{"title":"Inferring the feeding history of the castor bean tick, Ixodes ricinus from lipid and body measurements.","authors":"Munachimso Udobi, Richard Wall","doi":"10.1111/mve.12768","DOIUrl":null,"url":null,"abstract":"<p><p>The ability to determine when ticks last fed and assign them to a specific feeding cohort is important in attempts to explain their population dynamics; the biochemical measurement of stored lipid, has been widely used for this purpose. However, when relating feeding history to behaviour or infection status, a non-destructive approach to its assessment would be of value and, to this end, previous studies have attempted to use morphometric indices. Within any instar, the sclerotised scutal components of the body will not vary with increasing starvation while the alloscutal components will, and the resulting ratio should provide a measure of time since feeding. Here, the aim was to determine whether such a morphological ratio (described here as the hunger index) changed predictably with starvation in Ixodes ricinus L. (Ixodida: Ixodidae). For this a cohort of 300 I. ricinus nymphs was collected from the field in February 2021 and starved in a humidified incubator at 15°C and 80% relative humidity (RH). Every 2 weeks, 50 nymphs selected at random were removed and killed by freezing; morphometric measurement was followed by the measurement of lipid using a standard spectrophotometric approach. Both hunger index and stored lipid changed significantly with increasing starvation and were positively correlated with each other. However, the change in morphometric ratio was relatively slight (11%) over 9 weeks and the variation was high. The data suggest therefore that morphological measurements could be used to provide, at best, only broad categorisation of the hunger status of individual I. ricinus ticks in the field.</p>","PeriodicalId":18350,"journal":{"name":"Medical and Veterinary Entomology","volume":" ","pages":""},"PeriodicalIF":1.6000,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Medical and Veterinary Entomology","FirstCategoryId":"97","ListUrlMain":"https://doi.org/10.1111/mve.12768","RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENTOMOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
The ability to determine when ticks last fed and assign them to a specific feeding cohort is important in attempts to explain their population dynamics; the biochemical measurement of stored lipid, has been widely used for this purpose. However, when relating feeding history to behaviour or infection status, a non-destructive approach to its assessment would be of value and, to this end, previous studies have attempted to use morphometric indices. Within any instar, the sclerotised scutal components of the body will not vary with increasing starvation while the alloscutal components will, and the resulting ratio should provide a measure of time since feeding. Here, the aim was to determine whether such a morphological ratio (described here as the hunger index) changed predictably with starvation in Ixodes ricinus L. (Ixodida: Ixodidae). For this a cohort of 300 I. ricinus nymphs was collected from the field in February 2021 and starved in a humidified incubator at 15°C and 80% relative humidity (RH). Every 2 weeks, 50 nymphs selected at random were removed and killed by freezing; morphometric measurement was followed by the measurement of lipid using a standard spectrophotometric approach. Both hunger index and stored lipid changed significantly with increasing starvation and were positively correlated with each other. However, the change in morphometric ratio was relatively slight (11%) over 9 weeks and the variation was high. The data suggest therefore that morphological measurements could be used to provide, at best, only broad categorisation of the hunger status of individual I. ricinus ticks in the field.
期刊介绍:
Medical and Veterinary Entomology is the leading periodical in its field. The Journal covers the biology and control of insects, ticks, mites and other arthropods of medical and veterinary importance. The main strengths of the Journal lie in the fields of:
-epidemiology and transmission of vector-borne pathogens
changes in vector distribution that have impact on the pathogen transmission-
arthropod behaviour and ecology-
novel, field evaluated, approaches to biological and chemical control methods-
host arthropod interactions.
Please note that we do not consider submissions in forensic entomology.