Giovanni Bazzocchi

Biological traits and life table of the exotic Harmonia axyridis compared with Hippodamia variegata, and Adalia bipunctata (Col., Coccinellidae)

Abstract:  As part of an environmental risk assessment study of exotic natural enemies used in inundative biological control, life‐history characteristics of Harmonia axyridis (Pallas), Hippodamia variegata (Goeze) and Adalia bipunctata (L.) (Col., Coccinellidae) were quantified under laboratory conditions at 25°C on Myzus persicae (Sulzer) as prey. Comparative studies showed significant differences among pre‐adult development times: H. axyridis developed slower ( = 19.8 days) than H. variegata ( = 18.1 days) and A. bipunctata ( = 18.4 days). Differences were also evident in the duration of egg, larval and pupal stages. No measurable differences among the three species were found for fecundity, oviposition rate and adult longevity. Harmonia axyridis exhibited the longest pre‐oviposition ( = 7.4 days) and interoviposition ( = 3.6 days) periods and the shortest oviposition period ( = 13.7 days). The Bieri model was used to describe age‐specific fecundity for the three species of coccinellids. The intrinsic rate of increase (rm), net reproductive rate (R0) and mean generation time (T) were higher for H. variegata (rm = 0.114, R0 = 52.75, T = 41.88 days) than for H. axyridis (rm = 0.089, R0 = 26.27, T = 38.81 days) or A. bipunctata (rm = 0.081, R0 = 18.49, T = 40.06 days). Our findings show that the biological traits of H. axyridis do not seem to be factors that may contribute to the invasiveness of this coccinellid.

Overwintering, phenology and fecundity of Harmonia axyridis in comparison with native coccinellid species in Italy

Classical biological control is generallyunderstood as an environmentally safe practiceof insect pest management. However, questionshave been raised about possible negativeeffects for native species. As part of a riskassessment study a semi-field trial was carriedout in northern Italy in order to compare theoverwintering of the native species Propylea quatuordecimpunctata (L.) and Adalia bipunctata (L.) (Coleoptera:Coccinellidae) with the exotic Harmoniaaxyridis (Pallas) (Coleoptera: Coccinellidae).All the experiments were carried out from April1998 to April 2001. Harmonia axyridis wasable to overwinter successfully in northernItaly. Fecundity, oviposition rate, longevityand rate of increase of overwintering femaleswere calculated and the phenology of the threespecies was studied. Harmonia axyridisoverwintering mortality (31.9%) was lower incomparison with mortality of native species(68.9% for P. quatuordecimpunctata and61.3% for A. bipunctata). As aconsequence, post-overwintering rate ofincrease of the exotic species was higher.Longevity of overwintered females was similaramong the species. Mean fecundity of H. axyridis (783.8 eggs per female) was slightlyhigher than A. bipunctata (720.2 eggs perfemale), and much higher than P. quatuordecimpunctata (193.7 eggs per female). H. axyridis and A. bipunctatacompleted four generations and P. quatuordecimpunctata three generations in a year. The results show that H. axyridisappears to posses a high potential for establishment in Italy.

Comparative Life History of Liriomyza trifolii and Liriomyza huidobrensis (Diptera: Agromyzidae) on Beans: Effect of Temperature on Development

Abstract The influence of four constant temperatures (15, 20, 25, and 30°C) on development time and survivorship of Liriomyza trifolii (Burgess) and Liriomyza huidobrensis (Blanchard) was studied in laboratory experiments. L. huidobrensis required more time for embryonic development at 25 and 30°C, and less time at 15°C, compared with L. trifolii; at 20°C there were no differences between the two species. Larval development time for L. huidobrensis was longer than for L. trifolii at 20, 25, and 30°C. At 15°C no differences were detected. Pupal development of L. huidobrensis was always faster at 15, 20, and 25°C than that of L. trifolii. Total preimaginal development time was quicker at 15 and 20°C in L. huidobrensis than in L. trifolii; at 25°C no significant differences were found. Highest survival of L. trifolii (68%) occurred at 20°C, while that of L. huidobrensis (61%) occurred at 15°C. At 30°C no adults of L. huidobrensis emerged. The estimated lower threshold temperatures for egg, larva, pupa and total development of L. huidobrensis ranged between 7.3 and 8.1°C, and they were always lower than L. trifolii thresholds, which ranged between 9.9 and 10.7°C. The Logan model was used to describe the relationship between development rate and temperature. The quantification of development times presented in this study, combined with fecundity under different temperatures, could be incorporated into a phenological model that will aid in predicting population charges of leafminers.

The Influence of Pine Volatile Compounds on the Olfactory Response by Neodiprion sertifer (Geoffroy) Females

Females of the pine sawfly Neodiprion sertifer (Hymenoptera Diprionidae) usually avoid Pinus pinea trees as host plants. In contrast, this sawfly species is highly attracted by P. sylvestris and P. nigra trees. Here, we investigated which pine volatiles might mediate this behavior by in situ sampling experiments and olfactometer laboratory tests. Volatiles emitted from P. pinea, P. sylvestris, and P. nigra foliage were sampled by solid-phase microextraction (SPME). Analysis of these volatiles by coupled gaschromatography/mass spectrometry revealed that the relative amounts of the compounds emitted by the three species were significantly different. A discriminant analysis showed that the amounts of limonene and myrcene significantly contributed to the species-specific volatile patterns. Pinus pinea emitted higher relative amounts of limonene than the other pine species. Pinus sylvestris emitted the highest relative amounts of myrcene. When testing the response of N. sertifer females to these pine terpenoids in an olfactometer bioassay, a low amount of limonene was attractive, while a repellent effect was evident when higher amounts were used. The sawfly females showed no significant olfactory response to myrcene. These data suggest that low relative amounts of limonene have a significant function in attracting N. sertifer females, while high amounts might contribute to avoidance of a tree.

Toward the Creation of Urban Foodscapes: Case Studies of Successful Urban Agriculture Projects for Income Generation, Food Security, and Social Cohesion

Urban agriculture (UA) is a strategic means of achieving sustainable urban food security now and into the future. While a number of different models of agriculture will be required to provide food for the concentrated number of people in urban spaces, UA can be key tool in helping urban residents meet micronutrient requirements, whose deficiency is now recognized as the most important cause of “hidden hunger” globally. UA, or the cultivation of crops for food in small and irregular spaces within a city and its periphery, has been practiced for as long as cities have existed. However, it is gaining increased attention for both its limited scale, its effects on nutrition and community building, the associated possibilities for employment and social mobility, its relevance in a vibrant and diverse food system and for all of these reasons, its sustainability. UA projects are springing up in cities all over the world, always engaging the collaboration of multiple urban stakeholders and increasingly with a focus on the most vulnerable people in society: the poor, the elderly, children, and those suffering malnutrition and chronic disease. For all city dwellers, UA improves livelihoods within the city environment by reducing city ecological footprint, strengthening city resilience to climate change and environmental hazards, reducing noise, improving air quality and the city microclimate, minimizing drought by improving storm water management, and contributing to solid waste management. It increases human health and well-being through stress recovery, encouragement of exercise, reduction of urban violence, facilitating social contact, and providing sources of added employment and income. Using the concept of urban political ecology as a foundation for understanding food dynamics, this chapter will describe a range of different UA initiatives across the globe, giving special attention to their multifunctionality in the context of social vulnerabilities within urban spaces. In so doing, it will present UA as an important platform for community engagement and sustainability building toward increased food security. Turning concrete into green productive lands results in changes in physical, psychological, environmental, and community health. At the same time, the application of social leftovers (abandoned lands, unused rooftops, plastic and wood containers, etc.) onto productive means creates a new model for adding micronutrition to urban diets that integrates and takes seriously social, cultural, nutritional, and economic outcomes.

Sustainable Pest Management

This section addresses the application of an ecosystemic approach in pest control issues in rooftop agriculture. Biotope (e.g., physical and climatic characteristics), possible biocenosis (e.g., insect pests, plant diseases, beneficials) and related ecological relationships are described, altogether with their practical consequences.

HORTI LUMEN: TURNING ON THE LIGHT IN INTERIOR FARMING

Home gardening in cities is expanding as a way for reducing food costs and the environmental impact of the urban food supply. In metropolitan spaces, plant life is mainly constrained by land availability and access to light. Soilless gardens may allow cultivation in courtyards and rooftops, but often farming turns out to be unfeasible due to lacking light availability. Horti lumen are professional LED systems for intensive vegetable cultivations. Their technology is based on the selection of frequency light range detectable by plants and the removal of surplus light. Due to their flexible vertical and horizontal structure they can be used in domestic spaces such as, for instance, kitchens, cabinets, basements or in work spaces, offices, etc. Their adjustable structure allows the light source height to be modulated following the whole vegetation cycle, and adapting them to variable growing surfaces. In the present paper, experimental results of Horti lumen vs. traditional cool-light neon lamps on lettuce (Lactuca sativa L.) cultivation will be described, including energetic consumptions, as well as crop performances and plant physiological response.