Insect Pest Management Strategies Research Articles

Qualitative Sybr Green real-time detection of single nucleotide polymorphisms responsible for target-site resistance in insect pests: the example of Myzus persicae and Musca domestica.

Chemical insecticides have been widely used to control insect pests, leading to the selection of resistant populations. To date, several single nucleotide polymorphisms (SNPs) have already been associated with insecticide resistance, causing reduced sensitivity to many classes of products. Monitoring and detection of target-site resistance is currently one of the most important factors for insect pest management strategies. Several methods are available for this purpose: automated and high-throughput techniques (i.e. TaqMan or pyrosequencing) are very costly; cheaper alternatives (i.e. RFLP or PASA-PCRs) are time-consuming and limited by the necessity of a final visualization step. This work presents a new approach (QSGG, Qualitative Sybr Green Genotyping) which combines the specificity of PASA-PCR with the rapidity of real-time PCR analysis. The specific real-time detection of Cq values of wild-type or mutant alleles (amplified used allele-specific primers) allows the calculation of ΔCqW-M values and the consequent identification of the genotypes of unknown samples, on the basis of ranges previously defined with reference clones. The methodology is applied here to characterize mutations described in Myzus persicae and Musca domestica and we demonstrate it represents a valid, rapid and cost-effective technique that can be adopted for monitoring target-site resistance in field populations of these and other insect species.

INDUCTION OF PLANT IMMUNE BY MICROBIAL INOCULANTS AGAINST TOMATO FRUIT WORM

Tomato (Lycopersicon esculentum Mill.) is one of the important and remunerative vegetable crops grown around the world for fresh market and processing. The production and productivity of the crop is greatly hampered by the fruit borer, Helicoverpa armigera (Hübner) which causes damage to the developing fruits and results in yield loss. The indiscriminate use of synthetic chemical pesticides to control this pest resulted in development of resistance and harmful pesticide residues in fruits. To avoid such problems caused due to indiscriminate use of insecticides, utilization of Host Plant Resistance (HPR) is an ecologically viable, alternate insect pest management strategy. The tomato accession Varushanadu Local along with a popular variety PKM1 was tested for induction of resistance by various microbial inoculants viz., Azospirillum, Phosphobacteria, Pseudomonas, K-solubilizer, Azospirillum + Phosphobacteria, Azospirillum + Pseudomonas, Azospirillum + K-solubilizer, Phosphobacteria + Pseudomonas, Phosphobacteria + K - solubilizer. and Pseudomonas. Based on the preliminary study, the promising microbial inoculants viz., Pseudomonas, K-solubilizer, Azospirillum, + k-solubilizer, pseudomonas + k-solubilizer, and phosphobacteria + Ksolubilizer were selected. Feeding preference of H. armigera to the leaves and fruits was the minimum towards the accessions Varushanadu Local treated with Pseudomonas + Ksolubilizer. Plants of the accessions Varushanadu Local supplied with Pseudomonas + Ksolubilizer exerted profound antibiosis effects against the life stages of H. armigera as evidenced by higher larval mortality, reduced pupation, reduced larval, pupal and adult duration.

Fungal allelochemicals in insect pest management

Interactions between insects and fungi are widespread, and important mediators of these interactions are fungal chemicals that can therefore be considered as allelochemicals. Numerous studies suggest that fungal chemicals can affect insects in many different ways. Here, we apply the terminology established by insect-plant ecologists for categorizing the effect of fungal allelochemicals on insects and for evaluating the application potential of these chemicals in insect pest management. Our literature survey shows that fungal volatile and non-volatile chemicals have an enormous potential to influence insect behavior and fitness. Many of them still remain to be discovered, but some recent examples of repellents and toxins could open up new ways for developing safe insect control strategies. However, we also identified shortcomings in our understanding of the chemical ecology of insect-fungus interactions and the way they have been investigated. In particular, the mode-of-action of fungal allelochemicals has often not been appropriately designated or examined, and the way in which induction by insects affects fungal chemical diversity is poorly understood. This review should raise awareness that in-depth ecological studies of insect-fungus interactions can reveal novel allelochemicals of particular benefit for the development of innovative insect pest management strategies.

RNAi‐mediated plant protection against aphids

Aphids (Aphididae) are major agricultural pests that cause significant yield losses of crop plants each year by inflicting damage both through the direct effects of feeding and by vectoring harmful plant viruses. Expression of double-stranded RNA (dsRNA) directed against suitable insect target genes in transgenic plants has been shown to give protection against pests through plant-mediated RNA interference (RNAi). Thus, as a potential alternative and effective strategy for insect pest management in agricultural practice, plant-mediated RNAi for aphid control has received close attention in recent years. In this review, the mechanism of RNAi in insects and the so far explored effective RNAi target genes in aphids, their potential applications in the development of transgenic plants for aphid control and the major challenges in this regard are reviewed, and the future prospects of using plant-mediated RNAi for aphid control are discussed. This review is intended to be a helpful insight into the generation of aphid-resistant plants through plant-mediated RNAi strategy. © 2016 Society of Chemical Industry.

Diet-Delivered dsRNAs for Juvenile Hormone-Binding Protein and Vacuolar ATPase-H Implied Their Potential in the Management of the Melon Aphid (Hemiptera: Aphididae).

RNA interference is a sequence-specific gene silencing mechanism mediated by double-stranded RNA (dsRNA), which has been harnessed as a useful tool in devising novel insect pest management strategies for various pests such as melon aphid, Aphis gossypii (Glover). In the current study, we cloned and sequenced juvenile hormone-binding protein (JHBP) and vacuolar ATPase subunit H (V-ATPase-H) from A. gossypii. We also showed the effectiveness of diet-mediated delivery of dsRNA for JHBP and V-ATPase-H, which silenced the above genes and resulted in mortality. The extent of silencing and mortality were similar for both genes up until 96 h. Bioassay results revealed that the target genes were silenced variably, 1.0 µg/µl concentration having a more profound effect than 0.5 and 0.25 µg/µl concentration in reducing the cognate mRNA transcript level. Results indicated a 9.56–73.21% down regulation (across time and concentrations for both the genes) that resulted in the mortality of A. gossypii. Mortality was in the range of 10–63% for both these genes. Thus, the current study demonstrated the potentiality of both JHBP and V-ATPase-H as excellent targets for the management of A. gossypii.

Scenario of Entomological Research in Legume Crops in Nepal

This review paper highlights scenario of entomological research in grain legumes in Nepal into headings of the monitoring, survey and surveillance, insect pest management, existing problem and future strategies. A survey study on yield loss assessment of chickpea due to Helicoverpa pod borer under field condition has been recorded up to 75% in the year 1996-1998 at Banke and Bardiya district. While monitored Helicoverpa armigera through pheromone trap, during the 2nd week of March, peak catches of 91 male moths were recorded at Rampur, while it was the maximum (42 male moths) during the 3rd week of March. Synthetic pyrethroids, deltamethrin, fenvalerate and cypermethrin used at 0.01% concentration (a.i.), were effective in controlling the chickpea pod borer, Helicoverpa armigera Hubner. Genotypes NCH-18, NCH -31, NCH-138 and ICC 3075 WR were found resistant. Ripcord 10%@0.05% was found to be superior and effective chemical insecticides to control stem fly and soybean hairy caterpillar. The late sowing date December, 10 showed significantly higher percentage of chickpea pod borer damage with lower grain yield. Inter crops combinations of Chickpea +wheat (2:1) ratio was found effective against Helicoverpa armigera damage (1.2%) followed by chickpea+barley (2.36%) and Chickpea+linseed (2:1) ratio (3.7%). Bakaino (Melia azederach L.) was identified as the best indigenous pesticides to check the normal growth of hairy caterpillar (Spilarctia casigneta kollar) under laboratory condition. Metarhizium anisopliae was found effective for the management of Helicoverpa armigera that caused maximum mortality (94.67%), infection (45.33%) within 7.49 days (LT50). Similarly, Beauveria bassiana caused maximum mortality (98.67%), infection (80.00%) with the least LT50 value (5 days). Crop sprayed with HaNPV had the lowest pod damage (0.3%) and the highest in Racer (2.2%). This review work provided a lot of information to conduct entomological research activity conducted in grain legumes and opens the door for future research and strategy.Int J Appl Sci Biotechnol, Vol 3(3): 367-372

Impact of insecticide resistance management strategies for cotton insect pests in Punjab

Impact of insecticide resistance management strategies for cotton insect pests in Punjab

DNA Barcoding and Elucidation of Cryptic Diversity in Thrips (Thysanoptera)

Accurate and timely identification of invasive insect pests underpins most biological endeavors ranging from biodiversity estimation to insect pest management. In this regard, identification of thrips, an invasive insect pest is important and challenging due to their complex life cycles, parthenogenetic mode of reproduction, sex and color morphs. In the recent years, DNA barcoding employing 5′ region of the mitochondrial Cytochrome Oxidase I (CO-I) gene has become a popular tool for species identification. In this study, we employed CO-I gene sequences for discriminating 151 species of thrips for the first time. Analyses of the intraspecific and intrageneric distances of the CO-I sequences ranged from 0.0 to 7.91% and 8.65% to 31.15% respectively. This study has revealed the existence of cryptic species in Thrips hawaiiensis (Morgan) (Thysanoptera: Thripidae) and Scirtothrips perseae Nakahara (Thysanoptera: Thripidae) for the first time, along with previously reported cryptic species such as Thrips palmi Karny (Thysanoptera: Thripidae), T. tabaci Lindeman, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), Scirtothrips dorsalis Hood. We are proposing, the feasibility of hosting an independent integrated taxonomy library for thrips and indicate that it can serve as an effective system for species identification, this approach could potentially play a key role in formulating effective insect pest management strategies.

Bioecology of some key cashew insect pests and diseases in diverse habitats and landscapes in Tanzania

AbstractCashew (Anacardium occidentale) is an economically important cash crop for many rural households in Tanzania. However, its production is constrained by some insect pests and diseases. As a prerequisite for the development of a more sustainable integrated insect pest and disease management strategy for cashew, information on the biology and ecology of the key insect pests and diseases in a changing environment, and on influencing biotic and abiotic factors, is needed. Surveys were conducted in the major cashew nut‐producing areas of Tanzania for two seasons: August to December, 2009, and August to December, 2010. Data on number of infested and infected shoots by key insect pests and diseases, natural enemies and associated farmer practices, namely synthetic pesticide use and intercropping systems, were collected from different subzones within agroecological zones. Our data showed that abundance and diversity of key cashew insect pests and diseases were influenced by agroecological zones and subzones. Intercropping was more commonly practised in the northern than in the southern zone. Agrochemicals were most frequently used in the southern agroecological zone and affected the occurrence of natural enemies, notably the weaver ant that was more abundant in the northern zone. Furthermore, our findings revealed that Helopeltis sp. and the powdery mildew remained the major constraints to cashew nut production in Tanzania.

Effect of climate change on the occurrence of overwintered moths of orchards in South Korea

AbstractAccording to the Intergovernmental Panel on Climate Change (IPCC), the global mean surface temperature increased by 0.74°C between 1906 and 2005, and is expected to continue rising. In Korea, the temperature increased rapidly by 1.8°C between 1912 and 2010. The effect of global warming are expected to cause phenological changes in exothermic organisms such as insect pests which are highly dependent on temperature. In present study, we estimated the emergence time of three lepidopteran pests (Carposina sasakii, Grapholita molesta, and Phyllonorycter ringoniella) in apple orchards during 2000, 2020s, 2050s, and 2090s, by means of Representative Concentration Pathway (RCP) 8.5 climate change scenario. In comparison with 2000, the emergence of C. sasakii is predicted to occur 5.5 ± 0.49 days earlier in 2020s, 14.9 ± 0.40 days earlier in 2050s, and 40.0 ± 0.75 days earlier in 2090s; the emergence of G. molesta is predicted to occur 8.2 ± 0.36 days earlier in 2020s, 16.9 ± 0.40 days earlier in 2050s, and 49.7 ± 0.61 days earlier in 2090s; and the emergence of P. ringoniella is predicted to occur 9.0 ± 0.34 days earlier in 2020s, 20.5 ± 0.58 days earlier in 2050s, and 52.5 ± 0.63 days earlier in 2090s. The number of generations a year is expected to increase by 0.5–2.8 generations in 2050s, 1.3–6.7 in 2090s. Our predictions provide basic data for the development of insect pest management strategies in spring under conditions of global warming.

Entomofauna Associated withHeliconiaspp. (Zingiberales: Heliconiaceae) Grown in the Central Area of Colombia

We conducted a survey of insects and pest management practices on 40 farms growing Heliconia spp. and other Zingiberales in the central coffee region of Colombia in 2006 and 2007. Most farmers (87%) were concerned about insect pests in the plantation and 90% used broad-spectrum insecticides (chlorpyrifos, carbofuran, acephate and malathion) at least monthly. Fewer (approximately one third) used biological or cultural control practices. In total insects from 13 orders and 99 families were collected from Heliconia farms. The most abundant orders were Diptera (23 families), Hemiptera (22 families), Hymenoptera (14 families), Coleoptera (13 families), and Lepidoptera (7 families). The most common phytophagous species were hispine beetles (Chrysomelidae), scales (Coccidae: Ceroplastes sp., Saissetia sp.), leafhoppers (Cicadellidae), stinkbugs (Pentatomidae), squash bugs (Coreidae) and leaf cutting ants (Atta and Acromyrmex spp.). Other insects such as Metamasius and Pandeleteius weevils were found on the rhizome or pseudostem. Beneficial insects collected included several predatory families (Coccinelidae, Chrysopidae and Reduviidae) but only low numbers of parasitoids (Ichneumonidae, Braconidae, Chalcididae and Stephanidae). A range of insects occurred in empty and water-filled bracts of inflorescences notably flower feeding or detritivorous Diptera (Chironomidae, Drosophilidae, Richardiidae, Syrphidae, Tephritidae and Ulidiidae). Our survey suggests many new insect host associations for Heliconia. The use of broad-spectrum insecticides may not be the best long term strategy for insect pest management in Heliconia due to adverse risks to human and environmental health.

The First International CSPP/IAPPS Symposium on New Management Strategies for Diseases and Insect Pests of Rice, October 26 , Beijing, China

The First International CSPP/IAPPS Symposium on New Management Strategies for Diseases and Insect Pests of Rice, October 26 , Beijing, China

Inventory of insects associated with shea trees (Vitellaria paradoxa) (Sapotaceae) in central and northern Benin

Shea parklands have a great socio-economic, cultural and ecological interest but suffer pest attack, which is among the major causes for their deterioration in Africa. To establish an inventory of insects associated with shea trees, the foliage, stems and fruits were regularly examined on 180 trees randomly chosen at six sites in the central and northern regions of Benin. From June to October 2010, a total of 196 samples containing 1415 specimens were collected. These insects belong to 8 orders, 36 families and 56 genera. Forty-seven insects were identified to the species level. The defoliator Girina forda (Westwood) and the stemborer Neoplocaedaerus spp. were the two most damaging insect species occurring on shea trees. This study stresses the need to protect the shea parklands in Benin through the implementation of integrated insect pest management strategies against shea tree pests.

Biological effects of three Annona species on Callosobruchus chinensis: A green alternative for storage pest management

Plants have been known as a rich source of bioactive chemicals. These have been exploited in insect-pest management strategies as repellents, feeding deterrents, ovipositional deterrents and in many other ways in the biology of insects. The possible use of Annona species as eco-friendly alternatives to synthetic insecticides for the management of Callasobrucus chinensis in legumes was investigated from this perspective. In the present study, methanol extracts of leaves of Annona squamosa (Sugar apple), A. reticulata (Custard apple), and A. glabra (Pond apple) were evaluated to determine their effects on the oviposition, egg incubation and hatchability of C. chinensis. The effect of leaf extracts on the viability of cowpea seeds was also determined. Three doses (2.5, 7.5 and 12.5g/l) of leaf extracts were used in all tests. All the extracts tested resulted in significant reduction in oviposition in females. This reduction was dose-dependent and increased with the increase of dosage. Extracts of A. squamosa induced significantly the highest oviposition deterrence of 49.4% in the insects at the highest dose of 12.5g/l. A. reticulata (42.5%) and A. glabra (32.3%) on the other hand caused respectively lower deterrence. No deterrence of oviposition (0.0%) was observed with the control. In contrast, egg hatchability decreased with the increase of the dosage of extracts. A. squamosa at the highest dose evoked the lowest percentage egg hatch (35.2%) while 96.4% eggs hatch was observed with the control. Egg hatchabilty caused by A. reticulata extract at the same dose was 70.3% which was twice as much observed with A. squamosa. Furthermore, incubation period of eggs also increased with time and dose. In comparison to the control (4.0 days), the highest incubation period was recorded from eggs treated with A. glabra at the dose of 12.5g/l (7.7 days) followed by A. squamosa (6.9 days). None of the plant extracts elicited any adverse effects on the germination capability (viability) of cowpea seeds which varied between 99-100%. The overall results of the study indicate that all three Annona species have a positive impact on the management of this beetle. Moreover, A. squamosa could be considered as the most effective compared to the other two species. As all three plant species tested are locally available, the outcome of this study may certainly help in paving the way for their usage against post-harvest pests.

Green fluorescent protein (GFP)-labeling of enterobacteria associated with fruit flies (Diptera: Tephritidae) and persistence in their natural hostRhagoletis completaCresson.

Fruit flies (Diptera: Tephritidae) are a highly successful, widespread group of insects that cause economic damage in agriculture. Data available so far on the composition of the bacterial community associated with their digestive tract indicate that members of Enterobacteriaceae are the species most often isolated. Bacteria naturally occurring in insect guts may be engineered and used to study the spatial and functional interactions of microbes within the insect system and offer one route to meet the demand for novel insect pest management strategies. With this aim we introduced by conjugation the gfp gene carried by the suicide plasmid pTn5gfpmut1 into Klebsiella oxytoca and Raoultella (formerly Klebsiella ) spp. strains isolated from the oesophageal bulb of the fruit flies Ceratitis capitata (Wiedemann) and Rhagoletis completa Cresson, respectively. The GFP-encoding gene was stably maintained in two tested transgenic strains, both originally isolated from R. completa. In one case, GFP-labeled bacterial cells were used to feed larvae and adults of the original host. Genetically modified bacteria were able to colonize the gut of larvae and persisted through all larval instars to pupal stage.

Electrophysiological Measurements from a Moth Olfactory System

Insect olfactory systems provide unique opportunities for recording odorant-induced responses in the forms of electroantennograms (EAG) and single sensillum recordings (SSR), which are summed responses from all odorant receptor neurons (ORNs) located on the antenna and from those housed in individual sensilla, respectively. These approaches have been exploited for getting a better understanding of insect chemical communication. The identified stimuli can then be used as either attractants or repellents in management strategies for insect pests.

Pyrethroid resistance monitoring in European populations of pollen beetle (Meligethes spp.): a coordinated approach through the Insecticide Resistance Action Committee (IRAC)

Pollen beetle (Meligethes spp.) is a major pest of European oilseed rape crops. Its resistance to pyrethroid insecticides has been recorded in samples of beetles collected in Europe since at least 1999, and problems with the control of the beetle in the field have been widely reported. In 2007, a Pollen Beetle Working Group was formed through the Insecticide Resistance Action Committee (IRAC) in order to coordinate efforts for surveying pyrethroid resistance development. The results of the first 3 years of the pollen beetle pyrethroid susceptibility survey using a laboratory test are presented in this paper. Resistant beetle samples were collected from 20 of the 21 countries surveyed, with a general trend of increasing frequency and spread of resistant samples in European oilseed-rape-growing regions. Pyrethroid-resistant beetles dominate in Western and Central Europe and are becoming established in the North and East, the main oilseed-rape-growing areas of Europe. The development and spread of pyrethroid-resistant pollen beetles highlights the need for effective management strategies for oilseed rape insect pests.

Insect Pest Control on Potato: Harmonization of Alternative and Conventional Control Methods

The development of insect pest management strategies for potato has long been based on the eventual replacement of insecticides by alternative methods. This paper discusses the importance of moving away from this confrontational approach and toward the harmonization of conventional and alternative insect control concepts. A harmonized set of control methods should speed up progress towards a truly integrated management approach that provides both long and short term crop protection. Changing the paradigm does not resolve all the problems. Constraints to the development and implementation of the different types of control methods are discussed using selected examples. The harmonization concept has been discussed in general terms elsewhere but to the best of my knowledge it is applied here for the first time specifically to potato crop protection.

Integration of cultural and mechanical practices for management of the mango mealybug Drosicha mangiferae

Mango (Mangifera indica L.) is one of the most economically important trees which has been cultivated for several centuries. The tree is susceptible to insect damage and is attacked by leaf eaters, termites, root grubs, sapsuckers, gall formers, stem borers, pod borers and fruit borers. The mango mealybug Drosicha mangiferae Green (Hemiptera: Monophlebidae) is one of the most destructive pests in the Indo-Pak subcontinent, sometimes causing premature fruit drop. A combination of several management strategies such as use of entomopathogens, chemical insecticides and burning of adult females has been used to control D. mangiferae. Overreliance on insecticides has eliminated natural enemies, and we were therefore interested in investigating the impact of alternative insect pest management strategies such as cultural and mechanical techniques on D. mangiferae. The results of our studies suggested that different bands significantly stopped the upward movement of overwintering and surviving populations of D. mangiferae. To augment the bands’ results, mounding the tree with debris on a plastic sheet once a year was the most effective technique and resulted in maximum reduction of the nymphal population of D. mangiferae. The newly developed Haider band—designed in our laboratory in the present studies—was very successful in the field in controlling the upward movement of newly hatched nymphs on trees: only 0.8% of the nymphs crossed the band. Only 7% to 10% of the nymphs crossed plastic sheets, polyethylene sheets and funnel bands. The cotton and gunny bag (jute) bands were the least effective: 42% of the nymphs managed to cross them. The results suggested that employing cultural practices and bands together could reduce the need for insecticide treatments and offer a sustainable method for D. mangiferae control.

Using Image Analysis to Design a Prototype Autodissemination Device Intended for the Biorational Control of <I>Plodia Interpunctella</I>

The extent to which a carrier powder was taken up and horizontally transferred by contaminated Indianmeal moth, Plodia interpunctella (Hübner) individuals to conspecifics was evaluated. Using a marker dye, which was shown to be colocalized with the carrier powder, the amount of powder on the Indianmeal moth, as determined by spectrophotometry, was correlated with quantification based on a novel image analysis approach that enabled differentiation of powder uptake by body region. Over a 48-h period, more powder was retained on the ventral surface than the dorsal side, with the head region showing the greatest amount of powder uptake and retention. During courtship, powder was horizontally transferred by treated males to 1.6% of the head and 0.06% of the untreated females' body. To inoculate moths, a pit-fall style autodissemination station was determined as being more effective than a powder tray, as significantly more material was taken up to the key areas of the moth's body where powder is more effectively retained and more likely to be horizontally transferred. Additionally, a pit-fall station prevented moths from exhibiting avoidance behavior from the powder, which was frequently encountered if they had to walk into a powder tray. This study shows that different regions of the Indianmeal moth body vary in capacity to carry powder and that future research efforts should target these specific regions. Although the proposed autodissemination system was optimized for management strategies of Indianmeal moth, we believe the results presented here can be used to develop novel management strategies for other insect pests.