Beetle Pests Research Articles

Ecophysiological Responses of the Lesser Mealworm Alphitobius diaperinus Exposed to Desiccating Conditions.

In order to improve predictions of the impacts of climate change on insects, this study aimed to uncover how exposure to dry conditions can affect the biology of the invasive pest beetle Alphitobius diaperinus in terms of longevity, activity, water content, metabolic profiles, and fecundity. We measured desiccation resistance in adults of A. diaperinus by recording the time the beetles could survive desiccation stress. We found that the species was highly desiccation resistant, with about 50% of the insects exposed to desiccation being able to survive for 30 days, and some individuals even survived for up to 50 days at 10% ± 2 relative humidity. There was no evidence of active upregulation of sugars or other metabolites which the beetles could have used to better tolerate desiccation. Food deprivation affected both control (food deprivation, no desiccation) and treatment (food deprivation, desiccation) groups, as their metabolic phenotypes changed similarly after 1 week of treatment. Also, the activity of beetles from both control and desiccation treatments was similarly increased 2 weeks after the experiment had started. Even if there were no changes in the metabolic phenotypes of the insects experiencing desiccating conditions, beetles exposed to desiccation for 8 days had a significantly reduced reproductive output as compared with control insects. This result indicated a physiological cost of drought resistance or repair of stress-incurred damages. The exact nature of that effect (e.g., direct or indirect physiological costs) has not yet been described for tenebrionid beetles and should be investigated in future studies.

Mate choice errors may contribute to slow spread of an invasive Eurasian longhorn beetle in North America

Tetropium fuscum (Coleoptera: Cerambycidae) is a Eurasian longhorn beetle and forest pest that first became invasive to Nova Scotia, Canada around 1990. In the time since its introduction, T. fuscum has spread only about 150 km from its point of introduction. In its invasive range, T. fuscum co-exists with its congener Tetropium cinnamopterum. Although they are ecologically similar species, T. fuscum tends to infest healthier trees and has a smaller host range than T. cinnamopterum. If they successfully interbreed, this could lead to hybrid individuals that are more problematic than either parent species. On the other hand, if T. fuscum can make mating errors in the field, but is not producing hybrid offspring, then this waste of mating resources could help explain the slow spread of T. fuscum in North America. We conducted no-choice and choice mating experiments between T. fuscum and T. cinnamopterum males and females and determined that both T. fuscum and T. cinnamopterum males make mate-choice errors with heterospecific females in a laboratory setting. Our results suggest that mating errors may play a role in the slow spread of T. fuscum in North America.

(Z,E)‐α‐Farnesene – sex pheromone component of female click beetle Selatosomus aeripennis destructor with intra‐ and inter‐sexual communication function

AbstractSex pheromones are known for only a few major click beetle (Coleoptera: Elateridae) pests in North America. These pheromones could be used to monitor, as well as control, adult beetles. Our objective was to identify the sex pheromone of female Selatosomus aeripennis destructor (Brown), a predominant elaterid pest species in farmland in the Canadian Prairie provinces. Headspace volatiles from a group of S. a. destructor females were collected and analyzed by coupled gas chromatography‐electroantennographic detection (GC‐EAD) and gas chromatography‐mass spectrometry (GC‐MS). The GC‐EAD recordings revealed two candidate pheromone components that elicited weak (CPC‐1) or strong (CPC‐2) responses from adult male S. a. destructor antennae. The mass spectra of CPC‐1 and CPC‐2 indicated, and authentic standards confirmed, that they were the isomers (E)‐β‐farnesene and (Z,E)‐α‐farnesene, respectively. In three field experiments at various sites in Alberta, Canada, traps baited with synthetic (Z,E)‐α‐farnesene captured 7.1×, 6.8×, and 2.6× more males than unbaited control traps. In follow‐up experiments, traps baited with (Z,E)‐α‐farnesene captured significantly more males, but significantly fewer females, than unbaited control traps, indicating sex pheromone autodetection by females. (E)‐β‐Farnesene on its own was not attractive as a trap lure, and when added to (Z,E)‐α‐farnesene at a 20:1 ratio, it reduced the lure’s attractiveness. Our data support the conclusion that (Z,E)‐α‐farnesene is the major sex pheromone component of S. a. destructor females, with both an intra‐ and inter‐sexual communication function.

Nutritional symbionts enhance structural defence against predation and fungal infection in a grain pest beetle.

ABSTRACTMany insects benefit from bacterial symbionts that provide essential nutrients and thereby extend the hosts’ adaptive potential and their ability to cope with challenging environments. However, the implications of nutritional symbioses for the hosts’ defence against natural enemies remain largely unstudied. Here, we investigated whether the cuticle-enhancing nutritional symbiosis of the saw-toothed grain beetle Oryzaephilus surinamensis confers protection against predation and fungal infection. We exposed age-defined symbiotic and symbiont-depleted (aposymbiotic) beetles to two antagonists that must actively penetrate the cuticle for a successful attack: wolf spiders (Lycosidae) and the fungal entomopathogen Beauveria bassiana. While young beetles suffered from high predation and fungal infection rates regardless of symbiont presence, symbiotic beetles were able to escape this period of vulnerability and reach high survival probabilities significantly faster than aposymbiotic beetles. To understand the mechanistic basis of these differences, we conducted a time-series analysis of cuticle development in symbiotic and aposymbiotic beetles by measuring cuticular melanisation and thickness. The results reveal that the symbionts accelerate their host's cuticle formation and thereby enable it to quickly reach a cuticle quality threshold that confers structural protection against predation and fungal infection. Considering the widespread occurrence of cuticle enhancement via symbiont-mediated tyrosine supplementation in beetles and other insects, our findings demonstrate how nutritional symbioses can have important ecological implications reaching beyond the immediate nutrient-provisioning benefits.

Evaluation and optimization of nanosuspensions of Chrysanthemum coronarium and Azadirachta indica using Response Surface Methodology for pest management

The rapidly emerging field of nanotechnology is considered an important achievement in the agriculture sector to increase the pest mortality rate and improve the crop production. The present study evaluates the novel pesticidal and anti-microbial activities of Chrysanthemum coronarium and Azadirachta indica in the nano-suspensions form. The anti-solvent precipitation method was used to formulate nano-suspensions proposed by Response Surface Methodology (RSM). Physicochemical nature of plant extracts and nano-suspensions was characterized through analysis of Zeta-sizer, FT-IR, and HPLC. Characterization results revealed a minimum particle size of 121.1 and 170.1 nm for Chrysanthemum coronarium and Azadirachta indica, respectively. The pesticidal activity of nano-suspension was performed against red flour beetle (RFB) and lesser grain borer (LGB) pests, which showed the maximum mortality rate of 100% with 100% concentration of plant extracts and nano-suspensions of Chrysanthemum coronarium and Azadirachta indica against both insects. In comparison, the combination of these both plant extracts revealed the maximum 100% mortality with a 50% concentration of nano-suspensions (mixing ratio 1:1) after 72 h. The antibacterial activity showed the maximum zone inhibition of 9.96 ± 0.17 and 14.17 ± 0.50 mm against S.aureus and E. coli with nano-suspension of Chrysanthemum coronarium, and 12.09 ± 0.11 and 14.10 ± 0.49 mm with nano-suspension of Azadirachta indica, respectively. It is concluded that individual nano-suspensions showed better pesticidal as well as antimicrobial activities than combinations. However, the constructed nanosuspension can be applied to control the plant pests and diseases simultaneously.

The contents availability of N, P, K, and Mg in empty fruit composting of oil palms with symbiont bacteria from rhinoceros beetle larvae (Oryctes rhinoceros) (Coleoptera: Scarabidae)

The using of palm oil waste had not been optimal lately. It could be seen in oil empty fruit bunches (EFB). It was placed along the oil palm plantations. The condition was not only the trigger of air pollution but also could invite rhinoceros beetle pests (Oryctes rhinoceros) to lay their eggs and carry out reproductive activities due to availability organic matter of the trees. Oil palm plants required large amounts of macro nutrients, especially potassium. However, the potassium nutrient was found in EFB was too slow available because of its relatively long breakdown. That was the reason why it was needed a method of using EFB waste into a capable of high use value product, environmentally friendly, and could give a lot of benefits to oil palm farmers. The purpose of this study was to determine the availability of nutrient content in EFB composting by the using of symbiont bacteria from larvae O. rhinoceros. The research was experimentally conducted a factorial randomized block design (RBD) with 2 factors, namely the type of bacteria and the time of decomposition. The composting stage was carried out by coarsely chopping the EFB then 75 ml of bacterial culture was applied to 1 kg of EFB. Analysis, results indicated C/N ratio (35.56% and 36.97%) and high K content (1.64% and 1.48%). The EFB composting method is achievable in 6 weeks with activators of Bacillus stratosphericus and Bacillus siamensis.

The transposable element-rich genome of the cereal pest Sitophilus oryzae

BackgroundThe rice weevil Sitophilus oryzae is one of the most important agricultural pests, causing extensive damage to cereal in fields and to stored grains. S. oryzae has an intracellular symbiotic relationship (endosymbiosis) with the Gram-negative bacterium Sodalis pierantonius and is a valuable model to decipher host-symbiont molecular interactions.ResultsWe sequenced the Sitophilus oryzae genome using a combination of short and long reads to produce the best assembly for a Curculionidae species to date. We show that S. oryzae has undergone successive bursts of transposable element (TE) amplification, representing 72% of the genome. In addition, we show that many TE families are transcriptionally active, and changes in their expression are associated with insect endosymbiotic state. S. oryzae has undergone a high gene expansion rate, when compared to other beetles. Reconstruction of host-symbiont metabolic networks revealed that, despite its recent association with cereal weevils (30 kyear), S. pierantonius relies on the host for several amino acids and nucleotides to survive and to produce vitamins and essential amino acids required for insect development and cuticle biosynthesis.ConclusionsHere we present the genome of an agricultural pest beetle, which may act as a foundation for pest control. In addition, S. oryzae may be a useful model for endosymbiosis, and studying TE evolution and regulation, along with the impact of TEs on eukaryotic genomes.

Common Bark Beetle Pests of Florida

This new 4-page guide was created specifically as an aid for youth forestry knowledge competitions, including 4-H and Future Farmers of America. Along with a collection of the listed beetles, it is suitable as a beginner’s introduction to the most important pine pests in Florida. Written by Sawyer Adams and Jiri Hulcr and published by the UF/IFAS 4-H Youth Development Program.https://edis.ifas.ufl.edu/4h417

Nuclear receptor HR96 up‐regulates cytochrome P450 for insecticide detoxification in Tribolium castaneum

Red flour beetle, Tribolium castaneum (T. castaneum), is a major agricultural pest that causes significant damage to stored grains and products. Although hormone receptor 96 (HR96) is known to be the single ortholog corresponding to mammalian constitutive androstane receptor and pregnane X receptor, the structural features of Tribolium HR96 (TcHR96) and its role in insecticide-mediated transcription control of cytochrome P450 enzyme genes in T. castaneum have not been elucidated yet. We cloned full-length complementary DNA encoding TcHR96 and revealed the role of TcHR96 in transcriptional control of cytochrome P450 enzyme genes. Interestingly, genome-wide transcriptome analysis of HR96-deficient beetles using RNA sequencing showed a positive correlation between TcHR96 and gene transcription of metabolizing enzymes involved in phase I detoxification processes. Moreover, TcHR96 overexpression significantly increased the promoter activity of genes encoding phase I P450 enzymes such as CYP4Q4, CYP4G7, CYP4BR3, and CYP345A1. Chromatin immunoprecipitation analysis showed that TcHR96 could directly bind to the promoter of gene encoding CYP345A1, an enzyme for metabolizing insecticides in T. castaneum. Furthermore, imidacloprid, a neonicotinoid insecticide, significantly increased gene expression of phase I P450 enzymes in old larvae of T. castaneum, which were reversed by TcHR96 knockdown. Finally, TcHR96 knockdown significantly decreased the resistance of old larvae to imidacloprid concomitant with reduction of imidacloprid-mediated phase I P450 enzyme gene expression. TcHR96 plays a major role in transcriptional control of P450 enzyme for imidacloprid detoxification. Controlling TcHR96 might facilitate the regulation of insecticide tolerance in T. castaneum, thus providing a promising new strategy to manage pest beetle populations. © 2021 Society of Chemical Industry.

Wood ants as biological control of the forest pest beetles Ips spp.

Climate change is one of the major threats to biodiversity, but its impact varies among the species. Bark beetles (Ips spp.), as well as other wood-boring pests of European forests, show escalating numbers in response to the changes driven by climate change and seriously affect the survival of the forests through the massive killing of trees. Many methods were developed to control these wood-boring beetles, however, their implementation can be detrimental for other forest specialists. Ants are widely used for biological pest-control, so in our study, we aimed to test the effect of Formica polyctena on the control of the wood-boring beetles. The results show that the proportion of infested trees is significantly reduced by the increase of the number of F. polyctena nests, with a strong effect on those infested by Ips species. We also show that the boring beetle community is shaped by different biotic and abiotic factors, including the presence of F. polyctena nests. However, the boring beetle infestation was not related to the latitude, altitude and age of the forests. Based on our results, we assert the effectiveness of the red wood ants as biological pest control and the importance of their conservation to keep the health of the forests.

Distribution of two European elaterids, Agriotes obscurus and A. lineatus in British Columbia: New records, and potential implications of their dispersal

• Two invasive click beetle pest species have established in southwestern British Columbia. • Surveys conducted in 2017–2019 reveal both species have now dispersed widely. • Crop damage, displacement of native species, and continued spread is expected. • Several native, non-pest species are attracted to the pheromone of these pests. Two European click beetle species, Agriotes obscurus L. (AO) and A. lineatus L. (AL) have become serious pests of agriculture in the Fraser Valley and Vancouver Island areas of British Columbia (BC), but prior to the start of this survey (2017) it was unknown if they had established elsewhere in the Province. Pitfall traps baited with sex pheromone of AO and AL were placed throughout BC in 2017–2019 and collected a total of 4,988 AO and 20,103 AL beetles in 150 trap pairs. Both species were found to be distributed throughout southern BC, including high numbers in Creston, Kelowna, Pemberton, and Salmon Arm. Traps placed in northern BC, northern Alberta, northern Idaho, or the Willamette valley in western Oregon did not collect AO or AL. Traps were also deployed for A. sputator L., a related European species that has become a serious pest of potato in eastern Canada, but this species was not collected. AO and AL traps placed in the Pemberton valley of BC also collected 474 A. ferrugineipennis (LeConte), and traps placed in the northern Okanagan valley collected 75 A. oregonensis Becker. Both are native Agriotes species not closely related to AO or AL; this is the first time A. oregonensis was collected in Canada. We discuss the potential implications of the spread of AO and AL to other agricultural areas in BC and beyond.

Evaluation of Varietal, Infochemicals and Bio-pesticidal Effects in the Management of Cucumber Beetles in Cucumber (Cucumis Sativus Linn.) in the Southern Guinea Savanna

The experiments were laid out in the Teaching and Research farms of Federal University Wukari, Nigeria. Six cucumber cultivars were treated on varietal effects; five infochemicals and a control for second experiment, while four bio-pesticides materials, Cypermethrin and untreated control were also studied. Each treatment was laid out in RCBD and replicated three times. The vine length was higher in cultivars Penino and Seminis, 50.87cm and 50.70cm respectively, number of branches were uniform, but Poinsett had larger leaves area 141.33cm2, hence higher yield (141.67) and much heavier fruits 31.30g, both were not significantly different (P>0.05). Mean fruit damage was highest in Griffaton (4.55), Seminis gave longer and larger fruit sizes. Marketer had high pests’ invasion (200.33). Naphthalene treated plants gave better growth, and yields, 164.67, weighing 38.07g. Other infochemicals performed below the untreated control. Average fruit damage was least in cinnamon oil treated plots, but fruits length and diameter were uniform across the treatments. The untreated control had higher pest beetle population effects. Better yields were recorded in ANSE treated cucumber plants (186.00), heavier fruits and less fruit damage recorded in the Cypermethrin treated crops, but a higher beetle population was in control. The bio-pesticides gave varied levels of protection. Combining varietal, info chemicals and bio-pesticides impacts secures marketable fruits. This study lacks explanations on differences in relative beetle population, fruit yield inconsistencies, weight and variability recorded across the experiments. However, further studies will improve the results of these studies. Also, statistically significant impacts were difficult to prove, probably due to the low number of plots that reduced the power of our data, leading to type 2 error masking important differences.

Rethinking strategies for coexistence with bark beetles in Mexico and beyond

Temperate forests in Mexico are often inhabited by humans and as such function as social–ecological systems (SES). As elsewhere in the world, these forests are increasingly under threat from bark beetle pests, outbreaks of which will be exacerbated by climate change. Current strategies for confronting bark beetle infestations are typically more technical and reactive, and technology and science have not yet provided economic and practical solutions. Taking into consideration future climate‐change scenarios, forest policy agendas must embrace more holistic strategies focused on improving resistance, resilience, and adaptive capacity of forest SES. Forest landowners are crucial stakeholders worldwide, and when provided with reliable information, training, and incentives, can perform the complex and highly demanding responsibilities of forest monitoring, sanitation logging, and restoration. Participatory sanitation logging in Mexico highlights the opportunities and challenges of dealing with bark beetles, from which lessons can be drawn. A holistic strategy that includes management and public policy recommendations for Mexico and elsewhere is proposed as a potential means of coexisting with this challenge to forest health.

Evidence of the Involvement of a Plus-C Odorant-Binding Protein HparOBP14 in Host Plant Selection and Oviposition of the Scarab Beetle Holotrichia parallela.

Holotrichia parallela is one of the agriculturally important scarab beetle pests in China. In this study, HparOBP14 was cloned, which is the most abundantly expressed among the OBP genes in the legs of female H. parallela adults. Sequence comparison and phylogenetic analysis showed that HparOBP14 has a Plus-C structure motif. The expression profile analysis revealed that HparOBP14 expression was the highest in the female antennae and then in the legs. The fluorescence competitive binding experiment of the recombinant HparOBP14 protein showed that HparOBP14 had an affinity with 6-methyl-5-heptene-2-one (plant volatile), 3-methylindole, p-cymene, methanol, formaldehyde, α-pinene, and geraniol (organic fertilizer volatile). Knockdown HparOBP14 expression decreased significantly the EAG response of the injected female adults to p-cymene, methanol, formaldehyde, α-pinene, and geraniol. Similarly, the injected female adults were significantly less attracted to geraniol and methanol. Therefore, HparOBP14 might bind organic matter volatiles during oviposition. These results are not only helpful to analyze the olfactory recognition mechanism of female adult H. parallela when choosing suitable oviposition sites, but also to provide target genes for green prevention and control of H. parallela in the future.

Metarhizium robertsii in combination with Trichoderma asperellum reduce the malathion doses used to control ambrosia beetles: the case of Xyleborus affinis

ABSTRACT Invasive ambrosia beetles and their symbiotic fungi are responsible for destructive diseases like Laurel Wilt and Fusarium Dieback. Some biological treatments and chemical pesticides (e.g. malathion) have been proposed as alternatives to control these pests, however, to date there are no effective treatments. Here we evaluated the susceptibility of the ambrosia beetle Xyleborus affinis Eichhoff to the entomopathogenic fungus Metarhizium robertsii strain Xoch 8.1, and the efficacy of the mycopathogenic fungus Trichoderma asperellum strain Th-T4 (3) to inhibit the growth of the pathogenic ambrosia fungus Fusarium euwallaceae strain 744. Also, we compared the efficacy of a combination of M. robertsii Xoch 8.1 and T. asperellum Th-T4 (3) against X. affinis, and examined the feasibility of using this combination as an alternative to reduce the malathion doses that have been proposed to control ambrosia beetles. The treatment of X. affinis with M. robertsii (1 × 107 con/mL) alone or in combination with T. asperellum (1 × 106 con/mL) resulted in an average mortality of 76% (±7.5), which was statistically similar to that obtained with malathion at 600 ppm (96% ± 4.0). The combination of a lower concentration of malathion (60 ppm or 200 ppm) and both fungi was as efficient as malathion at 600 ppm. Mortality in negative controls (without fungal conidia or malathion) resulted in an average of 16% (±7.5). The proposed combined treatment reduces by up to one order of magnitude the required amount of malathion, and thus represents a potential alternative to control ambrosia beetle pests.

Diagnosis of three Pumkin Leaf Beetle (Aulacophora spp.: Chrysomelidae; Coleoptera) pests through mtDNA-COI barcode molecular approach

Pest management relies on proper identification of insect species, which usually depends on morphological keys. In this research, DNA barcoding was used to identify three pest species of genus Aulacophora (A. foveicollis, A. lewisii and A. indica) attacking horticultural crops in Bangladesh. Accurate phylogenetic information and evolutionary divergence data were supported and evidenced by various parameters, including the rates of substitution, nucleotide composition and genetic divergence. The nucleotide composition of these three species indicates that the total adenine and thiamine content (A+T, 67.3%) was higher than the guanine and cytosine content (G+C, 32.87%). Intraspecific genetic divergence ranged from 0.0158-0.1415. To confirm the origin and evolution, phylogenetic tree and haplotype network was drawn. Both the maximum likelihood and neighbor joining analyses showed that A. indica and A. foveicollis were clustered in one group, and A. lewisii was originated from another group. Haplotype showed that A. lewisii has the highest amount of mutational steps among the sequenced pests and genetically distant species from its common ancestors by 78 mutational numbers. Present investigation can be reliably treated for developing reference libraries for species identification via sequence matches and designing specific pest management approach.
 Bangladesh J. Zool. 48(2): 399-411, 2020

Estimating Potential Distribution of Sweetgum Pest Acanthotomicus suncei and Potential Economic Losses in Nursery Stock and Urban Areas in China.

Simple SummaryAmerican sweetgum Liquidambar styraciflua (Altingiaceae) was introduced to China over 60 years ago. It is an important tree species for increasing landscape value and promoting afforestation in urbanized areas of eastern China in the past 20 years. Sweetgum inscriber Acanthotomicus suncei is a local bark beetle pest and lethal to the introduced American sweetgum. To estimate the potential economic losses caused by the sweetgum inscriber, we survey the beetles’ natural distribution in China. Based on field collections, potential distribution was predicted. Nurseries stocking American sweetgum were found in the high suitability area of this pest. Additionally, we predict the direct loss incorporating tree and removal cost. A questionnaire was sent to maintenance companies, growers, and gardener associations for tree removal prices. In addition, the market price and inventory were also gained from telephone interview. Our economic analysis indicates that if sweetgum inscriber were to become established in the main American sweetgum business, the potential losses of nursery stock and urban area could range from USD 12.81 to 14.41 million. The results will serve as a baseline measure to control urban forest pests.American sweetgum Liquidambar styraciflua (Altingiaceae) was first introduced to China over 60 years ago. It is an important tree species for increasing landscape value and promoting afforestation in urbanized areas of eastern China in the past 20 years. Sweetgum inscriber Acanthotomicus suncei (Coleoptera: Curculionidae) is a local bark beetle pest and lethal to the introduced American sweetgum. To provide preliminary estimates of the potential economic losses caused by the sweetgum inscriber, a field investigation was conducted to survey the beetles’ natural distribution in China. Based on field collections, potential distribution was predicted using Maxent. All nurseries stocking American sweetgum were in the high and very high suitability area of sweetgum inscriber. Additionally, we employed a model of direct loss incorporating tree and removal cost. A questionnaire was sent to maintenance companies, growers, and gardener associations for tree removal prices. We estimated the removal cost of each tree. In addition, the market price and inventory were also gained from telephone interview. Our economic analysis indicates that if sweetgum inscriber were to become established in the main American sweetgum business, the potential losses of nursery stock and urban area could range from USD 12.81 to 14.41 million.

Biology and associated fungi of an emerging bark beetle pest, the sweetgum inscriber Acanthotomicus suncei (Coleoptera: Curculionidae)

AbstractThe sweetgum inscriber (SI) Acanthotomicus suncei Cognato is an emerging bark beetle pest that seriously damages American sweetgum trees (Liquidambar styraciflua) and Chinese sweetgum trees (L. formosana) in China. Since 2013, SI has killed more than 30,000 sweetgum trees in Shanghai and adjacent areas. In Shanghai, SI was observed to emerge from infested wood between April–September and exhibited two generations per year. Both the flying populations and those in colonized logs were female‐biased. After the parental adult initiates a gallery, the emergence of new adults required 73.4 ± 0.7 days at 30°C and 163.5 ± 0.9 days at 20°C. SI could not sustain population development at constant temperatures ≤15°C. The fungi Geosmithia spp. and Phaeoacremonium tuscanum were common associates of SI. The results suggest that SI has a long flight period, and its development is sensitive to low temperatures. Fungi associated with SI were not pathogenic to American sweetgum trees, but their presence may indirectly increase the probability of tree mortality. Our findings contribute to the prevention and control of this important emerging bark beetle pest.

Insect fauna associated with small millets in mid hills of Uttarakhand

India is the largest producer of small millets, which are often referred to as coarse cereals. Various biotic variables significantly affect the output and productivity of these small millets and among them, insect pests are major production barriers that cause high crop losses from sowing to crop harvesting. Although the current status of all the pests affecting small millet crops in Uttarakhand is unknown but shoot fly and stem borer have been identified as major pests of small millets in mid hills of Uttarakhand. Major small millets growing areas as well as various trials conducted under AICRP on Small Millets at Ranichauri Centre, VCSG UUHF, Bharsar, Uttarakhand were surveyed at different crop stages in ten different locations during Kharif- 2019 and Kharif- 2020 to ascertain the status of insect fauna associated with the small millets. A total of sixteen species of insect pests damaging small millets from seedling stage to harvesting were reported. During survey, it was found that shoot fly caused infestation during early crop stage while stem borer induced infestation was noticed during the later crop stage. Shoot fly infestation contributed to stunted crop growth and side tillering with dead heart structure with potential to inflict damage up to 36.67 percent in state varieties of barnyard millet when control measures were not intervened at Gaja farm while stem borer infestation produced white ear heads and stem tunneling with maximum infestation of 33.33 percent in finger millet at Gaja farm and 20.00 percent infestation in barnyard millet at Gunogi village. Grasshopper caused infestation was in the range of 13.33 to 26.67 percent and 13.33 to 33.33 percent and aphid infestation ranged between 10.00 to 20.83 percent and 6.67 to 20.00 percent in finger millet and barnyard millet, respectively at different locations. The flea beetle, semilooper, chaffer beetle, sting bug and other pests were also reported in surveyed small millet crops as occasional occurrence. The present study thus contributed in the data available on insect fauna associated with small millets, major insect pests causing damage from seedling to harvesting stage along with average per cent infestation and their respective nature of damage and damaging stage in mid hills of Uttarakhand.

Semiochemicals for management of the southern pine beetle (Coleoptera: Curculionidae: Scolytinae): successes, failures, and obstacles to progress

AbstractThe southern pine beetle,Dendroctonus frontalisZimmermann (Coleoptera: Curculionidae: Scolytinae), is among the most destructive bark beetle pests of pines (Pinaceae) of the southeast and mid-Atlantic United States of America, Mexico, and Central America. Numerous volatile compounds can stimulate or reduce attraction of the beetle, but efforts to incorporate these into effective, practical technologies for pest management have yielded mixed results. Attractants have been incorporated into lures used in monitoring traps that are employed operationally to forecast outbreaks and detect emerging populations. The attraction inhibitor, verbenone, shows efficacy for suppressing southern pine beetle infestations but has not yet been adopted operationally. No effective semiochemical tree protectant has been developed for the beetle. We discuss complexities in the chemical ecology of the beetle that likely have impeded research and development of semiochemical management tools, and we describe basic science gaps that may hinder further progress if not addressed. We also report some supporting, original experimental data indicating (1) that a verbenone device can inhibit the beetle’s response to sources of attractant in a radius of at least several metres, (2) similar olfactory responses by the beetle to both enantiomers of verbenone, and (3) that pheromone background can cause conflicting results in semiochemical field tests.