Toxicity of Alpholate to Cattle

Although Apholate is used as a sexual sterilant of both sexes of houseflies (Musca domestica L.) it can not be used for ;systemic' chemosterilization of the prehypodermic larvae of the warble flies Hypoderma bovis (L.) and H. lineatum (De Vill.) because of its high toxicity to 4- to 5-month-old calves. An intramuscular dose of 2.5 mg./Kg. killed the calves in 5 to 7 days. The pathognomonic clinical signs were impaction of the rumen, anorexia, depression, and general weakness. The hematopoietic system was affected. There was marked leukocytopenia characterized by lymphocytopenia within 24 hours of Apholate injections.     

Uptake of bovine IgG by first instars of the common cattle grub, Hypoderma lineatum

The midgut of first instar Hypoderma lineatum (De Vill.) (Diptera: Oestridae) was examined for the presence of bovine immunoglobulin using immuno-gold staining in conjunction with image analysis. Newly hatched larvae, unexposed to fluids or tissues of the host, showed little or no deposit of colloidal gold particles. Midgut lumen, microvillar border, epithelial cell bodies and basement membrane of first instars, 6-7 months of age, recovered from the host oesophagus, all showed colloidal gold staining. This indicates that immuno-reactive portions of bovine immunoglobulin survive exposure to extracorporeal larval enzymes, as well as transit of the midgut, and pass through epithelial cells to enter the larval haemocoel.     

Immunization and Parenteral Chemotherapy for the Control of Cattle Grubs Hypoderma Lineatum

Immunization with two types of warble larvae antigens A and B, the latter treated with tannic acid, and injections of dimethoate, an organic phosphate, were tried for the control of prehypodermic larvae of Hypoderma lineatum De Vill., and H. bovis L., in range calves. In test groups of 20 calves, given intramuscularly, antigen A had no effect, but combined treatment with antigens A and B reduced the number of H. bovis L., larvae by 81 per cent (P<.001), and proved as effective as dimethoate subcutaneously or intramuscularly. H. lineatum De Vill., did not respond to any treatment. Antigen B and dimethoate were free from harmful effects on the host, but antigen A caused anaphylaxis and irritation at the site of injection.     

Sequential homology of the collagenase from eucaryote Hypoderma lineatum with the proteinases of the trypsin family

The sequence of 32 N-terminal amino acid residues of the collagenase from the larvae Hypoderma lineatum of mol. weight 24000 is homologous with the sequences of pancreatic proteinases. This analysis confirms the hypothesis of similarity made on the basis of amino acid composition, physico-chemical properties and inhibition studies. It is proposed that within the trypsin-like family exists a group of eucaryote collagenases with digestive rather than morphogenic function which cleave specifically native collagen at $\text{3}\text{4}$ from its N-terminus.     

Use of a crude extract or purified antigen from first‐instar cattle grubs,Hypoderma lineatum,for the detection of anti‐Hypoderma antibodies in free‐ranging cervids from southern Spain

During the 2003–2005 hunting seasons, a total of 120 Cervidae, including 39 red deer (Cervus elaphus hispanicus) and 81 fallow deer (Dama dama), were examined for subcutaneous myiasis. Animals were shot from January to June in southern Spain. Specific antibodies against Hypodermatinae (Diptera: Oestridae) were detected by indirect enzyme‐linked immunosorbent assay (iELISA) using a crude larval extract (CLE) and a purified antigen [hypodermin C (HC)] obtained from first instars of Hypoderma lineatum (De Villers) (Diptera: Oestridae). Hypoderma actaeon Brauer was the only species detected in this study, which represents the first confirmation of this species in fallow deer from Spain. The overall prevalence of animals presenting subcutaneous larvae (14.2%) was considerably lower than the prevalences determined by iELISA with CLE (43.3%) and HC (40.0%). Red deer showed a higher prevalence of Hypoderma than fallow deer. The concordance between larval examination during the hunting season and iELISA using both antigens was low, whereas the concordance between the CLE and HC ELISAs was good. Larval antigens obtained from H. lineatum constitute a good tool for the diagnosis of H. actaeon in Cervidae, especially when the hunting season does not coincide with the maximum presence of larvae on the back.     

Wachstum und Sauerstoffverbrauch der Larven von Hypoderma bovis (De Geer) (Diptera,Hypodermatidae)

Zusammenfassung Eine Analyse der Wachstumsvorgänge der Larven von Hypoderma bovis ergab, daß diese am Ende des Wanderstadiums ca. 42% ihrer endgültigen Länge aber höchstens 10% ihres endgültigen Körpergewichts erreicht haben. Der Sauerstoffverbrauch der Beulenlarven nimmt, auf das Körpergewicht bezogen, im Laufe der Larvalentwicklung ab. Er beträgt bei einer 50 mg schweren Larve 800 mm³/mg·h, bei einem 1500 mg schweren Tier nur noch 100 mm³/mg·h. Mit dem Häutungsschritt von LII zu LIII ist eine vorübergehende sprunghafte Erhöhung des Sauerstoffverbrauchs verbunden. Das Verhältnis Sauerstoffverbrauch/Körpergewicht stimmt in den beiden untersuchten Larvenstadien nicht überein. Der Sauerstoffverbrauch der Tiere ist temperaturabhängig. Das Maximum liegt zwischen 32° und 37°C. Mit zunehmendem Alter verschiebt es sich gegen 32°C.

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Growth and oxygenium-consum of the larvae of Hyderma bovis (De Geer) (Diptera, Hypodermatidae)

Summary At the end of their migration larvae of Hypoderma bovis have reached about 42% of their final length, but only 10% of their final body-weight. Oxygenium-consum/mg body-weight decreased during the larval development: a larva of 50 mg weight needs 800 mm³/mg·h, one of 1500 mg weight only 100 mm³/mg·h. Third instar larvae have a much higher oxygenium-consum after moulting than second instar larvae have just before. The relation of oxygenium-consum/body-weight differs in the two larval stages. Respiration depends on the temperature, its maximum is between 32°C and 37°C. Young animals have a higher maximum than old ones.

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Durchgeführt mit Unterstützung der Deutschen Forschungsgemeinschaft im Rahmen einer Herrn Prof. Dr. W. Kloft gewährten Sachbeihilfe.     

Sitona weevils (Coleoptera: Curculionidae) as agents for rapid transfer of nitrogen from white clover (Trifolium repens L.) to perennial ryegrass (Lolium perenne L.)

The effects of root feeding by larvae of Sitona hispidulus (F.) (a common weevil pest of white clover) on the rate of transfer of nitrogen between plants of white clover (Trifolium repens L.) and perennial ryegrass (Lolium perenne L.) were investigated using a nutrient slant board technique. Clover plants, labelled with ¹⁵N were grown adjacent to ryegrass plants and were either infested with Sitona larvae or not infested. Ryegrass plants associated with the infested clover plants had a significantly higher dry matter yield and nitrogen content (75% and 74% respectively) than the uninvested plants, after 33 days exposure to insect herbivory. It was concluded that root feeding insects could play an important role in the cycling of nitrogen in grass/clover swards.     

Early detection of cattle grub (Hypoderma lineatum and H.bovis) (Diptera, Oestridae) using ELISA

An enzyme-linked immunosorbent assay (ELISA) to detect cattle grub-infested animals in the autumn in Alberta has been developed. Antibody to Hypoderma lineatum de Vill. was detectable as early as 6 weeks post-infestation in artificially infested steers. Peak antibody concentrations preceded the peak in maximum 'apparent' grub numbers which occurred between 37 and 43 weeks after infestation. Natural infestations with H. lineatum and H. bovis L., ranging from one to ninety-two grubs per calf, were readily detected by November and the incidence of false positives in uninfested calves was only 5%. Low level (1-4 grubs) infestations of H. bovis only became detectable in February with peak antibody concentrations occurring at the end of April. Prevalence of cattle grub infestations in southern Alberta was shown to be 37% during this study.     

Crystallization and preliminary X-ray diffraction data for the collagenase of Hypoderma lineatum larvae

Collagenase from the larvae of the arthropod Hypoderma lineatum has been crystallized. The crystals are tetragonal, space group I422, $\text{a = b = 112}\text{A}\text{?}\text{, c = 166}\text{A}\text{?}$, with two molecules in the asymmetric unit.     

Olfactory host location and learning in the granary weevil parasitoidLariophagus distinguendus (Hymenoptera: Pteromalidae)

The sources of volatiles that attract the parasitoid Lariophagus distinguendus(Först.) to its hosts, the larvae of the granary weevil Sitophilus granarius(L.) infesting grains of Triticum aestivumL., were investigated in bioassays. The influence of oviposition experience on the responsiveness of the parasitoids to the sources of volatiles was considered. The potential sources of attractants are the host larvae, their feces, and the grain infested by the host. Weevil larvae were not attractive. Feces were attractive to females without and females with oviposition experience. Infested grains from which the larvae and feces were removed were slightly attractive to inexperienced, but very attractive to experienced females. Healthy and artificially damaged grains were attractive to experienced parasitoids only. Refering to the “variable response model,” we discuss the effect of experience on the response of the parasitoids to the several stimuli. Stimuli from different trophic levels are used by the foraging parasitoids: feces of the host larvae is an important source of attractants, but also the grains, particularly after experience.     

The mitochondrial genome of the common cattle grub,Hypoderma lineatum

The mitochondrial DNA of the cattle grub Hypoderma lineatum (de Villers) (Diptera: Oestridae) was completely sequenced. The entire molecule was 16 354 bp long and presented a heavy bias towards A + T, which accounted for 77.8% of the whole genome. Hypoderma lineatum genes were organized in the same order and orientation as in the mitochondrial genomes available for other species belonging to the Oestroidea superfamily and compared in this study [Chrysomya putoria (Wiedemann), Cochliomyia hominivorax (Coquerel), Lucilia sericata (Meigen) and Dermatobia hominis (L.)], except for the occurrence of a 102‐bp non‐coding region partially present in other species. The complete sequence of H. lineatum will represent a useful dataset to evaluate the evolutionary pattern of mtDNA within Oestroidea by using molecular information in diagnostic, taxonomic and evolutionary studies.     

Citrus rootstock responses to herbivory by larvae of the sugarcane rootstock borer weevil (Diaprepes abbreviatus)

The responses of roots to feeding by larvae of a citrus root weevil (Diaprepes abbreviatus) were investigated in Citrus grandis (L.) Osb. x Poncirus trifoliata (2N) (L.) Raf.; C. grandis x P. trifoliata (4N); P. trifoliata x C. grandis (Flying Dragon x Nakon); C. paradisi Macf. x P. trifoliata (Swingle citrumelo); C. aurantifolia (Christm.) Swingle (Citrus macrophylla); C. reticulata Blanco (Cleopatra mandarin); C. sinensis (L.) Osb. x P. trifoliata (Carrizo citrange); C. aurantium (L.) (sour orange). Chitinase, chitosanase. β-1,3-glucanase, peroxidase and lysozyme activities were measured and significant differences were observed for some of the cultivars between infested and uninfested rootstocks. Generally, increased activities were observed for chitinases and decreased activities were observed for the other enzymes measured. Numerous significant differences in hydrolase and peroxidase activities were observed between cultivars. Immunological detection revealed that new protein bands occurred in root protein extracts for six of the eight cultivars infested with larvae when an antibody to a class I potato leaf chitinase was used. Antibodies generated against two citrus chitinases of M_r 24 000 (basic chitinase cv. Valencia (C. sinensis) callus, BCVC) and M_r 28 000 (basic chitinase/lysozyme cv. Valencia callus, BCLVC) indicated that chitinases in Carrizo were induced in infested roots when the BCVC antibody was employed. These findings justify calling these proteins pathogenesis-related proteins. The chitinase that BCLVC was prepared from exhibited high lysozyme activities, and the results of western blots showed the presence of proteins at M_r 24 000 and 27 000 which are presumed to be lysozymes. Similar tests using antibodies against β-1, 3-glucanases and peroxidases indicated a diminution of protein bands that cross-reacted with infested root protein extracts compared with what occurred in controls. All of the root extracts were tested against chitosans with various percentages of acetylation; activities were linearly dependent on the amount of chitosan acetylation; i.e. the larger the amount of acetylation, the greater the activity. Significant differences in hydrolase activities were observed between infested and uninfested roots for the rootstocks using the variously acetylated substrates. All of the root protein extracts were capable of degrading peritrophic membranes removed from larvae of D. abbreviatus. This suggests that citrus chitinases may play a role in disrupting the peritrophic membrane such that ingested substances that pose a hazard to the insect may penetrate the membrane more easily.     

Impacts of laurel wilt disease on redbay (Persea borbonia (L.) Spreng.) population structure and forest communities in the coastal plain of Georgia, USA

Laurel wilt disease (LWD), a fungal disease vectored by the non-native redbay ambrosia beetle (Xyleborus glabratus Eichhoff), has caused mortality of redbay (Persea borbonia (L.) Spreng.) in the coastal plain of Georgia since 2003. Despite its rapid spread, little research has evaluated its impacts on redbay population structure and forest communities. Diseased populations of redbay in five sites (2–4 years post infestation) were compared to healthy populations in three uninfested sites in five counties in Georgia. The results showed high redbay mortality, shifts in size structure, and changes in community composition. An average of 90 % of redbay trees ≥3 cm diameter at breast height (DBH) were dead in infested sites, compared to 0–35 % in control sites. Mortality was seen in individuals of the smallest stem diameter category (<1.00 cm diameter at ground height). DBH of live redbay trees in control sites was twice that of those in infested sites. Photosynthetically active radiation was 4.8 times greater at infested sites than control sites due to loss of redbay canopy. Community structure measurements showed redbay trees had the greatest mean importance value (IV) at control sites compared to the 8th mean IV at infested sites for live stems. Two species co-dominant to redbay, sweetbay (Magnolia virginiana L.) and loblolly bay (Gordonia lasianthus (L.) J. Ellis), were of higher importance at infested than control sites, suggesting they are increasing in dominance following the mortality of redbay. This study shows LWD has impacted redbay populations and altered associated forest communities in Georgia.     

Larval and adult seed consumption affected by the degree of food specialization in Amara (Coleoptera: Carabidae)

Many carabid beetles (Coleoptera: Carabidae) are known to feed on plant seeds, but the level of specialization on this food differs. This is the first study in which seed consumption is assessed for all larval instars and adults of ground beetles. Three species of Amara with syntopic occurrence, Amara aenea (DeGeer), Amara familiaris (Duftschmid) and Amara similata (Gyllenhal), were examined. Larvae of all three instars and adults were fed seeds of Stellaria media (L.) Vill., Capsella bursa‐pastoris (L.) Med. and Taraxacum officinale Wick. ex Wigg. in a laboratory no‐choice experiment. In general, larvae, particularly the first instar, showed greater differences in seed consumption than the adults, although the latter showed similar but less marked pattern. Amara aenea consumed all offered seed diets in all life stages. All three larval instars of granivorous A. familiaris almost exclusively fed on seeds of S. media and the adults also ate significantly more of this than other seeds. Amara similata consumed mostly seeds of C. bursa‐pastoris in the first instar and adult stages, whereas the larvae of the later instars seemed to be unspecialized on particular seed diet. Differences in seed‐specific consumption between larval instars in granivorous carabids are reported for the first time. The results provide further support for the parallel evolution of various degrees of granivory in the genus Amara, which may ultimately facilitate species coexistence. The daily seed consumption by the larvae was comparable or (in case of the third instar) even higher than that by the adults. Hence, we suggest that larvae may be the important consumers of seed in the field and should not be forgotten when seed predation is assessed.     

Host plant defenses of black (Solanum nigrum L.) and red nightshade (Solanum villosum Mill.) against specialist Solanaceae herbivore Leptinotarsa decemlineata (Say)

Black nightshade (Solanum nigrum, S. nigrum L.) and red nightshade ( Solanum villosum, S. villosum Mill.) are medicinal plants from the Solanaceae family that synthesize glycoalkaloids and other secondary metabolites. To recognize the potential insecticide activity of these compounds, leaf extracts (containing glycoalkaloid and methanol fractions) were tested for enzyme inhibition, antifeedant activity and toxicity. For in‐vitro glutathione S‐transferase (GST) inhibition activity, we used insecticide‐resistant Colorado potato beetle, Leptinotarsa decemlineata ( L. decemlineata; Say) midgut and fat‐body homogenate. In‐vivo toxicity and the antifeedant activity were performed using larval bioassays. The methanol extracts had greater GST inhibitory activity compared to the glycoalkaloids, as well as greater 2nd instar larvae mortality and antifeedant activity. Furthermore, the green leaf volatile compound, cis‐hex‐3‐enyl acetate, at the concentration of 5 ppm, caused 50% mortality of 2nd instar larvae. Our findings suggest the potential usefulness of S. nigrum and S. villosum extracts to control L. decemlineata.     

Induction of volatile emissions from ripening apple fruits infested with Cydia pomonella and the attraction of adult females

We studied the effect of herbivory by Cydia pomonella L. (Lepidoptera: Tortricidae) first instar larvae on the volatile emissions from immature apples collected at the end of August. Volatiles from infested, artificially damaged, and healthy fruit were collected using solid-phase microextraction and analysed using combined gas chromatography mass spectrometry. The results show that neonate C. pomonella larvae induce the release of E--ocimene from immature fruit compared to healthy or artificially damaged fruit. Seven further compounds, a terpene, an alcohol, four aldehydes, and a ketone, were consistently found in all treatments. There were no significant differences amongst these latter compounds, although the amount of the terpene E,E--farnesene was three to five times higher from the infested as compared to healthy fruits. Headspace volatiles were also collected on Tenax to test for behavioural responses to the volatiles. Volatile collections from infested fruit attracted mated adult females in a Y-tube olfactometer, whereas no preference was evinced for volatiles from healthy or artificially damaged fruits when compared to a solvent control.     

Secretory process of salivary glands of female Amblyomma cajennense (Acari: Ixodidae) ticks fed on resistant rabbits

Ticks have great economic and health importance since infested animals have reduced milk and meat production, and, besides that, they are expensive ectoparasites to control. While feeding, ticks can transmit to their hosts a large amount of pathogens, including Rickettsia rickettsii responsible for the ??spotted fever?? or ??fever of the mountains.?? It is known that animals infested with ticks or artificially immunized with their salivary gland extracts develop resistance, which is related to a decrease in engorged female weight, in egg-laying by adults, in egg viability and, in some cases, in the capacity of pathogens transmission. The present study aimed to examine morpho-histochemically the female salivary glands of semi and engorged Amblyomma cajennense fed on resistant rabbits. The results revealed that acinus I had no changes when compared to that of females fed on naive rabbits. The c cells of acinus II showed signs of early degeneration, which may result in feeding efficiency decrease. In acinus III d cells, activity time was longer. Such occurrence was associated with the time of female fixation, which increased in females fed on resistant hosts.     

Some newly characterized collagenases from procaryotes and lower eucaryotes

Summary Chemical and enzymatic properties of four collagenases newly isolated from anaerobic Clostridium histolyticum, aerobic Achromobacter iophagus, and from two lower eucaryotes, the fungus Entomophthora coronata and the insect Hypoderma lineatum are reviewed.The problems of their biosynthesis and precursors, namely the effect of induction of collagenase and neutral proteinase in Achromobacter by their macromolecular substrates are discussed.The two bacterial collagenases are Zn-metallo-enzymes; the highly purified Clostridium collagenase contains cyst(e)ine, serine phosphate and tryptophan additionally to amino acids reported previously. Achromobacter collagenase has the highest specific activity of all collagenases; it yields by autolysis enzymatically active degraded forms. The active dimer is composed of two identical subunits of molecular weight 35,000. Similarities between Achromobacter collagenase, thermolysin and Bacillus subtilis neutral proteinase in molecular weight, amino acid composition, and amino acids important for the active sites are discussed.The two collagenases from low eucaryotes are serine proteinases; Hypoderma collagenase is homologous to the trypsin family in the amino terminal sequence.The initial cleavage of native collagen by highly purified bacterial collagenases occurs in the central helical part of the a chains and not progressively from the amino terminal end. One of the two initial cleavages produced by Achromobacter collagenase is situated in the region cleaved specifically by vertebrate collagenases, but with different bond specificity. The same is true for the insect collagenase. Entomophthora collagenase is a proteinase of broad specificity which also cleaves collagen in its helical parts. All four collagenases also degrade other proteins according to their bond specificity.     

Parasitism by Pteromalus cerealellae (Hymenoptera: Pteromalidae) on the Cowpea weevil, Callosbruchus maculatus (Coleoptera: Bruchidae): Host density, temperature effects, and host finding ability

Studies on interactions between a larval parasitoid, Pteromalus cerealellae (Boucek) and one of its hosts, Callosobruchus maculatus (F.) were carried out in the laboratory. The number of host larvae parasitized by P. cerealellae increased with host larvae at low densities and tended to a plateau at a density of 25 larvae per female parasitoid. Each parasitoid was able to parasitize more hosts and produced more offspring at 20 and 25 °C than at 30 °C. The number of non-infested seeds mixed with seeds infested with the last instar of C. maculatus did not preclude P. cerealellae from identifying infested seeds and attacking larvae inside them. When infested seeds were tightly packed, several host larvae escaped parasitism. P. cerealellae may be a useful biological control agent in newly harvested cowpea with low C. maculatus infestation, and lowering the temperature of the storage system may enhance the effectiveness of this parasitoid.     

Some effects of time,temperature and feeding on infection rates with Babesia bovis and Babesia bigemina in Boophilus microplus larvae

Dalgliesh R. J. and Stewart N. P. 1982. Some effects of time, temperature and feeding on infection rates with Babesia bovis and Babesia bigemina in Boophilus microplus larvae. International Journal for Parasitology12: 323–326. Percentages of larval ticks in which Babesia bovis and B. bigemina parasites could be detected (infection rates) were determined after the larvae had been exposed to temperatures between 9°C and 27°C for periods of 1–35 days and then either fed on calves or heated at 37°C to stimulate babesial development. Infection rates with both species increased during 2–4 weeks after the larvae hatched, regardless of the temperature of exposure. Infection rates with B. bovis were higher after exposure of larvae to 14°C than to 27°C. This effect was less pronounced with B. bigemina. Infection rates were higher in fed larvae than in unfed, ‘heat stimulated’ larvae. The findings indicate that infected larval ticks become more efficient vectors of Babesia during the first 2–4 weeks after hatching and that repeated sampling of a tick population is necessary to determine valid infection rates.