Showing papers on "Infestation published in 1993"
TL;DR: The relationship in canola (oilseed rape) between the percentage of petals infested with Sclerotinia sclerotiorum and the incidence of Sclerosis stem rot was investigated relative to changes in petal infestation during flowering and to canopy density.
Abstract: The relationship in canola (oilseed rape) between the percentage of petals infested with Sclerotinia sclerotiorum and the incidence of Sclerotinia stem rot was investigated relative to changes in petal infestation during flowering and to canopy density. Using an agar-plate test, percent petal infestation was assessed in commercial crops of Brassica napes and B. rapa (=B. campestris) in various regions of Saskatchewan. Crop height, stem thickness, percent light penetration of the canopy, leaf area index, and the number of plants per square meter also were assessed at some locations. The incidence of stem rot was determined before harvest. Substantial changes in petal infestation were observed between early and late bloom. Most changes were increases; in 1989, however, infestation generally decreased [...]
86 citations
TL;DR: Boophilus microplus saliva suppressed 47% of the response of bovine PBL to PHA in vitro, which may contribute to the lowerresponsiveness of PBL from tick-infested cattle.
72 citations
TL;DR: There was a significant reduction in protein nitrogen and true protein contents of three cereal grains at 75% infestation level but the decrease was non-significant at the 25 and 50% levels of grain infestation as compared to control (uninfested grains).
71 citations
TL;DR: It was found that the effects of nymphal ticks on blood composition and body condition depended on the age of the lizard host and whether the lizard was also infected with malaria, and lizards parasitized with both ticks and malaria had significantly lower body condition.
Abstract: Ectoparasites infest many lizard species, but the physiological consequences of infestation in free-living lizards have not been studied. We examined male western fence lizards, Sceloporus occidentalis, infested with ticks, Ixodes pacificus, in northern California. Many lizards in this population were also infected with malaria, Plasmodium mexicanum. We found that the effects of nymphal ticks on blood composition and body condition (relative body weight) depended on the age of the lizard host and whether the lizard was also infected with malaria. Adult male lizards, but not juveniles, infested with ticks had lower hematocrits than uninfested lizards. Although the reduction in hematocrit that accompanies the mean level of tick infestation probably does not substantially affect the lizards, heavy infestations (>5 ticks per lizard) may significantly limit the aerobic capacity and behavior of the lizard host. Lizards parasitized with both ticks and malaria had significantly lower body condition than lizards with one or neither parasite.
63 citations
TL;DR: Seaweed concentrate (SWC), prepared from Ecklonia maxima, when applied as a soil drench to tomato seedlings, significantly increased plant growth and reduced infestation by Meloidogyne incognita.
Abstract: Seaweed concentrate (SWC), prepared fromEcklonia maxima, when applied as a soil drench to tomato seedlings, significantly increased plant growth and reduced infestation byMeloidogyne incognita. Foliar applied SWC had little effect on plant growth and increased nematode galling. Ashing SWC reduced the suppressive effect on nematode infestation. In anin vitro experiment, SWC lessened infestation of root-knot nematodes on excised roots of a susceptible cultivar of tomato. Application of the same concentrations of SWC to a nematode-resistant cultivar increased the number of egg masses.
63 citations
61 citations
TL;DR: Infestation parameters for the caligid copepod Lepeophtheirus salmonis (Kroyer) infesting sea trout, Salmo trutta L., were established for a number of locations off the west coast of Ireland during 1990 and 1991 and suggested either host or parasite mortality as the parasite matured.
Abstract: . Infestation parameters for the caligid copepod Lepeophtheirus salmonis (Kroyer) infesting sea trout, Salmo trutta L., were established for a number of locations off the west coast of Ireland during 1990 and 1991. Based on these parameters sites were classified into two groups in 1990 and three in 1991. Median parasitic intensity in these groups was 11·6 and 77 in 1990 and 9·5, 29·5 and 55 in 1991. Fish were parasitized mainly by chalimus stages of the parasite which attached preferentially to the fins. Heaviest infestations were invariably due to chalimus stages and early pre-adult lice and there was a progressive decrease in the correlation between parasitic intensity and the number of each successive stage in the life cycle. This suggested either host or parasite mortality as the parasite matured. Large numbers of lice-infested fish returned prematurely from the sea to estuarine areas at a number of sites. Extensive morphological damage, especially to the fins, was apparent on a proportion of these fish as a result of the infestation. Mortality of heavily infested fish was directly observed.
56 citations
TL;DR: Total soluble sugar, reducing sugar, non-reducing sugar and starch contents of wheat, maize and sorghum grains were affected adversely at 25, 50 and 75% insect infestation caused by Trigoderma granarium Everts and Rhizopertha dominica Fabricius, separately and mixed population.
Abstract: Total soluble sugar, reducing sugar, non-reducing sugar and starch contents of wheat, maize and sorghum grains were affected adversely at 25, 50 and 75% insect infestation caused byTrogoderma granarium Everts andRhizopertha dominica Fabricius, separately and mixed population.R. dominica caused significant (P<0.05) reduction in available carbohydrates at 50 and 75% infestation levels whereasT. granarium achieved similar effect at 75%. Mixture of both insect species caused intermediate losses. Storage of cereal grains up to 4 months resulted in substantial increase in sugars and decrease in starch content, but storage for a shorter period of time did not cause any significant changes in levels of carbohydrates.
50 citations
TL;DR: Tested only following the spring period of infestation, both protein content and mixing time of the resulting flour were reduced by the Russian wheat aphid, however, mixing time was still within the acceptable range for bread-making.
Abstract: The effect of Russian wheat aphid, Diuraphis noxia (Mordvilko), feeding on yield and quality of winter wheat, Triticum aestivum L., was studied in the greenhouse and field. Cages were used to contain the aphids and to exclude natural enemies. Greenhouse experiments showed that plant height, shoot weight, and number of spikes were significantly reduced by Russian wheat aphid feeding through the jointing stage. Yield per plant was significantly reduced by infestation through the heading stage. In 1987-1988 and in 1988-1989, field study yields were significantly reduced by fall and spring periods of infestation. Yield was significantly affected by fall and spring infestations in 1987-1988 but not in 1988-1989. The economic injury levels for the spring infestations of 1988 and 1989 were 0.9 and 2.4 aphids per seven plants, respectively; those for the fall period of infestation were higher at 2.2 and 4.0, respectively. Tested only following the spring period of infestation, both protein content and mixing time of the resulting flour were reduced by the Russian wheat aphid. However, mixing time was still within the acceptable range (1.5-3.0 min) for bread-making.
49 citations
TL;DR: The blastogenic response of peripheral blood lymphocytes and antibody production against ticks were assessed and specific antibody response to salivary and integument antigens were always the highest in high infestation rabbits.
Abstract: Two groups of rabbits were infested twice with different numbers of Ixodes ricinus adults: one group (high infestation) with twenty-five females and twenty-five males and the other group (low infestation) with five pairs. A third infestation was performed in both groups with fifteen adult pairs. Tick biology was monitored for resistance effects. At the second infestation, the feeding and the egg production were more perturbed in ticks fed on high infestation rabbits. The embryogenesis was only affected in ticks from high infestation rabbits. At the third infestation, resistance was increased only in low infestation rabbits, which became more resistant than high infestation rabbits. The blastogenic response of peripheral blood lymphocytes and antibody production against ticks were assessed. A salivary gland extract and an integumental antigen from I. ricinus adult females were able to initiate lymphocyte proliferation. The response was significantly higher in high infestation rabbits, especially at the end of the second infestation, and higher in low infestation rabbits during the third infestation. Non-specific proliferation with concanavalin A was temporarily decreased in both rabbits groups during the first and the second infestations. Specific antibody response to salivary and integument antigens were always the highest in high infestation rabbits. The involvement of tick-induced immunosuppression is discussed.
43 citations
TL;DR: The performances of the two herds during the dry season were similar, showing that infestation by larvae and nymphs of A. variegatum has no impact on the zebu LWG, and that tick control during that period is not profitable.
TL;DR: Results showed marked temporal differences in peak trap catches of the fly in lowland areas compared with upland areas and the seasonal appearance of C. capitata in traps in Kokee and Polihale coincided with their emergence from collected fruits.
Abstract: Mediterranean fruit fly, Ceratitis captitata (Wiedemann), was monitored with male lure trap collections and periodic collections of ripe fruits on the island of Kauai to determine its temporal appearance and distribution patterns. Results showed marked temporal differences in peak trap catches of the fly in lowland areas compared with upland areas. Flies were caught in two upland locations compared with catches in six lowland locations. Strawberry guava, Psidium cattleianum Sabine, and common guava, Psidium guajava L., form a discontinuous belt of plants around Kauai Infestation of this fruit by C. capitata was nearly absent in wet areas and consistent but variable in dry areas. The seasonal appearance of C. capitata in traps in Kokee and Polihale coincided with their emergence from collected fruits. The mean infestation rate of C. capitata in guava was 0.43 ± 0.27 (mean ± SEM) per kg of fruit compared with 37.5 ± 15.3 for Bactrocera dorsalis (Hendel), Infestation of all fruits collected by B. dorsalis was widespread in all areas when these plants produced ripe fruits. Utilization of all fruits by C. capitata was very limited in comparison with the distribution and abundance of host plants.
TL;DR: The prevalence rates of the head louse infestation in school children in Kangwon-do, Korea in December 1990 was revealed, with the significance of worm positive rate because it represents the potentiality of active transmission.
Abstract: We tried to reveal the prevalence rates of the head louse infestation in school children in Kangwon-do, Korea in December 1990. A total of 912 children in four primary schools was examined. The positive rate for adults and/or nits of Pediculus humanus capitis was 37.2%. One school was followed-up without specific intervention. There was no significant change of the prevalence rate 6 months after the first examination from 66.0% to 57.3%. We could see the persistent infestation rate if there was no intervention. We are emphasizing the significance of worm positive rate because it represents the potentiality of active transmission.
TL;DR: A close correlation was found between infestation of R. padi in different wheat genotypes and losses of grain yield and loss of thousand-kernel mass, and there were tolerance differences among genotypes even within the same level of infestation.
Abstract: In Hungary the bird cherry-oat aphid (Rhopalosiphum padi L.) is the most frequent aphid species in winter wheat (Triticum aestivum L.). Estimations of infestation by R. padi as well as measurements of grain yield and thousand-kernel mass were carried out in 26 winter wheat genotypes in conditions of naturally infested and not infested (protected) control plots. The experiment was performed in isolated conditions in two field cages covered by nets. The aphids overwintered on wheat and got into cage, extremely quickly multiplied, therefore there was no need to apply any artificial aphid infestation. Highly significant differences were demonstrated among genotypes in infestation severity of R. padi as well as in losses of grain yield and thousand-kernel mass. The most resistant variety ‘GK Zombor’ had 25% infestation, and the most susceptible one ‘GK Lili’ had 79.2%. The reduction of grain yield of the most tolerant genotypes (‘GK Korany’, ‘Downy’, ‘Mv 4’, ‘Jubilejnaja 50’, ‘Mv 8’, ‘GK Kincso’ and ‘GK Zombor’) was 26–33%, and that of thousand-kernel mass was 23–30%. The most sensitive genotypes (‘GK Lili’, ‘GK Orzse’, ‘GK Koppany’ and ‘Mv 13’) suffered 58–63% losses in yield, and 40–50% in thousand-kernel mass. A close correlation was found between infestation of R. padi in different wheat genotypes and losses of grain yield (r=0.7572, P<0.001). Also there were tolerance differences among genotypes even within the same level of infestation. The reductions of thousand-kernel mass correlated very closely with the reductions of grain yield (r=0.9212, P<0.001), that makes screening possible by reductions of thousand-kernel mass. These results have found application in breeding. The leaf pubescence of the varieties studied did not generally influence the infestation by R. padi.
TL;DR: Fruits of 55 plant species of the tropical rain forest of Mexico were sampled and the possible existence of a diapause period in some Anastrepha species is noted, and some fruit characteristics affecting the degree of infestation are discussed.
Abstract: The relationships between Anastrepha species and their host plants are recorded and analyzed from a study carried out in a natural tropical community of Mexico (Estacion de Biologia Tropical Los Tuxtlas, Veracruz). We sampled fruits of 55 plant species of the tropical rain forest and found the following associations: Tapirira mexicana Marchand was infested with A. sp. and A. obliqua (Macquart); Spondias radlkoferi J. D. Smith with A. obliqua; Tabernaemontana alba Mill. with A. cordata Aldrich; Quararibea funebris (Llave) Vischer with A. crebra Stone; Inga sapindoides Willid. with A. distincta Greene; Brosimum alicastrum Sw. and Pseudolmedia oxyphyllaria J. D. Smith with A. bahiensis Costa Lima; Psidium guajava L. with A. striata Schiner and A. fraterculus (Wiedemann); Citrus aurantium L. and C. maxima (Burm.) Merrill with A. ludens (Loew); Chrysophyllum mexicanum Brandegee ex Standley, Pouteria sapota (Jacq.) H. Moore & Stearn and Pouteria sp. with A. serpentina (Wiedemann). Also, we found the species A. hamata (Loew), A. leptozona Hendel and A. minuta Stone, whose hosts in the Los Tuxtlas region are still unknown. We sampled infestation rates in 10 of the 13 host plants. Of the 3704 fruits examined, 23.1% were infested. We encountered 2290 larvae, of which 1600 pupated. Parasitoids or adult flies emerged from 85% of these. Infestation percentages of the different fruit species were highly variable, ranging from 1.5% for P. oxyphyllaria to 66.7% for Pouteria sapota. The mean number of larvae per fruit usually was between 1.25 and 2.59, and in only the largest and heaviest fruits (such as C. aurantium, P. sapota and P. sp.) were there more than 9.0 larvae present. Some fruit characteristics affecting the degree of infestation are discussed, and the possible existence of a diapause period in some Anastrepha species is noted.
TL;DR: Seasonal variation in the capacity of bank voles to infect larval Ixodes ricinus (L.) ticks with Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner was examined at Bogesund, near Stockholm in south-central Sweden.
Abstract: Seasonal variation in the capacity of bank voles, Clethrionomys glareolus (Schreber), to infect larval Ixodes ricinus (L.) ticks with Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner was examined from May through October 1991 at Bogesund, near Stockholm in south-central Sweden. Although larval infestations of bank voles were greatest in June and July, nearly 70% of all larval ticks infected with spirochetes by bank voles at this site became infected during August and September. Seasonality of infectivity was related to the degree of earlier nymphal infestation on voles as well as to the age composition of the vole population. These factors may influence the infectivity of other rodent reservoirs of B. burgdorferi, both in Europe and North America. Moreover, in determining the reservoir potential of tick hosts, a host population's spirochetal infectivity should be determined for the entire period of larval infestation rather than just during the period of peak larval infestation.
TL;DR: The results confirmed that C. serratus is a serious pest of stored seeds and suggested collection of good quality insect-free seeds for storage, and treatment of seeds with a suitable contact insecticide or a fumigant to provide further protection during storage.
TL;DR: Levels of both pest and nonpest arthropods were compared among four pairs of fields of conventional and organic rice, Oryza sativa L., in California, and revealed a high degree of taxonomic similarity between conventional andorganic treatments.
Abstract: Levels of both pest and nonpest arthropods were compared among four pairs of fields of conventional and organic rice, Oryza sativa L., in California. For seven major pests, there were no significant differences in abundance or in level of damage between conventional and organic treatments. However, in two organic fields, the combination of high infestation level (>5% of rice plants infested) by immature Hydrellia griseola Fallen, an ephydrid leafminer, and low stand densities (<25 plants per 0.09 m2) warranted preventive action to avoid economic loss. Collections revealed a high degree of taxonomic similarity between conventional and organic treatments; species richness did not differ significantly between treatments. However, three predatory taxa—Belostoma flumineum Say, Notonecta spp., and adult Thermonectus basillaris (Harris)—were significantly more abundant in the organic than in the conventional treatment.
TL;DR: A major role of the eastern chipmunk as a host for immature I. dammini in upland forest habitat in northwestern Illinois can be established and in bottomland and ecotone habitats where chipmunks were scarce, P. leucopus contributed most to the feeding of larval ticks.
Abstract: Infestation of the eastern chipmunk, Tamias striatus L., by immature Ixodes dammini Spielman, Clifford, Piesman and Corwin was studied in Castle Rock State Park in northwestern Illinois during June-October 1991. Mean larval density peaked in August, while nymphal density declined steadily through the study period. Prevalence of tick infestation was high throughout the trapping period. Tick distribution on chipmunks was aggregated in most of the sampling periods. Levels of I. dammini infestation recorded on chipmunks in this survey are higher than previous results recorded in the northeastern and midwestern United States. Chipmunks had significantly higher levels of nymphal I. dammini infestation than white-footed mice (Peromyscus leucopus Rafinesque). A major role of the eastern chipmunk as a host for immature I. dammini in upland forest habitat in northwestern Illinois can be established. In bottomland and ecotone habitats where chipmunks were scarce, P. leucopus contributed most to the feeding of larval ticks.
Journal Article•
TL;DR: Newly arrived Ethiopian immigrants in Israel were screened for ectoparasitic insects and mites and the rate of infestation with this parasite was higher in adults than in children and higher in females than males.
Abstract: Newly arrived Ethiopian immigrants in Israel were screened for ectoparasitic insects and mites. Of 304 individuals examined 65.1% were infested with the head louse (Pediculus humanus capitis). The infestation rate among children varied between 65 and 100%. Children aged 6-11 years were the most infested group and no differences between girls and boys were found. The infestation rate in children was significantly higher than that found in adults. Approximately 39% of those examined were infested with the body louse (Pediculus humanus humanus). The rate of infestation with this parasite was higher in adults than in children and higher in females than males. Ten percent of the immigrants examined were infested with the scabies mite (Sarcoptes scabiei) and 4.3% with the human flea (Pulex irritans).
TL;DR: Although the trial demonstrated the efficacy of chemical treatments in reducing the number of aphids, the infestation did not seem to have consistent effects on fruit production.
Abstract: The ecology and biology of green peach aphids, Myzus persicae (Sulzer), were studied on greenhouse tomatoes with the goals of learning more about the biology of the species in these conditions and of measuring parameters to implement a computer simulation that could be used in programs for resistance management. Control groups and groups of tomatoes (‘Ausonio’and‘Acor’) treated with deltamethrin were observed throughout the growing season, and selected plants were observed in detail. At weekly intervals, the following measurements were recorded: height of the plant, number of leaves and flower clusters, health condition, phenological phase of the plant, presenceabsence of M. persicae (and if present, the numbers for each life stage on each leaf or flower bud), and the presence-absence of other parasitoids and predators. Although the trial demonstrated the efficacy of chemical treatments in reducing the number of aphids, the infestation did not seem to have consistent effects on fruit production.
TL;DR: Sex pheromone-mediated mating disruption was used to control the grape berry moth at two farms in the Niagara peninsula, Ontario, during three consecutive growing seasons to determine if earlier observed between-generation increases in the percentage of infested grape clusters would continue between growing seasons.
Abstract: Sex pheromone-mediated mating disruption was used to control the grape berry moth, Endopiza viteana (Clemens) (Lepidoptera: Tortricidae), at two farms in the Niagara peninsula, Ontario, during three consecutive growing seasons, 1989 through 1991, to determine if earlier observed between-generation increases in the percentage of infested grape clusters would continue between growing seasons. The relative performance of the pheromone treatment was assessed by comparing the percentage of infested clusters in the pheromone-treated plot with the percentage of infested clusters in an adjacent, insecticide-treated plot. Although the percentage of infested clusters increased from 1.7- to 56.5-fold between successive generations in the pheromone-treated plots, there was no indication that the level of infestation at harvest affected the level of infestation the following spring. At one farm, the percentage of infested clusters was greater in the pheromone-treated than in the insecticide-treated plot during 1989, but during 1990 and 1991, the level of infestation was similar in the two plots. At the other farm, the level of infestation was from 2- to 3-fold greater in the insecticide-treated than in the pheromone-treated plot.
TL;DR: Generations derived from crosses between inbred lines were used to analyze the genetics of hydroxycinnamic acid accumulation in maize grain and susceptibility to infestation by the maize weevil.
Abstract: Generations derived from crosses between inbred lines were used to analyze the genetics of hydroxycinnamic acid accumulation in maize grain and susceptibility to infestation by the maize weevil Sitophilus zeamais. There was a significant negative correlation between phenolic content and susceptibility of the grain to weevil infestation, and the estimates of genetic parameters indicate that a close relationship between those two traits exists. Key words: insect resistance, maize, maize weevil, genetics, phenolics.
TL;DR: It is suggested that a major component of sugarcane's resistance to Sugarcane borer is reducing the frequency of the establishment of young larvae in the stalk.
Abstract: The movement and establishment of sugarcane borer, Diatraea saccharalis (F.), larvae was studied on resistant and susceptible sugarcane. A field study was conducted over three years on the cultivars `CP 74-383' (susceptible), `CP 65-357' (intermediate), and `CP 70-321' (resistant). Stalks of each cultivar were artificially infested with neonate sugarcane borer larvae and sampled at 10, 20, and 30 days after infestation. Larval movement, entrance holes, and plant growth were mapped and recorded for each cultivar and sample date. Larval recovery at 30 days after infestation was low and varied among cultivars totalling 10.2% on CP 74-383, 7.0% on CP 65-357, and 3.5% on CP 70-321. Larvae entered stalks of CP 74-383 earlier than those of CP 65-357 and CP 70-321; at 10 days after infestation, 48% of the larvae on CP 74-383 had entered the stalk, but only 19% on CP 65-357 and CP 70-321. Larvae generally moved up the stalk before entering, indicating that young internodes were preferred to older internodes for entry sites. Larvae feeding on CP 74-383 were also more likely to damage multiple internodes. This study suggests that a major component of sugarcane's resistance to sugarcane borer is reducing the frequency of the establishment of young larvae in the stalk.
TL;DR: In a field trial, reductions in insect population and damage to the crop were achieved by early treatment with the nematodes as well as by Heptachlor, leading to reductions in the insect population of 60 and 90% respectively, when recorded 4 weeks after nematode application.
Abstract: Single, double and triple releases of the entomopathogenic nematode Heterorhabditis bacteriophora Poinar, reduced the population of the beetle Maladera matrida Argaman, infesting peanuts (’Shulamit’ cv.) by 70, 75 and 93% respectively in microplot tests. Simultaneous and late (2 weeks after infestation) applications reduced beetle numbers by 63 and 79% respectively, in the microplots, while early application (2 weeks prior to infestation) did not reduce the beetle population. In a field trial, reductions in insect population and damage to the crop were achieved by early treatment with the nematode as well as by Heptachlor, leading to reductions in the insect population of 60 and 90% respectively, when recorded 4 weeks after nematode application. However, the nematode treatment did not maintain its effectiveness for a longer period and pest damage increased to the same level as the untreated control after 7 weeks. When the nematodes were applied at different concentrations (0.25–1.0 x 106 infective juvenil...
TL;DR: Beta density function for describing larval distribution showed that larval instar, infestation date and environmental conditions did not influence this process.
Abstract: Field experiments on the within-plant distribution of larvae of the fall armyworm, Spodoptera frugiperda (J E Smith) (Lepidoptera: Noctuidae), on the early-whorl to late-whorl stage of corn, Zea mays L, revealed that most larvae were found in the wrapped leaves of the whorl Beta density function for describing larval distribution showed that larval instar, infestation date and environmental conditions did not influence this process Larval distribution and its time course was accurately described with a single Beta density function for all infestations This function gave 64%, 25%, 8%, 2% and 1% of larvae in the highest visible leaf and leaves just above, respectively When the tassel began development in the whorl (pre-tasseling corn stage), most larvae (80%) were found in this location After tasseling, larvae moved down to the lower leaves and into the ear (75%)
TL;DR: The data suggest that the resistance against larval H. longicornis ticks in mice may be expressed as a result of immediate hypersensitivity and many eosinophils infiltrating from the blood to the feeding sites might contribute to the tick rejection.
Abstract: Summary
WBB6F1 -+- /+ mice were infested with larval Haemaphysalis longicornis ticks twice at an interval of 14 days: apparent resistance against ticks was expressed in the second infestation. The first infestation induced degranula-tion of a small number of mast cells at the feeding sites within 6 days, and resulted in two-fold increases of mast cell numbers on day 14 with a significant elevation of total immunoglobulin E (IgE) levels in sera and high proportion of IgE-bound mast cells. The second infestation resulted in the intensive degranulation of the increased mast cells at the feeding sites. Eosinophils infiltrated into the feeding sites of ticks: the second infestation led to a greater maximal level of the infiltrating eosinophils. These data suggest that the resistance against larval H. longicornis ticks in mice may be expressed as a result of immediate hypersensitivity and many eosinophils infiltrating from the blood to the feeding sites might contribute to the tick rejection.
TL;DR: Infestation of banana and plantain suckers by nematodes and weevils increased with time from establishment in a field of eight different cultivars and there was a strong association between nematode and weevil infestation.
Abstract: SUMMARY
Infestation of banana and plantain suckers by nematodes (Pratylenchus good-eyi, Radopholus similis and Helicotylenchus multicinctus) and weevils (Cosmopolites sordidus) increased with time from establishment in a field of eight different cultivars. There was a strong association between nematode and weevil infestation; suckers infested with nematodes were more than four times more likely to be infected by weevil than suckers without nematodes. Weevil damage, measured by percentage coefficient of infestation (PCI) at harvest of the bunch, was higher on a plantain (cv. Gonja) and on an east African highland cooking banana (cv. Lusumba) than on the sweet and multi-purpose cultivars. There was a correlation between numbers of male weevils caught in a plot and the mean PCI measured in the plot, but no correlation with female numbers.
TL;DR: It is inferred that insecticidal sprays may be scheduled when 9–12 moths are captured per trap per night, which is associated with economically damaging infestation of pink bollworm.
Journal Article•
TL;DR: By using the first generation offspring of field-collected larvae for artificial infestation of plants, an effective resistance breeding programme for maize can be maintained without the need for continuous rearing of larvae on meridic diets.
Abstract: Techniques are descriptionbed for continual re-establishment of laboratory colonies of Busseola fusca (Fuller) by collecting diapausing larvae from commercial maize fields. By using the first generation offspring of field-collected larvae for artificial infestation of plants, an effective resistance breeding programme for maize can be maintained without the need for continuous rearing of larvae on meridic diets. Methods for artificial infestation of maize with B. fusca are descriptionbed.