Marco Pezzi

Insecticidal activity and fungitoxicity of plant extracts and components of horseradish (Armoracia rusticana) and garlic (Allium sativum).

To avoid environmental pollution and health problems caused by the use of traditional synthetic pesticides, there is a trend to search for naturally occurring toxicants from plants. Among the compounds discussed for anti-fungal and insecticidal activity, the natural extracts from garlic and horseradish have attracted considerable attention. The objective of this study is to determine the insecticidal and anti-fungal activity of Armoracia rusticana and Allium sativum L. extracts against larvae of Aedes albopictus (Skuse) and some pathogenic fungi. For the insecticidal test, horseradish and garlic extracts were prepared from fresh plants (cultivated in Emilia Romagna region) in a solution of ethanol 80 % and the two different solutions were used at different concentrations (for the determination of the lethal dose) against the fourth instar mosquitos larvae. The fungicidal test was carried out by the agar plates technique using garlic and horseradish extracts in a 10 % ethanol solution against the following organisms: Sclerotium rolfsii Sacc., Trichoderma longibrachiatum, Botrytis cinerea Pers., Fusarium oxysporum Schlecht. and Fusarium culmorum (Wm. G. Sm.) Sacc. The first results demonstrated that the horseradish ethanol extracts present only a fungistatic activity against Sclerotium rolfsii Sacc., Fusarium oxysporum Schlecht. and F. culmorum (Wm.G. Sm) Sacc. while garlic extracts at the same concentration provided a good fungicidal activity above all against Botrytis cinerea Pers. and S. rolfsii. A. rusticana and A. sativum preparations showed also an interesting and significant insecticidal activity against larvae of A. albopictus, even if horseradish presented a higher efficacy (LC50 value of 2.34 g/L), approximately two times higher than garlic one (LC50 value of 4.48 g/L).

Traumatic Myiasis Caused by an Association of Sarcophaga tibialis (Diptera: Sarcophagidae) and Lucilia sericata (Diptera: Calliphoridae) in a Domestic Cat in Italy

We describe here a rare case of traumatic myiasis occurred in August 2014, caused by an association of 2 Diptera species, Sarcophaga tibialis Macquart (Diptera: Sarcophagidae) and Lucilia sericata (Meigen) (Diptera: Calliphoridae), in a domestic cat in northern Italy. Species identification was based on adult male morphology. The present case is the first report of S. tibialis as an agent of myiasis in Italy, and also the first ever report of myiasis caused by an association of S. tibialis and L. sericata. The cat developed an extensive traumatic myiasis in a large wound on the rump, which was treated pharmacologically and surgically. The biology, ecology, and distribution of S. tibialis and L. sericata are also discussed. A literature review is provided on cases of myiasis caused by S. tibialis, and cases of myiasis by L. sericata involving cats worldwide and humans and animals in Italy.

Ultrastructural Morphology of the Antenna and Maxillary Palp of Sarcophaga tibialis (Diptera: Sarcophagidae)

Abstract A scanning electron microscopy investigation of the antenna and maxillary palp of the adult of Sarcophaga tibialis Macquart (Diptera: Sarcophagidae), a species of medical, veterinary, and forensic relevance, is presented for the first time. Adults of both sexes used in this study were obtained from larvae collected in a case of traumatic myiasis in a domestic cat in northern Italy. The antenna of S. tibialis is that typical of cyclorrhaphan Diptera, consisting of three segments: the scape, the pedicel, and the postpedicel, bearing the arista. The scape is covered by microtrichia and has a row of long chaetic sensilla. The pedicel is also covered by microtrichia and has three types of chaetic sensilla and a cluster of setiferous plaques. Trichoid, styloconic, clavate, and basiconic sensilla are distributed among the microtrichia on the postpedicel. Invaginated basiconic-like sensilla and olfactory pits are also present, the latter ones more numerous in the female. Our results are compared with those obtained for other calyptrate flies, mainly in the family Sarcophagidae. The data obtained may represent a basis for electrophysiological studies on the sensorial activity of the species related to the search for food sources, mates, and suitable larviposition sites, and for comparative morphological studies with other Diptera.

Preliminary evaluation of insecticide resistance in a strain of Musca domestica (Diptera: Muscidae) from an intensive chicken farm of Northern Italy.

The house fly, Musca domestica L., a relevant sanitary pest, is mainly controlled by insecticides. However, an inappropriate use of chemicals may induce resistance, treatment efficacy decline and environmental damages. We evaluated toxicity of some organophosphates, pyrethroids, spinosad and neonicotinoids by topical applications on adults of a M. domestica strain (OcRo) collected from an intensive chicken farm in Northern Italy, in comparison to a susceptible strain (s-DBF). The OcRo strain exhibited higher levels of resistance (RR50) to four pesticides in comparison to s-DBF. Spinosad and imidacloprid had very low RR50, thus were still efficient in OcRo control. We also tested resistance to pesticides in OcRo after topical applications of synergistic compounds. Hydrolases were involved in phosphorganic detoxification and cytochrome P450 monoxygenases in that of pyrethroids. These results indicate that OcRo strain is now multiresistant to organophosphates and pyrethroids, and this should be considered for an environmentally safe pest management.

Gamasoidosis caused by the special lineage L1 of Dermanyssus gallinae (Acarina: Dermanyssidae): A case of heavy infestation in a public place in Italy

Among Gamasina (Acari: Mesostigmata) mites, some dermanyssoid species are known to cause gamasoidosis, a human dermatitis characterized by papulosquamous eruptions and urticarian lesions. We describe a case of mite infestation which occurred in public conference halls in Ferrara (Italy), affecting four people who attended the place and showed signs of gamasoidosis. The mites were collected and characterized using scanning electron microscopy, light microscopy and mitochondrial DNA sequencing (Cytochrome c oxidase subunit I partial CDS). Based on morphological and molecular data, the species responsible for the infestation was identified as the special lineage L1 of the poultry red mite, Dermanyssus gallinae (De Geer) (Acarina: Dermanissydae), a cryptic species known to be associated with pigeons. Rock doves, Columba livia Gmelin (Columbiformes: Columbidae) were roosting on the top of the public building, thus the mites probably gained access to the halls through small window openings. The present case report is the first one providing morpho-molecular identification of a D. gallinae cryptic species responsible of gamasoidosis in Italy.

Scanning Electron Microscopy Investigations of Third-Instar Larva of Cordylobia rodhaini (Diptera: Calliphoridae), an Agent of Furuncular Myiasis.

ABSTRACT A scanning electron microscopy study of the third larval instar of Cordylobia rodhaini Gedoelst (Diptera: Calliphoridae), causing obligatory furuncular myiasis, is presented here for the first time. The larvae were collected from a patient exposed to them in the tropical rainforest of Kibale National Park (Uganda). Distinctive features are described in sequence from the anterior region to the posterior region, highlighting the morphological features of antennae, maxillary palps, structures related to mouth opening, sensory structures, thoracic and abdominal spines, and anterior and posterior spiracles. The results are compared with those of other Calyptrata flies, mainly from the family Calliphoridae and, when possible, with Cordylobia anthropophaga Blanchard (Diptera: Calliphoridae), the only other species of genus Cordylobia investigated by scanning electron microscopy.

Furuncular Myiasis Caused by Cordylobia rodhaini (Diptera: Calliphoridae): A Case Report and a Literature Review

ABSTRACT Some African flies may cause myiasis not only in animals but also in humans, representing a serious health problem for the local population and for tourists.We report a rare case of furuncular myiasis due to larvae of Lunds fly Cordylobia rodhaini Gedoelst (Diptera: Calliphoridae), a species which usually parasitizes small mammals. The myiasis was diagnosed in Italy in a tourist guide who travelled in Central African rainforests of Uganda. The clinical case and the morphological criteria used for species identification are described here, together with a review of all literature cases of human furuncularmyiasis due to C. rodhaini.

Facultative myiasis of domestic cats by Sarcophaga argyrostoma (Diptera: Sarcophagidae), Calliphora vicina and Lucilia sericata (Diptera: Calliphoridae) in northern Italy

We describe five cases of myiasis of domestic cats, Felis silvestris catus L. (Carnivora: Felidae), reported in 2016 in northern Italy and caused by three Diptera species: Sarcophaga argyrostoma (Robineau-Desvoidy) (Sarcophagidae), Calliphora vicina Robineau-Desvoidy and Lucilia sericata (Meigen) (Calliphoridae). Three were cases of traumatic myiasis, one by S. argyrostoma and two by L. sericata, one was a case of auricular myiasis by C. vicina and one was a case of ophthalmomyiasis caused by an association of L. sericata and C. vicina. The myiasis by S. argyrostoma is the first reported case of this species in a cat, whereas the two myiases by C. vicina are the first reported cases in cats in Italy.

Morphology of the Antenna of Hermetia illucens (Diptera: Stratiomyidae): An Ultrastructural Investigation

Abstract The black soldier fly, Hermetia illucens (L.) (Diptera: Stratiomyidae), is a relevant species in waste and pest management, but is also of forensic and medical importance. A scanning electron microscopy (SEM) investigation of the antennae of both sexes of H. illucens is presented here for the first time. The antenna is composed of three regions: the scape, the pedicel, and the flagellum. The first two regions are single segments, whereas the third region, the longest one, is composed of eight flagellomeres. The scape and pedicel have microtrichia, chaetic sensilla, and rounded perforations. The flagellum is covered by different microtrichia, the morphology of which is described in detail. Two types of sensory pit are found on flagellomeres 1 to 6. An oval depression with trichoid sensilla extends from flagellomeres 4 to 6. On both sides of flagellomere 8 is a lanceolate depression covered by hair-like microtrichia. Morphometric and morphological analyses revealed some sex-related differences. The results of the SEM investigations are compared with those obtained on other species of the family Stratiomyidae and other brachyceran Diptera. The possible role of sensilla in sensory perception is also discussed in comparison with nondipteran species.

Evaluation of larvicidal activity of esters of 4-mercapto-2-butenoic acid against Aedes albopictus (Diptera: Culicidae)

Aedes albopictus (Skuse) (Diptera: Culicidae), an aggressive and annoying vector of several arbovirus including Chikungunya and Zika, is a serious health problem worldwide. Control of this mosquito is difficult because of high adaptability, egg resistance to dehydration and ability to exploit many man-made microhabitats. The most effective strategy appears the control of larval population. Based on previous data showing a larvicidal effect of plant extracts containing sulfhydryl and isothiocyanate compounds, we evaluated by bioassays the toxicity of three synthetic esters of 4-mercapto-2-butenoic acid on larvae of A. albopictus in comparison to cypermethrin. Among the compounds tested, the most effective was n-octyl 4-mercapto-2-butenoate, about 5 times more effective than ethyl 4-mercaptobut-2-enoate and about 20 times more effective than menthyl 4-mercaptobut-2-enoate. We advance the hypothesis that the larvicidal properties of n-octyl 4-mercapto-2-butenoate are due to its hydrophobic alkyl chain, longer than that of the other two compounds. This chain confers to the molecule the ability to spread on water surface and interfere with larval respiration. The larvicidal activity of n-octyl 4-mercapto-2-butenoate against A. albopictus appears interesting and may be developed after toxicological evaluation on vertebrates and humans, and environmental toxicity tests in compliance with WHO and ECDC rules.