Fast trap jaws and giant neurons in the ant odontomachus

Ants of the ponerine genus Odontomachus use a trap jaw mechanism when hunting fast prey. When particular trigger hairs, located on the inner edge of the mandibles, are touched by prey, the jaws close extremely rapidly and trap the target. This trap jaw response lasts only 0.33 to 1 millisecond. Electrophysiological recordings demonstrated that the trigger hairs function as mechanoreceptors. Associated with each trigger hair are large sensory cells, the sensory axons of which measure 15 to 20 micrometers in diameter. These are among the largest sensory neurons, and their size implies that these axons conduct information very rapidly.     

Veterinary experiences as a Japanese prisoner of war and ex-POW along the Burma railroad from 1942 to January 1946

Summary As a prisoner of war the writer was working for nearly three years in different POW camps, and outside them, along the Burma railway from Thanbyuyzat in southern Burma up to Kanchanabury in Thailand. In the army of the Netherlands-Indian archipelago (KNIL) he had the military rank of reserve horse-doctor. In civilian life he was attached to the Veterinary Institute in Buitenzorg (now Bogor) as a veterinary bacteriologist. His task as a POW became that of meathygienist and supervisor of the living animals in the camps. In this function he diagnosed swine fever in growing pigs which had mainly been fed on the offal of the Japanese kitchen. The acute course and the pathological alterations observed during the post-mortem examinations were identical with those of the Southern-African type of the disease. In slaughter cattle the author diagnosed some cases of lung tuberculosis, one of anthrax, several of rinderpest, some of rhinal granulomatosis and one of foot and mouth disease. In chickens he found NCD (pseudo-fowlpest) and in ducklings a mortal disease which the author then called 'keeling disease' but which he many years later, recognized as virus hepatitis. As assistant bacteriologist and ex-POW he joined the British regimental hospital in Bangkok. Here he had the opportunity to assist the bacteriologist pathologist, Maj. C. R. Peck IMS / IAMC in diagnosing the first case of melioidosis in an ex-POW of the KNIL who died from the sub-acute infection, notwithstanding treatment in the hospital with sulfa-drugs and penicillin.     

Induction of acquired cellular resistance in mice with viable and macrophage-processed Listeria monocytogenes

Intracutaneous immunization of mice with 10(5) or 10(6) viable listeria resulted in acquired cellular resistance (ACR) of short duration (7 days). The period during which viable Listeria monocytogenes had to be present in order to induce ACR was estimated by killing the listeria at different times after immunization by injecting the bactericidal antibiotic amoxycillin. The killing of listeria within 6 h after injection prevented the induction of A CR completely, between 6 and 12 h partially, while survival of listeria within animals for at least 18 h was required for the induction of complete protection. To determine whether multiplication of viable listeria was a prerequisite for the induction of ACR, the bacteriostatic antibiotic minocycline was injected for four days after immunization. Induction of ACR was only possible if the dose of viable listeria was large enough to permit a proportion of the listeria to escape bacteriostasis. Interaction of peritoneal macrophages of normal mice and viable listeria yielded a supernatant which induced specific ACR in normal recipient mice. No ACR could be induced with supernatant obtained from normal macrophages after digestion of killed listeria. A reduced level of ACR was obtained with supernatant collected after interaction of macrophages from immune mice and viable listeria. The immunogenic material present in the supernatant of normal macrophages after interaction with viable listeria is thermolabile, has a molecular weight of over 300,000, and is not affected by treatment with DNase, RNase, or trypsin.     

Salmonella isolated from feeds and feed ingredients during the period 1982-1988: animal and public health implications

The prevalence of Salmonella in southern Africa in farm feeds and by-products of animal origin during 1982-1988 was determined. Salmonella occurred in 5.18% of the farm feed samples and in 9.54% of the by-product samples. Different serovars were isolated, some only once. The findings underestimate the true prevalence of Salmonella in farm feeds and by-products, and is representative of only the most severely contaminated products. The epidemiology of salmonellosis is discussed with special reference to the importance of multiple resistance to antibiotics, the increase in the number of cases of salmonellosis worldwide and "Salmonella free" feeds and foods. More detailed research on the role of farm feeds in the epidemiology of salmonellosis is required. Efforts should be made to increase awareness of the problem, to improve quality management at farm feed production plants and to develop efficient systems to monitor the hygienic safety of feeds and foods.     

The effect of Prussian blue and sodium-ethylenediaminetetraacetic acid on the faecal and urinary elimination of thallium by the dog.

After oral administration of sublethal doses of thallium (lower than 10 mg/kg) to dogs, 75.5 +/- 3.9 per cent of the dose was eliminated from the body--47 per cent faecal and 28 per cent urinary. Cumulative excretion reached 50 and 70 per cent after 10 and 25 days respectively, and was almost complete after 75 days. This was slightly lower at higher doses. The total body-burden of thallium, calculated from the cumulative excretion, decreased exponentially for at least the first 40 days with a half-time (T 1/2) of 6.5 days. Oral doses of Prussian blue after 10 days resulted in an acceleration of the thallium elimination from the body (T 1/2 2.5 days), an increase of the faecal (49 per cent) and a decrease of the urinary excretion (18 per cent). Nevertheless, the cumulative faecal and urinary thallium excretion was not influenced. Minor transitory influences of Prussian blue on the faecal thallium excretion could be observed up to day 26. After 40 days, Prussian blue could no longer influence the faecal thallium excretion. At no time did sodium-ethylenediaminetetraacetic (Na2EDTA) acid significantly change faecal or urinary thallium excretion.     

Effects of chlordimeform on mitochondria from eggs of Spodoptera littoralis

Mitochondria were isolated from eggs of Spodoptera littoralis. With succinate (+pyruvate) as substrate, respiratory control ratios between 1.70 and 2.54 were obtained. Uncouplers and the energy transfer inhibitor oligomycin influenced these mitochondria in the well-known manner. The uncoupling activity of chlordimeform in vitro was very weak and decreased with increasing age of the eggs. Electron transport in mitochondria from chlordimeform-treated eggs was not uncoupled. Therefore, it is concluded that the ovicidal effect of this pesticide is not due to its uncoupling effect.     

A leaf spot disease of Nymphaea alba in the Netherlands

A destructive leaf spot disease was found onNymphaea alba in the lakes near Kortenhoef, Netherlands. After comparison of fresh material and herbarium specimens the causal agent is namedColletotrichum nymphaeae (Pass.) van der Aa, comb. nov. Synonymy, morphology and cultural characters of the fungus are described and discussed. Some remarks on the relationship with several host plants are given and the provisional conclusion is that the species is a widespread parasite, but that the destructive attack in the Kortenhoef region is probably caused by a combination of various factors.     

Tentative description of Hippeastrum latent virus in Hippeastrum hybridum plants and differentiation from Hippeastrum mosaic virus

In mosaic-diseased plants ofHippeastrum hybridum two viruses were found. One virus with a normal length of 706 nm caused local lesions onHyoscyamus niger test plants and mosaic symptoms in the leaves ofH. hybridum. This virus was identified with theHippeastrum mosaic virus (HMV) (*/*∶*/*∶E/E∶S/*) and had a dilution end point between 10^?3 and 10^?4, a thermal inactivation point between 55–60°C and a longevity at room temperature of 28–32 hours. The second virus had a normal length between 584 and 611 nm depending on the method used. It caused local lesions onGomphrena globosa andChenopodium quinoa leaves, and after inoculation ofH. hybridum was found to be present without showing symptoms. It was readily purified from inoculated leaf tissue ofC. quinoa andNicotiana clevelandii by differential centrifugation and ofH. hybridum by density-gradient centrifugation. Purified virus had an absorption minimum at 242 nm, a maximum at 262 nm and a 260/280 absorption ratio of 1.19. The dilution end point was between 10^?3 and 10^?4, the thermal inactivation point between 70 and 80°C and the longevity in vitro at room temperature 28–32 hours. Although no direct comparisons have been made with other members of the potexvirus group, the virus seems to be a new one now namedHippeastrum latent virus. Both viruses were not seed-borne.     

Biological features and life table parameters of the mealy plum aphidHyalopterus pruni on different apricot cultivars

Development, survival, reproduction rate, and population growth parameters of the mealy plum aphidHyalopterus pruni (Geoffroy) (Hom.: Aphididae) were evaluated on four different apricot cultivars (Tyrinte, Sakıt, Colomer, and Bebeco) under field conditions in the Van region of Turkey. Experiments were carried out on exterior leaves of trees, 1.5–2 m above the ground. Plexiglas clip-cells (25×6 mm) with the upper side covered by muslin were used in the experiments. The mealy plum aphid performed better on Tyrinte than on the other cultivars tested. The fastest development time (first instar to adult; 9.4 days), highest daily reproduction rate (2.6 offspring/aphid/day), and highest total fecundity (48.1 offspring/aphid) were obtained on Tyrinte. The intrinsic rate of increase — a good indicator of the growth potential of a population — of individuals fed on Tyrinte was significantly greater than that of individuals fed on cvs. Colomer and Bebeco. While mean generation times (T _o ) of populations on different cultivars were close to each other, the net reproductive rate was the highest (29.45 offspring/aphid/generation) on Tyrinte and the population doubling time on Tyrinte was 18.7%, 25.2% and 26.3% faster than those of individuals on other cultivars tested. The results obtained in this study indicated that Tyrinte appeared to be the most susceptible to the mealy plum aphid among the cultivars tested. http://www.phytoparasitica.org. posting Nov. 23, 2004.     

Kohlfliegenauftreten im Raps

A new pest in oilseed rape the cabbage root fly (Delia radicum L.) has succeded to establish – at least regional –during the recent years. It is not easy to monitor the cabbage root fly. Although the usual yellow water trap works quite well, it is still difficult for the farmers to determine Delia radicum exactly. The amount of infestation can be assessed best in the middle of November by analysing the damages of the roots. In this article a classification scheme is proposed. It is also difficult to control this pest. While applications of Pyrethroids against the imagines and the use of Dimethoat against the larva mostly showed only little effect in the tests, some new dressing-substances proved better against the standard “Chinook” (Imidacloprid+beta-Cyfluthrin). To forward this research and to clarify factors, which influence the infestation, a project titled “Possibilities of defence and control of cabbage root fly in winter oilseed rape” has been started in November 2003. Eight crop-protection services at German Federal State level and the BBA are involved in this project, which is supported by UFOP.