Parasitism of <i>Plutella xylostella</i> (Lepidoptera, Plutellidae): Field and laboratory observations

Waladde, S. M.; Leutle, M. F.; Villet, Martin H.

doi:10.1080/02571862.2001.10634397

Cited by 15 publications

(8 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the greatest influence of temperature on trap catches (r 2 = 0.891; F 1,5 = 40.94, P = 0.0014), and infestations (r 2 = 0.841; F 1,5 = 26.47, P = 0.0036) was observed during September–early October when average temperatures ranged between 17 and 21 °C. Contrary to previous assumptions (Waladde et al., 2001; Smith, 2004), no influence of higher average temperatures during November–May was observed on trap catches (r 2 = 0.068; F 1,31 = 2.24, P = 0.14) and infestations (r 2 = 0.0016; F 1,31 = 0.048, P = 0.83).…”

Section: Resultscontrasting

confidence: 83%

“…The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), a cosmopolitan pest of Brassica plants, is a classic example of an insect pest whose high pest status in many parts of the world is a result of lack of effective parasitoid species and/or their decimation by broad‐spectrum insecticides (Talekar & Shelton, 1993; Hill & Foster, 2000; Kfir & Thomas, 2001; Kfir, 2004; Sarfraz et al., 2005; Gichini et al., 2008). Studies on biological control of P. xylostella in South Africa have shown that indigenous parasitoids can effectively suppress populations of this pest during warm seasons (Kfir, 1997; Waladde et al., 2001; Nofemela & Kfir, 2005). Yet, growers continue to rely exclusively on insecticide applications for management of P. xylostella.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The ability of synthetic sex pheromone traps to forecast Plutella xylostella infestations depends on survival of immature stages

Nofemela¹

2010

Entomologia Exp Applicata

View full text Add to dashboard Cite

The potential for using synthetic sex pheromone traps as a simple and practical method of monitoring population densities of insect pests has been investigated in many crop systems. Yet, factors enabling the forecast of infestations based on pheromone trap catches are not fully understood. This study tested the prediction that high survival of immature stages of the target pest is a pre‐requisite for trap catches to correlate well with future infestations on the crop. The influence of parasitoids, as an important natural mortality factor of diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), larvae and pupae in South Africa, on the ability of pheromone traps to forecast infestations was investigated continuously at weekly intervals over 6 years on unsprayed cabbage. During late October–May, when parasitism levels were high (≥50%), infestations and trap catches were significantly lower than during low parasitism (<50%) observed during June–early October. Because infestations were negatively related to parasitism level, trap catches correlated with infestations better when observations were made in the same week during periods of high parasitism. Conversely, when survival of P. xylostella immature stages was high due to low parasitism levels, trap catches correlated with future infestations well for up to 2 weeks. Thus, trap catches can be used to forecast infestations during September–October, a period that coincides with high P. xylostella infestations as a consequence of low natural control by parasitoids. This is the first study to show that the ability of pheromone trap catches to forecast infestations depends on survival of the immature stages of the target pest.

show abstract

Section: Resultscontrasting

confidence: 83%

Section: Introductionmentioning

confidence: 99%

The ability of synthetic sex pheromone traps to forecast Plutella xylostella infestations depends on survival of immature stages

Nofemela¹

2010

Entomologia Exp Applicata

View full text Add to dashboard Cite

show abstract

“…1). This result is in agreement with previous studies on biological control of P. xylostella in South Africa (Kfir, 1997;Waladde et al, 2001;Mosiane et al, 2003;Smith, 2004;Nofemela andKfir, 2005, 2008).…”

Section: Resultssupporting

confidence: 83%

“…In this system, only immature stages of the most abundant primary parasitoid species (C. vestalis) are vulnerable to resident obligate hyperparasitoid species (Waladde et al, 2001;Mosiane et al, 2003;Smith, 2004;Nofemela and Kfir, 2008). This study showed that as hyperparasitism levels increased, population density of C. vestalis declined significantly.…”

Section: Discussionmentioning

confidence: 99%

“…However, its larval and pupal stages are in turn attacked by three species of obligate hyperparasitoids (Waladde et al, 2001;Mosiane et al, 2003;Smith, 2004;Nofemela and Kfir, 2005). In this study, I use long-term data sets to establish whether: (1) the effect of obligate hyperparasitoids on C. vestalis populations are significantly high to limit its impact on P. xylostella, (2) the invulnerable primary parasitoid species increase their contribution to total parasitism levels as populations of C. vestalis decline, and (3) the population increase of invulnerable primary parasitoids effectively counteracts the effect of hyperparasitoids on C. vestalis.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The effect of obligate hyperparasitoids on biological control: Differential vulnerability of primary parasitoids to hyperparasitism can mitigate trophic cascades

Nofemela

2013

Biological Control

View full text Add to dashboard Cite

Highlights-Cotesia vestalis was a dominant primary parasitoid of Plutella xylostella.-It was also a secondary host to three obligate hyperparasitoid species.-At low hyperparasitism, C. vestalis limited hosts available to competitors. -As C. vestalis population declined, competitors parasitized more of available hosts.-Species that are invulnerable to hyperparasitism took over role of the vulnerable. Graphical abstractAbstract : Obligate hyperparasitoids are widely considered an important ecological disturbance to biological control of insect pests, as they develop at the expense of primary parasitoids. However, supporting evidence is largely derived from direct trophic interactions in simple food webs. Yet, a multitude of insect pest populations simultaneously support development of several primary parasitoid species in horticultural and natural systems. Since primary parasitoid species in a community can differ in vulnerability to obligate hyperparasitoids, it is desirable to establish if the invulnerable primary parasitoids can take advantage of reduced competition from affected species by increasing their contribution to total primary parasitism levels thereby mitigating effects of hyperparasitism on biological control. To investigate this question, populations of the diamondback moth, Plutella xylostella (Linnaeus) (Plutellidae), its primary parasitoids and hyperparasitoids were monitored on unsprayed cabbage plots at weekly intervals over six consecutive years. Cotesia vestalis (Haliday) (Braconidae), a dominant primary parasitoid in this system, was a secondary host to three obligate hyperparasitoids: Mesochorus sp. (Ichneumonidae), Eurytoma sp. (Eurytomidae) and Pteromalus sp. (Pteromalidae). The higher efficiency of C. vestalis in utilizing younger host larvae at lower hyperparasitism levels limited host availability to other major primary parasitoids. But, as hyperparasitism levels increased and its populations declined, populations of Oomyzus sokolowskii (Kurdjumov) (Eulophidae) and Diadromus collaris (Gravenhorst) (Ichneumonidae) increased significantly as they parasitized a greater proportion of available hosts. As a consequence, the impact of hyperparasitoids did not result in trophic cascades, as their impact on total primary parasitism levels and infestation levels was insignificant. This study shows that primary parasitoid species that are invulnerable to hyper-parasitism can take over the function of vulnerable ones in communities where interspecific interactions among species are strong. Thus, an approach that considers both direct and indirect effects of hyperparasitoids in primary parasitoid communities improves our understanding of the net impact of hyperparasitism on biological control of insect pests.

show abstract

Establishment of an Exotic Parasitoid Cotesia vestalis in Coastal Areas of Kenya as Biological Control Agent of Plutella xylostella

Mukiri

Nyasani

Muya

et al. 2020

Sustainable Management of Invasive Pests in Africa

View full text Add to dashboard Cite

The aims of this study were to follow up on the establishment of Cotesia vestalis in the coastal regions of Kenya, assessing its contribution in the management of the diamondback moth (Plutella xylostella), parasitism rates, and cultural practices affecting its establishment. Post-release surveys were carried out in five counties in Kenya, Kitui, Kajiado, Kwale, Machakos and Makueni, between 2015 and 2016. The results showed that the overall parasitism rate of C. vestalis in 2015 ranged between 0% and 37.86% while that in 2016 ranged from 0% to 32.19% in the different counties. Farmers carry out routine sprays, either weekly or fortnightly, with different synthetic insecticides. Pyrethroids (60.56%) constituted most of the insecticides used, while only 3.18% of the products used were plant or microorganismbased. Farmers did most of their cabbage production during the rainy season, with

show abstract

Parasitism of Plutella xylostella (Lepidoptera, Plutellidae): Field and laboratory observations

Cited by 15 publications

References 13 publications

The ability of synthetic sex pheromone traps to forecast Plutella xylostella infestations depends on survival of immature stages

The ability of synthetic sex pheromone traps to forecast Plutella xylostella infestations depends on survival of immature stages

The effect of obligate hyperparasitoids on biological control: Differential vulnerability of primary parasitoids to hyperparasitism can mitigate trophic cascades

Establishment of an Exotic Parasitoid Cotesia vestalis in Coastal Areas of Kenya as Biological Control Agent of Plutella xylostella

Contact Info

Product

Resources

About