{"title":"Using weapons instead of perfume: chemical association strategies of the myrmecophilous bug Scolopostethus pacificus (Rhyparochromidae)","authors":"Adrian Brückner","doi":"10.1007/s00049-022-00374-8","DOIUrl":null,"url":null,"abstract":"<div><p>A vast diversity of parasites associates with ants. Living in and around ant nests of these organisms must overcome ant colony defenses. As ant defensive behavior is mainly mediated by species-specific cuticular hydrocarbons (CHCs) or alarm pheromones, and ant-associated parasites can either crack their hosts’ chemical communication code by modifying their own CHC profiles or use pro-active strategies like chemical weaponry for distraction and repellency. While the chemical nature of ant–parasite interactions has been intensively studied for highly host-specific parasites, the chemical-deceptive strategies of the rather rare ant-resembling heteropterans are unknown. To gain insight into this system, I studied the bug <i>Scolopostethus pacificus</i> (Barber 1918) which can be found near the nests of the ecologically dominant and aggressive velvety tree ant (<i>Liometopum occidentale</i>, Emery 1895). Using behavioral, chemical, and molecular approaches, I disentangled the relationship of <i>S. pacificus</i> and its host ant. Chemical profiling of the bug and the ant revealed that the bug does not make use of CHC insignificance or mimicry, but instead uses a cocktail of volatile compounds released from its metathoracic glands that likely moderates encounters with its aggressive host. Feeding trials with armed and artificially disarmed bugs revealed a defensive function of the gland exudates. Targeted molecular gut barcoding showed that <i>S. pacificus</i> does not feed on <i>L. occidentale</i>. These results suggest that chemical weaponry, rather than a chemical code-cracking CHC matching or chemical insignificance, enables <i>S. pacificus</i> to get along with and live in close proximity to its host ant.</p></div>","PeriodicalId":515,"journal":{"name":"Chemoecology","volume":"32 4-5","pages":"147 - 157"},"PeriodicalIF":1.6000,"publicationDate":"2022-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00049-022-00374-8.pdf","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemoecology","FirstCategoryId":"93","ListUrlMain":"https://link.springer.com/article/10.1007/s00049-022-00374-8","RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 2
Abstract
A vast diversity of parasites associates with ants. Living in and around ant nests of these organisms must overcome ant colony defenses. As ant defensive behavior is mainly mediated by species-specific cuticular hydrocarbons (CHCs) or alarm pheromones, and ant-associated parasites can either crack their hosts’ chemical communication code by modifying their own CHC profiles or use pro-active strategies like chemical weaponry for distraction and repellency. While the chemical nature of ant–parasite interactions has been intensively studied for highly host-specific parasites, the chemical-deceptive strategies of the rather rare ant-resembling heteropterans are unknown. To gain insight into this system, I studied the bug Scolopostethus pacificus (Barber 1918) which can be found near the nests of the ecologically dominant and aggressive velvety tree ant (Liometopum occidentale, Emery 1895). Using behavioral, chemical, and molecular approaches, I disentangled the relationship of S. pacificus and its host ant. Chemical profiling of the bug and the ant revealed that the bug does not make use of CHC insignificance or mimicry, but instead uses a cocktail of volatile compounds released from its metathoracic glands that likely moderates encounters with its aggressive host. Feeding trials with armed and artificially disarmed bugs revealed a defensive function of the gland exudates. Targeted molecular gut barcoding showed that S. pacificus does not feed on L. occidentale. These results suggest that chemical weaponry, rather than a chemical code-cracking CHC matching or chemical insignificance, enables S. pacificus to get along with and live in close proximity to its host ant.
期刊介绍:
It is the aim of Chemoecology to promote and stimulate basic science in the field of chemical ecology by publishing research papers that integrate evolution and/or ecology and chemistry in an attempt to increase our understanding of the biological significance of natural products. Its scopes cover the evolutionary biology, mechanisms and chemistry of biotic interactions and the evolution and synthesis of the underlying natural products. Manuscripts on the evolution and ecology of trophic relationships, intra- and interspecific communication, competition, and other kinds of chemical communication in all types of organismic interactions will be considered suitable for publication. Ecological studies of trophic interactions will be considered also if they are based on the information of the transmission of natural products (e.g. fatty acids) through the food-chain. Chemoecology further publishes papers that relate to the evolution and ecology of interactions mediated by non-volatile compounds (e.g. adhesive secretions). Mechanistic approaches may include the identification, biosynthesis and metabolism of substances that carry information and the elucidation of receptor- and transduction systems using physiological, biochemical and molecular techniques. Papers describing the structure and functional morphology of organs involved in chemical communication will also be considered.