Giovanna tropea garzia - Academia.edu (original) (raw)

Papers by Giovanna tropea garzia

PLOS ONE

Exotic ambrosia beetles are increasing in Europe due to global trade and global warming. Among th... more Exotic ambrosia beetles are increasing in Europe due to global trade and global warming. Among these xylomycetophagous insects, Xylosandrus compactus (Eichhoff) (Coleoptera: Curculionidae) is a serious threat for several Mediterranean host plants. Carob trees growing in Sicily (Italy) have been extensively attacked by beetles leading to rapid tree decline. Although X. compactus has been found in Europe for several years, most aspects of its ecology are still unknown. We thus studied the population structure and dynamics of X. compactus, together with its twig size preference during a sampling of infested carob trees in south east Sicily. In addition, fungi associated with insects or galleries were isolated and characterized. The results showed that, in this newly-colonized environment and host plant, adult X. compactus overwinters inside twigs and starts to fly and reproduce in mid spring, completing five generations before overwintering in late fall. The mean diameter of carob twigs infested by the beetle varied significantly over the seasons, with the insect tending to infest larger twigs as season progresses. The mean number of adults/gallery was 19.21, ranging from 6 to 28. The minimum temperature significantly affected the overwintering adult mortality. Ambrosiella xylebori and Fusarium solani were the main symbionts associated with the pest in this study. Acremonium sp. was instead recorded for the first time in Europe inside X. compactus galleries. Several other fungi species were also found for the first time in association with X. compactus. Our findings provide useful insights into the sustainable management of this noxious pest.

FIGURE 1. COI gene restriction patterns of Ps. longispinus (L), Pl. citri (C) and Pl. ficus (F) g... more FIGURE 1. COI gene restriction patterns of Ps. longispinus (L), Pl. citri (C) and Pl. ficus (F) generated by BspPI, HinfI and SspI.

FIGURE 2. RFLP analysis with HinfI restriction enzyme of COI gene. Digested products were separat... more FIGURE 2. RFLP analysis with HinfI restriction enzyme of COI gene. Digested products were separated on 2% agarose gels stained with ethidium bromide. Lanes: 1-8, Pl citri; 9-13, Pl ficus; M, 100 bp ladder.

EPPO Bulletin, 2017

In October 2014 samples were collected from olive trees growing in SouthEastern Sicily (Italy) th... more In October 2014 samples were collected from olive trees growing in SouthEastern Sicily (Italy) that were showing wilting symptoms. In the field, clear signs of flagging appeared on young twigs and lateral shoots, and many leaves had fallen to the ground. Initial laboratory examinations of attacked twigs revealed the presence of a large number of adults of Rhyzopertha dominica (F., 1792). Sampling was repeated during the following 2 years, and while an outbreak of the pest did not occur, continuous damage was observed. In 2016, exclusively using pheromone-baited traps in olive trees, a large number of adults were captured. The main local climatic parameters were monitored from 2014 to 2016 and compared with the population levels. The incidence of damage and survival of R. dominica in an environment different from its usual one (stored grain) deserves attention, especially considering that climate change could greatly affect pest demographics and put olive trees in this area and further afield at risk of increased damage.

Acta Horticulturae, 2011

ABSTRACT The correct identification of pests is a basic requirement in IPM strategies for crop pr... more ABSTRACT The correct identification of pests is a basic requirement in IPM strategies for crop protection. In the case of Planococcus species the discrimination between similar taxa using morphological features is sometimes difficult because it is based on few microscopic characteristics not easily detectable. This is the case of the polyphagous and cosmopolitan mealybug Pl. citri (Risso), closely related to the congeneric Pl. ficus (Signoret). In the last years, given the increasing interest of economic damage of these insects, new methods were developed to distinguish the two species, all based on molecular techniques as RAPD-PCR and multiplex-PCR. With the aim of discriminating the two mealybugs, in our research we used two alternative methods: analysis of the ITS1 region and restriction fragment length polymorphism (RFLP) analysis of the mitochondrial gene cytochrome oxidase subunit I (COI) amplified by PCR. Furthermore, ITS1 analysis adds information on genetic variability of populations, but it requires significant time and is expensive. The PCR-RFLP used in the present study is more reproducible than RAPD-PCR and it is easier to develop than multiplex-PCR. All these methods provide researchers with powerful alternative tools for the rapid, accurate and unequivocal identification of these mealybugs in different agricultural fields, especially for the correct choice of parasitoids in integrated pest management. Moreover these techniques offer a new approach in the knowledge of biology and relationships between mealybugs, their host plants and natural enemies.

Pest Management Science, 2017

BACKGROUND: Complexity of both natural and managed ecosystems involves various forms of interacti... more BACKGROUND: Complexity of both natural and managed ecosystems involves various forms of interaction among organisms. Two or more species that exploit the same resource can engage in competitive behaviors, usually referred to as intra-guild interactions. These can be direct, i.e. one species feeds directly upon the competitor (intra-guild predation) or indirect, e.g. when the dominant organism competes for a food source which another organism is feeding on (kleptoparasitism). We investigated the potential for such interactions in a biological model composed by the South American tomato pinworm, Tuta absoluta, and three of its newly associated natural enemies: the zoophytophagous predator Nesidiocoris tenuis, and two idiobiont ectoparasitoids Bracon nigricans, and Necremnus tutae.

2016 International Congress of Entomology, 2016

International Journal of Acarology, 2015

ABSTRACT The Persea Mite Oligonychus perseae Tuttle, Baker and Abbatiello, is reported for the fi... more ABSTRACT The Persea Mite Oligonychus perseae Tuttle, Baker and Abbatiello, is reported for the first time in Italy. The pest was found on avocado in Sicily (South Italy), in August 2014. The predatory mite Iphiseius degenerans (Berlese) was found in association with O. perseae colonies.

EPPO Bulletin, 2002

ABSTRACT

EPPO Bulletin, 2012

ABSTRACT Tuta absoluta (Meyrick) is an invasive pest of tomato native to South America, where it ... more ABSTRACT Tuta absoluta (Meyrick) is an invasive pest of tomato native to South America, where it is responsible for extensive damage. It rapidly spread into several European countries, becom-ing a key pest. Knowledge of its main biological traits can be used to develop effective plant protection management strategies. It is a multivoltine species with a homodynamous behaviour, and the length of its life cycle depends on environmental conditions, particularly temperature. The larvae feed and develop inside tomato leaves, stems and fruits throughout the entire growing cycle. The adults have crepuscular habits, and in Mediterranean condi-tions they can be easily detected throughout the year. Damage is directly related to the reduction of plants' photosynthetic capacity and of production levels in both protected and open-field tomato crops; indirect damage can be also caused by secondary infections, with pathogens developing on the infested plant and fruit tissues.

The tomato borer Tuta absoluta (Meyrick) is an invasive pest native to South America and since it... more The tomato borer Tuta absoluta (Meyrick) is an invasive pest native to South America and since its arrival in Europe the tomato production has faced severe yield loss. The complex of indigenous parasitoids that colonized this new host species was monitored in Southern Italy during 2009-2011, in some of the regions where T. absoluta was initially detected (Campania, Sardinia and Sicily) with the aim of identifying the parasitoid complex of the tomato borer as well as finding potential biocontrol agents of this invasive pest. The survey was carried out by sampling the tomato borer on open field and protected greenhouse crops, on wild secondary hosts and by exposing sentinel infested tomato plants. A quick shift of native parasitoids to the new invasive host was observed and the parasitoid complex associated to T. absoluta seems to follow the typical pattern of colonization on exotic pests. The recovered species were, in fact, mainly generalist idiobiont parasitoids causing low levels of parasitism in open field. The species found belong to 13 genera and 6 families (Ichneumonidae, Braconidae, Eulophidae, Elasmidae, Pteromalidae and Trichogrammatidae). In particular, the 10 identified species were: Diadegma pulchripes (Kokujev), Bracon osculator (Nees), Bracon (Habrobracon) nigricans Szepligeti, Necremnus sp. near tidius (Walker), Necremnus sp. near artynes (Walker), Neochrysocharis formosa (Westwood), Pnigalio soemius s.l. (Walker), Pnigalio cristatus (Ratzeburg), Pnigalio incompletus (Boucek) and Halticoptera aenea (Walker). For seven of these species, the finding on T. absoluta is the first host-parasitoid association report. This survey highlighted that conservation of indigenous natural enemies, also by means of habitat management techniques, should be taken seriously into account when planning integrated management strategy of the tomato borer in the Mediterranean area.

Journal of Economic Entomology, 2015

Insect-proof nets are thought to be effective physical barriers to protect tomato crops against s... more Insect-proof nets are thought to be effective physical barriers to protect tomato crops against several insect pests, including the invasive tomato pest, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae). However, protected tomato crops are frequently infested by this destructive pest, and there is a higher infestation of plants closer to openings in Mediterranean greenhouses, suggesting that immigrating adults can easily walk on these protective materials and find a way to reach the crop. Laboratory bioassays were carried out to characterize the potential toxicity of a-cypermethrin-treated insect-proof nets (Agronet) against T. absoluta adults. The data showed that the net acts mainly through a variety of chronic sublethal effects rather than acute ones. Reduced longevity and, more markedly, a reduced number of laid eggs were observed after the moths were exposed to the treated net over the duration of their lifetimes. A Y-tube experiment showed that the treated net does not affect the T. absoluta olfaction cues for host location. In contrast, when the moths were given the option to choose either the treated or the untreated net in laboratory cages, they significantly preferred the untreated one. The toxicological significance and the functional implications of these subtle effects for the implementation of integrated T. absoluta management strategies are discussed.

Insects, 2015

Megalurothrips sjostedti Trybom is an important pest of cowpea (Vigna unguiculata L.) in Africa. ... more Megalurothrips sjostedti Trybom is an important pest of cowpea (Vigna unguiculata L.) in Africa. To propose an alternative to chemical control, the repellency of 24 plant extracts was evaluated against adult female thrips of M. sjostedti in the laboratory. Plant extracts in ethanol were separately applied on a filter paper disk in a still air visual cue olfactometer. The results showed highly significant differences in repellency among extract type, concentration and their interactions. We classified the level of repellency into four categories as strong, good, moderate and weak or non-repellent based on hierarchical ascendant classification. We identified Piper nigrum, Cinnamomum zeylanicum, Cinnamomum cassia as strong repellents. Five extracts were classified as good, eight as moderate and the remaining eight extracts were weak or non-repellent. Repellency of the extracts increased with the concentration suggesting that the behavioral response of M. sjostedti was dose-dependent. Mono-and sesquiterpene hydrocarbon compounds from seven highly repellent extracts were identified by gas chromatography-mass spectrometry (GC/MS). The use of repellent extracts could be useful in developing integrated pest management strategies for thrips on legume crops. In

The vine mealybug, Planococcus ficus (Signoret), and the citrus mealybug, Planococcus citri (Riss... more The vine mealybug, Planococcus ficus (Signoret), and the citrus mealybug, Planococcus citri (Risso), are currently the most economically important pseudococcids in vineyards in Italy (Dalla Montà et al., 2001). Pl. ficus is also considered to be a key pest in many other countries (Ben-Dov, 1994). The two species cause severe damage to the host plant, and significantly reduce the crop due to the production of honeydew, which allows the growth of sooty molds, and to their potential as virus vectors. The vine mealybug, in particular, is known to transmit grapevine leafroll and corky-bark diseases (Engelbrecht & Kasdorf, 1990; Tanne et al., 1989). Populations of these two sibling species may coexist apparently without mutual interference (Rotundo & Tremblay, 1982), but some differences occur on their relationships with parasitoids. For instance, Pl. citri is successfully controlled by Leptomastix dactylopii Howard (Hymenoptera Encyrtidae) but this parasitic wasp is ineffective in contro...

The present work contributes to an accurate quantification method of the parameters of the biotic... more The present work contributes to an accurate quantification method of the parameters of the biotic potential of Encarsia formosa Gahan (Hymenoptera Aphelinidae), applicable to other species of whitefly parasitoids. The oviposition devices are easy to make and they allow standardisation of a whitefly parasitoid study by daily observations of the main parameters such as fecundity, lon-gevity and host-feeding by adult parasitoids, which are important for the parasitoids mass-production and biological control of whiteflies. Results show that two physical parameters determine the expression of biotic potential: the confinement induces an important decrease of the fecundity and longevity of E. formosa; the position of plant leaf with nymphs of Trialeurodes vaporari-orum (Westwood) (Homoptera Aleyrodidae) that the parasitoid female can explore for oviposition and host-feeding influences on the biotic potential. The heterogeneity observed in the replicates suggests that during their mass-pro...