Vorratsschutz im Ökologischen Landbau: Entscheidungshilfe durch das Computerprogramm VOEL 1.0

VOEL 1.0 is a decision-support software for the protection of organic stored-products that was developed for store-keepers, farmers and pest control specialists in Ger-many. Most of the information given applies to all Central European countries, except for some legislative aspects concerning registration, which are specific for Germany. The program contains a decision-support module for monitoring and control of stored product pest, an encyclopedia on pests and beneficial organisms, a key for the deter-mination of these organisms, information on registered products for stored product protection in Germany, a data bank where literature concerning associations of pests and beneficials can be retrieved, a list of references on stored product protection in general and several original papers on stored-product protection

Seal whiskers vibrate over broad frequencies during hydrodynamic tracking

© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Scientific Reports 7 (2017): 8350, doi:10.1038/s41598-017-07676-w.Although it is known that seals can use their whiskers (vibrissae) to extract relevant information from complex underwater flow fields, the underlying functioning of the system and the signals received by the sensors are poorly understood. Here we show that the vibrations of seal whiskers may provide information about hydrodynamic events and enable the sophisticated wake-tracking abilities of these animals. We developed a miniature accelerometer tag to study seal whisker movement in situ. We tested the ability of the tag to measure vibration in excised whiskers in a flume in response to laminar flow and disturbed flow. We then trained a seal to wear the tag and follow an underwater hydrodynamic trail to measure the whisker signals available to the seal. The results showed that whiskers vibrated at frequencies of 100–300 Hz, with a dynamic response. These measurements are the first to capture the incoming signals received by the vibrissae of a live seal and show that there are prominent signals at frequencies where the seal tactogram shows good sensitivity. Tapping into the mechanoreceptive interface between the animal and the environment may help to decipher the functional basis of this extraordinary hydrodynamic detection ability.Funding was provided by the NSF GRFP and NISE section 219 to C. Murphy and by the Office of Naval Research (N000141910468) to B. Calhoun

Field trials with the diatomaceous earth SilicoSec® for treatment of empty rooms and bulk grain

Diatomaceous earths (DE) are fossil diatoms (phytoplankton) that contain silicon dioxide (SiO2), the particles absorb the waterproof lipids from the arthropod cuticle resulting in death through desiccation. The DE SilicoSec® is registered in Germany. The field trials presented here were performed in order to determine (1) the efficacy of SilicoSec® under temperate Central European climatic conditions, (2) the distribution in empty rooms and (3) the possible effect of different surface materials. For empty room treatment, a 41 m² storage room was treated with 20 g/m², the total surface treated including walls was 145 m². At 19 sampling points the amount of DE on the floor was determined. Distinctly less DE attached to the walls compared to the floor, and an uneven distribution on the floor ranging from 2.6 to 49.5 g/m² with a mean±SD of 15.4±14 g/m² per sampling point was measured. Additionally, test pieces with 5 different surface types were placed in the treatment room prior to the treatment. Adult Tribolium confusum and Cryptolestes ferrugineus were placed on all surfaces at 15 to 19°C and 65-81% r.h.. Mean corrected mortality after 14 d in T. confusum and C. ferrugineus was 94% and 65%, respectively. No significantly different mortality was recorded for T. confusum depending on surface type, but in C. ferrugineus significantly less beetles (20%) died on concrete flagstone compared to natural flagstone, glazed ceramic flagging, plywood and porcelain stoneware. For bulk grain, 10 t of wheat were treated with either 0.7 kg/t or 2 kg/t DE. Sitophilus granarius, Oryzaephilus surinamensis and C. ferrugineus adults were placed in vials with treated wheat together with data loggers and placed deep within the bulk for 19 d. Corrected mortality was around 90% for all treatments except for S. granarius at the lower dose where 60% mortality was achieved only. Keywords: Diatomaceous earth, Efficiency, Cryptolestes ferrugineus, Sitophilus granarius, Oryzaephilus surinamensi

Penetration ability of Holepyris sylvanidis into the feeding substrate of its host Tribolium confusum

The bethylid wasp Holepyris sylvanidis (Brèthes, 1913) is an antagonist of the confused flour beetle Tribolium confusum Jacquelin du Val 1868, a severe pest in the food processing industry and in grain products, primarily in flour mills and bakeries. Females of the larval ectoparasitoid H. sylvanidis have to detect hosts that feed in different depths inside stored products like flour or grist. This study addresses the questions (1) whether successful host finding by H. sylvanidis is dependent on the location of Tribolium larvae in the substrate and (2) whether the type of substrate affects host finding. In laboratory experiments, T. confusum larvae in a Petri dish accessible to the wasps were placed 1, 2, 4 or 8 cm deep in either fine or coarse ground wholemeal grist of wheat (main particle size: < 0.2 mm or 1.4 – 3 mm) in fifteen replicates per substrate and depth. Parasitoids were released onto the surface of the substrate. Tribolium confusum larvae were not able to  leave the Petri dish, however they could be pulled outside into the grist by H. sylvanidis. Within the behavioural sequence of parasitisation, pulling away of host larvae is the typical behaviour preceding oviposition. In order to determine host finding success by the parasitoid, the number of missing host larvae was assessed 2 wks after release of the wasps. In fine grist larvae were attacked down to 4 cm depth; however, larvae placed deeper (8 cm) were not found anymore. In contrast, host larvae in coarse grist were still detected at 8 cm depth. The results suggest that host finding by H. sylvanidis is hindered by decrease in particle size of the substrate. Nevertheless, H. sylvanidis may be considered a promising candidate for biological control of T. confusum larvae feeding in coarse grist and in thin layers of fine grist. Keywords: Holepyris sylvanidis, Tribolium confusum, Biological control, Penetration ability, Host findin

Efficacy of propionic acid against the granary weevil Sitophilus granarius (L.)

Propionic acid is used to preserve feed grain, especially against fungal attack, and is known to affect stored product insects as well. In the study presented here, the effect of wheat treated with different amounts of pure propionic acid on both adult Sitophilus granarius and its progeny was investigated. Propionic acid (99.5% purity) was added to samples of 150 g of wheat at the doses of 0.5, 0.7 and 1% by weight. Subsequently, 100 adult S. granarius were released into each vial with treated wheat. Each trial was repeated three times. The untreated controls received water instead of propionic acid. Dead weevils were counted after 7 and 14 days. Insects surviving 7 days were placed back into the vials, all adults were removed after 14 days. During the period of 8 and 11 weeks after start of the experiment, the number of progeny was counted weekly. In the trials with 0.5%, 0.7% and 1% by weight, after 14 days 73.7, 37.3 and 3.7% of the adults were alive, respectively. While the mean number of progeny was 1549 in the untreated control, 1.3 and 0.3 progeny on average emerged from the grain treated with 0.5% and 0.7% propionic acid, respectively. No progeny survived in the treatment with 1% by weight. Even though complete control of adult S. granarius could not be achieved with the tested conditions, under practical situations of storage of feed grain, the described application of propionic acid will effectively suppress the mass-development of S. granarius. Keywords: Granary weevil, Sitophilus granarius, Propionic acid, Control, Feed storag

Efficacy of diatomaceous earth and botanical powders against the maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) on maize

The effectiveness of the diatomaceous earth SilicoSec, neem seed powder and Plectranthus glandulosus leaf powder, applied at four different rates with four exposure intervals (1, 3, 7 and 14 d) for the control of maize weevil, Sitophilus zeamais Motschulsky, on maize in the laboratory was determined. Treatment with SilicoSec was the most effective followed by neem seed powder and P. glandulosus powder. The highest tested content (2 g/kg) of SilicoSec caused 81.1% and 100% mortality of S. zeamais within 3 and 14 days of exposure, respectively. The application of the highest content (40 g/kg) for neem seed powder and P. glandulosus powder resulted in 86.8% and 59.5% mortality, respectively 14 days after exposure. Seven-day LC50-values were 0.56 g/kg for SilicoSec, 19.7 g/kg for neem seed powder and 45.24 g/kg for P. glandulosus powder. The treatments reduced progeny emergence, percentage of grain damage, percentage of weight loss and percentage of germination loss, although P. glandulosus powder was less active for these parameters. Results suggest that SilicoSec can be considered as a potential component of an integrated pest management strategy against the maize weevil. However, in the poor tropical countries were the plant powders are widely available and food production dominated by subsistence agriculture, neem seed powder and P. glandulosus powder could be adopted also for the protection of stored maize against the infestation of S. zeamais. Keywords: Diatomaceous earth, Botanical powders, Maize, Integrated weevil management, Sitophilus zeamai

Comparative toxicity of four local botanical powders to Sitophilus zeamais and influence of drying regime and particle size on insecticidal efficacy

The toxicity of Azadirachta indica seed powder and leaf powders from Plectranthus glandulosus, Steganotaenia araliacea and Annona senegalensis to adult Sitophilus zeamais was determined in the laboratory. The influence of drying regime and particle size on the insecticidal efficacy of P. glandulosus and S. araliacea powders was also assessed. The seeds and leaves were either dried under shade or sunlight, pulverized until the particles passed through a 1 mm or 0.2 mm mesh-sieve. Maize grains were admixed with the powders at the rates0, 5, 10, 20 and 40 g/kg for the assessment of mortality over a 14-d or 30-d period, as well as for population increase and damage. Within 14-d exposure, P. glandulosus powder caused the highest weevil mortality followed by A. indica. A. indica powder was by far more effective in reducing grain damage and population increase compared with all the other powders during three-month storage period. Powders from the leaves dried under shade compared with those dried under sunlight and the smaller compared with the larger particle size, caused higher weevil mortality. Neem seed powder and powdered leaves of P. glandulosus have a great potential in the protection of maize against S. zeamais infestation in subsistence storage systems.Keywords: Plant products, storage pest, maize, infestation, Cameroon

Vocal tract dynamics shape the formant structure of conditioned vocalizations in a harbor seal

Formants, or resonance frequencies of the upper vocal tract, are an essential part of acoustic communication. Articulatory gestures—such as jaw, tongue, lip, and soft palate movements—shape formant structure in human vocalizations, but little is known about how nonhuman mammals use those gestures to modify formant frequencies. Here, we report a case study with an adult male harbor seal trained to produce an arbitrary vocalization composed of multiple repetitions of the sound wa. We analyzed jaw movements frame-by-frame and matched them to the tracked formant modulation in the corresponding vocalizations. We found that the jaw opening angle was strongly correlated with the first (F1) and, to a lesser degree, with the second formant (F2). F2 variation was better explained by the jaw angle opening when the seal was lying on his back rather than on the belly, which might derive from soft tissue displacement due to gravity. These results show that harbor seals share some common articulatory traits with humans, where the F1 depends more on the jaw position than F2. We propose further in vivo investigations of seals to further test the role of the tongue on formant modulation in mammalian sound production