BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access t... more BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.
Diamond back moth (DBM), Plutella xylostella (L.), an important pest of cole crops has developed ... more Diamond back moth (DBM), Plutella xylostella (L.), an important pest of cole crops has developed resistance to almost all the groups of insecticides. Northeastern region of India uses relatively less quantity of pesticides for pest management of pests. Hence in vitro efficacy and co-toxicity of profenofos 50EC, cypermethrin 10EC, indoxacarb 14.5% and chlorpyrifos 20EC were evaluated using leaf dip bioassay on the field collected DBM populations. Indoxacarb 14.5% (LC50 20 ppm) was found to be the most effective, while the binary mixture of profenofos + chlorpyrifos and cypermethrin + chlorpyrifos (tested for all three combinations- 1:1, 1:2 and 2:1), showed synergistic effects. The results serve to promote use mixtures of insecticides having different mode of action.
Parasitoid populations having optimum male: female ratios are generally released in the field dur... more Parasitoid populations having optimum male: female ratios are generally released in the field during the cocoon stage for an effective bio-control program. Due to the distinctive habit of forming a cocoon within the shrunken larval body of the host, cocoons of both sexes of the icheneumonid wasp, Hyposoter ebeninus, displayed morphological similarities. Therefore, male and female co coons cannot be differentiated based on normal morphological parameters. In this report, we tested several combinations of morphological parameters and size indices and developed a simple technique for separation of sexes at the cocoon stage of this wasp. Among ten possible parameters tested, the weight of the cocoon was found to be the most appropriate and reliable parameter for sex separation with a 100% success rate. Since this technique involves only one parameter, it is simple, robust and requires minimum technical skill. This technique would be very useful for research workers, commercial biological control laboratories and other related agencies working on H. ebeninus.
Helicoverpa armigera is an important pest of cotton and other agricultural crops in the Old World... more Helicoverpa armigera is an important pest of cotton and other agricultural crops in the Old World. Its wide host range, high mobility and fecundity, and the ability to adapt and develop resistance against all common groups of insecticides used for its management have exacerbated its pest status. An understanding of the population genetic structure in H. armigera under Indian agricultural conditions will help ascertain gene flow patterns across different agricultural zones. This study inferred the population genetic structure of Indian H. armigera using five Exon-Primed Intron-Crossing (EPIC)-PCR markers. Nested alternative EPIC markers detected moderate null allele frequencies (4.3% to 9.4%) in loci used to infer population genetic structure but the apparently genome-wide heterozygote deficit suggests inbreeding or a Wahlund effect rather than a null allele effect. Population genetic analysis of the 26 populations suggested significant genetic differentiation within India but especially in cotton-feeding populations in the 2006-07 cropping season. In contrast, overall pair-wise F ST estimates from populations feeding on food crops indicated no significant population substructure irrespective of cropping seasons. A Baysian cluster analysis was used to assign the genetic make-up of individuals to likely membership of population clusters. Some evidence was found for four major clusters with individuals in two populations from cotton in one year (from two populations in northern India) showing especially high homogeneity. Taken as a whole, this study found evidence of population substructure at host crop, temporal and spatial levels in Indian H. armigera, without, however, a clear biological rationale for these structures being evident.
The behavior of most destructive pest of cabbage, Pieris brassicae and that of its potential para... more The behavior of most destructive pest of cabbage, Pieris brassicae and that of its potential parasitoid, Hyposoter ebeninus, were studied under the influence of 4 common Brassica host plantspecies, cabbage, broccoli, cauliflower and knol-kohl. These host plant species were found to have considerable influence on egg distribution and leaf surface preference for oviposition and pupation. The number of egg masses was highest on knol-khol; however, the number of eggs per mass was highest on cabbage. Similarly, larval incidence was also highest on cabbage throughout the season, indicating that cabbage is the most preferred host. Natural parasitism on P. brassicae larvae by Hyposoter ebeninus was higher on knol-khol and cabbage. The weight of the third instar parasitized caterpillars was the highest on cabbage, suggesting that cabbage is the most favorable of these 4 hosts of P. brassicae for mass rearing of H. ebeninus. The development time of H. ebeninus was also shortest for cabbagereared larvae. Also the cocoon weight of the parasitoid was significantly higher when its host larvae were reared on cabbage. Overall from this study it can be concluded that, of the host plants evaluated, cabbage was preferred for oviposition by P. brassicae and its parasitoid. In addition, cabbage was found to be the best host plant for producing excellent quality H. ebeninus parasitoids.
BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access t... more BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.
Guava, Psidium guajava (L.) (Myrtaceae), is the fourth most intensely cultivated tree fruit on th... more Guava, Psidium guajava (L.) (Myrtaceae), is the fourth most intensely cultivated tree fruit on the Indian subcontinent (Chandy 2002). Guava is exceptionally hardy, and even on marginal lands it bears marketable fruit with high vitamin C content and maintains for its producers an attractive income versus investment profile (Singh 2010). In India, guava is cultivated on about 205,000 hectares which yield about 2,500 metric tons per annum (Anonymous 2011). The subtropical climatic conditions of the northeastern Indian state of Meghalaya generate a single, relatively well defined guava fruiting and harvest cycle. During April and May, guava produces its flowers and then fruits in September to October. A large number of insect pests have been reported to occur on guava, but only a few of those reported are known to constitute a significant impediment to the successful cultivation of this crop (Shylesha et al. 2000; Firake et al. 2013). Recently, adult specimens of the elephant beetle genus Xylotrupes Hope were found feeding on the flesh of guava fruits in Meghalaya (Fig. 1), causing considerable losses in yield (35–45%). Furthermore, the often minimal damage inflicted by these beetles on the mature fruits can predispose the fruits to secondary attack by other insects (Fig. 2) and pathogens, all of which can augment market losses. On occasion, up to 98% of fruit can be damaged by Xylotrupes. Three male specimens of Xylotrupes from Meghalaya were sequenced at the 5′ region of the COI gene (NCBI Accession No: KF494189) and these sequences were found by Jen-Pan Huang, University of Michigan (personal communication) to nest within an unpublished, large series of specimens sequenced at the same region of COI gene. The latter series was assembled from diverse localities across Southeast Asia and had been previously identified as Xylotrupes siamensis Minck by criteria in Rowland (2003, 2011). According to the latter evidence, the identity of the Xylotrupes beetles found attacking guava in Meghalaya is here assigned as X. siamensis. Xylotrupes siamensis is reddish brown to black in color and 30–40 mm in body length. The males bear cephalic and pronotal horns, and the females are smaller and do not bear horns (Endrödi 1985; Waite and Elder 2000). The genus Xylotrupes is one of the most widespread genera of large beetles in the world. Its natural distribution extends over nearly a third of the earth’s circumference from the high valleys of Himalayan Pakistan east and south into India, Southeast Asia, China, the Malay Archipelago, Australasia into Melanesia as far as Vanuatu in the South Pacific (CAB International 2002; Rowland 2003, 2011, in Foreword in Hwang 2011). Xylotrupes beetles are known to be polyphagous, feeding on bark, fruits, panicles, and inflorescences of a large number of host plants viz., Acacia mearnsii De Wild (Fabaceae), Toona australis Kuntz (Meliaceae), pineapple, longan, lychee (Waite and Elder 2000), bamboo, coconut, cashewnut, cinnamon, African oil palm, rubber, banana, plantain, sugarcane, potato (CAB International 2002), passion fruit (Shylesha and Rao 2004), maize, sword bean (Shylesha et al. 2006), okra (Nair et al. 2001), poinciana, gulmohar, cacao, and som (Eswarareddy and Rajan 2011). To our knowledge, infestation or management of Xylotrupes beetles on guava has not been previously reported. For this reason, we have initiated studies based upon quantifiable variables associated with feeding by X. siamensis on guava fruit in the orchards of our experimental farm in Meghalaya, so that feasible
The four significant pest species in theHelicoverpagenus (H. armigera, H. assulta,H. punctigeraan... more The four significant pest species in theHelicoverpagenus (H. armigera, H. assulta,H. punctigeraandH. zea) are morphologically similar and can only be reliably distinguished through dissection of adult genitalia. Two partial regions of the mitochondrial DNA (mtDNA), the cytochrome oxidase subunit I (COI) and the cytochromeb(Cytb) genes were amplified by PCR and digested with restriction endonucleases. The restriction patterns, generated by the endonucleasesBstZ17I andHphI, demonstrated reliable differentiation of the fourHelicoverpapest species. This technique is fast, reliable and effective at distinguishing specimens irrespective of their life stages and offers support to conventional taxonomic differentiation based on morphological characters.
The mirid bug, Helopeltis cinchonae Mann (Order: Hemiptera) has been recorded for the first time ... more The mirid bug, Helopeltis cinchonae Mann (Order: Hemiptera) has been recorded for the first time on six economically important horticultural crops in India. The infestation of H. cinchonae was considerably higher during June-July on guava, geranium and chrysanthemum plants; whereas during August-September on brinjal and chili plants. Mirid bug, H. cinchonae was found causing significant yield losses to guava fruits and chili plants in Meghalaya. This study provides basic knowledge on biology, feeding damage and morphological characters of H. cinchonae supported with its DNA barcode and phylogeny.
The vegetable leaf miner, Liriomyza sativae (Diptera:Agromyzidae), is an invasive polyphagous spe... more The vegetable leaf miner, Liriomyza sativae (Diptera:Agromyzidae), is an invasive polyphagous species originally known to be found in America and now spread in many parts of Africa, Asia, and the Pacific region. During 2016, L. sativae was observed for the first time infesting tomato (Solanum lycopersicum L.) leaves in experimental farms of an institute at Umiam (Meghalaya state of northeastern India). Based on museum specimens, this species was reported from India on tomato during 1994. Nevertheless, no further information is hitherto available from India apart from just new record. Considering the pest status of L. sativae across the globe, it is crucial to understand its expansion range, severity, biological attributes, and seasonal incidence on tomato in India. Taxonomic Q3 identification of different species of Liriomyza leaf miners is very complex due to morphological resemblance, and consequently, species-level identification is often done incorrectly by mistaking one species for another. Therefore, we characterized L. sativae at the molecular level and developed species specific DNA barcodes by using mitochondrial cytochrome oxidase gene. Moreover, the information on the correct distribution, seasonal incidence, and basic biological attributes of different stages of L. sativae is reported and discussed.
The genus Helicoverpa comprises of 2 species in India—H. armigera and H. assulta. This paper comp... more The genus Helicoverpa comprises of 2 species in India—H. armigera and H. assulta. This paper compares partial CO-1 sequences of the two-field-collected species with a laboratory strain of H. armigera and Drosophila yakuba whose entire mitochondrial genome has been sequenced. The region sequenced in the study corresponds to 2111 to 2601 bp sequence of D. yakuba mitochondrial genome, i.e mid to near terminal segment of the CO-I region. When analyzed, at least 18 nucleotide and 8 amino acid substitutions were observed between the two species. Using this information, a specific PCR-RFLP tool was designed that distinguishes between the two species at the egg stage itself, thus, influencing pest control options significantly, especially in areas and crops where the two may occur simultaneously. Introduction The genus Helicoverpa comprises of only two species in India—H. armigera and H. assulta that are visually different as adults. H. armigera (Huebner) is a polyphagous pest, recorded on ...
The cotton bollworm, Helicoverpa armigera, is a quarantine agricultural pest for the American con... more The cotton bollworm, Helicoverpa armigera, is a quarantine agricultural pest for the American continents. It is thought to have invaded the American continents and led the founding of current H. zea populations in the American continents ~1.5 million years ago. This relatively recent divergence is evident via hybridisation under laboratory conditions. Despite periodic incursions of H. armigera into North America, this pest species is not believed to have successfully established significant populations in the New World. For the first time, we provide molecular evidence via mitochondrial DNA (mtDNA), cytochrome oxidase I (COI) and cytochrome b (Cyt b) partial gene sequences the successful recent incursion of H. armigera into the New World, with populations from the state of Mato Grosso (central-eastern and southern regions) in Brazil, likely to have taken place post 2006. The mtDNA haplotypes detected in the Brazilian H. armigera individuals are common throughout the Old World, thus ...
The highly polyphagous Old World cotton bollworm Helicoverpa armigera is a quarantine agricultura... more The highly polyphagous Old World cotton bollworm Helicoverpa armigera is a quarantine agricultural pest for the American continents. Historically H. armigera is thought to have colonised the American continents around 1.5 to 2 million years ago, leading to the current H. zea populations on the American continents. The relatively recent species divergence history is evident in mating compatibility between H. zea and H. armigera under laboratory conditions. Despite periodic interceptions of H. armigera into North America, this pest species is not believed to have successfully established significant populations on either continent. In this study, we provide molecular evidence via mitochondrial DNA (mtDNA) cytochrome oxidase I (COI) and cytochrome b (Cyt b) partial gene sequences for the successful recent incursion of H. armigera into the New World, with individuals being detected at two sites (Primavera do Leste, Pedra Preta) within the State of Mato Grosso in Brazil. The mtDNA COI and Cyt b haplotypes detected in the Brazilian H. armigera individuals are common throughout the Old World, thus precluding identification of the founder populations. Combining the two partial mtDNA gene sequences showed that at least two matrilines are present in Brazil, while the inclusion of three nuclear DNA Exon-Primed Intron-Crossing (EPIC) markers identified a further two possible matrilines in our samples. The economic, biosecurity, resistance management, ecological and evolutionary implications of this incursion are discussed in relation to the current agricultural practices in the Americas.
BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access t... more BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.
Diamond back moth (DBM), Plutella xylostella (L.), an important pest of cole crops has developed ... more Diamond back moth (DBM), Plutella xylostella (L.), an important pest of cole crops has developed resistance to almost all the groups of insecticides. Northeastern region of India uses relatively less quantity of pesticides for pest management of pests. Hence in vitro efficacy and co-toxicity of profenofos 50EC, cypermethrin 10EC, indoxacarb 14.5% and chlorpyrifos 20EC were evaluated using leaf dip bioassay on the field collected DBM populations. Indoxacarb 14.5% (LC50 20 ppm) was found to be the most effective, while the binary mixture of profenofos + chlorpyrifos and cypermethrin + chlorpyrifos (tested for all three combinations- 1:1, 1:2 and 2:1), showed synergistic effects. The results serve to promote use mixtures of insecticides having different mode of action.
Parasitoid populations having optimum male: female ratios are generally released in the field dur... more Parasitoid populations having optimum male: female ratios are generally released in the field during the cocoon stage for an effective bio-control program. Due to the distinctive habit of forming a cocoon within the shrunken larval body of the host, cocoons of both sexes of the icheneumonid wasp, Hyposoter ebeninus, displayed morphological similarities. Therefore, male and female co coons cannot be differentiated based on normal morphological parameters. In this report, we tested several combinations of morphological parameters and size indices and developed a simple technique for separation of sexes at the cocoon stage of this wasp. Among ten possible parameters tested, the weight of the cocoon was found to be the most appropriate and reliable parameter for sex separation with a 100% success rate. Since this technique involves only one parameter, it is simple, robust and requires minimum technical skill. This technique would be very useful for research workers, commercial biological control laboratories and other related agencies working on H. ebeninus.
Helicoverpa armigera is an important pest of cotton and other agricultural crops in the Old World... more Helicoverpa armigera is an important pest of cotton and other agricultural crops in the Old World. Its wide host range, high mobility and fecundity, and the ability to adapt and develop resistance against all common groups of insecticides used for its management have exacerbated its pest status. An understanding of the population genetic structure in H. armigera under Indian agricultural conditions will help ascertain gene flow patterns across different agricultural zones. This study inferred the population genetic structure of Indian H. armigera using five Exon-Primed Intron-Crossing (EPIC)-PCR markers. Nested alternative EPIC markers detected moderate null allele frequencies (4.3% to 9.4%) in loci used to infer population genetic structure but the apparently genome-wide heterozygote deficit suggests inbreeding or a Wahlund effect rather than a null allele effect. Population genetic analysis of the 26 populations suggested significant genetic differentiation within India but especially in cotton-feeding populations in the 2006-07 cropping season. In contrast, overall pair-wise F ST estimates from populations feeding on food crops indicated no significant population substructure irrespective of cropping seasons. A Baysian cluster analysis was used to assign the genetic make-up of individuals to likely membership of population clusters. Some evidence was found for four major clusters with individuals in two populations from cotton in one year (from two populations in northern India) showing especially high homogeneity. Taken as a whole, this study found evidence of population substructure at host crop, temporal and spatial levels in Indian H. armigera, without, however, a clear biological rationale for these structures being evident.
The behavior of most destructive pest of cabbage, Pieris brassicae and that of its potential para... more The behavior of most destructive pest of cabbage, Pieris brassicae and that of its potential parasitoid, Hyposoter ebeninus, were studied under the influence of 4 common Brassica host plantspecies, cabbage, broccoli, cauliflower and knol-kohl. These host plant species were found to have considerable influence on egg distribution and leaf surface preference for oviposition and pupation. The number of egg masses was highest on knol-khol; however, the number of eggs per mass was highest on cabbage. Similarly, larval incidence was also highest on cabbage throughout the season, indicating that cabbage is the most preferred host. Natural parasitism on P. brassicae larvae by Hyposoter ebeninus was higher on knol-khol and cabbage. The weight of the third instar parasitized caterpillars was the highest on cabbage, suggesting that cabbage is the most favorable of these 4 hosts of P. brassicae for mass rearing of H. ebeninus. The development time of H. ebeninus was also shortest for cabbagereared larvae. Also the cocoon weight of the parasitoid was significantly higher when its host larvae were reared on cabbage. Overall from this study it can be concluded that, of the host plants evaluated, cabbage was preferred for oviposition by P. brassicae and its parasitoid. In addition, cabbage was found to be the best host plant for producing excellent quality H. ebeninus parasitoids.
BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access t... more BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.
Guava, Psidium guajava (L.) (Myrtaceae), is the fourth most intensely cultivated tree fruit on th... more Guava, Psidium guajava (L.) (Myrtaceae), is the fourth most intensely cultivated tree fruit on the Indian subcontinent (Chandy 2002). Guava is exceptionally hardy, and even on marginal lands it bears marketable fruit with high vitamin C content and maintains for its producers an attractive income versus investment profile (Singh 2010). In India, guava is cultivated on about 205,000 hectares which yield about 2,500 metric tons per annum (Anonymous 2011). The subtropical climatic conditions of the northeastern Indian state of Meghalaya generate a single, relatively well defined guava fruiting and harvest cycle. During April and May, guava produces its flowers and then fruits in September to October. A large number of insect pests have been reported to occur on guava, but only a few of those reported are known to constitute a significant impediment to the successful cultivation of this crop (Shylesha et al. 2000; Firake et al. 2013). Recently, adult specimens of the elephant beetle genus Xylotrupes Hope were found feeding on the flesh of guava fruits in Meghalaya (Fig. 1), causing considerable losses in yield (35–45%). Furthermore, the often minimal damage inflicted by these beetles on the mature fruits can predispose the fruits to secondary attack by other insects (Fig. 2) and pathogens, all of which can augment market losses. On occasion, up to 98% of fruit can be damaged by Xylotrupes. Three male specimens of Xylotrupes from Meghalaya were sequenced at the 5′ region of the COI gene (NCBI Accession No: KF494189) and these sequences were found by Jen-Pan Huang, University of Michigan (personal communication) to nest within an unpublished, large series of specimens sequenced at the same region of COI gene. The latter series was assembled from diverse localities across Southeast Asia and had been previously identified as Xylotrupes siamensis Minck by criteria in Rowland (2003, 2011). According to the latter evidence, the identity of the Xylotrupes beetles found attacking guava in Meghalaya is here assigned as X. siamensis. Xylotrupes siamensis is reddish brown to black in color and 30–40 mm in body length. The males bear cephalic and pronotal horns, and the females are smaller and do not bear horns (Endrödi 1985; Waite and Elder 2000). The genus Xylotrupes is one of the most widespread genera of large beetles in the world. Its natural distribution extends over nearly a third of the earth’s circumference from the high valleys of Himalayan Pakistan east and south into India, Southeast Asia, China, the Malay Archipelago, Australasia into Melanesia as far as Vanuatu in the South Pacific (CAB International 2002; Rowland 2003, 2011, in Foreword in Hwang 2011). Xylotrupes beetles are known to be polyphagous, feeding on bark, fruits, panicles, and inflorescences of a large number of host plants viz., Acacia mearnsii De Wild (Fabaceae), Toona australis Kuntz (Meliaceae), pineapple, longan, lychee (Waite and Elder 2000), bamboo, coconut, cashewnut, cinnamon, African oil palm, rubber, banana, plantain, sugarcane, potato (CAB International 2002), passion fruit (Shylesha and Rao 2004), maize, sword bean (Shylesha et al. 2006), okra (Nair et al. 2001), poinciana, gulmohar, cacao, and som (Eswarareddy and Rajan 2011). To our knowledge, infestation or management of Xylotrupes beetles on guava has not been previously reported. For this reason, we have initiated studies based upon quantifiable variables associated with feeding by X. siamensis on guava fruit in the orchards of our experimental farm in Meghalaya, so that feasible
The four significant pest species in theHelicoverpagenus (H. armigera, H. assulta,H. punctigeraan... more The four significant pest species in theHelicoverpagenus (H. armigera, H. assulta,H. punctigeraandH. zea) are morphologically similar and can only be reliably distinguished through dissection of adult genitalia. Two partial regions of the mitochondrial DNA (mtDNA), the cytochrome oxidase subunit I (COI) and the cytochromeb(Cytb) genes were amplified by PCR and digested with restriction endonucleases. The restriction patterns, generated by the endonucleasesBstZ17I andHphI, demonstrated reliable differentiation of the fourHelicoverpapest species. This technique is fast, reliable and effective at distinguishing specimens irrespective of their life stages and offers support to conventional taxonomic differentiation based on morphological characters.
The mirid bug, Helopeltis cinchonae Mann (Order: Hemiptera) has been recorded for the first time ... more The mirid bug, Helopeltis cinchonae Mann (Order: Hemiptera) has been recorded for the first time on six economically important horticultural crops in India. The infestation of H. cinchonae was considerably higher during June-July on guava, geranium and chrysanthemum plants; whereas during August-September on brinjal and chili plants. Mirid bug, H. cinchonae was found causing significant yield losses to guava fruits and chili plants in Meghalaya. This study provides basic knowledge on biology, feeding damage and morphological characters of H. cinchonae supported with its DNA barcode and phylogeny.
The vegetable leaf miner, Liriomyza sativae (Diptera:Agromyzidae), is an invasive polyphagous spe... more The vegetable leaf miner, Liriomyza sativae (Diptera:Agromyzidae), is an invasive polyphagous species originally known to be found in America and now spread in many parts of Africa, Asia, and the Pacific region. During 2016, L. sativae was observed for the first time infesting tomato (Solanum lycopersicum L.) leaves in experimental farms of an institute at Umiam (Meghalaya state of northeastern India). Based on museum specimens, this species was reported from India on tomato during 1994. Nevertheless, no further information is hitherto available from India apart from just new record. Considering the pest status of L. sativae across the globe, it is crucial to understand its expansion range, severity, biological attributes, and seasonal incidence on tomato in India. Taxonomic Q3 identification of different species of Liriomyza leaf miners is very complex due to morphological resemblance, and consequently, species-level identification is often done incorrectly by mistaking one species for another. Therefore, we characterized L. sativae at the molecular level and developed species specific DNA barcodes by using mitochondrial cytochrome oxidase gene. Moreover, the information on the correct distribution, seasonal incidence, and basic biological attributes of different stages of L. sativae is reported and discussed.
The genus Helicoverpa comprises of 2 species in India—H. armigera and H. assulta. This paper comp... more The genus Helicoverpa comprises of 2 species in India—H. armigera and H. assulta. This paper compares partial CO-1 sequences of the two-field-collected species with a laboratory strain of H. armigera and Drosophila yakuba whose entire mitochondrial genome has been sequenced. The region sequenced in the study corresponds to 2111 to 2601 bp sequence of D. yakuba mitochondrial genome, i.e mid to near terminal segment of the CO-I region. When analyzed, at least 18 nucleotide and 8 amino acid substitutions were observed between the two species. Using this information, a specific PCR-RFLP tool was designed that distinguishes between the two species at the egg stage itself, thus, influencing pest control options significantly, especially in areas and crops where the two may occur simultaneously. Introduction The genus Helicoverpa comprises of only two species in India—H. armigera and H. assulta that are visually different as adults. H. armigera (Huebner) is a polyphagous pest, recorded on ...
The cotton bollworm, Helicoverpa armigera, is a quarantine agricultural pest for the American con... more The cotton bollworm, Helicoverpa armigera, is a quarantine agricultural pest for the American continents. It is thought to have invaded the American continents and led the founding of current H. zea populations in the American continents ~1.5 million years ago. This relatively recent divergence is evident via hybridisation under laboratory conditions. Despite periodic incursions of H. armigera into North America, this pest species is not believed to have successfully established significant populations in the New World. For the first time, we provide molecular evidence via mitochondrial DNA (mtDNA), cytochrome oxidase I (COI) and cytochrome b (Cyt b) partial gene sequences the successful recent incursion of H. armigera into the New World, with populations from the state of Mato Grosso (central-eastern and southern regions) in Brazil, likely to have taken place post 2006. The mtDNA haplotypes detected in the Brazilian H. armigera individuals are common throughout the Old World, thus ...
The highly polyphagous Old World cotton bollworm Helicoverpa armigera is a quarantine agricultura... more The highly polyphagous Old World cotton bollworm Helicoverpa armigera is a quarantine agricultural pest for the American continents. Historically H. armigera is thought to have colonised the American continents around 1.5 to 2 million years ago, leading to the current H. zea populations on the American continents. The relatively recent species divergence history is evident in mating compatibility between H. zea and H. armigera under laboratory conditions. Despite periodic interceptions of H. armigera into North America, this pest species is not believed to have successfully established significant populations on either continent. In this study, we provide molecular evidence via mitochondrial DNA (mtDNA) cytochrome oxidase I (COI) and cytochrome b (Cyt b) partial gene sequences for the successful recent incursion of H. armigera into the New World, with individuals being detected at two sites (Primavera do Leste, Pedra Preta) within the State of Mato Grosso in Brazil. The mtDNA COI and Cyt b haplotypes detected in the Brazilian H. armigera individuals are common throughout the Old World, thus precluding identification of the founder populations. Combining the two partial mtDNA gene sequences showed that at least two matrilines are present in Brazil, while the inclusion of three nuclear DNA Exon-Primed Intron-Crossing (EPIC) markers identified a further two possible matrilines in our samples. The economic, biosecurity, resistance management, ecological and evolutionary implications of this incursion are discussed in relation to the current agricultural practices in the Americas.
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Papers by Ganesh Behere