Ladybird Beetle Populations Research Articles

Seasonal Incidence of Insect-Pests of Field Pea

During both seasons, aphid incidence peaked at 38.40 aphids/10cm shoot at the 5th SMW and 40.51 aphids/10cm shoot at the 4th SMW, respectively. While the activity of leafhoppers attained the peak of 14.20 leafhoppers/3 leaves during 7th SMW and 13.20 leafhoppers/3 leaves during 6th SMW during both seasons, respectively. During 2019-20, the whitefly population initiated at 5th WAS and persisted until the 13th WAS (1.44 to 11.28 whiteflies/3 leaves), whereas, in 2020-21, the population began in the 6th WAS and peaked during 12th WAS (12.21 whiteflies/3 leaves). Pod borer population started in 5th WAS and peaked (1.34 larvae/plant) in 10th WAS during 2019-20; in 2020-21, the population peaked (1.12 larvae/plant) during 11th WAS. The ladybird beetle population was active from 6th to 13th WAS and reached a peak (2.86 beetles/plant) during the 10th WAS in 2019-20. During the second season, the population of ladybird beetles started in the 7th WAS and peaked at 2.30 beetles/plant in 10th WAS. The spider appeared on the crop on the 5th WAS and remained active until 14th WAS, with the peak activity (0.34 and 0.30 spider/plant) reported during 6th SMW in both seasons. Significantly negative correlation was seen between evening relative humidity and leafhopper population during both seasons. Other insect-pests (aphid, leafhopper, whitefly and H. armigera) showed non significant impact of weather parameters during both seasons. Whereas, H. armigera larvae had positive correlation with bright sunshine hours and wind velocity during both seasons. Ladybird beetle showed highly significant and positive correlation with aphid, leafhopper and whitefly population during both seasons. Spider showed significant and positive correlation with aphid, leafhopper and whitefly population in both seasons.

Henosepilachna vigintioctomaculata Motschulsky (Coleoptera: Coccinellidae): morphotypes in an East Asian population

The 28-spotted potato ladybird beetle Henosepilachna vigintioctomaculata is an endemic pest of field crops in the Russian Far East. The study on the morphotypic structure of a population of this phytophagous insect can facilitate the monitoring of processes occurring in ecosystems. It might contribute to the research on the endemic fauna of the Russian Far East and reveal how varieties form resistance to pesticides. To study the polymorphism and structure of a potato ladybird beetle population, an analysis of elytral color patterns was conducted. The following features were considered: the size and shape of spots, the intensity of color, the position of spots on the elytra relative to the elytral suture, the presence of merged spots. As the result, nine morphotypes were identified. The morphotype A2 was the most frequent (47.81 %) and followed by the morphotypes A1 and A6. The morphotype A9 had the lowest frequency of occurrence (1.82 %). It was also determined that morphotypes differed in the linear dimension of spots on the elytra. The form A2 was characterized by the largest spots. The size of the color patterns varied from 104.98 ± 0.071 to 297.01 ± 0.065 µ. The form A1 had the smallest spots.

Population Dynamics of Insect Pests and Beneficials on Different Snap Bean Cultivars

Snap bean is an important crop in the United States. Insecticides are commonly used against pests on snap bean, but many pests have developed resistance to the insecticides and beneficials are threatened by the insecticides. Therefore, host plant resistance is a sustainable alternative. Population dynamics of insect pests and beneficials were assessed on 24 snap bean cultivars every week for six weeks. The lowest number of sweetpotato whitefly (Bemisia tabaci) eggs was observed on cultivar 'Jade', and the fewest nymphs were found on cultivars 'Gold Mine', 'Golden Rod', 'Long Tendergreen', and 'Royal Burgundy'. The numbers of potato leafhopper (Empoasca fabae) and tarnished plant bug (Lygus lineolaris) adults were the lowest on cultivars 'Greencrop' and 'PV-857'. The highest numbers of adults were found in Week 1 (25 days following plant emergence) for B. tabaci and Mexican bean beetle (Epilachna varivestis); Week 3 for cucumber beetle, kudzu bug (Megacopta cribraria), and E. fabae; Weeks 3 and 4 for thrips; Week 4 for L. lineolaris; and Weeks 5 and 6 for bees. Temperature and relative humidity correlated with B. tabaci, E. varivestis, bee, and predator ladybird beetle populations. These results provide valuable information on the integrated pest management of snap beans.

Phenology of the 28-spotted potato ladybird beetle <i>Henosepilachna vigintioctomaculata</i> in the south of the Russian Far East

Relevance. The 28-spotted potato ladybird beetle, Henosepilachna vigintioctomaculata, causes severe damage to plants of the Solanaceae family in the south of the Russian Far East. Today the application of chemicals is the main method for protecting crops against the potato ladybird beetle. This leads not only to the eradication of the pest, but also to the pollution of agricultural ecosystems and the emergence of potato ladybird beetle populations that are resistant to pesticides. A study on the seasonal cycles of the development of the potato ladybird beetle may help to devise new methods for controlling this pest.Methods. We conducted laboratory experiments to study the developmental timing ofa potato ladybird beetlepopulation. The number of eggs was counted, and then the eggs were placed in Petri dishes. The number of emerged larvae was recorded on a daily basis. The hatched larvae were transferred to glass containers (hereafter rearing cages) in batches of 10. We recorded the dates of the transition from one immature developmental stage to another notingthe simultaneity of these transitions. At the onset of the pupal stage, the date was recorded and food was withdrawn from the rearing cages. Scientific observations were carried out on the emergence ofyoung beetles. Field research on the phenology of the potato ladybird beetle was conducted at afield site of 40 m2. The timing of the following events was recorded: the emergence of the adult beetles from diapause, the colonization of the potato field, the beginning and the end of oviposition, the emergence of the larvae and the pupae, the flight of the new insect generation.Results and conclusion. Our laboratory experiment on the immature developmental stages of the potato ladybird beetle revealed that the egg stage was 4-5 days in duration, the larval stage was 16-17 days and the pupal stage was 4-5 daysunder optimal conditions. We also observed deviations from the mean values, which could be conditioned by external factors. For instance, the duration of embryonic development depended either on humidity or on the time range of hatching from one egg mass. The observed deviations of the developmental timing of the larvae and the pupae were most probably due to the quantity and quality of the available food, and the presence of secondary metabolites and glycoalkaloids in it. The field research on thephenology of the potato ladybird beetle showed that there was only one generation in 2020, but two generations in 2021. After comparing climatic conditions in 2020 and 2021, we concluded that Henosepilachna vigintioctomaculata can produce two generations during dry and hot years.

Seasonal incidence of major pest of chilli and their natural enemies under Western Vidharbha condition

Seasonal incidences of major pests of chilli viz., thrips, aphid, mites and fruit borer with natural enemies such as lady bird beetle, spider etc. were studied at Agriculture Research Station, Achalpur (Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola) during Kharif 2018-19 and 2019-20. The results of two years study revealed that the aphid population was observed from 33rd MW (0.28 and 3.20, respectively) throughout the whole growing season for both the year and it attained its initial peak during 44th and 45th MW, respectively. During the low rainfall year non significant positive correlation (0.410) was recorded. However, in next year significantly higher and positive (0.645) correlation was recorded with rainfall. The maximum population of thrips was observed at 39th MW (6.20 per leaf) and 44th MW (10.30 per leaf), the correlation between thrips population and rainfall was positively non-significant (0.389 and 0.033) for Kharif 2018 and 2019, respectively. The mites population were reached at its peak during 39th MW (2.70 per leaf) and 40th MW (2.15 per leaf) during both the year, respectively. The correlation studies for both the years revealed that, the mite’s population showed positively non-significant correlation with rainfall. The incidences of fruit borer commenced from 38th and 37th i.e. 0.80 per larvae per plant for both the year. The fruit borer population exhibited a negative non significant correlation with rainfall during Kharif 2018 and vice-versa during Kharif 2019. The lady bird beetle population was commenced from 31st with a mean population 0.30 per plant in Kharif 2018 and 0.10 per plant in Kharif 2019. The correlation studies between the population of lady bird beetle and rainfall was negatively non-significant for both the seasons. In case of spider, it attained its peak during 37th and 50th (0.40 and 0.60 per plant), respectively for both the season. The correlation studies between spider and rainfall were revealed that the population was negatively non-significant with rainfall during Kharif 2018 and 2019.

De Novo Transcriptome Sequencing of Serangium japonicum (Coleoptera: Coccinellidae) and Application of Two Assembled Unigenes.

The ladybird beetle Serangium japonicum is an important predator of whiteflies. Investigations of the molecular mechanisms of this predatory beetle have been hindered by the scarcity of gene sequence data. To obtain gene sequences for the ladybird beetle and determine differences in gene expression between the summer and winter seasons, paired-end sequencing was performed. Real-time PCR was used to validate differences in Krueppel homolog 1 gene (Kr-h1) mRNA expression in summer vs. winter samples. To determined the diversity of the population, annotated cytochrome c oxidase subunit I gene (COX1) gene fragments were amplified from several ladybird beetle populations. The analysis yielded 191,246 assembled unigenes, 127,016 of which (66.4%) were annotated. These functional annotations of gene sequences are currently available from the National Center for Biotechnology Information (NCBI), and will provide a basis for studying the molecular mechanisms underlying the biological characteristics of S. japonicum. We found a change in expression of ribosome-associated genes across seasons, and postulate that this change is because of seasonal variation in temperature and photoperiod. The differential expression of Kr-h1 suggests that S. japonicum can successfully overwinter because the adults enter diapause. To explain the effects of season on Kr-h1 gene expression, we hypothesize a model in which that a short photoperiod affects the density of Ca2+, the subsequent activity of methyl farnesoate epoxidase and the synthesis of JH, and in turn Kr-h1 gene expression. COX1 annotation was concordant with the morphological ID. The same COX1 sequence was found in the samples from several provinces in China. Therefore, the COX1 sequence is worth further study to distinguish beetle species and populations.

Field efficacy of Tolfenpyrad 15 EC against thrips, Thrips palmi Karny on Cucumber

The thrips (Thrips palmi) on cucumber revealed that excellent control of the thrips was observed in the treatment Tolfenpyrad 15 EC @ 150 g a.i./ha at 15 days after spraying registering 82.5 and 83.6% reduction in the population over control during kharif, 2015 and rabi, 2015–16, respectively. Tolfenpyrad 15 EC @ 100.5 and 124.5 g a.i./ha, imidacloprid 17.8 SL @ 22.5 g a.i./ha, fipronil 5 SC @ 40 g a.i./ha and chlorpyriphos 20 EC @ 250 g a.i./ha did not give satisfactory control of thrips at 15 days after spraying on cucumber both during kharif, 2015 and rabi, 2015–16. The chemical Tolfenpyrad 15 EC @ 100.5, 124.5, and 150 g a.i./ha and imidacloprid 17.8 SL @ 22.5 g a.i./ha did not harm the natural enemy, ladybird beetle population at 1, 3, 7 10 and 15 days after each spraying of the chemicals. But, fipronil 5 SC @ 40 g a.i./ha and chlorpyriphos 20 EC @ 250 g a.i./ha reduced the predatory lady bird beetle population significantly over control.

Correlation and regression of aphids on cauliflower with abiotic and biotic factors of environment

The aphid population showed negatively significant correlation with minimum temperature. Similarly negatively significant correlation of syrphid fly maggot was noticed with minimum temperature. However, it was positively significant with aphid. The ladybird beetle population showed negative correlation with maximum and minimum temperature while positive with aphid population. The correlation between aphid and mummified aphid was positively significant. The high values of coefficient of determination showed that weather parameters and biotic factors (natural enemies) were the critical factors for abundance of population of aphid on cauliflower.

Can Entomopathogenic Fungi Clearly Differentiate between Harmful and Beneficial Insects in Nature?

For two successive years, a survey was conducted of entomopathogenic fungi associated with two naturally infected predatory insect species on different plantations of the Nile Delta in northern Egypt. Adults of the eleven-spotted ladybird beetle, Coccinella undecimpunctata L. (Coleoptera: Coccinellidae), are frequently observed with infections of the entomopathogenic fungus Beauveria bassiana, which caused mortality of 4.1 % and 5.4 % in the adult ladybird beetle population sampled in July 2006 and 2007, respectively. However, mycosed individuals of the seven-spotted ladybird, Coccinella septempunctata, were rarely encountered. Adults of the syrphid fly Syrphus corollae (Diptera: Syrphidae) are also subject to infection with the entomopathogenic fungus Entomophthora syrphi. Data showed that E. syrphi caused mortality in syrphid fly adults at rates of 4.6 % in April to 0.2 % in June 2006, whereas mortality rates ranged from 6.1 % in April to 0.9 % in June 2007. Mycosed syrphid adults were always found in a...

Population dynamics of major insect pests of cowpea [Vigna ungiculata (L.) Walp.

Investigations were carried out on population dynamics of major insect pests that attack cowpea [ Vigna ungiculata (L.) Walp.] at Regional Horticultural Research Station, Navsari Agricultural University, Navsari during 2012-13. The results revealed that aphid and jassid population started from 3 rd week of October, reached a peak of 3.4 aphid index and 3.8 jassids/ leaf by 1 st week of December whereas whitefly population started from 3 rd week of October and reached to a peak level of 3.7 whiteflies per leaf in 4 th week of November. Cowpea pod borer population started in 2 nd week of November and reached to a peak level (2.8 larvae/plant) in 1 st week of December and thereafter, decreased gradually. Spotted pod borer population started from 1 st week of November coinciding with the flower initiation and reached to a peak of 2.8 larvae per leaf in 1st week of December. Among various weather parameters, evening relative humidity showed a significantly negative influence on population of almost all pests and minimum temperature showed a significantly negative correlation with aphid, cowpea pod borer and ladybird beetle population.

Evaluation of Certain Botanical Preparations against African Bollworm, Helicoverpa armigera Hubner (Lepidoptera: noctuidae) and Non Target Organisms in Chickpea, Cicer arietinum L

Aqueous extract of individual and mixed form of Azadirachta indica A. Juss seeds kernel and leaves of Milletia ferruginea, Hochst and Croton macrostachyus Hochst was tested against African bollworm, Helicoverpa armigera Hubner. Antifeedant activity of selected plant extract was tested at 1%, 2.5%, 5% and 10% concentration against 4th instar larvae of H. armigera in the laboratory and 5% concentration was tested under field condition. All the tested plant extract showed 100% protection at 5% and 10% concentration. Among the various botanical treatment Neem Seed Kernel Extract (NSKE) and NSKE+BLE (Birbira Leaves Extract) was effective at 2.5% concentration with minimum pod damage. In the field observation among the botanicals, reduction of larval population in the treatment of NSKE, BLE and NSKE+BLE was statistically not significant (p>0.05; LSD). The lowest percentage pod damage (0.45%) was observed in Diazinon 60% EC treated plot followed by NSKE treated plot (3.90%) after second spray. The highest mean yield was obtained from NSKE treated plot (781 g) followed by Diazinon 60% EC treated plot (719.33 g), NSKE+BLE (656.67 g) and BLE treated plot (653.33 g). Five days after second treatment there was a significant difference in the mean number of ants between NSKE+BLE, control and other treatments. The highest mean number of spiders was observed in control plot (3.6) and lowest (0.3) was in plot treated with Diazinon 60% EC. The reduction of lady bird beetle population among the botanicals treated plots was statistically not significant (p>0.05; LSD). The mean number of wasp population was the highest in control plot (3.3) and there was no wasp observed in Diazinon 60% EC treated plot. In conclusion, even though Diazinon 60% EC was found to be effective by considering the interaction of beneficial in the field botanical preparations are much better particularly NSKE and also suitable to spray under rain fed condition to protect the crop by small farming communities.

Influence of aphid–host plant pairs on the survivorship and development of the multicolored Asian ladybird beetle: implications for the management of vegetation in rural landscapes

AbstractAlthough the value of noncrop vegetation for biological control has been extensively studied in agricultural landscapes, there are few reports on how it functions mechanistically. When focusing on the pest control function provided by noncrop vegetation, tritrophic interactions among a predatory natural enemy, its prey, and the prey's host plant need to be examined. In Japan, the multicolored Asian ladybird beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), an aphidophage, serves as a natural pest control agent in agricultural production, although the species’ introduction into Europe and North America for pest control has had a negative impact on native ecosystems. In the present study, 33 aphid–plant pairs from an agricultural landscape in the eastern Kanto region of Japan were examined experimentally for initial larval survivorship and development of H. axyridis. Significant differences were found among plant–aphid pairs with regard to these parameters. In addition, the larval survivorship of H. axyridis was not consistently determined by host plant or aphid species alone but was context‐dependently influenced by the aphid–plant combination. Some alien host plants showed positive effects on the ladybird beetle. Others, however, served as hosts for unsuitable prey species, such as the competitive alien plants Solidago canadensis L. and Robinia pseudoacacia L., which are the host plants of Uroleucon nigrotuberculatum (Olive) and Aphis craccivora Koch, respectively. These findings suggest that various noncrop plants could be managed to promote ladybird beetle populations in rural landscapes.

Relative efficacy of some botanicals, detergent and kerosene in controlling the pea aphid Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae) on grass pea Lathyrus sativus

Grass pea Lathyrus sativus L. plays a major role in the nutrition of many poor people in Ethiopia. However, the crop suffers heavy damage by pea aphids Acyrthosiphon pisum (Hemiptera: Aphididae). To test potentially more sustainable and harmless alternatives to the commonly used insecticides, some botanicals (neem, garlic and hot pepper), soap, kerosene and the aphicide pirimicarb, were tested for their efficacy against A. pisum at Wondata village, close to the town of Bahir Dar, in northwestern Ethiopia, from 1999 to 2002. After pirimicarb, hot pepper was consistently the most effective botanical in controlling the pea aphid in terms of both pea aphid population as well as grain yield. Compared to the untreated control, there was up to 83 and 55% lower aphid population on pirimicarb- and hot pepper-treated plots in the 2000/2001 cropping season, respectively. There was also up to 93 and 54% higher grain yield on plots treated with pirimicarb and hot pepper extract, respectively. Soap was less effective, while kerosene caused phytotoxicity. Infestation levels increased with advancing maturity of the crop, rising exceptionally suddenly and dramatically near crop maturity. Combined ANOVA over years and crop growth stages indicated that aphid populations varied with years and growth stages. In 2001/2002, aphid populations were higher and grain yields were lower compared with the other years. Percentage parasitism of aphids was significantly higher on pirimicarb-treated plots (~40%) than other treatments (<20%). Parasitism was essentially a late-season occurrence. Predator population, especially of ladybird beetles (Adonia spp.), was especially higher on hot pepper- and garlic-treated plots, and lowest on pirimicarb treated plots. Grain yield was positively correlated with level of aphid parasitism, ladybird beetle population and number of pods per plant, and strongly negatively correlated with aphid population. In conclusion, a fresh extract of hot pepper sprayed at the rate of 70 ml/4 m2 was selected for further research on rate, frequency and cost of application.

Soil and foliage arthropod communities in conventional, reduced and no-tillage corn (maize, Zea mays L.) systems: A comparison after 20 years of continuous cropping

The influence of long-term (20 years) tillage - moldboard-plowed, reduced- and no-tillage practices - on soil-inhabiting and canopy arthropod communities was examined in corn (maize) systems during a 3-year period. Effects of a soil-applied insecticide (terbufos) on the anrthropod communities were also investigated. Damage by 3 major insect pest species of maize were evaluated: black cutworm, Agrotis ipsilon (Lepidoptera: Noctuidae); European corn borer, Ostrinia nubilalis (Lepidoptera: Pyralidae); corn rootworm beetles, Diabrotica spp. (Coleoptera: Chrysomelidae). Cutworm damage to corn was lowest in the conventional-tillage treatment. Damage by this species was greater in soil-applied insecticide treatments versus no-insecticide treatment. Neither tillage treatment nor insecticide usage had a significant impact on European corn borer damage to corn. Rootworm feeding on corn varied from year to year, with no discernible effect of tillage treatment on damage levels. Total numbers of microarthropods (mites and collembola) were lowest in the conventionally- (moldboard-) plowed treatments and highest in no-tillage treatments. Insecticide treatment significantly increased oribatid mite density, but consistently lowered (although not significantly so) mesostigmatid mite populations. Insecticide application had little if any noticable influence on collembolan (springtail) numbers. With macroarthropod populations, there was a trend toward greater numbers of ground beetles and spiders in the no-tillage systems. Corn rootworm and ladybird beetles (Coccinellidae) accounted for over 95% of the arthropods collected from the corn foliage. With the exception of 2 sampling dates, western corn rootworm beetle density was greater in no-tillage compared with reduced- and conventional-tillage treatments. Ladybird beetle populations were not affected by tillage or insecticide treatments.