Infestation

About: Infestation is a research topic. Over the lifetime, 8308 publications have been published within this topic receiving 82305 citations.

Varroa jacobsoni infestation of adult Africanized and Italian honey bees (Apis mellifera) in mixed colonies in Brazil

Abstract: Different levels of infestation with the mite Varroa jacobsoni have been observed in the various Apis mellifera races. In general, bees of European races are more susceptible to the mite than African honey bees and their hybrids. In Brazil honey bee colonies are not treated against the mite, though apparently both climate and bee race influence the mite infestation. Six mixed colonies were made with Italian and Africanized honey bees. The percentage infestation by this parasite was found to be significantly lower in adult Africanized (1.69 ± 0.44) than Italian bees (2.79 ± 0.65). This ratio was similar to that found in Mexico, even though the Africanized bees tested there had not been in contact with varroa, compared to more than 20 years of the coexistence in Brazil. However, mean mite infestation in Brazil on both kinds of bees was only about a third of that found in Mexico.

Sampling for the sugarcane borer (Lepidoptera: Pyralidae) in sugarcane.

Abstract: A sampling study was conducted in sugarcane to estimate infestation levels of the sugarcane borer (SCB), Diatraea saccharalis (F.). A single sample consisted of five stalks per plant from five plants spaced 3 m apart. A mean of 7 min was required for one scout to take one sample in cane 0.6–1.2 m tall; 16 min was required in cane 3.0–3.6 m tall. Variance to mean ratios, Green’s coefficient of dispersion, and a simple linear regression of log10( s 2)against log10( x ¯) showed that SCB populations usually were aggregated in sugarcane. Number of SCB larvae per sample followed the negative binomial distribution. In 0.4- to 0.8-ha areas of sugarcane, aggregation was not detected at low population densities but was pronounced at high densities. Estimated SCB infestation levels (mean number of borers per 25 stalks × 100) ranged from 0.4 to 48.0% in the different fields sampled. Based on 90% CL and a mean of nine samples per 0.4- to 0.8-ha area, accuracy of estimates for SCB infestation levels ranged from ±0.8 to ±26.6% with an overall average of ±7.4% based on simple variance or ±7.1% based on a regression estimate of variance. At infestation levels <10%, estimates of SCB infestation levels were generally within ±4.5% of the true levels based on simple variance or ±3.9% based on regressed variance. Accuracy of infestation level estimates generally decreased as SCB infestation levels increased.

Determination of host status of citrus fruits against the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae)

Abstract: The Mediterranean fruit fly (Medfly), Ceratitis capitata (Wiedemann) is a pest of citrus in parts of Western Australia. Three citrus cultivars: Valencia oranges, Eureka lemons and Imperial mandarins, as well as non-citrus control fruits, were examined for attractiveness and suitability to Medfly in the field and in the laboratory using choice and no-choice experiments. Oranges were more susceptible to Medfly than mandarins and lemons. Punctures in the skin had a significant impact on the degree of infestation in both citrus and non-citrus control fruit. Artificial infestation and larval survivorship were used to investigate the suitability of each cultivar to Medfly under laboratory conditions. Oranges and mandarins were suitable for the development of Medfly, but lemons were a poor host. When each cultivar was in season, field cage trials demonstrated that infestation occurred in oranges and mandarins but not in lemons.

Relationship Between Fusarium Ear Rot and Corn Earworm Infestation 1

Abstract: Earworm Infestation Dale G. Smeltzer IN THE evaluation of commercial com hybrids for adaptation under California conditions, their reaction to Fusarium ear rot is an important consideration. The importance of this disease, caused by Fusarium moniliforme Sheld., has been discussed by Smith and Madsen. The pathogen has a wide host range and is generally distributed in the corn-growing areas of California. Damage is particularly serious in certain seasons in the Sacramento-San Joaquin Delta area and in the lower Sacramento Valley where corn is well adapted. Losses result from reduced yield and lowered quality of shelled grain.

Influence of genetic and non -genetic factors on quantity and quality of wool from sheep reared at rawalakot azad jammu and kashmir

Abstract: A study to investigate prevalence of theilleria infected hard ticks of dairy cattle and buffalo was carried out in Faisalabad, Jhang and Khanewal districts of Punjab, Pakistan. Ticks were collected during July and August, 2007 from infested dairy animals irrespetive of age, sex and weight. These animals were from 30 livestock farms, each having more than 25 animals (cattle and buffaloes). Six thousand two hundred and sixty three ticks were collected from 710 cattle and 320 buffaloes. Overall prevalence of Hyalomma species was significantly higher (61%) than that of other genera of hard ticks (p>0.05). In sex-wise distribution, it was found that female Hyalomma species were the highest (85%) followed by Amblyomma species (81%), while prevalence of Boophilus species and Haemaphysalis species were 77%. The ticks infestation rate in cattle (70%) was significantly higher than that of buffaloes (34%). PCR results showed that Theilleria annulata was detected in 50% Hyalomma anatolicum and 40% Hyalomma dromedary ticks. No theilerial organism was detected in Hyalomma marginatum, Boophilus annulatus and Amblyomma varigatum ticks. In conclusion, Theilleria annulata was prevailing in more than 40% Hyalomma species of cattle. It means that Hyalomma species are mainly responsible for transmission of the Theileria in dairy animals.