scholarly journals The effect of insecticide application by dropleg sprayers on pollen beetle parasitism in oilseed rape

BioControl ◽  
2021 ◽  
Author(s):  
Johannes Hausmann ◽  
Udo Heimbach ◽  
Michael Rostás ◽  
Meike Brandes
Keyword(s):  
Oilseed Rape ◽  
Insect Pests ◽  
Biological Control Agent ◽  
Control Agent ◽  
Total Catch ◽  
Pollen Beetle ◽  
Brassicogethes Aeneus ◽  
Larval Parasitoid ◽  
Parasitism Rates ◽  
The Impact

AbstractDropleg sprayers apply pesticides below the flower horizon of oilseed rape plants and thus reduce unwanted side effects on pollinating insects. Whether this technique benefits parasitoids of seed and pollen feeding insect pests has not been studied earlier. To answer this question, we first assessed the vertical distribution of pests and parasitoids using a portable aspirator. In addition, parasitism rates of pollen beetle, Brassicogethes aeneus Fabricius (Coleoptera: Nitidulidae), by the larval parasitoid Tersilochus heterocerus Thomson (Hymenoptera: Ichneumonidae) were compared in conventional and dropleg sprayed fields over four years (2016–2019), using the neonicotinoids thiacloprid and acetamiprid. Our results show that seed and pollen feeders were mainly found in the flowering canopy, while the predominant location of parasitoids was species-specific. Among pollen beetle parasitoids, Phradis interstitialis Thomson (Hymenoptera: Ichneumonidae) was more abundant below flowering canopy (63% of total catch), whereas T. heterocerus was mainly caught in the flowering canopy (84% of total catch). In the spraying experiments, average parasitism rates of pollen beetles by T. heterocerus ranged between 55 and 82% in the untreated controls. In the dropleg spray treatments, parasitism rates did not differ significantly from control levels, with the exception of thiacloprid application in 2019. In contrast, conventional spray applications resulted in a reduction of parasitism rates by up to 37% compared to the control for at least one of the insecticides in three out of four years. The impact of conventional application differed between years, which may be explained by the temporal coincidence between spray application and the immigration of parasitoids into the crop. We conclude that dropleg spraying exerts lower non-target effects on the main biological control agent of pollen beetle.

Population dynamics and foraging behaviour of Diaeretus leucopterus (Hymenoptera: Braconidae), and its potential for the biological control of pine damaging Eulachnus spp. (Homoptera: Aphididae)

1996 ◽  
Vol 86 (4) ◽  
pp. 397-405 ◽  
Author(s):  
S.T. Murphy ◽  
W. Völkl
Keyword(s):  
Biological Control ◽  
Foraging Behaviour ◽  
Biological Control Agent ◽  
Host Density ◽  
Scientific Basis ◽  
Control Agent ◽  
Foraging Activity ◽  
Parasitism Rates ◽  
The Mean ◽  
The Impact

AbstractThe Palaearctic pine aphids, Eulachnus agilis (Kaltenbach) and Eulachnus rileyi (Williams) have both been introduced into other continents where they have been reported causing damage to economically important pines. In Euorpe, they are attacked by the specialist parasitoid Diaeretus leucopterus (Haliday) which has been suggested as a possible biological control agent. Here we report on several aspects of the ecology of the parasitoid, conducted on E. agilis in Germany in 1993–94, to provide a more scientific basis for judging its potential for use in biological control. Parasitism of all instars in the field rarely exceeded 10% and was independent of host density. A high percentage of parasitized aphids were hyperparasitized. Measurements of the impact over 16 weeks in a greenhouse-release experiment showed that parasitism rates increased from 2 to 19% but were insufficient to suppress the aphid population below a damaging level. There was evidence of a density-dependent response. Studies on foraging behaviour showed that female parasitoids searched pines by quite extensive walks. There was no relationship between the number of aphids per tree and number of ovipositions, and the mean number of ovipositions per female per tree was 2.5 ± 0.4 eggs. The majority (55.1%) of encountered aphids did not respond to the parasitoids. However, female parasitoids attacked a much higher proportion of aphids that did respond but oviposition success on this group was poor. The number of aphid-infested needles on seedlings increased significantly owing to the parasitoid's foraging activity. On the basis of these results, it is suggested that D. leucopterus is only likely to be of benefit in biological control if used in conjunction with other complementary natural enemies.

scholarly journals Could Gnomoniopsis castaneae Be Used as a Biological Control Agent against Insect Pests?

2021 ◽  
Vol 11 (9) ◽  
pp. 4066
Author(s):  
Spiridon Mantzoukas ◽  
Ioannis Lagogiannis ◽  
Aristeidis Ntoukas ◽  
George T. Tziros ◽  
Konstantinos Poulas ◽  
...  
Keyword(s):  
Biocontrol Agent ◽  
Insect Pests ◽  
Biological Control Agent ◽  
Brown Rot ◽  
Control Agent ◽  
Effective Control ◽  
Mortality Factor ◽  
Perennial Crop ◽  
Gall Wasp ◽  
Pathogenic Potential

Gnomoniopsis castaneae is the cause of the chestnut brown rot but has been also regarded as an important mortality factor for the chestnut gall wasp Dryocosmus kuriphilus. The question to whether G. castaneae could serve as a natural biocontrol agent against insect pests is investigated in the present study. We used three serious insect pests as experimental model insects: Plodia interpuctella and Trogoderma granarium, which are important pests of stored products, and Myzus persicae, a cosmopolitan, serious pest of annual and perennial crop plants. Although chemical pesticides represent effective control means, they are also related to several environmental and health risks. In search for alternative pest management methods, scientific interest has been focused, inter alia, on the use of entomopathogenic fungi. While Isaria fumosorosea has long been recognized as an effective control agent against several pests, G.castaneae has been very little studied. The present study examined whether and to what extent G. castaneae and I. fumosorosea exhibit insecticidal activity against fourth-instar larvae of P. interpunctella and T. granarium and adults of M. persicae. Mortality was examined in interrelation with dosage and time exposure intervals. Both fungi exhibited pesticidal action. However, G. castaneae induced noteworthy mortality only at very high doses. In general, we concluded that G. castaneae failed to cause high insect pathogenicity at normal doses and may not be an efficient biocontrol agent compared with other entomopathogens. On the other hand, our study reiterates the pathogenic potential of I. fumosorosea. More studies are needed to further our insight into the potential of EF species as a component of IPM.

scholarly journals RNAi efficacy is enhanced by chronic dsRNA feeding in pollen beetle

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jonathan Willow ◽  
Liina Soonvald ◽  
Silva Sulg ◽  
Riina Kaasik ◽  
Ana Isabel Silva ◽  
...  
Keyword(s):  
Rna Interference ◽  
Pest Management ◽  
Oilseed Rape ◽  
Growth Stages ◽  
Short Term ◽  
Pollen Beetle ◽  
Brassicogethes Aeneus ◽  
Crop Growth Stages ◽  
Insecticidal Compounds ◽  
Significant Mortality

AbstractDouble-stranded RNAs (dsRNAs) represent a promising class of biosafe insecticidal compounds. We examined the ability to induce RNA interference (RNAi) in the pollen beetle Brassicogethes aeneus via anther feeding, and compared short-term (3 d) to chronic (17 d) feeding of various concentrations of dsRNA targeting αCOP (dsαCOP). In short-term dsαCOP feeding, only the highest concentration resulted in significant reductions in B. aeneus survival; whereas in chronic dsαCOP feeding, all three concentrations resulted in significant mortality. Chronic dsαCOP feeding also resulted in significantly greater mortality compared to short-term feeding of equivalent dsαCOP concentrations. Our results have implications for the economics and development of dsRNA spray approaches for managing crop pests, in that multiple lower-concentration dsRNA spray treatments across crop growth stages may result in greater pest management efficacy, compared to single treatments using higher dsRNA concentrations. Furthermore, our results highlight the need for research into the development of RNAi cultivars for oilseed rape protection, given the enhanced RNAi efficacy resulting from chronic, compared to short-term, dsRNA feeding in B. aeneus.

scholarly journals Biological Control of the Weedy Plant (Rumex crispus) at the Seedling Growth Stage by the Green Dock Beetle (Gastrophysa viridula)

2019 ◽  
Vol 28 (1) ◽  
pp. 21-31
Author(s):  
Khalid S. Alshallash Khalid S. Alshallash
Keyword(s):  
Biological Control ◽  
Seedling Growth ◽  
Growth Stage ◽  
Biological Control Agent ◽  
Dry Weight ◽  
Control Agent ◽  
Growth Stages ◽  
Rumex Crispus ◽  
Shoot Number ◽  
The Impact

In four glasshouse experiments, the effectiveness of the adult green dock beetle Gastrophysa viridula (Coleoptera: Chrysomelidae), at the effective number of applied individuals, for use as a biological control agent of curled dock, Rumex crispus (Polygonaceae) were studied. The feeding of the beetle was investigated at four different numbers of beetle (0, 1, 2, 3) and at four seedling growth stages of the plant, defined by the average of leaf area per plant (1-1.22 , 2-4.45, 3-11.56, and 4-71.52 cm2/plant). Grazing by one, two or three dock beetles did not result in a significant reduction in dock dry weight or shoot numbers at the youngest growth stage. However, both at later seedling growth stages were significantly affected (P ? 0.0001), at any beetles number. The increase of beetle numbers caused nonsignificant increased effect, in some trials, confirming the impact of a single beetle. Three months after beetle grazing, dock seedlings of first, second and third growth stages were not able to regrow, however, some plants at the 4th growth stage, re-emerged. This suggested that the highest effect of beetle's feeding occurs on the early seedling stages. Statistical analysis showed a positive correlation (0.77) between dry weight and shoot number at all the four seedling growth stages, thus confirming the impact of the beetle on both the dry weight and shoot numbers. Combining beetle grazing with other control methods at older dock seedling stages could, therefore, provide better suppression

scholarly journals Evaluation of cellulose substrates treated with Metarhizium anisopliae (Metschnikoff) Sorokin as a biological control agent against the termite Microcerotermes diversus Silvestri (Isoptera: Termitidae)

2011 ◽  
Vol 43 (2) ◽  
pp. 269
Author(s):  
Behzad Habibpour ◽  
Amir Cheraghi ◽  
Mohammad Saeed Mossadegh
Keyword(s):  
Biological Control ◽  
Metarhizium Anisopliae ◽  
Insect Pests ◽  
Biological Control Agent ◽  
Control Agent ◽  
Cellulose Substrates ◽  
Virulent Strains ◽  
Sustainable Protection ◽  
Chemical Pesticides

This article is the first report on the promising effect of an entomopathogenic fungus, <em>Metarhizium anisopliae</em> (Metschnikoff) Sorokin to control populations of <em>Microcerotermes diversus </em>Silvestri. Biological control is an alternative to the long-term usage of chemical pesticides.<em> M. anisopliae</em>, the causal agent of green muscardine disease of insects, is an important fungus in biological control of insect pests. Bait systems can eliminate entire colonies of subterranean termites. Baiting reduces adverse environmental impacts caused by organochlorine and organophosphate pesticides in the control of termites and creates sustainable protection of buildings against their invasion. Treated-sawdust bait was applied by two methods: a) combination of treated sawdust and untreated filter paper, and b) combination of treated sawdust and untreated sawdust. When combinations of treated sawdust and untreated sawdust were used, LC50 and LC90 were 8.4&times;106 and 3.9&times;107 (spore/ml), respectively. With the use of improved bait formula and more virulent strains, we hope to achieve better control of termite colonies and enable pathogens to become a useful element in the Integrated Pest Management system.

Corrigendum to: The impact of rabbit haemorrhagic disease on wild rabbit (Oryctolagus cuniculus) populations in Queensland

2004 ◽  
Vol 31 (6) ◽  
pp. 651
Author(s):  
G. Story ◽  
J. Scanlan ◽  
R. Palmer ◽  
D. Berman
Keyword(s):  
Biological Control Agent ◽  
South Australia ◽  
Control Agent ◽  
Wild Rabbit ◽  
Isolated Populations ◽  
Rabbit Haemorrhagic Disease ◽  
Northern Edge ◽  
The Mean ◽  
Haemorrhagic Disease ◽  
The Impact

Rabbit haemorrhagic disease virus (RHDV) escaped from quarantine facilities on Wardang Island in September 1995 and spread through South Australia to Queensland by December 1995. To determine the impact of this biological control agent on wild rabbit populations in Queensland, shot sample and spotlight count data were collected at six sites. RHDV spread across Queensland from the south-west to the east at a rate of at least 91 km month–1 between October 1995 and October 1996. The initial impact on rabbit density appeared highly variable, with an increase of 81% (255 ± 79 (s.e.) to 385 ± 73 rabbits km–2) at one site and a decrease of 83% (129 ± 27 to 22 ± 18 rabbits km–2) at another during the first outbreak. However, after 30 months of RHDV activity, counts were at least 90% below counts conducted before RHDV arrived. Using a population model to account for environmental conditions, the mean suppression of rabbit density caused by rabbit haemorrhagic disease (RHD) was estimated to be 74% (ranging from 43% to 94% between sites). No outbreaks were observed when the density of susceptible rabbits was lower than 12 km–2. Where rabbit density remains low for long periods RHDV may not persist. This is perhaps most likely to occur in the isolated populations towards the northern edge of the range of rabbits in Australia. RHDV may have to be reintroduced into these populations. Further south in areas more suitable for rabbits, RHDV is more likely to persist, resulting in a high density of immune rabbits. In such areas conventional control techniques may be more important to enhance the influence of RHD.

scholarly journals Impact Assessment of Biological Control-Based Integrated Pest Management in Rice and Maize in the Greater Mekong Subregion

Insects ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 226 ◽  
Author(s):  
Dirk Babendreier ◽  
Min Wan ◽  
Rui Tang ◽  
Rui Gu ◽  
Justice Tambo ◽  
...  
Keyword(s):  
Biological Control ◽  
Integrated Pest Management ◽  
Pest Management ◽  
Smallholder Farmers ◽  
Biological Control Agent ◽  
Control Agent ◽  
Target Area ◽  
Positive Effects ◽  
The Difference ◽  
The Impact

The impact and sustainability of two interventions that have been formulated to introduce integrated pest management (IPM) into rice and maize crops in Southwestern China, Laos, and Myanmar between 2011 and 2016, and were assessed at the end of 2017. From 22 Trichogramma rearing facilities established during the interventions, 11 were still producing substantial quantities of biocontrol agents 1.5 years after project support had ended, while seven had stopped operations completely, and four were doing stock rearing only. Through the implementation of biological control-based IPM, slightly higher yields were achieved in maize and rice (4–10%), when compared to control farmers, but the difference was not statistically significant. However, the use of pesticides nearly halved when farmers started using Trichogramma egg-cards as a biological control agent. Support from either public or private institutions was found to be important for ensuring the sustainability of Trichogramma rearing facilities. Many of the suggested IPM measures were not adopted by smallholder farmers, indicating that the positive impacts of the interventions mostly resulted from the application of Trichogramma biological control agents. The following assessment suggests that further promotion of IPM adoption among farmers is needed to upscale the already positive effects of interventions that facilitate reductions in synthetic pesticide use, and the effects on sustainable agricultural production of rice and maize in the target area more generally.

scholarly journals Characterization of the pollen beetle, Brassicogethes aeneus, dispersal from woodlands to winter oilseed rape fields

PLoS ONE ◽  
2017 ◽  
Vol 12 (8) ◽  
pp. e0183878 ◽  
Author(s):  
Amandine Suzanne Juhel ◽  
Corentin Mario Barbu ◽  
Pierre Franck ◽  
Jean Roger-Estrade ◽  
Arnaud Butier ◽  
...  
Keyword(s):  
Oilseed Rape ◽  
Winter Oilseed Rape ◽  
Pollen Beetle ◽  
Brassicogethes Aeneus

Survey of the native insect natural enemies of Hyphantria cunea (Drury) (Lepidoptera: Arctiidae) in China

2008 ◽  
Vol 98 (3) ◽  
pp. 293-302 ◽  
Author(s):  
Z.Q. Yang ◽  
X.Y. Wang ◽  
J.R. Wei ◽  
H.R. Qu ◽  
X.R. Qiao
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Biological Control Agent ◽  
Control Agent ◽  
Senior Author ◽  
Parasitoid Species ◽  
Hyphantria Cunea ◽  
Parasitism Rates ◽  
Fall Webworm ◽  
Chouioia Cunea

AbstractThe fall webworm, Hyphantria cunea (Drury) (Lepidoptera: Arctiidae), is an invasive and important pest in China. Investigations on insect natural enemies have been conducted from 1996 to 1999 in five provinces and one municipality of China in order to select effective species for biological control. Two carabid predators (Coleoptera) and 25 parasitoid species were found, among which 23 were parasitic wasps (Hymenoptera), including five hyperparasitic species and two tachinid flies (Diptera). The two carabids preyed on young larvae inside webs, two braconid wasps parasitized larvae, and 18 parasitoid species attacked the fall webworm during the pupal and/or ‘larval-pupal’ stages. Among these parasitoids, there were one genus and nine species that are new to science and four species new to China, which were described and published by the senior author Yang. The average parasitism rates of fall webworm pupae were 25.8% and 16.1% in the overwintering generation and the first generation (summer generation), respectively. These findings reveal that these natural enemies play an important role in the natural control of the pest. Chouioia cunea Yang (Hymenoptera: Eulophidae), a gregarious pupal endo-parasitoid, was recommended as a promising biological control agent against the fall webworm in China.

Sign in / Sign up

Export Citation Format

Share Document