Effect of ground cover vegetation on the abundance and diversity of beneficial arthropods in citrus orchards (original) (raw)
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We performed a study in nineteen citrus plots representative of the agricultural landscape of the municipality of Altea (100 km south of Valencia, in eastern Spain) in order to determine the influence of ecological infrastructures on biodiversity and conservation of beneficial arthropods. The landscape was dominated by small citrus orchards mixed with low density urban areas, a consequence of touristic urban pressure. We have considered five factors: pest management system (zero residues vs. conventional), size of the plot, distance to nearest natural habitat, presence/absence of cover crop, and presence/absence of other non-citrus fruits in the plot. Four of the five factors showed a positive influence on biodiversification and conservation of beneficials: small plot size, short distance to natural habitat, presence of vegetation cover and presence of other fruits. These are the factors to promote in order to develop biological strategies alternative to traditional pesticide use in...
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A study of natural enemies within hedgerows and on ground covers was carried out in two organic citrus orchards in two areas of Valencia (Spain) using two sampling methods, yellow sticky traps and a vacuum machine. Hedgerows had significantly higher levels of natural enemies, followed by citrus and ground covers. The species of natural enemies in hedgerows were similar to those found in citrus orchards, but different from those identified on ground cover. In hedgerows and citrus the predominant predators were Coniopterygidae (Neuroptera) and Cecidomyiidae (Diptera), and the most abundant parasitoids were Aphelinidae (Hymenoptera).
Influence of citrus orchard ground cover plants on arthropod communities in China: A review
Agriculture, Ecosystems & Environment, 1994
The weed Ageratum conyzoides, as well as other weeds which are beneficial for natural enemies of the citrus red mite Panonychus citri, has been planted or conserved as ground cover in an area of 135 000 ha of citrus orchards in China. Substantial ecological and economic benefits have been achieved. Studies on the effect of ground cover plants on arthropods in ground cover and in citrus trees are summarized. Ground cover plants function as supplementary sources of natural enemies of citrus arthropod pests.
Agronomy, 2020
The intensification of agriculture has led to the reduction of the diversity of arthropods in agroecosystems, including that of ground-dwelling species. The aim of our work was to assess the effect of a sown cover crop on the diversity of ground-dwelling arthropods, including key predators for pest control in pear orchards. The trial was carried out in a pear orchard divided in three blocks; two treatments (cover-cropping and control) were implemented in each block. A seed mixture of 10 plant species was used in the plots with the sown cover. The densities of ground-dwelling arthropods were sampled using pitfall traps. The ground cover had a significant impact on the diversity and abundance of arthropods. The Shannon–Wiener diversity index was significantly higher for the cover than for the control plots. Several families of spiders (Linyphiidae, Lycosidae), beetles (Carabidae, Staphylinidae) and hymenopterans (Scelionidae) were significantly more abundant in the cover-sown plots. A...
Citrus-orchard ground harbours a diverse, well-established and abundant ground-dwelling spider fauna
Spanish Journal of Agricultural Research, 2011
Ground-dwelling spider assemblages comprise one of the most representative predatory groups to be found in many crops. There is some evidence of the role that ground-dwelling spiders play in controlling certain citrus pests; however, there are almost no studies about the abundance and composition of this predatory group in citrus orchards. A three-year survey conducted using pitfall traps in three citrus orchards in Eastern Spain yielded more than five-thousand ground-dwelling spiders belonging to more than 50 species and 20 families. Wandering families such as Lycosidae, Gnaphosidae and Zodariidae were the most numerous in terms of captures. The generalist predator Pardosa cribata Simon (Araneae: Lycosidae) was the most common species, representing a quarter of all captures, followed by Zodarion cesari Pekar. (Araneae: Zodariidae) and Trachyzelotes fuscipes (Koch) (Araneae: Gnaphosidae). Spiders were active throughout the year with a peak population in summer. The species abundance data for the three spider assemblages sampled fitted a log normal statistical model which is consistent with a well-established community. The presence of a cover crop provided higher abundance of alternative prey and consequently higher abundance and diversity of ground-dwelling spiders. This work demonstrates that the citrus-orchard ground harbours a diverse and abundant ground-dwelling spider fauna, which is also active throughout the year. A challenge for future studies will be to establish conservation management strategies for these predators, that will improve biological control of those citrus pests that inhabit or spend part of their life cycle on the orchard floor.
Arthropod ecosystem services in apple orchards and their economic benefits
Ecological Entomology, 2015
Apple is grown as a long-term perennial crop and orchards provide relatively stable ecological habitats. Only a small proportion of the diverse fauna of arthropods that can inhabit the orchard ecosystem are important pests, the majority of species being minor pests, beneficial or benign. In this paper, the interacting ecosystem services provided by five contrasting naturally occurring arthropod groups in cool temperate apple orchards are reviewed, and their economic benefits broadly quantified. These are: • The roles of bees and other insects in apple pollination increasing yields and fruit quality, the economic value of which may be significantly underestimated. • Naturally occurring, pesticide-resistant phytoseiid predatory mites and their role in regulating phytophagous mites. They eliminate the need for 1-2 acaricide sprays per annum and the risk of acaricide resistance. • The earwig Forficula auricularia L. and its role in regulating several important apple pests. There is great variability in populations between orchards for reasons not fully understood. It is estimated that F. auricularia reduces insecticide applications by 2-3 per annum and reduces pest damage. • Mutualism between the common black ant Lasius niger (L.) and important pest aphids, the roles of competitors, natural and artificial food sources, and ant exclusion in disrupting mutualism which can foster biocontrol of aphids by generalist predators so greatly reducing the need for sprays. • Beneficial epigeic arthropods and their role in predating the soil dwelling life stages of insect pests. These contribute to the control of pest populations although the level of suppression is not consistent depending on several ecological factors.
Tetranychus urticae Koch (Acari: Tetranychidae) is an important pest of citrus that can also feed on most plant species occurring in the ground cover associated with this crop. To determine the effect of managing the ground cover on the biological control of this mite, we have studied the dynamics of both tetrany-chid and phytoseiid mites in four commercial citrus orchards under three different ground cover management strategies: (1) bare soil, (2) resident wild cover and (3) a sown cover of Festuca arundinacea Schreb. (Poaceae). The results obtained provide evidence that both bottom-up and top-down regulation processes related to the nature of the ground cover affected the tetranychid mite populations in citrus orchards (Panonychus citri (McGregor), Tetranychus evansi Baker & Pritchard and T. urticae). Best results were obtained with the ground cover of F. arundinacea, which did not allow the establishment of T. evansi, and offered a better regulation of both P. citri and T. urticae than either bare soil or the resident wild cover. We hypothesize that the selection of a host race of T. urticae specialized in F. arundinacea when this plant was used as a cover crop could partly explain the results obtained. Further trap cropping effects could also be relevant (bottom-up regulation).
Using cover crops to manage arthropod pests of orchards: A review
Agriculture, Ecosystems & Environment, 1994
A review of entomological studies of cover crops for tree nuts, pome fruits, stone fruits, and citrus suggests both opportunities and challenges. Various cover crops harbor distinctive complexes of beneficial and pest arthropods, and diverse trophic relationships have been well documented in the literature. More study is required to determine: ( 1 ) whether cover cropping modifies orchard microclimate and target crop nutritional status and thereby influences pest dynamics; (2) whether and how cover crop species composition, spatial interspersion of species, and management by irrigation, mowing, and tillage affect build-up and movement of arthropods, and resultant pest damage to the target crop. 0167-8809/94/$07.00
Role of hedgerows and ground cover management on arthropod populations in pear orchards
Agriculture, Ecosystems & Environment, 1999
With the failure of conventional chemical control against the pear tree psyllid Cacopsylla pyri (L.) (Homoptera: Psyllidae), strategies have been developed to enhance natural arthropod enemies of this pest. Modifying the vegetation adjacent to pear orchards is one integrated pest management (IPM) practice that can increase the agroecosystem plant diversity, thus favoring a natural balance between pest arthropods and their