Whitefly Populations Research Articles

Monitoring of the whitefly populations on cucumber plants in a greenhouse in Luxor region of South Egypt

Monitoring of the whitefly populations on cucumber plants in a greenhouse in Luxor region of South Egypt

Assessing the Resistance of Different Chili Genotypes to Chili Leaf Curl Virus (Chilcv) and Evaluating Insecticides for Controlling its Vector, Bemisia Tabaci

The production of chili in Pakistan is currently facing a significant threat from Chili leaf curl virus (ChiLCV). A study was conducted in the crop growing seasons 2019-2020 and 2020-2021 at Ayub Agriculture Research Institute Faisalabad to assess the susceptibility and resistance of nine chili genotypes to ChiLCV. Each genotype was replicated three times by using the Randomized Complete Block Design. Weekly documentation was carried out to record the incidence and severity of the disease. During the first and second crop growing seasons, it was observed that, Tarapuri (78%, 76.9%), CH 107 (67.8%, 63.7%), Talhari (65.7%, 56.8%), CH 109 (52.7%, 54.4%), CH 108 (50.8, 51.1), and GSL-111 (42.6%, 39.5%) genotypes showed susceptible response to ChiLCV. The two genotypes Hybrid-46 (17.7%, 18.5%) and Hot Queen (15.5%, 13.4%) exhibited a moderately resistant response and only one genotype CBS1292 (40.7%, 39.1%) showed a moderately susceptible response against ChiLCV. The results of the screening experiment indicated that a majority of chili varieties exhibit susceptibility to chili leaf curl disease and the most of the germplasm is deficient in terms of providing protection against the disease. In addition, another study was conducted to evaluate the effectiveness of five insecticides, namely Acephate 75 SP, Emamectin, Imidacloprid, Diafenthiuron, and a combination of these insecticides, in managing percent disease incidence, reducing whitefly population, and enhancing crop yield. Among the various insecticides evaluated, Diafenthiuron exhibited the highest efficacy in reducing disease incidence (7.70%, 6.66%), reducing white fly population (1.80, 1.56), and increasing the yield of green fruit (120.71, 132.52q/ha) followed by combination of all of these inecticides, Imidacloprid, Emamectin, and Acephate during both crop growing seasons. This approach has proved a high level of safety and ecological compatibility, and it appeared to be a practical disease management tool.

Performance of Tomato (Solanum lycopersicum L.) Genotypes for Earliness and Yield Traits in Late Kharif and Summer Season under North Eastern Region of Uttar Pradesh, India

Aims: This preliminary study's goal was to assess how well tomato genotypes performed in the north-eastern region of Uttar Pradesh in terms of earliness, yield, and quality traits in order to be used later in the production of hybrids with desirable characteristics.
 Study Design: Randomized Block Design.
 Place and Duration of Study: The current study was carried out at the Vegetable Research Farm of the ICAR-Indian Institute of Vegetable Research (ICAR-IIVR), Varanasi, during the years 2015-16 in both the consecutive seasons (late Kharif & summer).
 Methodology: The current study was carried out at the Vegetable Research Farm of the ICAR-Indian Institute of Vegetable Research (ICAR-IIVR), Varanasi 14 genotypes.. All the plant materials were grown on raised beds in the experimental plots of tomato breeding unit of ICAR-Indian Institute of Vegetable Research, Varanasi during late Kharif and summer season in the year 2015–2016. In both seasons, about 30 days old healthy seedlings grow in a nursery under net house and transplanted in a 4.50 x 1.20 m raised bed with a spacing of 60 x 45 cm in a Randomized Block Design with three replications in field. To grow a healthy harvest, a standard set of good agricultural practices of tomato was used. During the cropping season, no insecticides were used to protect the whitefly Population, allowing for maximal tomato leaf curl virus (ToLCV) spread and severe disease occurrence. Five plants from each plot were randomly tagged and observations recorded on days to first flowering, days to 50% flowering, number of leaves before truss, days to first ripening, number fruits/ plant, Average fruit weight, fruit yield/ plant, flesh thickness, TSS, texture and Lycopene content.. The data collected on different parameters during the course of investigation were subjected to statistical analysis as per method of analysis of variance (Panse and Sukhatme 1985).
 Results: The genotype EC 538411 was showed earliness and take minimum days to first ripening than others and H-88-78-2 was late in all the traits related to earliness in both season. The highest yield per plot (kg.) was recorded in Punjab Barkha Bahar- 1 (49.73, 25.84) in the both season, respectively. The mean values of Genotypes for flesh thickness (mm.) ranged from 4.37 (H-88-78-2) to 6.27 (VRT-2103-1-8) and 4.07 (H-88-78-2) to 05.99 (VRT-2103-6-1 and D-2-2-3) for season I and season II, With respect to TSS0 Brix, The maximum TSS0 Brix was recorded Genotypes D-2-2-3 (7.47 and 7.53) during the both season respectively. The early maturity and high yield genotype was desirable character for a good variety. So that, those parent which exhibited early maturity and good yielder may be used for development of hybrids.
 Conclusion: The genotypes EC 538411, EC 538411, and VRT-2103-1-4 are recommended as parents for earliness, Punjab Barkha Bahar-1 and D-2-2-3 for yield, and VRT-2103-6-1 and D-2-2-3 for yield and quality traits. These parents could be utilized to breed hybrids with desirable characteristics.

Induction of Resistance in Bhendi Accessions against Whitefly, Bemisia tabaci (Gennadius) under Field Condition

Two bhendi accessions were screened for the induction of resistance by seed treatment with agriculturally beneficial microorganisms like Azospirillum, Phosphobacteria and K-solubilizer against whitefly, Bemisia tabaci (Genn.) at the Department of Entomology, Faculty of Agriculture, Annamalai University. Accession Salem Local along with Arka Anamika was screened with different agriculturally beneficial microorganisms under field condition. The nymphal population of whitefly was recorded during two (Rabi and Kharif) seasons of 2022. Among the treatments, the accession Salem Local treated with K- solubilizer recorded the lowest nymphal population followed by the treatment, Azospirillum + Phosphobacteria + K-solubilizer. Whereas the maximum nymphal population was observed in Arka Anamika treated with Azospirillum with the mean nymphal population of 3.32 and 3.65 in the Rabi and Kharif seasons respectively. Hence, the accessions following seed treatment that conferred resistance against whitefly were selected for breeding in order to develop whitefly resistant varieties.

Leaf-mediated response of soybean genotypes to infestation by whitefly,Bemisia tabaci(Gennadius)

AbstractThe whitefly,Bemisia tabaci(Gennadius) is documented as a major pest on soybean. It was reported that whitefly response towards its hosts and their cultivars varies, and is mediated through various host-related factors. Considering the significance of leaf morphological characteristics in influencing the host–whitefly responses, the present investigation was conducted in screen-house conditions to study the prevailing variations in leaf morphological characteristics of soybean genotypes and their role in governing the adult whitefly attractiveness and oviposition preference. In the multiple-choice test, the whitefly population (eggs, nymphs and adults) was found to be lowest in moderately resistant genotypes (SL 1028 and SL 1074) compared to highly susceptible (DS 3105) and susceptible genotypes (SL 688, SL 958 and SL 1113). The foliar trichomes were characterized using scanning electron microscopy and leaf area, leaf lamina thickness and leaf shape data were acquired using standard procedures. To determine the factors involved in the resistance/susceptible responses towards whitefly, Pearson correlation was applied between the morphological characteristics and the whitefly population. The results show that the leaf area, trichome density, trichome length and trichome angle showed a significant positive correlation with the whitefly population, whereas leaf lamina thickness was negatively correlated. Thus, for developing whitefly-resistant germplasm, breeders should choose genotypes having narrow and thick leaves with sparse, short and flat trichomes.

Occurrence of Tomato Leaf Curl New Delhi Virus in Cucurbit Plants in China.

In August 2022, melon (Cucumis melo), cucumber (Cucumis sativus) and luffa (Luffa aegyptiaca) plants showed virus-like symptoms characteristic of geminiviruses (yellowish green, mosaic patterns and severe curling of leaves, short internodes, and stunting) in 10 greenhouses in Fengxian district and 20 greenhoues in Jiading district of Shanghai, China. Fifty symptomatic leaf samples were randomly collected: 28 from melon, 17 from cucumber, and 5 from luffa. To investigate the etiology of the observed disease, total DNA and RNA was extracted via a DNA extraction kit (Tiangen, Not: DP350) and TRIzol reagent (Sigma-Aldrich, Not: T9424), respectively. Healthy melon plants grown in a growth chamber served as negative control. The DNA and RNA samples were screened for the presence of geminiviruses, Cucurbit chlorotic yellow virus (CCYV), Melon yellow spot virus (MYSV), Cucumber mosaic virus (CMV), Zucchini yellow mosaic virus (ZYMV) and Cucumber green mottle mosaic virus (CGMMV) through PCR or RT‒PCR with geminiviruses (Deng et al. 1994), CCYV, MYSV, CMV, ZYMV and CGMMV (Zeng et al. 2011, 2019) primers. The PCR results showed that 28 melon leaves and 17 cucumber leaves were positive for geminivirus and CCYV, respectively, 5 luffa samples were infected with only geminivirus, and virus was not detected from the healthy plants. These results indicate that these two viruses are widely distributed throughout cucurbit crops in Shanghai, China. All the geminiviruses sequences (approximately 510 bp) were quite similar to each other and were most similar (99.4%) to the Tomato leaf curl New Delhi virus (ToLCNDV) sequence (GenBank Accession No. OP356207) (Li et al. 2022). To confirm the presence of geminiviruses, the segments of DNA-A and DNA-B were amplified by PCR with 4 ToLCNDV-specific primer sets (Mizutani et al. 2011) and sequenced from 10 samples (4 melon, 4 cucumber and 2 luffa). Both DNA-A and DNA-B of the ToLCNDV sequences and features were deposited in GenBank under the accession numbers OQ190939-OQ190948 (DNA-A, 2739 nt) and OQ190949-OQ190958 (DNA-B, 2693 nt). BLASTn analysis of Shanghai isolates of ToLCNDV (DNA-A and DNA-B) showed that the sequences shared nucleotide identities ranged from 99.3% to 100% among them and with values of more than 99.4% nucleotide identity with ToLCNDV isolates from tomato in China (OP356207 and OP356208) (Li et al. 2022). To confirm the virus infection, we have successfully constructed an infectious clone for 0823-1 isolate in the binary plasmid and inoculated melon with and without an infectious clone. The melon plants inoculated with ToLCNDV 15 dpi showed the high accumulation of the virus and displayed symptoms similar to viruses in greenhouse. Based on the complete sequences, results of the molecular phylogenetic analysis (Fig. 2) and infectious clone, these geminiviruses were identified as ToLCNDV. ToLCNDV has been reported to occur and spread by the whitefly (Bemisia tabaci) in many Asian countries (Sohrab et al. 2003; Sohrab et al. 2011; Aamir et al. 2020) and Europe (Juárez et al. 2014; Ruiz et al. 2015; Luigi et al. 2019). Large populations of whiteflies were also present in all our surveyed areas. However, to our knowledge, this is the first report of the occurrence of ToLCNDV in cucurbit plants in China. The presence of ToLCNDV and CCYV can cause severe losses in crop yields or even crop failure. In addition to TYLCV, ToLCNDV is another major geminivirus-induced disease threatening cucurbit and other vegetable production in China.

Seasonal incidence of major insect pests of bottle gourd (Lagenaria siceraria) in South-western Haryana

Bottle gourd is an important vegetable crop that fetches recurrent income from farmers. The present investigation was carried out during the kharif season of 2019 to study the incidence of prevailing four insect pests of bottle gourd in relation to weather. The seasonal incidence of major insect pests such as Aulacophora foveicollis Lucas, Bactrocera cucurbitae Coquillett, Aphis gossypii Glover and Bemicia tabaci Gennadius was studied. The fruit infestation by Bactrocera cucurbitae was initiated in the 34th SMW, and the maximum infestation was noticed in the 36th SMW. The fruit fly infestation was significant and positively correlated with evening relative humidity and rainfall. Aulacophora foveicollis incidence in bottle gourd was maximum in the 38th SMW. The beetle population was significantly and negatively correlated with minimum temperature and evening relative humidity. The maximum infestation of aphids and whitefly was noticed in the later stage of the crop during the 39th SMW, and the aphid population was significantly correlated with minimum temperature, evening relative humidity and rainfall, whereas the whitefly population was correlated significantly with evening relative humidity and rainfall.

Efficacy of Different Neonicotinoids and Bio Pesticides on Okra Against Bemisia Tabaci

The current study was investigated at the Agricultural Research Institute Tarnab, Peshawar during 2020 in a Randomized Complete Block Design (RCBD) with three replications. The study aimed was determining the efficacy of different neonicotinoids insecticides and bio- pesticides against Bemisia tabaci on okra crop. Results revealed that significantly maximum number of whitefly (Bemisia tabaci) population reduction was recorded in imidacloprid (7.55plant-1) treated plot followed by acetamiprid (8.88plant-1) and bio-pesticides (11.99 plant-1) while minimum population reduction was recorded in clothianidin (14.66 plant-1) treated plot over checked plot after 1st application while similar observation was recorded after the 2nd application. In terms of CB ratio, highest CB ratio was recorded by imidacloprid treated plot followed by bio pesticide, acetamiprid and clothianidin while lowest CB ratio was recorded by acetamiprid. Similarly, the research work concluded that overall best performed by imidacloprid after 1st and 2nd application while minimum control was observed by clothianidin treated plot over the control treatment. 
 

Relationship Between whitefly (Bemisia tabaci) Population and Pepper Yellow Leaf Curl Disease on Chili Plant Yield in The Field

Relationship Between whitefly (Bemisia tabaci) Population and Pepper Yellow Leaf Curl Disease on Chili Plant Yield in The Field

Determining Field Insecticide Efficacy on Whiteflies with Maximum Dose Bioassays.

We conducted a rapid bioassay method to assess insecticide efficacy for controlling adult sweetpotato whitefly Bemisia tabaci in squash and cucumber crops before insecticide applications. The study aimed to evaluate the accuracy of a 24-hour laboratory bioassay in determining maximum dose insecticide efficacy in the field. Ten insecticides were evaluated using leaf-dip bioassays, and their effectiveness was tested across eight cucurbit field experiments in Georgia, USA, during the 2021 and 2022 field seasons. The maximum dose, defined as the highest labeled rate of an insecticide diluted in the equivalent of 935 L ha-1 of water, was used for all bioassays. Adult survival observed in the bioassay was compared to adult field count-based survival 24 h after treatment. A low concentration (1/10 rate) was used for imidacloprid, flupyradifurone, pyriproxyfen, and cyantraniliprole to assess insecticide tolerance in the whitefly population. Overall, significant positive correlation between laboratory bioassay and field efficacy was reported, explaining 50-91% of the observed variation. The addition of the low dosage was helpful, indicating that no rate response was consistent with susceptibility to the tested insecticide, while a rate response was associated with a loss of susceptibility between 2021 and 2022.

Effect of several reduced-risk insecticides on the population of Bemisia tabaci Genn. and incidence of pepper yellow leaf curl Indonesia virus (PepYLCIV) on chili plants

Tobacco whitefly, Bemisia tabaci Genn. can directly, and indirectly damage chili plants by sucking the plant sap and transmitting Pepper yellow leaf curl Indonesia virus (PepYLCIV), respectively. Farmers control PepYLCIV by using synthetic insecticides with 2-3 applications a week to suppress the vector population. The intensive use of insecticide raises concern about potential detrimental effects on the environment and non-target organisms. An alternative control measure for B. tabaci is the use of reduced-risk insecticides that are effective but safer. Thus, the study aimed to determine the effectiveness of various reduced-risk insecticides in reducing the whitefly population and PepYLCIV incidence. This experiment consisted of 12 treatments using insecticides of abamectin, azadiractin, imidacloprid, deltamethrin, spinosad, and water (control), applied once and twice a week. The results showed that the low-risk insecticides had no significant effect on the numbers of adults and nymphs of B. tabaci and the PepYLCIV incidence. Imidacloprid had significantly lower egg number and PepYLCIV incidence than the control and the other insecticide treatments. Our results also showed that B. tabaci populations were low throughout the season but the incidences of PepYLCIV were relatively high. This indicated a possibility that PepYLCIV is seed-borne.

Evaluation of Host Plant Susceptibility Indices and Screening of Sugarcane Promising Lines for Resistance Potential Against Whitefly, Aleurolobus barodensis (Maskell) in Sindh, Pakistan.

The whiteflies are polyphagous, host, and feed on the sap of sugarcane leaves may cause a loss in yield production. This study was designed to screen out the fifteen sugarcane genotypes to recognize their comparative resistance/susceptibility during 2014-15 and 2015-16. The whitefly attack was first found in June, rapidly increased in August, and reached its maximum population in October. After that, the population gradually declined from November to December. The highest 1.80 per cm2 leaf-1 population of whitefly (nymph + puparia) was recorded on YT-53, followed by 1.56 per cm2 leaf-1 in S-2007-AUS-384, which showed moderate susceptibility. The genotypes Hoth-127, NARC-1, and CP-TJ-349, exhibited less susceptible responses with an average range of 1.01-1.50 per cm2 leaf-1. The other genotypes, i.e., CP-TJ-349, Hoth-326, Th-910, S-2005-CSSG-33, S-2007-AUS-384, Hoth-2109, LAM-76/TJ-803, Th-1201, S-2009-CPSG-06, S-1996-NSG-197, NARC-2, and Th-1210 showed resistance response with an average range of 0.01-1.00 per cm2 leaf-1. The maximum Host Plant Susceptibility Indices (HPSIs) during 2015 (16% and 15%), 2016 (13% and 14%), and cumulative (16% and 14%) were recorded in YT-53 and S-2007-AUS-384, respectively. Based on the cumulative result of HPSIs, these genotypes keep in the moderately susceptible category. Similarly, the genotypes Hoth-127, NARC-1, and CP-TJ-349 showed intermediate HPSIs (12, 11, and 9% respectively, found to be less susceptible. While the genotypes, i.e., Hoth-326, Th-910, S-2005-CSSG-33, LAM-76/TJ-803, Hoth-2109, Th-1201, S-1996-NSG-197, S-2009-CPSG-06, NARC-2, and Th-1210 were recorded minimum HPSIs in the range of 1-8% possibly found to be resistant.

REVIEW ON ECOLOGICAL WHITE FLY MANAGEMENT PRACTICES IN VEGETABLE CROPS

White flies Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) is a damaging sap-sucking insect pest of ornamental and vegetable crops. It causes yield reduction and crop damage by feeding on both immature and mature plants as well as spreading viral infections. Due to their widespread use throughout the world, synthetic chemical pesticides have a negative influence on human health, the environment, crop yield, and pollinator health. A few species have also evolved resistance to these pesticides. Sustainable and environmentally responsible management techniques are becoming more and more necessary to control whitefly populations as ecological concerns rise. The purpose of this review is to provide an overview and assessment of the effectiveness of various ecological management techniques used in vegetable crops to manage whiteflies. The review includes cultural, physical, and biological techniques as well as preventive and therapeutic treatments. Through altering their life cycle and habitat, cultural methods like crop rotation, intercropping, and trap cropping have showed promise in lowering whitefly populations. Physical controls like reflecting mulch, insect-proof screens, and sticky traps have proven successful in catching adult whiteflies and limiting their population. The employment of natural enemies like parasitoids, predators, and entomopathogenic fungi in biological control strategies has shown to be highly effective in reducing whitefly populations. These techniques reduce detrimental effects on the environment and human health in addition to providing long-term and sustainable management. These methods support environmentally sound and economically successful sustainable agriculture systems by fostering biodiversity, protecting natural enemies, and lowering the use of synthetic pesticides.

Population dynamics of major insect pests infesting chilly, bottle gourd and cucumber

A set of experiments was carried out to investigate the population dynamics of important insect pests that infest capsicum, bottle gourd and cucumber. Results revealed that aphid (Aphis gossypii Glover), whitefly (Bemisia tabaci Genn.) and leafhopper (Amrasca biguttula), and commenced the activity during the second and third week of October and November. The mean thrips peak population find in the second and third week of October in chilly (6.90) whereas third week for bottle gourd as well as cucumber (8.88 and 9.67 respectively). The average white fly density maximum is seen between the second of October in chilly, bottle gourd and cucumber (6.19, 8.88 and 9.67 respectively). Leaf hopper population also heigh in second week of October (5.02, 5.76 and 5.65) for chilly, bottle gourd and cucumber. Second and third week of October had maximum incidence of thrips and white fly population in bottle gourd as compare to chilly and cucumber.

The effect of subfreezing temperatures on survival of Bemisia tabaci MEAM1

The sweetpotato whitefly Bemisia tabaci is a destructive pest on a wide variety of agricultural crops. Whiteflies are managed largely through the use of insecticides, but B. tabaci has developed tolerance or resistance to a broad range of active ingredients. Identifying events where insecticide applications could be delayed or eliminated may mitigate insecticide resistance. One such event is cold weather, which can decrease whitefly activity including dispersal and mating, or kill a substantial proportion of the whitefly population when temperatures fall below freezing. The objective of this research was to quantify the effects of exposure period to subfreezing temperatures on the mortality of adult whitefly. Results showed that whitefly mortality could be predicted through a non-linear function of a composite variable of temperature and exposure time (x). This model was applied retroactively to six seasons of field data collected in southwest Florida during the months of November through February. Based on observation and model output, significant drops in the whitefly population were mostly associated with two or more cold events – separated by no more than 7 days – with at least one of those events with x > 13. Moreover, the decrease was sustained for 4–6 weeks after the last event. The ability to predict decreases in the whitefly population in response to freeze events gives growers the opportunity to relax insecticide schedules, particularly in the spring cropping season, with high confidence that their crop is at low risk to whitefly damage.

Screening of Germplasms and Population Dynamics of Major Insect Pests of Spring Green Gram Vigna Radiata (Linn.)

The present investigation was conducted during Spring season of 2021-22 at Norman. E. Borlaug. Crop Research Centre of G.B. Pant University of Agriculture and Technology, Pantnagar (Uttarakhand) and Morphology laboratory of Department of Entomology with the objectives screening of green gram germplasms in field as well as laboratory conditions and occurrence of major insect pests in field conditions. In field conditions major insect pests were observed using various methods such as whiteflies in a whitefly cage, jassids/trifoliate, knockdown approach for thrips and sweep net method for pod bug population. Under laboratory conditions germplasms were screened against Spodoptera litura using choice test method. Investigations on population dynamics shows that population of whitefly was highest during 17th SMW while thrips population was at peak during 19th SMW followed by jassid in 17th SMW and pod bugs in 19th SMW. Based on data recorded among various entries SSME 21-70, SSME 21-55 and SSME 21-53 were found superior among all the test entries against B. tabaci, M. distalis, E. kerri and C. gibbosa infesting green gram. Data of laboratory experiments revealed that when castor was used as standard host, preference index varied significantly from 0.02 (SSME 21-48) to 1.00 (SSME 21-55) at P = 0.05 level of significance while when PM-5 was taken as standard host, significant variation in preference index was recorded from SSME 21-70 (0.01) to SSME 21-43 (1.16) at P = 0.05.

Dynamics of Pests, Natural Enemies and Pollinators of Lycopersicon esculentum Mill and Correlation with Weather Parameters

The experiment was carried out at K.V.K. Instructional Farm located near College of Agriculture, Odisha University of Agriculture and Technology (O.U.A.T.), Bhawanipatna, Kalahandi, during the cropping season 2020–21. The most significant pests found in Lycopersicon esculentum Mill were tomato fruit worm, serpentine leaf miner, and whitefly, while flea beetle was of minor importance.The population of whitefly had significant negative correlation with evening and mean relative humidity (RH). The population of leaf miner had significant positive correlation with maximum, minimum and mean temperature but significant negative correlation with mean RH. There was a significant positive correlation of flea beetle population with minimum temperature. The tomato fruit borer population had significant positive correlation with maximum, minimum and mean temperature but significant negative correlation with morning and mean RH. The natural enemies, lady bird beetles, spiders, praying mantis, rove beetle, red ant, dragonfly (red body) and damselflies (blue, brick red and black body) were found in the plots. The population of spider had significant negative correlation with maximum, minimum and mean temperature but significant positive correlation with bright sunshine hours (BSH). The population of spider had significant negative correlation with evening RH but significant positive correlation with BSH. There was a significant positive correlation of red ant population with BSH. The population of rove beetle had significant positive correlation with maximum, minimum and mean temperature. The pollinators recorded from experimental field were honey bee and carpenter bee. Of which, carpenter bee was the most frequent floral visitor and considered the main pollinator of tomato. The pollinators appeared in higher numbers during the blooming period and was the dominant species found in the field. There was a significant negative correlation of population of carpenter bee with maximum, minimum and mean temperature. The population of honey bee had significant negative correlation with evening RH.

Seasonal Incidence of Insect-pests, Natural Enemies and Pollinators of Solanum melongena L. and Correlation between Their Daily Occurrences with Weather Parameters

The investigation was carried out at K.V.K Instructional Farm of Bhawanipatna, Kalahandi, Odisha, India during the cropping season 2020-21. Brinjal shoot and fruit borer (BSFB), whitefly, and jassid were the most significant pests found in brinjal, Solanum melongena L. while epilachna beetle was of minor importance as it was found in much lower numbers and caused less damage. They were found from 2nd to 16th Standard Meteorological Week (SMW). The population of whitefly had significant negative correlation with morning, evening and mean Relative Humidity (RH). There was a significant negative correlation of population of jassids with evening and mean RH but significant positive correlation with bright sunshine hours. The population of epilachna had significant negative correlation with morning, evening and mean RH but positive correlation with maximum, minimum and mean temperature. BSFB infestation on fruit had significant negative correlation with morning, evening and mean RH but positive correlation with maximum and mean temperature. There was a significant positive correlation of BSFB infestation on shoot with maximum, minimum and mean temperature but significant negative correlation with rainfall. The natural enemies found in brinjal ecosystem from 4th to 16th SMW and belonged to ladybird beetles, spiders, preying mantids, black ant, carabid beetle, syrphid flies, damselfly and chrysopids. The population of spiders had significant negative correlation with evening and mean RH but positive correlation with bright sunshine hours. There was a significant negative correlation of population of coccinellids with evening RH. The pollinators recorded from experimental field were honeybee and carpenter bee from 3rd to 16th SMW. Among them, carpenter bee, Xylocopa sp. was the most dominant visitor of brinjal flower in the field and was identified as potentially important in brinjal. The pollinators appeared in higher numbers during the blooming period and was the dominant species found in the field. The population of honey bees had significant negative correlation with evening RH.

Occurrence of cassava mosaic begomoviruses in national cassava germplasm preserved in two agro‐ecological zones of Ivory Coast

AbstractCassava production in Ivory Coast is hampered by cassava mosaic disease (CMD), which is caused by several begomovirus species. To increase cassava production and conserve genetic resources, the Centre National de Recherche Agronomique (CNRA) maintains a germplasm collection of 610 cassava accessions of various origins, which is kept in open fields in Bouaké and Man. We carried out an epidemiological assessment of the collection and a molecular characterization of the viruses infecting the CNRA cassava germplasm. The field in Man was less affected by CMD (incidence 49.78%, severity 2.23, whitefly infection 2.23%), despite the abundant whitefly populations (1.34 per plant), compared to Bouaké (incidence 74.54%, severity 2.92, whitefly infection 8.04% and whitefly population of 0.34 per plant). However, the predominant mode of CMD transmission was through infected cassava cuttings at both sites. PCR analysis showed that the East African cassava mosaic Cameroon virus (EACMCMV) was always found in co‐infection with African cassava mosaic virus (ACMV), which also occurred in single infection. Co‐infections of EACMCMV and ACMV were more prevalent in Bouaké (52.64%) than Man (13.87%). Eleven complete genome sequences of cassava mosaic begomoviruses infecting the CNRA germplasm were obtained, and phylogenetic analysis showed that they are closely related to ACMV and EACMCMV isolates from Ghana, Burkina Faso and Nigeria. The results of this study will assist breeders to screen accurately for CMD resistance in progeny resulting from parental lines, enabling the strategic distribution of new clean cassava planting materials to reduce the impact of CMD.

Determination of Begomovirus on chili plants (Capsicum sp.) in Buton and Muna Islands, Southeast Sulawesi, Indonesia

Abstract. Widodo CJ, Taufik M, Khaeruni A, Mallaranggeng R. 2023. Determination of Begomovirus on chili plants (Capsicum sp.) in Buton and Muna Islands, Southeast Sulawesi, Indonesia. Biodiversitas 24: 741-751. Begomovirus disease is one of the main factors inhibiting chili cultivation which could harm plants and result in crop failure. This study aimed to determine the symptoms of begomovirus disease in chili plants in Buton and Muna, Southeast Sulawesi. The methods used are disease incidence survey, insect vector observation, molecular identification using the polymerase chain reaction (PCR) technique, and Sanger sequencing (Applied Biosystem 3500). The survey was conducted in Southeast Sulawesi province, covering Bau-Bau City, Buton Regency, Central Buton, North Buton, Muna, and West Muna. The results showed that the incidence and severity of Begomovirus disease were observed highest in Buton islands, 73% and 49.5% (Buton City), followed by North Buton, Central Buton, and Buton, with the incidence and severity of Begomovirus, respectively, of 71.74% and 59.5%; 69.32% and 51.5%; and 68% and 61.5%. While in Muna Regency, 63.16% and 38.5%, West Muna, 73.79% and 53.50%. On the other hand, the highest percentage of the whitefly population was in Bau-Bau City, 24%, while the lowest was in West Muna, 15.5% supporting this observation. Furthermore, PCR analysis successfully amplified symptomatic isolates from Buton and Muna islands at a band length of 580 bp. On the other hand, Sanger sequencing analysis revealed the existence of the Indonesian Pepper Yellow Leaf Curl Virus (PepYLCIV) with more than 96% genetic homology to the Gene Bank data of MN094866 PepYLCIV Capsicum annuum Indonesia and MN738463 PepYLCIV Chili pepper Indonesian. This information is the first report of the presence of Begomovirus on the two islands.