Pest Of Vegetables Research Articles

A Novel Solid Artificial Diet for Zeugodacus cucurbitae (Diptera: Tephritidae) Larvae With Fitness Parameters Assessed by Two-Sex Life Table.

The melon fly, Zeugodacus cucurbitae (Coquillett), is a serious pest of many fruits and vegetables throughout the world. Here we have developed an easy and quick-to-prepare solid medium with multiple benefits including reductions in post-rearing waste, storage space, and labor for rearing Z. cucurbitae larvae. The development time from egg to pupa was 19.11 d when larvae were reared on the artificial diet, slightly longer than 17.73 d on pumpkin and 17.13 d on cucumber. Zeugodacus cucurbitae achieved higher values of pupal weight, length, and width on the artificial diet than two natural diet controls. The rates of pupation and adult emergence of Z. cucurbitae grown on the solid medium were comparable with those on pumpkin and cucumber. Furthermore, determined by age-specific two-sex life table method, the age-specific survival rate of Z. cucurbitae was higher on the artificial diet than cucumber but lower than pumpkin. The reproductive ability and population dynamics of Z. cucurbitae were not significantly affected on the solid medium compared with those on the two natural diets. The results suggest that our solid artificial diet is excellent for rearing Z. cucurbitae larvae in laboratory and may be used for its mass rearing, therefore facilitating its research and control.

Parasitism potential of Diadegma argenteopilosa (Cameron) (Hymenoptera : Ichneumonidae), an internal larval parasitoid of Spodoptera litura (Fab.) (Noctuidae: Lepidoptera)

Diadegma argenteopilosa (Cameron) (Ichneumonidae: Hymenoptera) is an internal larval parasitoid of Spodoptera litura (Fab.) (Noctuidae: Lepidoptera), a notorious and polyphagus pest of pulses and vegetables in India. Attempt has been made to initiate their mass multiplication for successful biocontrol programme. Behavioral studies, food stuffs, host selection aspects plays a crucial role in mass multiplication of biocontrol agents. Therefore, present work was conducted to study the optimum host age, specificity and host density for maximum progeny production of the parasitoid under laboratory conditions and later their release in the field for the management of pest species. The parasitoid caused highest mortality in the pest larvae of second instars, 4 day old larvae were attacked most with high percent parasitism, 39.00%. Optimum density for maximum progeny production of D. argenteopilosa was 20, which generate maximum parasitism (43.00%). Host specificity by exposing the parasitoids towards different host species and analyse parasitoid preference by S. litura > Helicoverpa armigera (Hubner) > Mythimna separata Walker > Achaea janata (Linnaeus). Nutritional requirement of parasitoid was tested with different foodstuffs and found 50% honey best suited for maximum longevity 8.2 and 11.4 days for males and females respectively. The longevity ratio also female biased, 1: 1.39 (Male: Female). From the results it concludes that D. argenteopilosa fed with 50% honey solution, exposed to 3-5 day old caterpillars of S. litura at density of 20 gave maximum progeny production and effectively utilized in the biocontrol programme.

The Potential for Decision Support Tools to Improve the Management of Root-Feeding Fly Pests of Vegetables in Western Europe.

Several important vegetable crops grown outdoors in temperate climates in Europe can be damaged by the root-feeding larvae of Diptera (Delia radicum, Delia floralis, Chamaepsila rosae, Delia platura, Delia florilega, Delia antiqua). Knowledge of pest insect phenology is a key component of any Integrated Pest Management (IPM) strategy, and this review considers the methods used to monitor and forecast the occurrence of root-feeding flies as a basis for decision-making by growers and the ways that such information can be applied. It has highlighted some current management approaches where such information is very useful for decision support, for example, the management of C. rosae with insecticidal sprays and the management of all of these pests using crop covers. There are other approaches, particularly those that need to be applied at sowing or transplanting, where knowledge of pest phenology and abundance is less necessary. Going forward, it is likely that the number of insecticidal control options available to European vegetable growers will diminish and they will need to move from a strategy which often involves using a single ‘silver bullet’ to a combination of approaches/tools with partial effects (applied within an IPM framework). For the less-effective, combined methods, accurate information about pest phenology and abundance and reliable decision support are likely to be extremely important.

Training need of Agro-input Dealers in Hazaribag District of North Chhota-Nagpur Region in Jharkhand

In rainfed faming state of Jharkhand, agro-input dealers play vital role in farm production. Input dealers can contribute towards strengthening agriculture extension system through creation sound technological linkage with farmers. So, it is very essential to know the knowledge level of input dealers with modern crop production technologies including agro machinery. Present study was conducted during 2016-18 in Hazaribag district of North Chhota-Nagpur region of Jharkhand to prioritize need for training of agro-input dealers. Through personnel interview of 40 retailers, 47.5 % were young (36-45years), and 35 % were graduates. Around 45 % of the respondents mobilized their own resources for the business and 37 % seek bank credit facility. Identification of pest in vegetables (Potato, Tomato, Cucurbits and Brinjal etc.) emerged as the most needed training area followed by identification of disease of vegetables (Potato, Tomato, Cucurbits and Brinjal etc.). Training in computer and its application with record keeping software was another preferred area. Food crop rice ranked first followed by vegetables as crop specific training needs. Seed based requirement was highest business followed by fertilizer and agro chemicals. The annual growth of business was 10.22 %, 8.63 %, 9.32% and 7.90% in respect of seed, fertilizer, agrochemical and agro machine in district of Hazaribag.

Bioefficacy of Farnesol, A Common Sesquiterpene, On the Survival, Growth, Development, and Morphogenesis of Spodoptera littoralis (Lepidoptera: Noctuidae).

Egyptian cotton leafworm Spodoptera littoralis (Boisduval) is a dangerous pest of many field crops and vegetables in the world. The present study was conducted to evaluate the toxicity of Farnesol and its effects on the growth, development, and morphogenesis of this insect. The newly moulted larvae of 5th (penultimate) or 6th (last) instar larvae were fed on castor bean leaves previously treated with 7 concentrations of Farnesol (400, 200, 100, 50, 25, 12.5 & 6.25 ppm) for 24 hr. The most important results could be summarized as follows. After treatment of 5th or 6th instar larvae with Farnesol, various mortalities were recorded among larvae, pupae, and adults. Depending onLC50values, Farnesol exhibited stronger insecticidal activity after treatment of 6th instar larvae(LC50= 33.67 ppm) than after treatment of 5th instar larvae(LC50= 36.56 ppm). Farnesol caused a serious reduction of larval weight gain and deleterious regression of the growth rate. The larval and pupal durations had been remarkably prolonged, in a dose-dependent course. Disruption of the developmental program was recorded as a failure of ecdysis after treatment of 5th instar larvae and production of larval-pupal intermediates, regardless the treated larval instar. Farnesol exerted considerable suppressing action on the pupation. At higher concentrations, Farnesol interfered with the adult emergence, since eclosion was completely prevented at the highest concentration and partially blocked at other concentrations. Irrespective of the treated larval instar, some deformed pupae were developed only at higher two concentrations of Farnesol.

Variable resistance to spinetoram in populations of Thrips palmi across a small area unconnected to genetic similarity.

The melon thrips, Thrips palmi, is an increasingly important pest of vegetables in northern China. Some populations have developed resistance in the field to the insecticide spinetoram. Understanding the origin and dispersal of insecticide‐resistant populations can shed light on resistance management strategies. In this study, we tested susceptibility of seven greenhouse populations of T. palmi to spinetoram collected from a small area of about 300 km2 in Shandong Province and examined population genetic structure across the area based on a segment of mitochondrial cox1 gene and 22 microsatellite loci to infer the possible origin and dispersal of insecticide resistance. Levels of resistance to spinetoram differed among seven populations, which included one population with high resistance (LC50 = 759.34 mg/L), three populations with medium resistance (LC50 ranged from 28.69 to 34.79 mg/L), and three populations with low resistance (LC50 ranged from 7.61 to 8.97 mg/L). The populations were genetically differentiated into two groups unrelated to both levels of resistance and geographic distance. The molecular data indicated high levels of gene flow between populations with different levels of resistance to spinetoram and low gene flow among populations with the same level of resistance, pointing to a likely separate history of resistance evolution. Resistance levels of two tested populations to spinetoram decreased 23 and 4.6 times after five generations without any exposure to the pesticide. We therefore suspect that resistance of T. palmi most likely evolved in response to local applications of the insecticide. Our study suggests that the development of resistance could be avoided or resistance even reversed by reducing usage of spinetoram.

Compatibility of entomopathogenic nematodes with pesticides registered in vegetable crops under laboratory conditions

Compatibility of the Turkish entomopathogenic nematode isolates Steinernema feltiae (Filipjev) and Heterorhabditis bacteriophora (Poinar) with six chemical pesticides registered for vegetable crops in Turkey was investigated. Mortality, infectivity, and reproduction capacity of pesticide-treated EPNs have been assessed. Our study indicated that imidacloprid and cyflumetofen showed no adverse effect on the survival, infectivity, and reproduction rates of EPNs and can be considered as the most compatible pesticides. The fungicides, fluxapyroxad + difenoconazole and ametoctradin + dimethomorph, caused significantly higher mortality on S. feltiae; however, only fluxapyroxad + difenoconazole showed the negative effect on the survival of H. bacteriophora. Although spiromesifen, spinosad and fluxapyroxad + difenoconazole treated H. bacteriophora had significantly lower reproduction capacity, no negative effect has been observed on the progeny production of S. feltiae among the tested pesticides. In this study, compatibility of cyflumetofen, fluxapyroxad + difenoconazole and ametoctradin + dimethomorph with EPNs have been reported for the first time. The results of the present study will contribute to cost-effective and sustainable management of vegetable pests.

Evaluation of a Genetic Sexing Strain of the Oriental Fruit Fly as a Candidate for Simultaneous Application of Male Annihilation and Sterile Insect Techniques (Diptera: Tephritidae).

The oriental fruit fly, Bactrocera dorsalis (Hendel), is an important pest of fruits and vegetables, and many countries operate surveillance programs to detect infestations and, if needed, implement costly control efforts. The Male Annihilation Technique (MAT), which involves deployment of the male lure methyl eugenol (ME) to reduce or eliminate the male population, has been used as a stand-alone strategy or as a precursor to the Sterile Insect Technique (SIT), which involves the release of sterile males to generate sterile male by wild female crosses and the production of inviable progeny. Modeling suggests that simultaneous implementation of MAT and SIT, rather than sequential deployment, increases the probability of successful eradication. Previous research has shown that B. dorsalis males that have fed on ME show reduced tendency to re-visit ME sources. Also, males fed ME gain a mating advantage over nonfed males. The goal of the present study was to evaluate the suitability of a genetic sexing strain of B. dorsalis as a candidate for concurrent implementation of MAT and SIT. Evaluation focused on the timing of prerelease exposure to methyl eugenol to identify the male age at which feeding upon the lure both i) reduces postrelease attraction to ME-baited traps (thus allowing the operation of MAT) and ii) enhances postrelease mating competitiveness (thus increasing the effectiveness of SIT). Results indicate that prerelease ME feeding by 6-d-old males, with release the following day, would allow effective, concurrent implementation of MAT and SIT.

Examining the willingness to produce organic vegetables in the Bono and Ahafo regions of Ghana

PurposeThe purpose of this paper was to analyse the demographic, crop choice, institutional and environmental factors that will influence the vegetable growers in Bono and Ahafo regions of Ghana to produce organic vegetables. The study also assessed the knowledge level of vegetable growers on organic certification processes.Design/methodology/approachPrimary data were collected with the help of a structured questionnaire from 120 vegetable growers via a multistage sampling technique. The Heckman selection model was used to analyse the factors that influence farmers' willingness to adopt organic production as well as the intensity of adoption.FindingsIn this study, pepper (Capsicum spp) production, residential status, knowledge of organic certification processes, perceived negative environmental effect of conventional farming on the soil, and climate change positively influenced willingness to produce organic vegetables. Likewise, pepper production perceived negative environmental effect of conventional farming on the soil positively influenced the intensity of adoption. Household headship status, garden egg (Solanum integrifolium) production, perceived knowledge on grading and standards of vegetables, as well as the perception that only pesticides can be used to control vegetable pests negatively influenced the willingness to produce organic vegetables however perceived expertise of the farmer on grades and standards influenced intensity of adoption negatively.Originality/valueIn Ghana, even though most vegetable farmers do not have the requisite knowledge in the safe handling of pesticides, usage is widespread. Subsequent to this, is a health risk to farmers, consumers and the environment. As a result, there is a growing awareness that organic agriculture has a role to play in addressing problems associated with agrochemical use and over usage. However, most studies are consumer oriented with limited empirical research on the willingness to produce organics by farmers.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/IJSE-12-2019-0723

Impact certain plant extracts on toxicity, biochemical effects and some biological measurements of peach fly, Bactrocera zonata (Saunders)

Bactrocera zonata (Saunders) flies are the dangerous insect pests of fruit, vegetables, and nuts over the world. This study provides the published information on toxicity, biochemical effects and some biological measurements of the peach fly, B. zonata by using some plant extracts (phytochemicals) namely Moringa oleifera oil, lemon peel oil and M. oleifera leaf extract, which would be more informative for publication facilitating related to integrated pest management (IPM) strategies of B. zonata. Effect of different concentrations of M. oleifera oil, lemon peel oil and M. oleifera leaf extract on biochemical effects (total proteins, total carbohydrates and acetylcholine esterase enzyme) and some biological aspects (pupal mortality, pupal duration, adult emergence, emerged deformed adult and malformation score) of the peach fly, B. zonata were studied. Results showed that M. oleifera oil is highly toxic to pupae of the peach fly, B. zonata with LC50 of 2.569, 2.773 and 2.370 ml/L and LC90 of 85.459, 92.171 and 18.314 ml/L in yellow, sandy and clay soils respectively. Whereas lemon peel oil come in the second position in order of toxicity and M. oleifera leaf extract was the least toxic compound. These results cleared that concentrations of total proteins, total carbohydrates and acetylcholine esterase enzyme activity markedly decreased in pupae of B. zonata after exposure to M. oleifera oil, lemon peel oil and M. oleifera leaf extract with highly significant effects compared with control. Obtained results showed that an inhibitory action of M. oleifera oil, lemon peel oil and M.oleifera leaf extract at all each of concentration levels when mixed with three types of soils namely, yellow soil, sandy soil and clay soil compared with untreated . These results suggest that three tested plant extracts has the probably to be used as a natural plant productions to control of the peach fly, B. zonata.

Fruit fly management in Nepal: A case from plant clinic

Fruit fly is one of the important insect pests of horticultural crops, both fruits and vegetables. After aphids, fruit fly was reported as a major insect problem in the plant clinic sessions from September 2013 to July 2016 in Nepal. The groups of horticultural crops most affected by fruit flies were cucurbitaceous vegetables, i.e. 79% of all fruit fly queries (bitter gourd, bottle gourd, chayote, cucumber, pumpkin, snake gourd, sponge gourd and squash) followed by fruits 14% (guava, sweet orange, mandarin, mango, peach, and pomegranate) and solanaceous vegetables 6% (brinjal, chillies and tomato). The fruit fly management measures, such as use of para-pheromone lure/traps, sanitation and cultural measures were mostly referred in plant clinics by plant doctors of Nepal. The availability of para-pheromone lures/traps as well as technical know-how of application focusing integrated management measures should be adopted to manage fruit fly in horticultural crops with the least disruption to the environment and human health.

An observation on the embryonic development in Thrips palmi (Thysanoptera: Thripidae) eggs obtained by an artificial oviposition setup

Embryonic development of Thrips palmi (Thysanoptera: Thripidae). • An artificial oviposition setup has been designed to collect intact eggs of T. palmi. • Pine pollen with 10% honey solution increases the rate of oviposition in T. palmi. • The embryonic development of T. palmi has been reported. Thrips palmi is an important insect pest of vegetables and ornamental crops worldwide. Besides direct damage caused by feeding, it transmits several tospoviruses in a persistent-propagative manner. Eggs of T. palmi are microscopic and embedded within plant tissue by the sharp ovipositor of adult female. In the present study, an artificial oviposition setup has been standardized for T. palmi . Eggs of T. palmi were harvested in sterile water between two thin membranes. The developmental stages of T. palmi embryo were studied starting from oviposition up to hatching by inverted and confocal reflection microscopy. Energids were homogeneously distributed at an early stage of development. The anterior end of the egg curved with a constriction post 38 h. Initiation of tissue organization, mouthparts, appendages, compound eyes were observed at different time points. Appendages were well developed and segmentation was prominent post 70 h. The embryo was completely developed at around 80 h and hatched by 86 h post oviposition at 28 °C temperature. The study first time reports the embryonic development of T. palmi that would be helpful in detailed investigations of thrips developmental biology and evolution.

Identification, Characterization and Expression Analysis of TRP Channel Genes in the Vegetable Pest, Pieris rapae.

Transient receptor potential (TRP) channels are critical for insects to detect environmental stimuli and regulate homeostasis. Moreover, this superfamily has become potential molecular targets for insecticides or repellents. Pieris rapae is one of the most common and widely spread pests of Brassicaceae plants. Therefore, it is necessary to study TRP channels (TRPs) in P. rapae. In this study, we identified 14 TRPs in P. rapae, including two Water witch (Wtrw) genes. By contrast, only one Wtrw gene exists in Drosophila and functions in hygrosensation. We also found splice isoforms of Pyrexia (Pyx), TRPgamma (TRPγ) and TRP-Melastatin (TRPM). These three genes are related to temperature and gravity sensation, fine motor control, homeostasis regulation of Mg2+ and Zn2+ in Drosophila, respectively. Evolutionary analysis showed that the TRPs of P. rapae were well clustered into their own subfamilies. Real-time quantitative PCR (qPCR) showed that PrTRPs were widely distributed in the external sensory organs, including antennae, mouthparts, legs, wings and in the internal physiological organs, including brains, fat bodies, guts, Malpighian tubules, ovaries, as well as testis. Our study established a solid foundation for functional studies of TRP channels in P. rapae, and would be benefit to developing new approaches to control P. rapae targeting these important ion channels.

Bottom-Up Effects of Organic Fertilizers on Plutella xylostella (L) with Selected Cruciferous Crop Plants

The diamondback moth, Plutella xylostella (L.) (Lep.: Plutellidae), is a key pest of cruciferous vegetables, throughout the world including Iran. In this study, the effects of vermicompost and humic acid fertilizers on the population growth of P. xylostella were investigated and, furthermore, root system development in the host plants, canola, white cabbage, and red cabbage, was evaluated under the same experimental conditions. Our results showed that brassicaceous plants fertilized by these fertilizers significantly reduced the immature survival rate of P. xylostella. Reared adults from larvae on the treated plants also showed statistically significant reductions in the longevity, oviposition period, and fecundity compared with the control. On canola, white cabbage and red cabbage, the values of R0 (35.4, 10.2 and 6.2 offspring/individual, respectively), r (0.151, 0.098 and 0.071 day-1, respectively), and λ (1.163, 1.103 and 1.074 day-1, respectively) on the plants fertilized with both humic acid and vermicompost were significantly lower than control plants. We also found that on the plants fertilized with humic acid and vermicompost, the number of eggs laid was lower than control plants. The tested fertilizers improved the development of root systems and subsequently enhanced the plant resistance to P. xylostella. Our results show that humic acid and vermicompost root application induces systemic defenses in canola, white cabbage, and red cabbage that have negative effects on the performance of P. xylostella. These findings will help to develop our knowledge regarding the effects of humic acid and vermicompost fertilizers on the resistance of plants to P. xylostella.

Evaluating the repellent effect of four botanicals against two Bactrocera species on mangoes.

BackgroundBactrocera dorsalis and B. correcta are economically important fruit fly pests of crops, vegetables, fruits, and nuts worldwide, especially in China. Nowadays in China, B. correcta is a second notorious pest of many fruits after B. dorsalis. Different botanicals have been tested against the B. dorsalis but in the case of B. correcta, no records were published.MethodologyThis study evaluated the repellency of four botanicals (Seriphidium brevifolium, Piper nigrum, Azadirachta indica and quercetin) in acetone dilutions (5%, 2.5% and 1%) against the B. dorsalis and B. correcta at the laboratory conditions (25 ± 2 °C, 60 ± 5% relative humidity, and a photoperiod of L:D 14:10 h).ResultsThe number of visits after 24–48 h, oviposition punctures, and pupae made by both species were lower on the treated mangoes in comparison to untreated mangoes. S. brevifolium, P. nigrum, A. indica and quercetin have significantly reduced the visits, ovipositional punctures, and pupae of both species. Among botanicals, the P. nigrum was the most effective repellent against B. correcta and as well as B. dorsalis. However, the harmful effects of these botanicals against natural enemies are still unknown.

Pendampingan Ibu-Ibu PKK Kecamatan Lowokwaru Malang melalui Pelatihan Pembuatan Pestisida Nabati sebagai Pengendalian Hama Sayuran Hidroponik

GUIDING OF PKK MOTHERS IN LOWOKWARU MALANG DISTRICT THROUGH TRAINING FOR MAKING VEGETABLE PESTICIDES AS A CONTROL OF HYDROPONIC VEGETABLE PEST. In general, chemical pesticides are used to eradicate pests in vegetables. That is because many chemical pesticides are sold in the market and very effective in eradicating pests. The users of chemical pesticides do not understand, if the use of chemical pesticides for a long time and continuously will be very dangerous. Steps that can be taken to prevent the dangers of chemical pesticides is using natural or vegetable pesticides. Vegetable pesticides are more environmentally friendly, the prices are much cheaper, and not dangerous, and the manufacturing process is very easy. The social role of PKK mothers is carried out to improve the activities of coaching, education, training, and counseling. Therefore, it is necessary to conduct socialization and training in the manufacture of plant-based pesticides for PKK mothers in Lowokwaru District, Malang. The methods used include counseling through lectures, direct practice of making vegetable pesticides, and evaluating the process of making vegetable pesticides. The results of a survey of partners showed that 63% of PKK present did not know about vegetable pesticides. In addition, 81% of partners before participating in training activities had never been aware of the process of making vegetable pesticides. Around 90% of partners are known to have never participated in training in making vegetable pesticides. After participating in training and practice in making vegetable pesticides, it is known that 100% of the community service partners have stated that they can increase their knowledge, skills and practice by making vegetable pesticides at home.

Modeling of agricultural soil compaction using discrete Bayesian networks

The intensive use of machinery in the agricultural area can have serious effects on the soil quality causing its compaction and changes in the related vegetation growth. In fact, consequent phenomena such as water stagnation due to lack of water infiltration, insects proliferation and vegetable pests attack might be observed. Accordingly, the soil compaction causes and diagnosis should be deeply studied. In this paper, based on Bayesian networks, a decision support system suitable for soil compaction risk assessment was built. A discrete Bayesian network was calibrated, starting from raw measured data, to discover the relationships between different variables characterizing the agricultural soil and the experimental conditions. These variables include humidity, the tractor’s weight, the number of passages and the wheels inflation pressure. The compaction phenomenon is studied through analyzing the sensitivity of the soil’s resistance to penetration and its bulk density to the above-cited factors. The developed Bayesian network is proven to be useful as a decision-making tool helping the users to perform both causal and diagnostic analysis on soil state.

Local Depletion of Click Beetle Populations by Pheromone Traps Is Weather and Species Dependent.

Several Agriotes click beetle species are important pests of vegetables and field crops. Monitoring for beetles is generally done with pheromone-baited traps maintained in permanent locations. Since dispersal is mostly by walking, such traps may deplete populations around them, leading to underestimations of populations relative to nontrapped areas, and of concomitant risk of wireworm damage to nearby crops. We placed sets of five pitfall traps in field headland areas in 2015-2017, of which two were baited with Agriotes obscurus (L) or Agriotes lineatus (L) (Coleoptera: Elateridae) pheromone. Of these, one was maintained in a permanent location, while the other moved among the remaining positions. Traps were checked weekly over the emergence period. For A. obscurus, fixed and moving traps initially collected similar numbers, but the latter collected significantly more later in the season, indicating depletion around fixed traps. Depletion was most pronounced after a period of cold weather, and around the peak swarming period. Depletion observed for A. lineatus was not statistically significant. This indicates pheromone-baited traps used for walking insects can underestimate populations, but depletion rates vary with species and temperature and should be accounted for when traps are used to develop action thresholds or time control strategies.

Expression Dynamics of Core RNAi Machinery Genes in Pea Aphids Upon Exposure to Artificially Synthesized dsRNA and miRNAs.

The pea aphid is an important pest of vegetables and causes serious losses worldwide. RNA interference (RNAi) is an effective pest control tool, and three sub-pathways have been described: The miRNA pathway, siRNA pathway, and piRNA pathway. A large number of genes in miRNA pathway and piRNA pathway are found to be expanded. To study the roles of these genes, the expression of 25 core RNAi genes was screened in spatiotemporal samples, artificially synthesized dsRNA and miRNA treated samples. The 25 genes were all expressed during different development stages and in different tissues. In dsRNA-treated samples and miRNA-treated samples, the expressions of genes in these three pathways were induced, especially the expanded genes. This suggests a complex network of RNAi core genes in the three sub-pathways. Treatment of miRNA seems to induce gene expression in a dosage-dependent manner. These results increase our knowledge of the siRNA pathway and related factors from RNAi pathway in aphids and promote the use of RNAi for the control of aphid pests.

Investigation of Varietal Characteristics of Tomato Plants for Determining the Diverse Preferences of Bemisia Tabaci (Aleyrodidea: Hemiptera)

The whitefly (Bemisia tabaci) is a well-known pest of vegetables and ornamental cash crops including tomato plant. Tomato plant disorders, in many instances, are related mostly with the silver leaf whitefly (Bemisia tabaci) feeding. It is well thought out that tomato plant is one of the most favorable host plants for the whitefly. Thus we aimed to study distinctive morphological characteristics of the leaves in seven selected tomato varieties including trichome density, trichome length, leaf lamina thickness and RGB value (red, green, blue) and HSB value (hue, saturation, brightness). Seven hybrid F1 tomato varieties such as TO-1057, TAI-1757, T‑1359, Advanta-1247, New Super, Sultan and Super were tested for the whitefly preferences. Our study suggests that T‑1359 is the highly preferred variety for the whitefly adults (5.32 ± 0.81) and nymphs (6.30 ± 1.13) population. In contrast, Advanta-1247 exhibits the lowest population of whitefly adults (2.71 ± 0.70) and nymphs (1.88 ± 0.43). This study systematically identifies the morphological characters of the tomato plants alongside the whitefly population. The study can be potentially extended to other crops as well.