Water Mite Larvae Research Articles

First record of water mite larvae, Hydrachna sp. (Acari, Hydrachnidae) parasitism as quiescent nymphophan on two major aquatic insects of Coleoptera and Hemiptera from West Bengal and Odisha, India

Occurrence of quiescent nymphophan of Hydrachna sp. attaching to the sternites and tergites of thorax and abdomen of water beetle (Hydrophilus sp.) and giant water bug (Lethocerus sp.) is reported for the first time from West Bengal and Odisha of India. After feeding from one to five weeks as a parasitic larva on its host, Hydrachna sp., stops feeding and enters a quiescent nymphophan (nymphochrysalid) stage of development in which the larva squeezes into its exoskeleton and forms a sac-like structure where metamorphosis occurs. By the means of gnathoma, it remains attached to the host body casts off its exoskeleton, and within a short time, the developing nymph can be seen within it. The nymph comes out of a slit in the exoskeleton and assumes a free-living existence. These nymphochrysalids ranged in length from 682.17 to 2112.45?m with lateral stripes adorning their external integuments. Body appeared to be bottle shaped with pointed or rounded posterior end. Preferences of water mites for insect host body parts and seasons, infection intensity and prevalence were reported.

Parasite-host relationships of water mites (Acari: Hydrachnidia) and black flies (Diptera: Simuliidae) in southeastern Spain

BackgroundDocumentation on water mites in Spain is scarce, as is information on the parasite-host relationship between certain water mite species and representatives of the dipteran family Simuliidae. The discomfort caused to humans and animals by black flies seems to be increasing in recent years. In this context, an investigation of parasitic water mites is of great importance, not only from the point of view of biodiversity, but also in terms of their potential to control black fly populations.MethodsRivers across a wide region of eastern Spain were sampled to determine the specific richness of simuliid dipterans and to investigate their possible parasites, such as water mites, mermithid nematodes and microsporidia (fungal microbes). Data on environmental variables, abundance, prevalence and intensity of parasitism on the collected specimens were analyzed.ResultsIn 10 streams, 15,396 simuliid pupae were collected and checked for the presence of water mite larvae; 426 pupae in seven streams were found to be associated with water mite larvae. Of the 21 simuliid species identified based on morphological characters, eight were found to be associated with water mite larvae. Water mite infection was not equally distributed among black fly species. Also, the prevalence of parasitism was low and differed among simuliid species, ranging from one to 13 water mites per black fly pupa. Variation at the intra- and interspecific levels was detected in terms of the number of water mites inside the black fly cocoons. Free-living deutonymphal and adult water mites representing 15 different species of six genera and five families were morphologically identified. The taxonomic identity of the parasitic mite larvae is unclear at present. Morphologically, they fit descriptions of larval Sperchon (Hispidosperchon) algeriensis Lundblad, 1942, but the possibility cannot be excluded that they represent Sperchon algeriensis, the most abundant species at the adult stage in this study and unknown at the larval stage, or even another species of the genus. A molecular analysis produced for the first time cytochrome oxidase I gene sequences for S. algeriensis.ConclusionsOur results contribute to current knowledge on Spanish Hydrachnidia and their relationships with simuliids as hosts. However, further research is needed to evaluate the diversity, distribution, bioecology and prevalence of this parasitism.Graphical

Meta-transcriptomics reveals potential virus transfer between Aedes communis mosquitoes and their parasitic water mites.

Arthropods harbor a largely undocumented diversity of RNA viruses. Some arthropods, like mosquitoes, can transmit viruses to vertebrates but are themselves parasitized by other arthropod species, such as mites. Very little is known about the viruses of these ectoparasites and how they move through the host-parasite relationship. To address this, we determined the virome of both mosquitoes and the mites that feed on them. The mosquito Aedes communis is an abundant and widely distributed species in Sweden, in northern Europe. These dipterans are commonly parasitized by water mite larvae (Trombidiformes: Mideopsidae) that are hypothesized to impose negative selection pressures on the mosquito by reducing fitness. In turn, viruses are dual-host agents in the mosquito-mite interaction. We determined the RNA virus diversity of mite-free and mite-detached mosquitoes, as well as their parasitic mites, using meta-transcriptomic sequencing. Our results revealed an extensive RNA virus diversity in both mites and mosquitoes, including thirty-seven putative novel RNA viruses that cover a wide taxonomic range. Notably, a high proportion of viruses (20/37) were shared between mites and mosquitoes, while a limited number of viruses were present in a single host. Comparisons of virus composition and abundance suggest potential virus transfer between mosquitoes and mites during their symbiotic interaction. These findings shed light on virome diversity and ecology in the context of arthropod host-parasite-virus relationships.

A new pattern of parasitism in water mites (Hydrachnidia)? An insight into their relationships with pupae of caddisflies (Trichoptera).

To date, relatively few data have been available regarding the parasitism of water mite larvae on caddisflies; most available information relates to the adult stadia, fewer to caddisfly larvae, with just single references to pupae. The present paper examines the occurrence (phoresy and parasitism) of Piona stjordalensis larvae (119 individuals) on the larvae and pupae of Mystacides longicornis. It is possible that water mite larvae exhibit a new type of parasitism on caddisflies, with two consecutive parasitic larval stadia: one on the pupa, the other on the imago.

Parasitism on Riparian Dragonflies (Odonata) at Biology Education and Research Forest, Universitas Andalas

Parasitism on dragonflies (Odonata) may become the least attention in most entomological studies in Indonesia, since it possesses much indirect effect to human being. The odonata parasitism is caused by the infestation of water mite larvae onto the body of adult dragonflies. In this paper we discuss the result of odonatological survey we did at two tributaries in Biology Education and Research Forest (BERF), Universitas Andalas. The survey had been conducted between August to November 2019. We recorded 17 dragonfly species bound to these tributaries, 12 Zygopterans and 5 Anispterans. Water mite infestation was observed to happen on four Zygopteran species and one Anisoptera. The highest prevalence was shown by Orthetrum testaceum (100%), followed by Euphaea variegata (16.67%), Prodasineura verticalis (14.29%), Euphaea modigliani (3.57%) and Heliocypha angusta angusta (0.85%). In overall, the prevalence on community level reached 3.29%. The parasitism case observed in the tributaries of BERF can be classified as low incident, each infested odonate only contained a single water mite except for O. testaceum with two water mites. We presume that habitat condition may contribute to the rate of dragonfly parasitism, where a good habitat help lowering the parasitism incident.

Aquatic larval of the genus Arrenurus (Trombidiformes: Parasitengonina: Arrenuridae) associated with Odonata species from Pampa Biome, Brazil

Abstract: Many studies have reported that the interaction between water mite larvae and their Odonata hosts affects mating success, flight, and longevity. Males and females of Odonata species collected in the steppes and coastal plains (Pampa Biome) of Rio Grande do Sul were analyzed. Mites were removed when present and the prevalence and intensity of parasites was calculated. The aim of this study was to search and report new Odonata hosts species that are parasitized by water mite larvae and also to evaluate the prevalence and intensity rates; the differences in mite occurrence and frequency between males and females, and between thorax and abdomen of the dragonflies and damselflies in the southern Pampa biome located in Rio Grande do Sul. A total of 162 larval mites were found associated to two Odonata families: Coenagrionidae (Acanthagrion lancea Selys, 1876, Ischnura capreolus Hagen, 1861 and Ischnura fluviatilis Selys, 1876) and Libelullidae (Micrathyria ocellata Martin, 1897 and Perithemis mooma Kirby, 1889). All mites were identified as Arrenurus (Arrenurus) sp. (Arrenuridae) and showed high numbers when attached to I. capreolus (55.5%), I. fluviatilis (33.3%), followed by low numbers on M. ocellata (6.1%), A. lancea (3.7%), and P. mooma (1.2%). Mites were found on males and females of I. capreolus and I. fluviatilis, females of A. lancea and P. mooma and in M. ocellata only in males. As the parasitized Odonata species are generalist and abundant in all water body types, traits associated with mating and oviposition or larval behavior are believed to explain the frequency of parasitism in these species.

Molecular Correlation between Larval, Deutonymph and Adult Stages of the Water Mite Arrenurus (Micruracarus) Novus.

The systematics of many groups of organisms has been based on the adult stage. Morphological transformations that occur during development from the embryonic to the adult stage make it difficult (or impossible) to identify a juvenile (larval) stage in some species. Hydrachnidia (Acari, Actinotrichida, which inhabit mainly continental waters) are characterized by three main active stages—larval, deutonymph and adult—with intermediate dormant stages. Deutonymphs and adults may be identified through diagnostic morphological characters. Larvae that have not been tracked directly from a gravid female are difficult to identify to the species level. In this work, we compared the morphology of five water mite larvae and obtained the molecular sequences of that found on a pupa of the common mosquito Culex (Culex) pipiens with the sequences of 51 adults diagnosed as Arrenurus species and identified the undescribed larvae as Arrenurus (Micruracarus) novus. Further corroborating this finding, adult A. novus was found thriving in the same mosquito habitat. We established the identity of adult and deutonymph A. novus by morphology and by correlating COI and cytB sequences of the water mites at the larval, deutonymph and adult (both male and female) life stages in a particular case of ‘reverse taxonomy’. In addition, we constructed the Arrenuridae phylogeny based on mitochondrial DNA, which supports the idea that three Arrenurus subgenera are ‘natural’: Arrenurus, Megaluracarus and Micruracarus, and the somewhat arbitrary distinction of the species assigned to the subgenus Truncaturus.

<p class="Body">Parasitism of mosquitoes (Diptera: Culicidae) by water mite larvae (Acari: Hydrachnidia) in Amol, Mazandaran Province, northern Iran

Mosquitoes transmit a wide range of vector-borne diseases to humans and animal. Due to the increase in insecticide resistance, there is a need for novel mosquito vector control programs, including biocontrol. Some water mite larvae, such as those of Arrenurus genus, act as parasites of mosquitoes. Mosquito larvae, pupae and adults were collected from three locations in Amol County, Iran by dipping and hand-catch collection methods, from May to late September 2015. Then mites were removed from mosquitoes and identified to genus level using valid identification keys. A total of 873 adults of anopheline mosquitoes belonging to three species (Anopheles maculipennis s.lat., An. pseudopictus and An. hyrcanus) were collected. We only found Arrenurus sp. mites. From 873 anopheline mosquitoes captured, 11% were parasitized by 151 mites, with a mean rate of 1.59, ranging from 1 to 14. Parasitism was higher in lowlands. Water mites, as biocontrol agents of vectors, could impact fecundity, fertility and induce other harms on host. As this study is the first research on water mite parasitism on mosquitoes in Iran, more detailed studies are needed to increase our knowledge on biology and ecology of water mites parasitizing mosquitoes in Amol and other areas in Caspian sea region in Iran.

Larval morphology of Hygrobates foreli (Lebert, 1874), H. longiporus Thor, 1898 and H. trigonicus Koenike, 1895 (Acari, Hydrachnidia, Hygrobatidae).

This study presents a detailed taxonomic review of water mite larvae and females of three species of the genus Hygrobates Koch, 1837 found in the Fauna of Russia: Hygrobates foreli (Lebert, 1874), H. longiporus Thor, 1898 and H. trigonicus Koenike, 1895. The larvae described by Wainstein (1980) under the name H. longiporus and H. foreli were probably misidentified and belong to other species.

Parasitism of diving beetles (Coleoptera: Dytiscidae) by larvae of the water mite Acherontacarus rutilans (Hydrachnidiae, Acari) in Diyarbakır Province, Turkey

ABSTRACTThis study was conducted in Diyarbakır Province in 2013–2014. Specimens of predatory diving beetles belonging to the family Dytiscidae Leach, 1815 were collected from various aquatic habitats. In total, 2115 specimens were collected that belong to 32 species of 12 genera: Agabus, Bidessus, Colymbetes, Dytiscus, Hydroglyphus, Hydroporus, Hygrotus, Ilybius, Laccophilus, Nebrioporus, Platambus, and Scarodytes. Twenty eight specimens belonging to seven species of the genus Agabus Leach, 1817 (Agabus biguttatus, A. bipustulatus, A. caraboides, A. conspersus, A. guttatus guttatus, A. nebulosus, and A. sturmii) and collected from eight different localities were parasitized by larvae of the water mite Acherontacarus rutilans E. Angelier, 1951. Except for A. biguttatus and A. nebulosus, host–parasite associations of A. rutilans are reported for the first time. The number of water mite larvae per host specimen ranged from 1 to 30. In our study area, the infestation rate of all Dytiscid beetles was 1.32% versus 5.99% in the genus Agabus. These infestation rates are compatible with previous reports.

New records of host-parasite relationships between Coenagrion scitulum (Rambur, 1842) (Odonata) and water mite larvae (Hydrachnidia) in core and edge host populations.

The relationships between water mite larvae parasitizing Coenagrion scitulum in core and edge populations were described. A total of 636 larvae of 7 water mite species were found on 143 C. scitulum adults (82 females and 61 males). C. scitulum was recorded for the first time as a host species for Arrenurus cuspidator, A. bruzelii, A. bicuspidator, A. tricuspidator, A. claviger and Hydryphantes octoporus. The degree of infestation by particular parasite species was typical for these species. In contrast, the parasites' preferences for host body parts were not typical, as they preferred abdominal segments 2-4, which in earlier studies had been avoided by water mite larvae. No differences were found in degree of infestation of Coenagrion scitulum individuals between core and edge populations, with the exception of Hydryphantes octoporus, which parasitized damselflies only in core populations.

Hyperparasitism of mosquitoes by water mite larvae.

Hyperparasitism of ectoparasitic water mite larvae on mosquitoes is still a neglected relationship and was investigated only in a few studies. We analysed 2313 female mosquitoes from six different sampling localities with regard to their degree of parasitism with water mite larvae. In total, we found 38 mosquito individuals parasitized by 93 water mite larvae, ranging from 1 to 12 larvae per mosquito. Water mite larvae detected are members of the two species Parathyas cf. barbigera (n = 92) and Arrenurus cf. globator (n = 1). Out of the analysed mosquitoes, individuals out of the species Aedes vexans, Anopheles claviger, Ochlerotatus communis, the Ochlerotatus cantans/annulipes group, Ochlerotatus cataphylla and Ochlerotatus sticticus were tested to be parasitized by water mite larvae. The highest prevalence was found within the species Oc. cataphylla (28.6%) and Oc. cantans/annulipes (21.7%). No water mite larvae were found, e.g. on individuals of Aedes cinereus, Coquillettidia richiardii, the Culex pipiens/torrentium group, Ochlerotatus caspius, Ochlerotatus dorsalis or Ochlerotatus punctor. All of the attachment sites were located between the neck and abdomen with the ventral thorax site being the most frequent one.

First record of parasitism of water mite larva (Acari: Hydrachnidia) on the pupa of Trichoptera.

During the studies on ecology of Trichoptera of anthropogenic water bodies we have unexpectedly discovered the parasitic larvae of water mites of the species Tiphys torris on the pupa of Triaenodes bicolor. This is the first documented case of the parasitism of water mites on the caddisfly pupa as well as the first ever record of the species which is regarded as a dipteran parasite on caddisflies. The situation is very untypical for preimaginal stages of caddisflies are used by phoretic and not parasitic water mite larvae. Parasitism has been confirmed in this case by the formation of stylostomes and enlarged sizes of the bodies of the larvae. This is probably the case of facultative parasitism in which the pupa has served as a substitute of the adult form of a caddisfly.

First observations in Turkish Thrace on water mite larvae parasitism of Ranatra linearis by Hydrachna gallica (Acari: Hydrachnidia)

Many aquatic insect species, including aquatic Hemiptera, are parasitized by water mite larvae. Although this situation may cause damaging impacts to the hosts, the mites can disperse and colonize new localities in this way. Little is known about the frequency of water mite ectoparasitism amongst the aquatic Hemiptera in Turkey. In this study, larval water mite parasitism on aquatic Hemiptera, which have been collected from different localities in Turkish Thrace, was evaluated. It was found that only nine individuals, belonging two different species in a total of 367 hemipteran specimens, were parasitized by larval water mites. Furthermore, variations in sizes and shapes of the mites on the waterscorpion Ranatra linearis Linne, 1758 and Nepa cinerea Linne, 1758 were determined. These are the first records for larval mite parasitism on R. linearis and N. cinerea in Turkish Thrace.

Adult Mosquitoes Parasitized by Larval Water Mites in Pennsylvania

A survey of water mite larvae parasitizing adult mosquitoes was conducted throughout Pennsylvania. In total, 929,873 individuals and 46 species of mosquitoes were collected from 6,499 sites, and mites were examined from a subset of the parasitized mosquitoes. From 282 of the sites, 1,836 mosquitoes were parasitized by 4,769 mites, with a mean intensity of 2.6, ranging from 1 to 31. Twenty-one species of mosquitoes representing Aedes, Anopheles, Coquillettidia, Culex, Ochlerotatus, Orthopodomyia, and Psorophora were parasitized by 1 Parathyas sp., 7 Arrenurus spp., and 7 Arrenurus morphotypes. All mite species are documented from Pennsylvania for the first time. The largest numbers of hosts were Coquillettidia perturbans and Ochlerotatus trivittatus, and of parasites were Arrenurus danbyensis and Parathyas barbigera. Aedes spp., Ochlerotatus spp., and Psorophora ferox were mostly parasitized by P. barbigera, Anopheles spp. and Cq. perturbans mostly by Arrenurus spp., and Culex spp. by both P. barbigera and Arrenurus spp. Thirty-three different associations were observed, and 17 of these are new records. Parasitism of individual mosquitoes by more than 1 mite species was rare. Most P. barbigera individuals were attached on the pre-abdominal region of their hosts, and, when not in this position, they were attached anterior on the thorax, and less commonly on the cervix or abdomen. Most A. danbyensis and Arrenurus delawarensis individuals were attached to the cervix of Cq. perturbans. Arrenurus danbyensis on Cq. perturbans had mean and maximum intensities of 2.8 and 31, and showed a clear trend in attachment site distribution, with sequential progression from head to abdomen.

Anatomy and ultrastructure of the salivary (prosomal) glands in unfed water mite larvae Piona carnea (C.L. Koch, 1836) (Acariformes: Pionidae)

Anatomy and ultrastructure of prosomal salivary glands in the unfed water mite larvae Piona carnea (C.L. Koch, 1836) were examined using serial semi-thin sections and transmission electron microscopy. Three pairs of alveolar salivary glands shown are termed lateral, ventro-lateral and medial in accordance with their spatial position. These glands belong to the podocephalic system and are situated on the common salivary duct from back to forth in the above mentioned sequence. The arrangement of the medial glands is unusual because they are situated one after another on the medial (axial) body line, therefore they are termed anterior and posterior medial glands. The secretory duct of the anterior medial gland mostly turns right, and the duct of the posterior gland turns left. The salivary glands are located in the body cavity partly inside the gnathosoma and in the idiosoma in front of the brain (synganglion). Each gland is represented by a single acinus (alveolus) and is composed of several cone shaped secretory cells arranged around the large central (intra-acinar) cavity with the secretory duct base. The cells of all glands are filled with secretory vesicles of different electron density. The remaining cell volume is occupied by elements of rough endoplasmic reticulum, and the membrane enveloping vesicles may have ribosomes on its external surface. Large nuclei provided with large nucleoli occupy the basal cell zones. The pronounced development of the prosomal salivary glands indicates their important role in extra-oral digestion of water mite larvae.

<p><strong>Comparative and functional morphology of the mouthparts in larvae of </strong><strong>Parasitengona (Acariformes)*</strong></p>

Anatomy and ultrastructural organization of the larval mouthparts in representatives of terrestrial (Trombiculidae parasitizing vertebrates and Microtrombidiidae parasitizing arthropods) as well as aquatic (Pionidae and Hydrodromidae parasitizing arthropods) families from the cohort Parasitengona were studied using whole-mount preparations, semi-thin sections and TEM and SEM methods. In these groups, the organization of the mouth apparatus differs significantly especially with regard to their particular functional specialization and adaptations reflecting evolutionary trends in these groups. In trombiculid larvae, the mouthparts reveal the simplest organization. The gnathosoma is totally free, the infracapitulum and the basal cheliceral segments are short and wide, and the latter are separated from each other. The flexible lateral lips form a temporary sucker, distinguishable when the larva feeds, and the pharynx is totally fused with the bottom of the infracapitulum. In microtrombidiid larvae, the gnathosoma is covered by the arched dorsal shield, the chelicerae are comparatively long and separated, and the lateral lips form a permanent sucker provided with an internal sclerite. Conversely, in water mite larvae, the chelicerae are fused together and either partially (Piona carnea) or totally (Hydrodroma despiciens) free from the overhanging idiosomal fold. The lateral lips are flexible and organized freely, and the pharynx is totally separated from the bottom of the infracapitulum. In general, water mite larvae show significant variations and specializations but at the same time seem to possess the most plesiomorphic characters in organization of the mouth apparatus. The ancestral parasitengone may have given rise to divergent groups of water mites as such, as well as to trombiculids with the secondary simplification of the mouth apparatus and to microtrombidiids with their particular additional adaptations and specialization in organization of the mouthparts.

Functional morphology and ultrastructure of mouthparts in unfed water mite larvae Piona carnea (Koch, 1836) (Acariformes: Pionidae)

Mouthparts of unfed larvae Piona carnea (Koch, 1836) (Acariformes: Pionidae) were studied on whole-mount preparations, semi-thin sections and with TEM and SEM methods. The mouth apparatus is incorporated within the pseudotagma, gnathosoma, composed of the infracapitulum and of the chelicerae resting on the roof of the latter. The gnathosoma inclines to the long axis of the body and is inserted at its base into the idiosoma by the circumcapitular fold. The basal cheliceral segments are long and fused. An anterior projection, the proposed fused fixed digits, protrudes from the distal end of the basal cheliceral segment forward between the movable digits. The movable digits are always found in protruded position, strongly curved upward and show a groove on their inner sides. The ventral wall of the infracapitulum is made of the mentum posterior and the malapophyses anterior to the palp articulation. The malapophyses are squeezed between the large palps and envelope the distal portion of the chelicerae from the sides. The ventral portion of the fused malapophyses are provided with a characteristic ventral cuticular fork of unknown function. Each malapophysis terminates by a flexible lateral lip provided by several rigid jags looking posterad. The palps face downward and backward, and bear on the tibia the large curved palpal claws turned laterad. The palp femur bears on the ventral aspect a characteristic wide spade-like projection provided with its own muscles originating on the dorsal wall of the femur. The labrum is a thick cuticular arrow-like structure protruding forward into the preoral cavity, whereas the cervix is a thin weakly sclerotized plate. The particular labral valve projects forward from the dorsal basis of the labrum into the preoral cavity. The labrum and the cervix are provided by their own small labral and cervical muscles originating on the cervical apodemes. The pharynx is totally separated from the ventral wall of the infracapitulum and is devoid of ventral dilators. The dorsal pharyngeal dilators originate on the thick and sclerotized capitular apodeme and, posteriorly, on the paired cuticular branches, capitular apodemes, which end freely in the body cavity and are combined with the common salivary duct. The short sigmoid pieces serve for origin of the levator muscles of the chelicerae. Retraction of the gnathosoma and the chelicerae is mediated by several sets of muscles originating on the dorsal plate.

Morphological characteristics of water mite larvae of the genus Arrenurus Duges, 1834, with notes on the phylogeny of the genus and an identification key

The larval characteristics of 42 European Arrenurus species are provided, based on earlier descriptions. Diagnostic characters are elucidated. The division of the genus into the subgenera Arrenurus s. str., Micrarrenurus, Megaluracarus, Micruracarus, and Truncaturus has been retained. Principal Components Analysis (PCA) and phylogenetic analysis using the Maximum Parsimony (MP) method were used to construct a phylogenetic tree of the genus. Recommendations on changes to the traditional subgeneric systematics are given, concerning mainly the subgenera Micruracarus and Truncaturus as well as subgeneric allocation of Arrenurus nobilis Neuman which is transferred from Arrenurus s. str. to Micruracarus. An identification key, supplemented with diagnostic descriptions of individual species, is supplied.

Parasite Infestation of Antocha (Antocha) bifidaAlexander, 1924 (Diptera: Tipulidae) by Water Mite Larvae (Sperchon plumiferThor, 1902) in the Middle Reaches of the Shinano River, Central Japan

AbstractThis is the first report of parasite infestation of Tipulidae by water mite larvae in the middle reaches of a river in Japan. Forty‐four species of adult crane flies were identified. The most abundant species was Antocha (Antocha) bifida Alexander 1924 with 22204 individuals (76.5% were male). Some 2113 individuals (9.5%) were parasitized by water mites, viz., Sperchon plumifer Thor 1902 (maximum: 40/host, mean value: 3.5 ± 2.5/host). 73.1% of S. plumifer larvae were attached to the abdomen. Many S. plumifer larvae parasitized A. bifida adults from late May to early July, but after a small flood, few S. plumifer larvae were collected. Floods have a major impact on both the A. bifida population and on its parasite, the S. plumifer larval population. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)