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The predatory mites of the Phytoseiidae family are crucial biological control agents widely utilized in biological pest management targeting phytophagous mites and insects. Key factors in these control strategies are that phytoseiids must be able to find their main target prey and to maintain high populations and efficacy. To reduce expenses and time-consuming production methods of mass rearing of phytoseiids, pollen and other factitious (i.e. non-natural/nontarget) hosts need to be present as an alternative food for predatory mite populations. The mass-rearing possibilities of these predators on alternative food sources, such as astigmatid mites (i.e. house and stored mites) and pollen, must be evaluated not only by the cost of rearing settings but on the basis of their efficiency maintenance in killing prey. The pest kill rate (k m ) is the average daily lifetime killing of the pest by the natural enemy under consideration and can represent a useful indicator for phytoseiids efficacy to rank them as BCAs on the basis of their effective killing/predation on target prey. In this study, we evidenced that 2 astigmatid mites, Glycyphagus domesticus (De Geer) and Lepidoglyphus destructor (Schrank), and Quercus ilex L. pollen can be successfully adopted as substitute food sources for mass rearing of the phytoseiid Neoseiulus californicus (MgGregor); then, we determined that these populations of BCAs maintained a consistent k m at new/first impact on the main target pest, Tetranychus urticae Koch. [ABSTRACT FROM AUTHOR]

Ham products play a fundamental role in the Italian economy, and attention to the problems of this sector is essential. The products of this sector can be attacked by parasites, which can cause direct and indirect damage. Piophila casei (L.) (Diptera: Piophilidae) a cheese and meat parasite, is currently responsible for hygiene problems in ham factories. The trophic activity of this pest on the products causes serious direct damage and it is a vector of various bacteria, including Clostridium botulinum. Another risk is human ingestion of the larvae, which are resistant to gastric juices action, potentially causing intestinal myiasis. Insecticide use of any type is not allowed in aging rooms, so biological control can represent a potential alternative. In this study, we investigate quality parameters such as successful rate of parasitism (SP), degree of parasitism (DP), sex-ratio (SR), life-span (LS), and emergence rates (ER) of 2 pupal parasitoids of Diptera: Pachycrepoideus vindemiae (Rondani) (Hymenoptera: Pteromalidae), currently the only known pupal parasitoid of P. casei , and Muscidifurax raptor (Girault and Sanders) (Hymenoptera: Pteromalidae). Our research confirmed P. vindemiae efficacy to parasitize P. casei and reported, for the first time, M. raptor as a pupal parasitoid of this Piophilidae. ER for both parasitoids were low, thus affecting the DP and SP estimations. This could be explained by the feeding behavior of the parasitoid host. The strongly female-biased SR for P. vindemiae supported previous studies. LS results in our experiment are crucial for determining the timing of release. [ABSTRACT FROM AUTHOR]

Conventional insecticide assays, which measure the effects of insecticide exposure on short-term mortality, overlook important traits, including persistence of toxicity or sub-lethal effects. Therefore, such approaches are especially inadequate for prediction of the overall impact of insecticides on beneficial arthropods. In this study, the side effects of four modern insecticides (chlorantraniliprole, emamectin benzoate, spinosad, and spirotetramat) on Adalia bipunctata (L.) (Coleoptera: Coccinellidae) were evaluated under laboratory conditions by exposition on treated potted plants. In addition to investigation of acute toxicity and persistence of harmful activity in both larvae and adults of A. bipunctata, demographic parameters were evaluated, to provide a comprehensive picture of the nontarget effects of these products. Field doses of the four insecticides caused detrimental effects to A. bipunctata; but in different ways. Overall, spinosad showed the best toxicological profile among the products tested. Emamectin benzoate could be considered a low-risk insecticide, but had high persistence. Chlorantraniliprole exhibited lethal effects on early instar larvae and adults, along with a long-lasting activity, instead spirotetramat showed a low impact on larval and adult mortality and can be considered a short-lived insecticide. However, demographic analysis demonstrated that chlorantraniliprole and spirotetramat caused sub-lethal effects. Our findings highlight that sole assessment of mortality can lead to underestimation of the full impact of pesticides on nontarget insects. Demographic analysis was demonstrated to be a sensitive method for detection of the sub-lethal effects of insecticides on A. bipunctata, and this approach should be considered for evaluation of insecticide selectivity. [ABSTRACT FROM AUTHOR]

Landscape structure as well as local vegetation influence biodiversity in agroecosystems. A study was performed to evaluate the effect of floristic diversity, vegetation patterns, and landscape structural connectivity on butterflies (Lepidoptera: Papilionoidea and Hesperiidae), carabids (Coleoptera: Carabidae), syrphids (Diptera: Syrphidae), and sawflies (Hymenoptera: Symphyta). Vegetation analysis and insect samplings were carried out in nine sites within an intensively farmed landscape in northern Italy. Plant species richness and the percentage of tree, shrub, and herb cover were determined by means of the phytosociological method of Braun-Blanquet. Landscape structural connectivity was measured as the total length of hedgerow network (LHN) in a radius of 500m around the center of each sampling transect. Butterflies species richness and abundance were positively associated both to herb cover and to plant species richness, but responded negatively to tree and shrub cover. Shrub cover was strictly correlated to both species richness and activity density of carabids. The species richness of syrphids was positively influenced by herb cover and plant richness, whereas their abundance was dependent on ligneous vegetation and LHN. Rarefaction analysis revealed that sawfly sampling was not robust and no relationship could be drawn with either vegetation parameters or structural connectivity. The specific responses of each insect group to the environmental factors should be considered in order to refine and optimize landscape management interventions targeting specific conservation endpoints. [ABSTRACT FROM AUTHOR]

Parasitoids (Hymenoptera) associated with agromyzid leafminers (Diptera: Agromyzidae) were studied in three rural farms located in northern Italy. The parasitoids were reared from mined foliage of weeds growing in field margins. We reared 998 Hymenoptera specimens, representing five families, 23 genera, and 53 species, from leafminers infesting weeds. Eulophidae was the most abundant family (67.64%), followed by Braconidae (28.86%), Eucoilinae (1.40%), Tetracampidae (1.40%), and Pteromalidae (0.7%). Braconids was the most species rich family, accounting for 28 species; eulophids were represented by 19 species, pteromalids by four species, and eucoilins and tetracampids by one species each. The dominant parasitoid was the eulophid Pediobius metallicus (Nees), representing 18.17% of the total, followed by Diglyphus isaea (Walker) (12.73%), and Neochrysocharisformosa (Westwood) (10.82%). The most abundant braconid parasitoid was Dacnusa maculipes Thomson (9.62%). More than 80% of parasitoids were recovered from 10 plant species: Cirsium arvense (L.) Scopoli, Plantago lanceolata L., Sonchus asper (L.) Hill, Papaver rhoeas L., Picris echioides L., Lactuca serriola L., Myagrum perfoliatum L., Ranunculus velutinus Tenore, Arctium lappa L., and Medicago sativa L. The retention and the management of wild plants within field margins can be crucial tools to enhance the populations of biological control agents of agromyzids and to conserve rare parasitic wasp species. [ABSTRACT FROM AUTHOR]

The pea leafminer, Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae), is a serious insect pest infesting open field lettuce plantings in northern Italy. In these cropping systems, it coexists with several other agromyzid species that have negligible economic importance on open field vegetables. The rapid detection of L. huidobrensis is crucial for effective management strategies, but the identification of agromyzids to species can be very difficult at adult as well at immature stages. In this study, a polymerase chain reaction (PCR)-restriction fragment length polymorphism assay is proposed to separate L. huidobrensis from Liriomyza bryoniae (Kaltenbach), Liriomyza trifolii (Burgess), and Chromatomyia horticola (Goureau), which usually occur in the same lettuce plantings. An ≈1,031-bp region of the mitochondrial genome encompassing the 3' region of cytochrome oxidase I, the whole leucine tRNA, and all of the cytochrome oxidase II was amplified by PCR and digested using the enzymes PvuII and SnaBI separately. Both endonucleases cut the amplicons of L. huidobrensis in two fragments, whereas the original band was not cleaved in the other analyzed species. The presence of Dacnusa spp. DNA does not bias the assay, because the PCR conditions and the primer set here described do not amplify ant tract of this endoparasitic wasp genome. [ABSTRACT FROM AUTHOR]

Metcalfa pruinosa (Say) is an exotic pest introduced into Italy in the early 1980s. It is a polyphagous pest and can infest several plant species used in agriculture, forest, and urban systems. To control this pest, Neodrynus, typhlocybae (Ashmead), a specialist parasitoid attacking young M. pruinosa instars, was introduced in Italy starting in 1987. From 1999 to 2001, the establishment of N. typhlocybae was evaluated and a sampling plan developed to estimate its cocoon population density. The spatial aggregation of the cocoons was analyzed by Taylor's power law. The aggregation index ranged from 1.064 to 1.136 and:a common value (b = 1.1) was estimated. Sequential sampling was shown to be the more practical and least time consuming sampling method. The peak of the parasitoid cocoon population at the end of July (26th to30th week of the year) is a suitable period in northern Italy to monitor the activity of the parasitoid and to estimate the field parasitization. The potential of the sampling method is discussed, with the aim to evaluate the impact of the parasitoid on M. pruinosa populations. [ABSTRACT FROM AUTHOR]

Field experiments were carried out in 2000 and 2001 in northern Italy, with the aim of developing a composite sampling strategy for estimating populations of Liriomyza huidobrensis (Blanchard) larvae and mines on lettuce. Larval parasitoid populations also were sampled to estimate the contribution of these beneficials to pest control. Covariance analysis and parallelism test indicated that there were not significant differences in the coefficient of Taylor's power law between treatments (untreated versus treated) and between seasons (2000 versus 2001) for both pest and parasitoid stages. The slope of each regression was significantly >1 for L. huidobrensis mines and larvae, and endoparasitoid and ectoparasitoid larvae, indicating a clumped distribution of both pest and parasitoids. Constant precision level stoplines for mines and larvae of L. huidobrensis and for endoparasitoid and ectoparasitoid larvae were calculated, by using the common a and b derived from Taylor's power law. Wilson and Room binomial sampling was used to estimate the mean number of L. huidobrensis mines or live larvae from the ratio of leaves with mines. In this way, it is possible to estimate the mean density of L. huidobrensis by counting the leaves with mines, an index parameter easy to obtain in field sampling. Validation of the presence-absence sampling plan by using field data collected in 2002 and 2003 seasons, showed that the Wilson and Room model fits very well empirical data. Statistical analysis does not show any significant difference between observed and predicted data. [ABSTRACT FROM AUTHOR]

Extensive surveys of weedy plant species among hedgerows of different complexity and floristical composition were conducted with the aim to evaluate the role of weeds as reservoirs of agromyzids and to study the trophic relationships between these Diptera and noncrop plants. Field samplings were carried out weekly collecting foliage infested by leafminers from the representative weedy plants in three sites located in Bologna province, Italy. During 1998-1999, a total of 646 agromyzid specimens were reared, representing eight genera and 24 species. The most abundant species were Chromatomyia horticola (Goureau), Phytomyza lappae Goureau, Phytomyza ranunculi Schrank, Phytomyza plantaginis Robineau-Desvoidy, Liriomyza trifolii (Burgess), and Ophiomyia pulicaria (Meigen). C. horticola was the dominant species accounting for 35.76% of adults reared. Agromyzids mined 25 plant species belonging to nine families. The Asteraceae, in particular Cirsium arvense (L.) Scopoli and Sonchus as-per (L.) Hill, were the most important sources of leafminers considering both species richness and population densities. Shannon-Weaver (H'), Simpson (D), and Berger-Parker (d) indices all pointed out that agromyzid species diversity was higher in the site characterized by the highest floristic richness, the highest complexity of ecological net and nonintensive agriculture. Most of the weeds sampled proved to be reservoirs for noneconomically important agromyzids in open-field crops in Italy. [ABSTRACT FROM AUTHOR]