Aerial spraying ofBacillus thuringiensis var.kurstaki for the control ofThaumetopoea processionea in Turkey oak woods

Thaumetopoea processionea L. is an important oak defoliator whose outbreaks have become increasingly frequent in Europe and thus have received a great deal of attention from foresters. Field trials were carried out in central Italy (Tuscany) to test the efficacy of aerial spraying ofBacillus thuringiensis var.kurstaki [Btk] in early spring for the control of processionary infestations inQuercus cerris L. woods. The experimental sites were located in a hilly area of 1640 ha witha maximum altitude of 593 m a.s.l. and a yearly mean temperature of 10°C. Turkey oak woods were divided into three areas to be treated with 31.75 BIU ha⁻¹ (2.5l ha⁻¹) on 578 ha, 44.45 BIU ha⁻¹ (3.5l ha⁻¹) on 306 ha and 57.15 BIU ha⁻¹ (4.5l ha⁻¹) on 756 ha, respectively. Five days after treatment, larval mortality was less than 40% in the control plot, but over 60% in the treated areas. Thirteen days after treatment, larval mortality varied from 75.05% to 96.42% in the three treated areas. Surveys conducted 2 months after the treatment showed a strong decline in the number of oak processionary nests in all the treated plots. It was possible to control the pest effectively in turkey oak woods usingBtk at 31.75 BIU ha⁻¹ distributed at ultra-low volume at the time of bud opening when nonurticating larvae were present. http://www.phytoparasitica.org posting March 12, 2008.     

Pine volatiles and terpenoid compounds attractive to European xylophagous species,vectors of <Emphasis Type="Italic">Bursaphelenchus</Emphasis> spp. nematodes

The attractiveness of different combinations of volatile compounds to several scolytid and cerambycid species, potential vectors of phytoparasitic nematodes of the genus Bursaphelenchus Fuchs, was investigated in pine woods of central Italy. The blend composed of α-pinene, ethanol, ipsenol, ipsdienol and 2-methyl-3-buten-2-ol was very efficient in trapping the cerambycids Monochamus galloprovincialis, Acanthocinus griseus and Arhopalus syriacus and the scolytids Ips sexdentatus, Orthotomicus erosus and Hylurgus ligniperda. This blend is proposed for operational surveys of Bursaphelenchus spp. associated with these beetles. Comparison of the capture levels with cross-vane and funnel traps baited with α-pinene, ethanol, ipsenol, ipsdienol, 2-methyl-3-buten-2-ol and cis-verbenol revealed the higher efficacy of the cross-vane traps for the above-mentioned cerambycids and the scolytid I. sexdentatus but greater effectiveness of the funnel traps in capturing H. ligniperda and O. erosus. Cross-vane traps were more efficient in capturing large numbers of these insects. Data on non-target xylophagous beetles and predator species are also reported.     

Introduction into Italy of Gryon pennsylvanicum (Ashmead), an egg parasitoid of the alien invasive bug Leptoglossus occidentalis Heidemann

Leptoglossus occidentalis (Heteroptera, Coreidae), a Nearctic species, was accidentally introduced into Northern Italy in the late 1990s, from where it has spread throughout Europe. The bug causes abortion of immature cones of Pinus pinea L., with economic impact on the pine‐nut industry. As part of a pest control research program, the egg parasitoid Gryon pennsylvanicum Ashmead (Hymenoptera, Platygastridae) was collected from British Columbia, Canada, and legally introduced to a quarantine climatic chamber in Florence, Italy. The egg parasitoid will be tested against native non‐target heteropterans, an environmental impact assessment will be conducted, and a mass rearing method will be developed if appropriate. The ultimate goal is to release G. pennsylvanicum into Italian P. pinea forests for classical biological control of L. occidentalis.     

Physiological host range of Trissolcus mitsukurii,a candidate biological control agent of Halyomorpha halys in Europe

Journal of Pest Science - The invasive stink bug Halyomorpha halys, native to East Asia, is a severe agricultural pest of worldwide importance, and chemical insecticides are largely sprayed for its...     

Antibody multispecificity mediated by conformational diversity

A single antibody was shown to adopt different binding-site conformations and thereby bind unrelated antigens. Analysis by both x-ray crystallography and pre-steady-state kinetics revealed an equilibrium between different preexisting isomers, one of which possessed a promiscuous, low-affinity binding site for aromatic ligands, including the immunizing hapten. A subsequent induced-fit isomerization led to high-affinity complexes with a deep and narrow binding site. A protein antigen identified by repertoire selection made use of an unrelated antibody isomer with a wide, shallow binding site. Conformational diversity, whereby one sequence adopts multiple structures and multiple functions, can increase the effective size of the antibody repertoire but may also lead to autoimmunity and allergy.     

Pest risk analysis of rice root-knot nematode (Meloidogyne graminicola) for the Italian territory

Meloidogyne graminicola is one of the most harmful organisms associated with rice cultivation throughout the world. Until recently, M. graminicola was present only in Asia, parts of the Americas, Madagascar and South Africa. In 2016, it was detected for the first time in mainland Europe (Northern Italy) and subsequently added to the EPPO Alert List. In this study, the risk posed by this nematode to rice in Italy was assessed using an internationally developed pest risk analysis scheme. In the risk assessment section, information about biology, pathways for entry, the likelihood of establishment, spread and negative impact of M. graminicola are reviewed. Internationally, its spread is more likely through the movement of infested host plants, soil or growing medium and non-host plant parts that may have growing medium attached, from areas where this nematode occurs. Migrant waterbirds, machinery and travellers were also considered as possible pathways for entry. The probability of establishment is very likely due to the suitable environmental conditions and the large range of host plant species present in Italy. This and the nematodes’ ability to survive for long periods in low oxygen environments make the control of M. graminicola very difficult.     

Combining physiological host range,behavior and host characteristics for predictive risk analysis of Trissolcus japonicus

Halyomorpha halys is an Asian pentatomid that has recently invaded several countries worldwide, where it has become a severe pest. Classical biological control focused on the scelionid egg parasitoid Trissolcus japonicus appears to be the most promising long-term solution. However, non-target risks need to be included in cost/benefit analyses. Physiological host range tests were conducted by offering T. japonicus females a single hemipteran egg for short (2 h) and long (24 h) exposure periods, and recording the behavior and parasitization acceptance/success during the short exposures. Of the 16 different hemipteran species tested in no-choice experiments, 9 species were accepted and suitable for T. japonicus development. Among pentatomids, Palomena prasina and Rhaphigaster nebulosa were accepted at rates comparable to H. halys, while species accepted at lower rates included Acrosternum heegeri, Carpocoris mediterraneus, C. purpeiripennis, Dolycoris baccarum, Piezodorus lituratus and Peribalus strictus. The other 7 hemipterans tested, including two coreids and one reduviid, were never parasitized. The use of a short-term exposure of 2 h revealed no differences with the 24-h exposure that has been widely used in physiological host range testing. Thus, T. japonicus oligophagy observed in other studies was confirmed by using our extremely simplified laboratory protocol. Moreover, the host egg morphology was correlated with the acceptance rates, permitting us to propose a new predictive approach for non-target studies. However, further research with more complex experimental designs that account for environmental conditions is needed to confirm laboratory predictions of host specificity under actual field conditions.

     

Feeding and oviposition of <Emphasis Type="Italic">Anoplophora chinensis</Emphasis> on ornamental and forest trees

Studies were conducted on maturation feeding and oviposition of Anoplophora chinensis (Forster) (Coleoptera: Cerambycidae), a recently introduced quarantine pest in Europe on different plant species of great importance for urban and forest environments in Italy. The tested plant species were Aesculus hippocastanum, Acer negundo, A. campestris, Castanea sativa, Corylus avellana, Platanus x acerifolia, Quercus petrea, Q. pubescens, Q. rubra, Tilia platyphyllos, Ulmus minor and U. pumila. Tested adults of A. chinensis originated from a population of a recently infested site in Italy (Rome) and all experiments were conducted in a walk-in insect cage under quarantine conditions. Adults of A. chinensis showed a maturation feeding preference for twigs of Acer species (A. negundo and A. campestris) and for C. avellana. In the oviposition experiments conducted on bolts of tested plant species, A. chinensis females did not show clear preferences and some data did not reflect the preferences shown during the feeding experiments. Nevertheless, A. negundo and A. campestris were well accepted plant species for oviposition besides A. hippocastanum and T. platyphyllos.