Geostatistical characterization of the spatial distribution of Grapholita molesta and Anarsia lineatella males in an agricultural landscape

Abstract:  The results obtained in spatial analysis of pheromone trap catches of oriental fruit moth, Grapholita molesta (Busck) and Peach twig borer, Anarsia lineatella (Zeller), are reported. The studies were performed in the Molise region, central Italy, during 2002 and 2003. Local distributions of oriental fruit moth and peach twig borer males were considered in a heterogeneous landscape. The aim of the study was to determine the temporal and spatial variation in distribution and abundance of the insect pests inside small plots of fruit orchards (apple, kiwi, peach, pear and plum fruits) and outside (in field crops, irrigation channels, hedgerows and a river), and to evaluate the importance of the host plants in relation to the adult distributions. Results showed that the main 'hot spot' for both lepidopterous pests was in a stone fruit orchard in the northern zone of the study area; other infested areas were in stone orchards and, in the case of A. lineatella , also in plum orchards. The river seems to act as a barrier rather than an ecological corridor. The observed spatio-temporal distributions of G. molesta and A. lineatella differed and were determined mainly by the location of the most important host plants and by the tendency of males to move in the environment, i.e. inside and outside the breeding and mating sites. Adequate knowledge of these spatial processes should be considered as an essential prerequisite for integrated pest management programmes in a precision farming approach.     

Habitat structure and neighbor linear features influence more carabid functional diversity in olive groves than the farming system

The effects of land-use management and environmental features at different scales on carabid beetle diversity and trait structure were assessed across olive groves in northeastern Portugal. We selected organic and integrated olive groves that were distinct in terms of specific management practices, local linear features and landscape configurations. Besides the management intensification levels, differences in carabid diversity and community traits were mainly due to local habitat and ecological linear structures at a finer spatial scale. Carabid community traits related to disturbance, namely traits of body size and species dispersal ability, responded to land-use intensity and particular olive grove features were influencing diversity patterns. Within the olive grove patches, larger and brachypterous species were associated to plots with more dense vegetation cover while macropterous and small-sized species were more associated to open areas. Also, larger carabid species benefitted from higher patch size heterogeneity within the landscape mosaics. Our findings indicate that the effects of farming system is contingent on the specific management practices, local and linear features present in agroecosystems such as olive groves. Particularly, the influence of local features on carabid diversity patterns and community traits linked to dispersal and movement may be crucial in maintaining pest control at a landscape scale.     

Study of the relationship between sex pheromone trap catches of Lobesia botrana (Den. & Schiff.) (Lep., Tortricidae) and the accumulation of degree-days in Sherry vineyards (SW of Spain)

The relationship between temperature accumulations and pheromone trap captures of the males of Lobesia botrana (Den. & Schiff.) (Lep., Tortricidae) in the Sherry vineyards (SW of Spain) presents a statistically acceptable linear behaviour through conveniently transforming the variables. Data series ranging from 1990 to 1995 were used to compute the linear correlations. The reliability of the forecasts based on the resulting log-probit lines have shown to be acceptable in order to be considered as an useful tool to improve the effectiveness of the integrated pest management in the area.     

Limited benefits of non-crop vegetation on spiders in Australian vineyards: regional or crop differences?

In crops, invertebrate natural enemies such as spiders have been documented as responding to non-crop vegetation at the local and landscape scales, particularly in northern Europe. Much of this information is based on data from arable or annual crops and it is possible that spider numbers in more persistent perennial systems including vineyards may be less dependent on non-crop vegetation. To test the relationship between spider abundance and non-crop vegetation within the context of Australian vineyards, we sampled spiders in 54 vineyards with adjacent non-crop vegetation, from three different regions. Landscape composition in the area surrounding each of the 54 sites was characterized at 11 spatial scales from 95?m to 3?km radius and spiders were sampled monthly using canopy sticky traps and ground pitfall traps. There were only weak relationships between pasture or woody vegetation and the abundance of spiders in vineyards at all spatial scales. At the local scale, abundance of most spider families tended to be greater in vineyards with adjacent pasture. At the landscape scale there were inconsistent patterns. We discuss possible reasons for these apparent contrasting patterns between perennial and annual crops and European compared to Australian agroecosystems.     

The Importance of Rotational Crops for Biodiversity Conservation in Mediterranean Areas

Nowadays we are seeing the largest biodiversity loss since the extinction of the dinosaurs. To conserve biodiversity it is essential to plan protected areas using a prioritization approach, which takes into account the current biodiversity value of the sites. Considering that in the Mediterranean Basin the agro-ecosystems are one of the most important parts of the landscape, the conservation of crops is essential to biodiversity conservation. In the framework of agro-ecosystem conservation, farmland birds play an important role because of their representativeness, and because of their steady decline in the last Century in Western Europe. The main aim of this research was to define if crop dominated landscapes could be useful for biodiversity conservation in a Mediterranean area in which the landscape was modified by humans in the last thousand years and was affected by the important biogeographical phenomenon of peninsula effect. To assess this, we identify the hotspots and the coldspots of bird diversity in southern Italy both during the winter and in the breeding season. In particular we used a scoring method, defining a biodiversity value for each cell of a 1-km grid superimposed on the study area, using data collected by fieldwork following a stratified random sampling design. This value was analysed by a multiple linear regression analysis and was predicted in the whole study area. Then we defined the hotspots and the coldspots of the study area as 15% of the cells with higher and lower value of biodiversity, respectively. Finally, we used GAP analysis to compare hotspot distribution with the current network of protected areas. This study showed that the winter hotspots of bird diversity were associated with marshes and water bodies, shrublands, and irrigated crops, whilst the breeding hotspots were associated with more natural areas (e.g. transitional wood/shrubs), such as open areas (natural grasslands, pastures and not irrigated crops). Moreover, the results underlined the negative effects of permanent crops, such as vineyards, olive groves, and orchards, in particular during the winter season. This research highlights the importance of farmland areas mainly for wintering species and the importance of open areas for breeding species in the Mediterranean Basin. This may be true even when the species’ spatial distribution could be affected by biogeography. An important result showed that the hotspots for breeding species cannot be used as a surrogate for the wintering species, which were often not considered in the planning of protected areas.     

Biodiversity analysis of natural arthropods enemies in vineyard agroecosystems in La Rioja,Spain

Major knowledge gaps exist regarding effects of landscape-level agroecosystem composition on the presence of natural enemies of agricultural pests. The objective of this study was to evaluate the influence of landscape mosaic characteristics on the diversity of predators and parasitoids of a viticultural landscape in La Rioja, Spain. Five habitats were evaluated: Mediterranean forest, Mediterranean scrub, olive groves, natural grassland, and vineyards. In all, we collected 28,640 arthropods, representing 10 orders: Araneae, Coleoptera, Dermaptera, Diptera, Hemiptera, Hymenoptera, Mantodea, Neuroptera, Solifugae, and Thysanoptera. The grassland habitat presented the highest arthropod abundances. Carabid beetles showed preferences for Mediterranean forest and scrub, whereas reduviid bugs showed preferences for natural grassland. Landscape heterogeneity and connectivity with natural elements in the study area turn out to be effective in conservation of diversity of natural enemies of viticulture.     

Insectivorous birds are not effective pest control agents in olive groves

Although avian-mediated pest control is a significant ecosystem service with important economic implications, few experimental studies have ever documented its role in Mediterranean agroforests. Specifically, information on pest control by birds is lacking in certain permanent agroecosystems of worldwide importance such as olive groves.Here, we assess experimentally for the first time the effectiveness of insectivorous birds in controlling the two main olive-tree pests. We also explore the effects of distance to semi-natural habitat patches on avian insectivore abundance and pest control. We combined bird and pest surveys with pest damage monitoring and two field experiments (branch exclusion and plasticine models) at a regional scale.The experiments showed that birds played a negligible role as pest controllers (measured in terms of attack rates on plasticine models and controlled pest damage) in the studied olive groves; overall, pests were abundant and pest damage was high on most farms. In addition, surveys showed that insectivorous birds were more abundant and diverse in patches of semi-natural habitat, compared to the matrix of olive groves, and that proximity to semi-natural patches was not a driver of bird-driven pest control.This study experimentally demonstrates that insectivorous birds are not effective pest controllers in olive groves. The absence of patterns linking insectivorous birds’ availability and observed pest control suggests that birds are unable to exert effective control over the main olive-tree pests. This lack of biocontrol by birds is probably due to low accessibility and/or appetence for the current insectivorous groups. Habitat improvement aimed at encouraging some under-represented forager species could improve the likelihood that birds will provide this ecosystem service.     

Naturally occurring Trichogramma species in olive farms in Egypt

A survey of two-year studies (2001-2003) was carried out in two olive groves sited at two representative olive growing areas, namely Paradise Park (arid area) and Burg E1-Arab farm (semi-arid area) to monitor the frequency of endemic Trichogramma species on olive moth (Prays oleae) and jasmine moth (Palpita unionalis). The suspended host bait traps were found to be a more practical and effective tool for collecting Trichogramma wasps than the attached ones. Four naturally occurring Trichogramma species were collected for the first time in Egypt from the olive groves, where releases have never been conducted. T.bourarachae was collected exclusively from Burg El-Arab farm. It seems that this wasp species adapts well to the semi-arid area. Three species, namely T. cordubensis, T. nr.pretiosum and T. cacociae were isolated from Paradise Park farm. All of these wasps were also bred from naturally parasitized host eggs during favorable and even at unfavorable temperature conditions of June-August. However, these endemic species did not occur naturally in sufficient numbers to keep the pest populations from reaching damaging levels.The excessive usage of insecticides and the oophagous predators (e.g., ants and lacewing larvae) are some factors that affect the performance of Trichogramma wasps in olive farms.The presence of warm weather wasp strains suggests the existence of well-adapted wasp species or swains which may be appropriate candidates for the control of target pests in olive groves. Additional study is required to determine the best “habitat-specific” species/strains of Trichogramma for augmentative release of naturally occurring wasps and to incorporate them into integrated pest management programs. Efforts should be made to conserve these endemic species from oophagous predators, hot weather and insecticides.The olive and jasmine moth-larvae and pupae found under tree canopies were bred and emerged parasitoids were listed.     

Distribution and dispersal behavior of Trogoderma variabile and Plodia interpunctella outside a food processing plant

The distribution and dispersal distances of insects outside of food processing and storage facilities potentially have an important influence on the population dynamics and spatial distribution of insects inside facilities. In this study, Trogoderma variabile Ballion and Plodia interpunctella (Hübner) sex pheromone-baited trap captures outside and inside a food processing facility were measured, the relationship between trap captures outside and inside the facility was evaluated, and the dispersal ability of the males of these species was assessed using self-mark-recapture stations. T. variabile and P. interpunctella males were captured in high numbers outside the food facility. The two species differed in their spatial distribution around the facility, with T. variabile being more closely associated with the proximity of the building, but most likely originating from sources outside the building. For marked T. variabile, the average recapture distance was 75 m (range 21-508 m) and for marked P. interpunctella the average recapture distance was 135.6 m (range 21-276 m). In an immigration/emigration experiment, three T. variabile marked outside were recaptured inside, but no T. variabile marked inside were recaptured outside and no marked P. interpunctella were recaptured in either location. The potential for outside populations to influence inside populations has implications for the effectiveness of different management and monitoring tools.     

Effectiveness of insecticides in controlling the first and second generations of the Lobesia botrana (Lepidoptera: Tortricidae) in table grapes

The moth Lobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae) is a key pest of table and wine grape (Vitis spp.) varieties in Cyprus. Many different insecticide combinations were applied for three consecutive years (2006-2008) in a Sultana seedless table grape vineyard, aimed at controlling the first and second generations of this pest under warm and dry Mediterranean climatic conditions. In Cyprus, Sultana is the main early maturing table grape variety grown in the country. L. botrana has two generations and a partial third on this export variety, of which the first two generations are the most destructive. Applications were made according to pheromone trap captures of males. One application was used against the first and two applications against the second generation of L. botrana. A high rate of bunch damage was observed in the untreated rows during all years, reaching 56.7, 62.5, and 69.2% in 2006, 2007, and 2008, respectively. Differences between insecticide treatments and the untreated control were statistically significant. The treatment combination of lufenuron, spinosad, and indoxacarb as well as the combination of chlorpyrifos, spinosa and indoxacarb, used against the first and second generations of L. botrana, were the most effective compared with the untreated control. Satisfactory control of the pest also was observed with other combinations such as lufenuron, cypermethrin, and Bacillus thuringiensis; chlorpyrifos, cypermethrin, and B. thuringiensis; and lufenuron, deltamethrin, and azadirachtin.     

黄土丘陵区坡面林-草边界土壤水分特征

研究了黄土高原丘陵区林-草边界上旱季和雨季土壤水分的空间分布变化特征.结果表明,旱季林地土壤水分的变异系数都小于草地,林地内各个层次土壤含水量差异不大,草地内各个层次土壤含水量差别较大;雨季林地土壤水分的变异系数都大于草地,林地内各个层次土壤含水量差别较大,而草地内各个层次土壤含水量差异不显著;林-草边界各个层次土壤水分的变异程度为弱变异或中等变异.林-草边界在旱季和雨季具有不同的影响域,旱季边界影响域为从林外0.4倍树高距离到林内0.4倍树高距离;雨季边界影响域为从林外0.4倍树高距离到林内0.8倍树高距离.因此,可将林-草景观划分为3个区：草地区,即由距林缘0.4倍树高距离处向草地方向延伸;林缘区,即由林外0.4倍树高距离到林内0.4倍树高距离(旱季)或0.8倍树高距离(雨季);林地区,即由林内0.4倍树高距离(旱季)或0.8倍树高距离(雨季)处向林内方向延伸.林-草边界水平方向上3个分区的土壤水分垂直分布呈现出不同的变化规律,而且旱季的规律特征与雨季相反.     

Native Mediterranean plants as potential food sources for natural enemies of insect pests in olive groves

The diversity of native non-crop (weed) vegetation in agricultural landscapes can provide arthropod natural enemies with food sources and shelter, thus improving natural pest control and reducing dependence on chemical pesticides. Moreover, native plants to a region are uniquely positioned to provide cultural ecosystem services such as wild food and wild medicinal plants, as well as aesthetics values. The Mediterranean Basin is one of the world’s richest places in terms of plant diversity. Olive cultivation is the basic tree cultivation in the Mediterranean and dominates its rural landscape. The olive grove ecosystem, whose flora presents a notable resemblance to the flora of Mediterranean type ecosystems, is home to a myriad of species of insects, spiders and other arthropods. This includes over one hundred phytophagous species, plus an uncounted number of entomophagous that help to reduce phytophagous populations. Here we present data on flowering plant species from the ground cover of olive groves, store information on characteristics of plant species namely physiognomic type and flowering period, geographic information and some statistical values on olive groves study area and records in the flora of visitor arthropods and cultural ecosystem services. The data include information on 36 olive groves, 100 flora species (taxa), of which 86 native in Portugal, 5 endemic to Iberian Peninsula and 4 endemic to Portugal Continental, and present also a summary of the records of visitor arthropods in these flora (i.e. 2 classes, 6 orders and 12 families).     

Spatio‐temporal analysis of the relationship between landscape structure and the olive fruit fly Bactrocera oleae (Diptera: Tephritidae)

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Spatial scale of benefits from adjacent woody vegetation on natural enemies within vineyards

Abundance of predators in crops can be increased by augmenting the adjacent non-crop vegetation, with associated environmental benefits from reduced chemical inputs and landscape conservation. Fine-scale spatial analysis is required to assess the extent to which non-crop benefits extend into farmed areas. We used explicit spatial mapping to investigate benefits of woody vegetation in two vineyards. The abundance of canopy-dwelling predators and predation/parasitism rates was measured at two vineyards with woody vegetation on one margin. Grids were sampled monthly across two summer growing seasons and stability of spatial patterns determined for consecutive months for each season and between seasons. At these two locations small parasitoids and several species of ladybird beetles from the vine canopy exhibited spatial patterning, with regions of high and low abundance and activity, aggregated in rows near to woody vegetation. Aggregations varied in temporal stability, with some persisting throughout the season. When predation and parasitism of sentinel eggs of a moth pest were non-randomly distributed, levels were higher in vine rows closer to the woody vegetation and significantly associated with a known egg parasitoid and ladybird beetles. This study demonstrated predators and parasitoids had non random and stable distributions at two vineyards. Increased abundance of both Coccinellidae and parasitoids was seen over similar distances: extending approximately 40 m from the vegetated edge. Increase in parasitism and predation extended a similar distance in from the vegetation. These results suggest management of vineyards where non-crop vegetation can be used to increase numbers and impact of beneficials, with recommendations for planting woody vegetation a minimum of 50 m from vineyard edges.     

Land use and biodiversity patterns of the herpetofauna: The role of olive groves

The intensification of agriculture has significant environmental consequences. This intensification entails the simplification and homogenisation of the landscape, which leads to strong negative impacts at ecosystem level, including declines in animal biodiversity. The purpose of this study was to assess the effect of different land uses on reptilian and amphibian biodiversity patterns at a regional scale by analysing a large database on the presence of amphibians and reptiles in Andalusia (southern Spain). GIS techniques and the Ecological-Niche Factor Analysis (ENFA) were applied in order to assess whether the habitat was suitable for each reptilian and amphibian species, when the land use variables were excluded. The incongruence between the potential and the observed species richness was then correlated with the main types of land use in Andalusia. Our results showed that irrigated and unirrigated olive groves were associated with a biodiversity deficit of amphibians and reptiles respectively, whereas natural forests and pastures, along with more heterogeneous crops areas, were more suitable. A clustering analysis showed that generalist species were related to olive groves whereas rare and specialist species were related to land uses related to natural vegetation. In summary, our results indicate that large areas covered by olives groves harbour less amphibian and reptilian diversity, thus suggesting that agro-environmental schemes should be carried to promote the species richness in these crops.     

Arthropod biodiversity in olive groves under two soil management systems: presence versus absence of herbaceous cover crop

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Seasonality in the occurrence of two lepidopterous olive pests in Egypt

Abstract Prays oleae Bern, (OM) and Palpita unionalis Hüb., (JM) are two of the most important pests in olive groves in Egypt. A 3‐year monitoring study using sex pheromone traps in semi‐arid and arid olive groves was performed. In the semi‐arid grove, flight pattern of the OM was the same as in other Mediterranean countries, but in dates concordating plant phenology. The moth completes three generations annually: the first flight is in March to April, the second is in May to June and the third occurs in August to October. In the arid olive grove, an interesting flight pattern was observed. First flight was always very close or overlapped with the second one with no male catches during August to October. However, eggs were present most of the season, indicating unusually high female presence and oviposition activity of the OM during the absence of males in the traps. Generally, moth densities were significantly lower in low fruiting years than in higher ones and were also lower in the arid olive grove than in the semi‐arid one. In contrast, JM males were present all season, exhibiting six to seven and three to four overlapping flight peaks in arid and semi‐arid olive groves, respectively. Moth densities were significantly higher in the arid olive grove than those in the semi‐arid one. This study shows that trapping location and fruit bearing year are characteristics that strongly affect the grove‐specific information needed to estimate correctly adult emergence and thus the timing of control measures.     

Time course study of Bactrocera oleae (Diptera: Tephritidae) pupae predation in soil: the effect of landscape structure and soil condition

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