Occurrence of Coccinellids that Prey onDiaphorina citri(Hemiptera: Liviidae) onEuphorbia heterophylla(Euphorbiaceae) andChamaecrista fasciculata(Fabaceae) in a South Florida Residential Area

Mbega

et al. 2022

Plants

Flower-rich field margins provide habitats and food resources for natural enemies of pests (NEs), but their potential, particularly in the tropics and on smallholder farms, is poorly understood. We surveyed field margins for plant-NE interactions in bean fields. NEs most often interacted with Bidens pilosa (15.4% of all interactions) and Euphorbia heterophylla (11.3% of all interactions). In cage trials with an aphid-infested bean plant and a single flowering margin plant, the survival of Aphidius colemani, the most abundant parasitoid NE in bean fields, was greater in the presence of Euphorbia heterophylla than Bidens pilosa, Tagetes minuta, and Hyptis suaveolens. UV-fluorescent dye was applied to flowers of specific field margin plant species and NE sampled from within the bean crop and field margins using sweep-netting and pan-traps respectively. Captured insects were examined for the presence of the dye, indicative of a prior visit to the margin. Lady beetles and assassin bugs were most abundant in plots with B. pilosa margins; hoverflies with T. minuta and Parthenium hysterophorus margins; and lacewings with T. minuta and B. pilosa margins. Overall, NE benefitted from field margin plants, and those possessing extra floral nectaries had an added advantage. Field margin plants need careful selection to ensure benefits to different NE groups.

Section: Discussionsupporting

confidence: 90%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Field Margin Plants Support Natural Enemies in Sub-Saharan Africa Smallholder Common Bean Farming Systems

Mbega

et al. 2022

Plants

“…All of the plant species tested in this study grow well and readily flower in south Florida and are easily cultivated there during the warm season. Two of the plants, C. fasciculata and E. heterophylla are native to Florida and have been shown to harbor natural enemies of D. citri in residential landscapes [77,78]. E. milii and P. umbraticola are common landscaping plants in south Florida and T. radiata fed on E. milii nectaries in a laboratory test [77].…”

Section: Plantsmentioning

confidence: 99%

“…More recently, Martini et al [88] found significantly fewer D. citri on the edges of citrus groves with windbreaks as opposed to those without windbreaks and Tomaseto et al [89] showed that trap crops planted near grove borders were effective for intercepting psyllids. Plants with nutritional resources assessable to the natural enemies of D. citri [77][78] could be incorporated alongside windbreaks or trap crops to add a conservation biological control component to an area-wide psyllid management program. To this end, whether natural enemies commute between such plantings and citrus trees will need to be determined [90].…”

Section: Plos Onementioning

confidence: 99%

Response surface methodology reveals proportionality effects of plant species in conservation plantings on occurrence of generalist predatory arthropods

2020

Self Cite

Multivariate geometric designs for mixture experiments and response surface methodology (RSM) were tested as a means of optimizing plant mixtures to support generalist predatory arthropods. The mixture design included 14 treatment groups, each comprised of six planters and having a proportion of 0.00, 0.17, 0.33, 0.66, or 1.00 of each plant species. The response variable was the frequency of predators trapped on sticky card traps placed in each group and replaced 2 times per week. The following plant species were used: Spring 2017:

Field margin Plants support arthropod natural enemies in smallholder common bean farming systems in northern Tanzania

Ndakidemi

Field margin plants provide habitats and food resources for natural enemies of pests (NEs), but their potential is poorly understood, particularly in the tropics and on smallholder farms. The experiments were conducted to test the potential of field margin plants on NEs. Sentinel plants were developed to collect Aphis fabae and Maruca vitrata parasitoids. Aphidius colemani was identified as the primary parasitoid of A. fabae. The dominant M. vitrata larval parasitoids were the Braconidae and Dolichogenidea, while the Platygastridae were the abundant egg parasitoids. The survey of field margins for plant-NE interactions in bean fields found that NEs most often interacted with Bidens pilosa (15.4%) and Euphorbia heterophylla (11.3%). Flowering plant species (Bidens pilosa, Lantana camara, Euphorbia heterophylla and Ageratum conyzoides) supported NEs out of bean growing season. In cage trials with an aphid- infested bean plant and a single flowering margin plant, the survival of A. colemani was more significant in the presence of E. heterophylla than B. pilosa, Tagetes minuta and Hyptis suaveolens. UV-fluorescent dye was applied to flowers of specific field margin plant species and NE was sampled from within the bean crop and field margins using sweep-netting and pan- traps, respectively. Captured insects were examined for the presence of the dye, indicative of a prior visit to the margin. Lady beetles and assassin bugs were abundant in plots with B. pilosa margins, hoverflies with T. minuta and Parthenium hysterophorus margins, and lacewings with T. minuta and B. pilosa margins. NEs were also sampled from high and low plant diversity bean fields using sweep netting and coloured sticky traps, comparing monocropped and intercropped farms. Overall, high-plant diversity fields had higher NEs than low-diversity fields. The field margin had a significantly higher number of NEs than the crop field. However, marginally higher populations of NEs in intercropping than in monocropping were observed, although the effect was not significant. To confirm that NE communities on farms predated Aphis fabae, we extracted and amplified A. fabae DNA from predatory insects. Fourteen lady beetle larvae, two lacewing larvae, and one assassin bug analyzed were found to contain A. fabae DNA, indicating all these groups can regulate the significant aphid pest of beans, A. fabae. A. colemani was a parasitoid that emerged from several non-aphid species collected from the field margins. Overall, NEs benefitted from field margin plants; those possessing extra floral nectaries had an added advantage. Thus, smallholder farmers protect the field margins for the added benefit of natural pest regulation in their fields and thus for food security and enhancing their livelihoods.