Infestation

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

Open-ocean infestation by salmon lice (Lepeophtheirus salmonis): comparison of wild and escaped farmed Atlantic salmon (Salmo salar L.)

Abstract: Salmon lice (Lepeophtheirus sabnonis) infestation was investigated in 128 salmon (S&IO s&r L.) caught on floating long-lines in the Norwegian Sea during NovemberMarch 199331995. Overall prevalence was 99.2% and abundance 29.5 lice per salmon. Most lice were adults (90%) and 72% of these were ovigerous females. These adult lice were estimated to be at least 3 months old based on prevailing sea-surface temperatures at the sampling site: 7°C in November and 3°C in March. The prevalence and abundance of lice on one sea winter (1SW) salmon were significantly higher on escaped farmed fish than on wild salmon. However, no difference in abundance was observed between 2SW farmed and wild salmon. The average number of lice per surface area of fish (density) was significantly higher in 2SW wild salmon than in 1SW wild salmon, indicating an accumulation of lice on the salmon in the oceanic phase. No differences in density were observed between 1SW and 2SW farmed salmon. The prevalence of Cakgus elongutus was low (5.5%), with an abundance of 0.9 lice per salmon. 0 1997 International Council for the Exploration of the Sea

Accuracy of diagnosis of pediculosis capitis: visual inspection vs wet combing.

Abstract: Objective To determine the diagnostic accuracy of visual inspection and wet combing in pediculosis capitis (head lice infestation). Visual inspection of 5 predilection sites (temples, behind the ears, and neck) was performed first, followed by wet combing of hair moistened with conditioner. Presence of mobile stages was defined as active infestation, presence of nits alone as historic infestation. Design Observer-blinded comparison of 2 diagnostic methods. Setting Five primary schools in which head lice infestation was epidemic. Participants A total of 304 students aged 6 to 12 years. Main Outcome Measures Presence of nymph, adults, and nits; sensitivity, predictive value, and accuracy of both methods. Results Visual inspection underestimated the true prevalence of active infestation by a factor of 3.5. The sensitivity of wet combing in diagnosing active infestation was significantly higher than of visual inspection (90.5% vs 28.6%;P Conclusions Wet combing is a very accurate method to diagnose active head lice infestation. Visual inspection is the method of choice, if one aims to determine the frequency of carriers of eggs or nits.

Monogenean infestations and mortality in wild and cultured Red Sea fishes.

Abstract: Hyperinfection by the gill-infesting monogeneanAllobivagina sp. (Microcotylea) caused mass mortalities in juveniles ofSiganus luridus cultured in seawater earthen ponds and holding tanks in Eilat (Gulf of Aqaba, Red Sea). Other species ofSiganus and adults ofS. luridus cultured in the same systems acquired a low intensity of infestation. Most hyperinfected fish were emaciated and anaemic with hematocrit values below 10 %. Skin and mouth infestations by the monogeneanBenedenia monticelli (Capsaloidea) caused mass mortalities in grey mullets (Mugilidae). These mortalities occurred in large individuals in wild populations ofLiza carinata from lagoonal habitats in the Gulf of Suez and in most species of grey mullets cultured in Eilat. The intensity of infestation correlated positively with severity of infestation, and the common sites of infestation corresponded with areas of severe pathological alterations. Spontaneous recovery followed the climax of an epizootic, both for infestedS. luridus and infested grey mullets. Decline in infestation coincided with remission of the pathological signs.

Invasive Drosophila suzukii facilitates Drosophila melanogaster infestation and sour rot outbreaks in the vineyards

Abstract: How do invasive pests affect interactions between members of pre-existing agrosystems? The invasive pest Drosophila suzukii is suspected to be involved in the aetiology of sour rot, a grapevine disease that otherwise develops following Drosophila melanogaster infestation of wounded berries. We combined field observations with laboratory assays to disentangle the relative roles of both Drosophila in disease development. We observed the emergence of numerous D. suzukii , but no D. melanogaster flies, from bunches that started showing mild sour rot symptoms days after field collection. However, bunches that already showed severe rot symptoms in the field mostly contained D. melanogaster . In the laboratory, oviposition by D. suzukii triggered sour rot development. An independent assay showed the disease increased grape attractiveness to ovipositing D. melanogaster females. Our results suggest that in invaded vineyards, D. suzukii facilitates D. melanogaster infestation and, consequently, favours sour rot outbreaks. Rather than competing with close species, the invader subsequently permits their reproduction in otherwise non-accessible resources and may cause more frequent, or more extensive, disease outbreaks.