IEA joint trials: New lessons from old plantations

Two international trials of potential biomass species families and clones planted in 1985 have been analyzed to determine changing patterns in growth, diseases, and insects. In the Swedish trial, with close spacing and short rotations, Salix viminalis clones gave the best average yield of 17.4 Mg/Ha/yr on the first coppice rotation. In the Minnesota, USA trial, with wider spacings and a longer rotation Populus alba hybrid clones gave the best average yields of 5.5 Mg/Ha/yr. The most important disease and insect problems encountered were Septoria musiva stem cankers on some Populus clones; frost die back in some Salix clones; and the leaf blotch miner, Fenusa dohrnii, on most Alnus families. Recommendations for future international cooperation in field trials are presented.     

Odor Detection in Insects: Volatile Codes

Insect olfactory systems present models to study interactions between animal genomes and the environment. They have evolved for fast processing of specific odorant blends and for general chemical monitoring. Here, we review molecular and physiological mechanisms in the context of the ecology of chemical signals. Different classes of olfactory receptor neurons (ORNs) detect volatile chemicals with various degrees of specialization. Their sensitivities are determined by an insect-specific family of receptor genes along with other accessory proteins. Whereas moth pheromones are detected by highly specialized neurons, many insects share sensitivities to chemical signals from microbial processes and plant secondary metabolism. We promote a more integrated research approach that links molecular physiology of receptor neurons to the ecology of odorants.     

利用方向投影算法计算仓储害虫图像倾斜角度

针对无明显的直线特征的仓储害虫图像,提出了一种基于整数Bresenham算法求方向投影值,利用方向投影值检测图像的倾斜角度的方法。实验结果表明,该算法能快速准确地测量出仓储害虫图像的倾斜角度,并具有很强的抗干扰性和应用适应性。     

Insect and mite control by manipulating temperature and moisture before and during chemical-free storage

Insect and mite control by sufficient drying and cooling of commodities would satisfy growing market desire for pesticide-free storage and help control increased insect resistance, particularly to phosphine. The response of insects and mites to such conditions, as opposed to those specifically targeted for disinfestation, is reviewed. The responses to temperatures at various humidities within the range 9–55 °C are examined which include those that induce individual mortality, those at the threshold for population growth, and those where rates of growth are slow. Drying is examined mainly in terms of an enhancement to the detrimental effects of temperature. A 10 °C range in minimum threshold temperature for population growth was found among the insect and mite species examined. A substantial level of protection was seen at temperatures just above these thresholds. At conditions roughly 6 °C below the threshold for population growth, >99% mortality of major coleopteran species is possible after 9 months at 45% r.h. Insect mortality at moderately elevated grain temperatures (35–55 °C) is examined as an opportunity to disinfest grain during drying. Several coleopteran and psocopteran species were found to suffer at least 99% mortality at 50 °C after 2.5 h. The extent of variation among species is discussed in terms of targeting particular susceptibilities to moderately low or high temperatures at low humidities as an alternative to chemical treatments.     

Disinfestation of stored wheat grain and flour using gamma rays and microwave heating

Samples of wheat grain and flour (20 gm of each) were infested with 20 larvae or 5 pairs of adult insects of Tribolium confusum, Lasioderma serricorne, Corcyra cephalonica or Rhyzopertha dominica. The infested samples were tested as follows : (1) microwave heating at four temperature levels 40, 45,50 and 55 °C, for exposure times from10 to 50 s; (2) gamma irradiation over the dose range of 0.5-4 KGy; (3) gamma irradiation + microwave heating. Complete kill of all stages tested was achieved at 50 °C with an exposure time of 50 s. A dose of 2 KGy induced 100% mortality of R. dominica after three days, but it took up to 7 days for all T. confusum and L. serricorne adults to die after a 4-KGy exposure. All insects died within 24 h when exposed to the combination of 1KGy + 50 °C for 30 s.Biochemical analyses on the samples of wheat grain and flour subjected to those treatments at which high mortality was obtained generally showed no detectable changes in the quality of protein, fat, fiber, carbohydrates or ash. The germination of wheat grain was lowered after treatment with microwave radiation but was not affected by a dose of 1 KGy gamma radiation.     

Phosphine resistance in stored-product insects collected from various grain storage facilities in Morocco

Despite heavy dependence on phosphine (PH₃) for fumigating stored products, the resistance status of insect pests in Morocco has never undergone a thorough investigation. Some control failures with PH₃ were reported in Morocco, and a previous study showed two field populations of Sitophilus oryzae to be highly resistant to phosphine.We surveyed phosphine resistance in field populations of three major insect pests of stored wheat in Morocco. Around 32% of the samples collected at different storage facilities were found to be infested with one or more species of stored-product beetles. First-generation adult beetles, cultured from the field samples, were subjected to a discriminating dose test for phosphine resistance using an FAO method. The results indicated that, with the exception of one population of S. oryzae, all samples tested contained phosphine-resistant individuals. Treatments at up to 1.8 g m⁻³ of phosphine for 20 h, or at 0.18 g m⁻³ for up to 5 days, indicated that a high degree of resistance was already selected in some of the insect populations.Tests using [³²P]-radiolabelled phosphine showed that the mechanism of resistance in the three insect species tested involved a reduced uptake of the fumigant. The study has highlighted an urgent need for reviewing current fumigation practices in Morocco to ensure effective use of phosphine and avoid further selection of resistance.     

The meat of affliction: Insects and the future of food as seen in Expo 2015

BackgroundInsects are touted as a “food of the future” due to their lower environmental footprint relative to traditional livestock, raising interest in entomophagy as a sustainable diet. As such, they appeared at future-food themed Universal Exposition 2015 in Milan, Italy, in which 145 countries presented their nations’ food culture and contributions to innovative food science and technology.Scope and approachThe presence and absence of entomophagy in all the national and themed pavilions of Expo 2015 and the way developing and developed nations differed in their presentation of insects were analyzed as a microcosm of global attitudes to insects as food and the barriers towards its wider adoption.Key findings and conclusionsOnly Belgium and the Netherlands presented insects in their vision for the future, and only Angola as traditional cuisine. Nations noted for active entomophagy today such as Mexico and Thailand did not mention insects at all. Efforts to serve insects faced obstacles in Italian import restrictions, which changed by the event's end. Expo 2015 illustrates challenges in promoting global entomophagy, including the need for improved rearing methods, the risks of associating insects with starvation scenarios, and the preference of Westerners for processed insects over whole.     

The economic effects of Rhyzopertha dominica on rice quality: Objective and subjective measures

Infestations of internal feeders such as Rhyzopertha dominica cause damage to stored grains, including rice. Few studies, though, have measured the economic effects of that damage. In this study, samples of rough long grain rice were infested with R. dominica at several rates (0, 20, and 200 adults/kg). The effects of these infestations on rice quality and quantity were measured objectively using color and milling yield. They were also measured subjectively with a blind taste/sensory consumer taste test and a non-hypothetical auction measuring consumer willingness to pay for the different qualities of rice.The objective quantity and value loss ranged from 2% for lightly-infested rice to 3.5% for heavily-infested rice. For subjective effects, results of the auction suggested that participants on average were willing to pay only a small premium for less infested rice. This test confirmed results of the sensory taste panel, which showed that participants on average detected very little difference among rice samples with alternative levels of infestation. However, when they were given extra information verifying that rice with lower infestation levels was higher quality or that the rice was stored using IPM methods, the potential price increase from reducing R. dominica infestation could range from $0.44/kg. to $0.79/kg., plus a $0.13/kg. premium for using IPM storage methods. However, results suggest that in order to capture that value rice sellers must be able to convey information about quality and storage attributes to consumers in a way that is relevant and trustworthy.     

Ozone application in a modified screw conveyor to treat grain for insect pests, fungal contaminants, and mycotoxins

Recent efforts have focused on improving the application of ozone technology as a pest management tool for stored grain. This study evaluated the efficacy of a modified screw conveyor to treat grain with ozone in a continuous-flow system. The ozone concentration delivered into the screw conveyor was 47,800 ppm and the average retention time for a corn kernel moving through the system was 1.8 min. Under these conditions, 100% mortality of adult red flour beetle (Tribolium castaneum (Herbst)) and adult maize weevil (Sitophilus zeamais (Motsch.)) was achieved after three passes through the screw conveyor, which equated to a concentration × time (CT) product value of 258,120 ppm-min. The potential effectiveness of the continuous treatment to reduce mold on the surface of corn kernels was also explored. Aspergillus flavus counts were reduced by 96% in a single pass through the screw conveyor. Three passes through the screw conveyor reduced the mold count by more than 2-log units. Ozone treatment also reduced aflatoxin applied to the grain; however, the reduction was not sufficient enough to be of commercial value. The results of this study provide valuable information for estimating the parameters needed for effectively treating grain in a commercial scale continuous-flow treatment system.