Detection and differentiation of wild-type and vaccine strains of canine distemper virus by a duplex reverse transcription polymerase chain reaction

Canine distemper virus [CDV] is the cause of canine distemper [CD] which is a severe and highly contagious disease in dogs. In the present study, a duplex reverse transcription polymerase chain reaction [RT-PCR] method was developed for the detection and differentiation of wild-type and vaccine strains of CDV. Four primers were designed to detect and discriminate the two viruses by generating 638- and 781-bp cDNA products, respectively. Furthermore, the duplex RT-PCR method was used to detect 67 field samples suspected of CD from Guangdong province in China. Results showed that, 33 samples were to be wild-type-like. The duplex RT-PCR method exhibited high specificity and sensitivity which could be used to effectively detect and differentiate wild-type and vaccine CDV, indicating its use for clinical detection and epidemiological surveillance

Chemical compatibility testing of the entomopathogenic fungus Lecanicillium muscarium to control Bemisia tabaci in glasshouse environment

The potential for using the entomopathogenic fungus Lecanicillium muscarium to control the sweetpotato whitefly, Bemisia tabaci has been well established in previous studies under both laboratory and glasshouse conditions. In the current study, five chemicals were assessed for their compatibility with L. muscarium for control of B. tabaci under glasshouse conditions. On treatments following the sequential application of chemical product and fungus high mortality of second instar larvae was obtained [the known most susceptible B. tabaci life-stage to fungal infection]. Sequential treatment of Savona and Certis spraying oil with L. muscarium produced 95% and 96% larval mortality, respectively. Commercially, unacceptable poinsettia foliage damage was recorded seven days post application of Agri-50E. Other plant foliage may prove more tolerant to this product. Incorporation of these chemicals with L. muscarium into integrated control programmes for B. tabaci control in glasshouses is discussed. Further information has been added to the knowledge base for the combined use of chemicals and fungi for the control of B. tabaci

Environmental evaluation of hot water treatments to control Liriomyza huidobrensis infesting plant material in transit

Though quarantine disinfestation treatments have been exempt from the methyl bromide phase out, it is still required to research and develop alternative treatments for fumigation of plant material in transit. This study investigated the ability of both the egg and pupal stages of the quarantine pest, South Americian leafminer, Liriomyza huidobrensis to survive submersion in water heated to temperatures between 40 and 50°C for varying periods of time. Large reductions in egg viability were recorded. However, the treatments also resulted in unacceptable levels of damage to the host plant material. Damage was uneconomically viable. Pupae were all killed exposure to water at 44°C for 20 min. Incubation of insect and plant material at either 5 or 20°C for 24 h before submersion in the hot water did not significantly alter the pests' ability to survive the treatments. The potential of hot water treatments to act as an alternative to methyl bromide fumigation for disinfecting plants in transit is discussed

Leaf dipping as an environmental screening measure to test chemical efficacy against bemisia tabaci on poinsettia plants

The screening of potential chemicals for control of Bemisia tabaci on poinsettia [Euphorbia pulcherrima c.v. Lilo Pink] plants using a leaf dipping technique was investigated. All relevant B. tabaci lifestages [eggs, larvae and adults] were investigated. In leaf dipping tests, Certis spraying oil was the only compound to show potential to be used as a control agent against B. tabaci eggs, with 81% obtained mortality. Oberon resulted in no mortality of B. tabaci eggs in the reported experiments. Leaf dipping against second instar and adult B. tabaci proved more effective for all chemical products. Dipping techniques using Majestik, Certis spraying oil and Agri- 50 E all resulted in high second instar larval mortality [93, 87 and 85.5%, respectively]. Certis spraying oil again resulted in a high efficacy against adult B. tabaci with 100% mortality obtained. The potential of the various chemicals to be incorporated into integrated pest management strategies for the control of B. tabaci is discussed