 50 % test insect considered as potential for biological control. The potential isolates were then selected and would be developed as powder and liquid bio-pesticide through large scale production. The result of the study showed that 145 Bacillus thuringiensis isolates and 202 Bacillus cereus isolates were obtained from 103 samples. The screening of the isolates based on standard test insect for cabbage and broccoli were in progress. The potential isolates would be further selected on the basis of their pathogenicity test. Based on pathogenecity test, chosen isolates will be developed as bio-pasticide to control insect pest of cabbage and broccoli. Keywords : Exploration, entomopathogenic bacteria, biological control, Plutella xylostella, Spodoptera Sp.

Molecular Characterization of Novel Serovars of Bacillus thuringiensis Isolates from India

Novel Bacillus thuringiensis isolates GS4, GN24 and UP1 were isolated and characterized by determination of serotyping, insecticidal protein by SDS-PAGE, plasmid composition, cry gene content and insect toxicity. Serologically two isolates GS4 and UP1 were allocated to the H3abce which is a new serovar while isolate GN24 was of H3ab type. Isolate GS4 produced flat crystal inclusions while UP1 produced cuboidal crystals. PCR analysis found that both isolates contained cry1 and cry1Ac genes. The major protein bands found of isolate GS4 were of molecular weights 175, 135, 97, 88, 66, 54 and 27kDa, isolate UP1 were of 85, 60 and 40kDa and isolate GN24 were of 130, 90, 66 and 45kDa. Though isolates GS4 and UP1 belonged to a new serovar H3abce, they showed different crystal inclusions and cry gene content. Isolate GS4 was toxic to lepidopteran insect larvae of Helicoverpa armigera but UP1 did not showed any toxicity.

A pangenomic study of Bacillus thuringiensis

Bacillus thuringiensis (B. thuringiensis) is a soil-dwelling Gram-positive bacterium and its plasmid-encoded toxins (Cry) are commonly used as biological alternatives to pesticides. In a pangenomic study, we sequenced seven B. thuringiensis isolates in both high coverage and base-quality using the next-generation sequencing platform. The B. thuringiensis pangenome was extrapolated to have 4196 core genes and an asymptotic value of 558 unique genes when a new genome is added. Compared to the pangenomes of its closely related species of the same genus, B. thuringiensis pangenome shows an open characteristic, similar to B. cereus but not to B. anthracis; the latter has a closed pangenome. We also found extensive divergence among the seven B. thuringiensis genome assemblies, which harbor ample repeats and single nucleotide polymorphisms (SNPs). The identities among orthologous genes are greater than 84.5% and the hotspots for the genome variations were discovered in genomic regions of 2.3-2.8Mb and 5.0-5.6Mb. We concluded that high-coverage sequence assemblies from multiple strains, before all the gaps are closed, are very useful for pangenomic studies.

Qatari Bacillus T huringiensis Strains: Gene Bank and Molecular Investigation of the Insecticidal d-endotoxins and Coding Genes Towards a Sustainable Qatari and Gulf Environment Free from Chemical Pesticides

B. thuringiensis is a gram-positive bacterium which produces, during sporulation, crystalline inclusions containing one or more delta-endotoxins. The latter are selectively toxic against a wide variety of insects, including important pests. Formulations based on B. thuringiensis have been used safely in developed countries as bioinsecticides for agriculture, forestry and disease vector control. This kind of bioinsecticides occupies the first place in the biopesticides world market and is essential for crop protection. The importance of such bioinsecticides and the emergence of new insect resistance cases, promoted worldwide isolation and screening programmes of new strains with particularly high insecticidal activities. This project aims to develop an integrated approach that will explore activities of new B. thuringiensis isolates from Qatar and the Gulf region, an unexplored region, by performing an important programme of B. thuringiensis strains isolation from Qatar, screening using modern molecular techniques, gene investigation and bioassays. The screening of 151 B. thuringiensis strains isolated from Qatar, allowed the evidence of strains having different crystal forms. In fact, these strains produce parasporal crystals that have pyramidal, bipyramidal, cubical, spherical and amorphous forms. These results demonstrate the heterogeneity and the fact that they produce different bioinsecticides acting on different insect families. Among these B. thuringiensis strains, only 58 strains produce bipyramidal crystals (38 %). Similar results were obtained in the laboratory by Al-Zahra Attar and Sara Zakzouk who have screened respectively 199 and 87 other strains and obtained about the same ratio of bipyramidal crystal producing strains. The latter plasmid DNAs were analyzed showing different plasmid patterns. These results demonstrate that the bipyramidal crystal producing strains belong to different families. By PCR and electrophoresis of the amplified DNA fragments, we could predict the nature of the delta-endotoxin coding genes and the delta-endotoxin insecticidal activities. All the studied strain has protease activities except one that is protease minus. Such is very rare among Bacillus thuringiensis strains, but exists in Qatar. This strain is of high industrial value, since preventing proteolysis of delta-endotoxin and secreted active proteins and enzymes and could be considered as a suitable host for stable heterologous gene expression and protein secretion.

Diagnostic properties of three conventional selective plating media for selection of Bacillus cereus, B. thuringiensis and B. weihenstephanensis

The aim of this study was to assess the diagnostic properties of the two selective plating media and a chromogenic medium for identification of Bacillus cereus. The 324 isolates were B. cereus (37%), Bacillus weihenstephanensis (45%) or Bacillus thuringiensis (18%), as identified by a new combination of techniques. All isolates were growing on mannitol-egg yolk-polymyxin agar (MYP), and they did not form acid from mannitol. However, a significant lower number of B. thuringiensis isolates did not show lecithinase activity. All isolates were also growing on polymyxin-egg yolk-mannitol-bromothymol blue agar (PEMBA); however, 11% isolates indicated that they did produce acid from mannitol, and 15% isolates did not show any lecithinase activity. Five of the isolates did not grow at all on the chromogenic agar, and 14 of the growing isolates were β-glucosidase negative. It is concluded that the two recommended selective plating media MYP and PEMBA for detection of B. cereus group bacteria both have their limitations for identification of some B. cereus, B. weihenstephanensis or B. thuringiensis. However, MYP is preferable compared to PEMBA. The chromogenic medium has its own advantages and limitations, and some of the limitations seem to be solved by incubation at 30°C instead of the recommended 37°C.

Use of mixed cultures of biocontrol agents to control sheep nematodes

Biological control is a promising non-chemical approach for the control of gastrointestinal nematodes of sheep. Use of combinations of biocontrol agents have been reported to be an effective method to increase the efficacy of biological control effects. In this study, combinations of either two Bacillus thuringiensis (Bt) or Clonostachys rosea (C. rosea) isolates and Bt+C. rosea isolates were evaluated in vitro in microtitre plates for their biocontrol activity on sheep nematodes. The Baermann technique was used to extract the surviving L3 larval stages of intestinal nematodes and counted under a dissecting microscope to determine the larval counts. Results indicate that there was a significant reduction of nematode counts due to combination of biocontrol agents (P<0.001). Combinations of Bt isolates reduced nematodes counts by 72.8%, 64% and 29.8%. The results revealed a control level of 57% when C. rosea isolates P3+P8 were combined. Combination of Bt and C. rosea isolates B10+P8 caused the greatest mortality of 76.7%. Most combinations were antagonistic, with only a few combinations showing an additive effect. None were synergistic. The isolate combinations were more effective than when isolates were used alone.

Single cysteine substitution in Bacillus thuringiensis Cry7Ba1 improves the crystal solubility and produces toxicity to Plutella xylostella larvae

Many Bacillus thuringiensis isolates have no demonstrated toxicity against insects. In this study, a novel holotype crystal protein gene cry7Ba1 was isolated from a 'non-insecticidal'B. thuringiensis strain YBT-978. The Cry7Ba1 protein showed high toxicity against Plutella xylostella larvae after the crystals were dissolved at pH 12.5, suggesting that the 'non-insecticidal' properties of this protein were due to insolubility in the normal insect midgut pH environment. After the C-terminal half of Cry7Ba1 was replaced by that of Cry1Ac or Cry1C proteins, the recombinant protein inclusions could be dissolved at pH 9.5, and exhibited high toxicity against P. xylostella larvae. This result proved the insolubility of Cry7Ba1 crystal was determined by the structure of its C-terminal half. Further, six mutations were constructed by substituting cysteine residues with serine. Solubility studies showed that the crystals from mutants C697S, C834S and C854S could be dissolved at lower pH (10.5, 9.5 and 11.5 respectively). Bioassays showed that crystals from mutant C834S were toxic to P. xylostella larvae. Our discoveries suggest that a single cysteine residue located in the C-terminal half of the protein determines the solubility and toxicity of some nontoxic crystal proteins. This study provides a strategy to isolate novel insecticidal crystal protein genes from 'non-insecticidal'B. thuringiensis strains.

Identificação e caracterização de genes vip e cry coleóptero‑específicos em isolados de Bacillus thuringiensis

O objetivo deste trabalho foi identificar e caracterizar os genes cry3, vip1, vip2 e vip1/vip2 em uma coleção de 1.078 isolados de Bacillus thuringiensis potencialmente tóxicos para larvas de coleópteros. Foram utilizados pares de oligonucleotídeos iniciadores gerais obtidos a partir de regiões conservadas dos genes e do alinhamento de sequências consenso. Posteriormente, os isolados positivos foram caracterizados por meio da técnica de PCR‑RFLP, tendo-se utilizado enzimas de restrição específicas, para identificar novas subclasses de genes nos isolados. Cento e cinquenta e um isolados foram positivos para os genes avaliados, com maior frequência para o gene vip1/vip2 (139 isolados). Pela técnica de PCR‑RFLP, foram observados 14 perfis polimórficos, o que indica a presença de diferentes alelos e, consequentemente, de distintas subclasses desses genes.

Isolation and characterization of Bacillus thuringiensis from soils in contrasting agroecological zones of Ethiopia

Phenotypic and molecular methods were used to isolate and characterize B. thuringiensis from diverse agro-ecological zones of Ethiopia. Bioassays were used to test the insecticidal activity of B. thuringiensis strains against the major malaria vector, Anopheles arabiensis (Diptera). B. thuringiensis were isolated from 32% of the total 503 soil samples collected from the 16 agro-ecological zones. All sequenced isolates were 99%–100% identical to each other and to B. thuringiensis entries in Genbank. B. thuringiensis with similar 16S rRNA gene sequences from these different zones were characterized with regard to maximum growth rate and temperature optima for growth to test if there was local adaptation in these functional traits. The result showed a narrow temperature range around 30°C for maximal growth rate, and there were no significant differences between agro-ecological zones. Of 110 Bacillus thuringiensis isolates analyzed for the presence of crystal protein genes, 7 tested positive for cry 4, cry 11, and cyt toxin genes. Sequencing of these genes in positive strains demonstrated 99–100 % homology to known mosquitocidal cry and cyt genes in Bacillus thuringiensis subsp. israelensis. The present study shows that this biotechnologically important species is wide spread in Ethiopian soils and that it does not demonstrate local adaptation to temperature regimes, at least not for basic functions such as growth-temperature response. Our finding also pointed the potential for exploiting this species in vector control programs.