Pollination mechanism in southern Brazilian orchids which are exclusively or mainly pollinated by halictid bees

The pollination process is documented in three sympatric orchids found in Curitiba, Paraná State, southern Brazil. InCampylocentrum aromaticum (Epidendroideae: Angraeciinae) andPrescottia densiflora (Spiranthoideae: Prescotiinae) halictid bees act as main pollinators with minor contributions from other insects, such as Syrphid flies. Because of the pollinarium and column structure inCyclopogon diversifolius. (Spiranthoideae, Spiranthinae), halictid bees are the only insects capable of performing pollination. In the three studied species pollinarium removal and deposition are achieved by interaction between the column and bee's mouth parts. Morphological and ecological flower features in agreement with this pollination mode are discussed and pollination by halictid bees is suggested to occur in a number of South American orchids.     

Evolution of Campanula punctata Lam. in the Izu Islands: Changes of Pollinators and Evolution of Breeding Systems

Abstract The pollination and breeding systems of Campanula punctata both in the Izu Islands and the mainland (Honshu) adjacent to the islands were investigated. The predominant pollinators of campanulas are: 1) Bombus diversus in Honshu, 2) Bombus ardens and halictid bees on Oshima Island, and 3) halictid bees on the islands of Niijima, Kodzushma, and Hachijo. The absence of bumble bees except B. ardens on Oshima Island, and the abundance of halictid bees represent a kind of island effect. Flowers of the campanula in the Islands were found to be smaller than those of the mainland. This might have resulted from adaptation to the small pollinators. Pollination experiments with plants grown from seeds revealed the following differences in breeding system: 1) most of the campanulas from Honshu were highly self-incompatible (SI) and a few partially self-compatible (SC), 2) one half of the plants from Oshima Island were more or less SC and the remaining highly SI, 3) those from Hachijo Island were SC and potentially autogamous. The breakdown of dichogamy co-operated with self-compatibility in the development of self-fertilizing ability in Hachijo plants. Several possible causes for the change in the breeding system including the change in pollinators in the Islands are discussed.     

Ambush Predation by the Ponerine Ant Ectatomma ruidum Roger (Formicidae) on a Sweat Bee Lasioglossum umbripenne (Halictidae), in Panama

An individual ambush predation is used by huntresses of the ponerine ant Ectatomma ruidum to capture halictid bees (Lasioglossum umbripenne) in the Panamanian mountains. Workers, which use this strategy and originated from a colony (A) situated within a nest aggregation of halictid bees, capture almost four times more prey than colony (B) with a foraging area which does not include this type of bee's nest. Forty-eight percent of the prey of colony (A) are halictid bees, demonstrating the local importance of this predatory strategy in E. ruidum. A close examination of the behavioral sequence of predation shows that ambush is successful in only 4.8% of cases, a very low success rate in comparison to other predatory strategies described in this species. Nevertheless, due to the high repetition (16.1 ± 5.9 times on average) of very short waiting phases (6.3 ± 1.9 s), the true success rate (i.e., according to the number of individual trips) can reach up to 80%. A review of ambush predation among ant species allows us to distinguish approaches between jumping, long stealth approaches, and true ambushes. Implications of learning and expectation processes are also discussed.     

Parasitism of the Wheat Stem Sawfly (Hymenoptera: Cephidae) in Montana

The wheat stem sawfly,Cephus cinctusNorton (Hymenoptera: Cephidae) was first found in wild grasses and soon became an economically important pest of wheat after cultivation began in the northern Great Plains. Of the species of parasitoids that attackC. cinctusin wild grasses, onlyBracon cephi(Gahan) andB. lissogasterMuesebeck (Hymenoptera: Braconidae) have been found in wheat. Levels of parasitism vary between wheat-producing regions in Montana. Parasitism levels were increased by releasing individuals from a region with high levels of parasitism into a region where parasitism levels were low. This suggests that there has been unequal rates of parasitoid adaptation from wild grasses to wheat in different regions of Montana.     

Trichogramma egg parasitism ofHelicoverpa armigera on short-duration pigeonpea intercultured with sorghum

The levels of egg parasitism byTrichogramma spp. (Hymenoptera: Trichogrammatidae) on populations ofHelicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) were recorded on sorghum (Sorghum bicolor L.) and on two flushes of flowers on short-duration pigeonpea (Cajanus cajan L.).H. armigera oviposition was concentrated on the early flowering stage of sorghum and the flowering and early podding stages of both flushes of pigeonpea. Parasitism on sorghum increased rapidly as egg density increased and reached a peak of 74.6%. Parasitism on pigeonpea was concentrated onH. armigera eggs laid on the first flush of pigeonpea flowers with a maximum of 69.2%. These high levels of parasitism on pigeonpea coincided with the period of parasite activity on sorghum. The levels of parasitism then declined rapidly and only very low levels were detected on a second flush of flowers. This rapid decline resulted in the overall egg mortality caused byTrichogramma on pigeonpea to be low, with a maximum of 7.8% caused by parasitism, compared to 34.4% on sorghum. The pattern of parasitism suggests that a transfer of parasites occurred from sorghum to pigeonpea. The rapid decline of parasitism on the pigeonpea indicates that parasite populations cannot be sustained on pigeonpea once the influx from sorghum stops. The results are discussed in terms of a possible method of encouraging the transfer of parasites from sorghum to short-duration pigeonpea by producing a more continuous cropping environment.     

Contrasting scales of oviposition and parasitism in praying mantids

We report on spatial patterns of parasitism of oothecae (egg cases) of praying mantises (Stagmomantis limbata) by torymid wasps, Podagrion spp. Using collections of mapped mantid oothecae from Riparian sites in the Sonoran desert and Grassland sites in the Chiricahua Mountains (both in Arizona, USA), we characterized the spatial distributions of oothecae and parasitism. The likelihood of an egg case suffering some parasitism was higher at Grassland sites, which had high oothecal densities, than at low-density Riparian sites. However, experimental isolation of Grassland oothecae to densities comparable to Riparian sites reduced parasitism rates. At Riparian sites, parasitized oothecae exhibited on average the same extent of parasitism as parasitized oothecae at high densities but with much greater variation. Indeed, large fractions of Riparian oothecae suffered both severe (>50%) and light (<20%) parasitism, whereas most parasitized Grassland oothecae suffered intermediate levels of parasitism. Analysis of first nearest neighbor distances indicated that the parasite load of an ootheca did not depend on its immediate isolation. However, extending the analysis to include subsequent nearest neighbors (using a technique from spatial statistics called the R(K) function), we found that even though oothecae of S. limbata were spatially clustered, some oothecae in a (statistically defined) cluster escaped parasitism when overall oothecal densities were low. This pattern suggests that when oothecae are sparsely distributed, Podagrion wasps exploit only a fraction of the oothecae available locally, even though the oothecae are strongly aggregated relative to their overall density. We suggest this lack of congruency in the scales of oothecal deposition and parasitism at low densities (which is absent when oothecae are at high densities) may be explained in part by behavioral aspects of the parasite's reproduction, including increased host fidelity by relatively sedentary female parasites. Received: June 13, 2000 / Accepted: October 16, 2000     

Biological control of Lygus lineolaris by Peristenus spp. in strawberry

Peristenus digoneutis Loan (Hymenoptera: Braconidae) was introduced to the US for biological control of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae), and has since spread through much of the northeast. The purpose of this study was to determine if P. digoneutis and a native congener, Peristenus pallipes (Curtis), parasitize L. lineolaris in strawberry (where it is a key pest), and what factors relate to parasitism levels. During 1997–1999 we monitored parasitism on 17 strawberry farms in 14 counties in eastern and western New York State. We found that in eastern NY (where P. digoneutis has been established since the early 1990s), overall mean parasitism was 19.7% (ranging from 0 to 70%), mostly by P. digoneutis. Mean parasitism was significantly lower (12.3%, ranging from 0 to 58%) in western NY (where P. digoneutis was first recorded in 1999), and was mostly by P. pallipes. P. pallipes parasitism was significantly lower in eastern than western NY, suggesting the potential for competitive interaction with P. digoneutis. The insecticide regime of a farm was an important factor influencing parasitism rate, which was 5- to 6.5-fold higher on organic or casually sprayed farms than on intensely treated farms, though pest density under these three regimes was not significantly different. L. lineolaris density, and parasitism rate in nearby alfalfa and abandoned fields were also significant factors for parasitism in strawberry.     

Differences in egg parasitism of Chrysophtharta agricola (Chapuis) (Coleoptera: Chrysomelidae) by Enoggera nassaui Girault (Hymenoptera: Pteromalidae) in relation to host and parasitoid origin

Abstract The first instances of egg parasitism of Chrysophtharta agricola , a pest of eucalypt plantations, are recorded. Enoggera nassaui was found parasitising C. agricola egg batches in Tasmania, the Australian Capital Territory (ACT), New South Wales and Victoria: this is the first record of this parasitoid species from Victoria. One instance of Neopolycystus sp. parasitising C. agricola eggs in Victoria was also recorded. Parasitism of egg batches by E. nassaui ranged from 0 to 55% between five geographical populations collected in mainland Australia ( n  = 45), and from 0 to 2% between two populations collected in Tasmania ( n  = 300). For mainland sites at which parasitism was recorded, parasitism rates within sites differed significantly from either population in Tasmania. Reciprocal exposure experiments using one Tasmanian (Florentine Valley) and one parasitised mainland (Picadilly Circus, ACT) population were conducted in the laboratory to examine whether these different parasitism rates were attributable to egg or parasitoid origin. Parasitoids from the ACT parasitised C. agricola eggs of both origins more successfully than parasitoids from Tasmania, with up to 65% wasp emergence compared with 33% from Tasmania. Parasitoid origin significantly affected the number of wasps that emerged from exposed batches, but not the total loss from parasitism.     

Seasonal phenology and stage-specific parasitism of the apple ermine moth, Yponomeuta malinellus Zeller, in Korea

The apple ermine moth, Yponomeuta malinellus Zeller (Lepidoptera: Yponomeutidae), is a tent caterpillar that feeds on Malus spp. in Korea. Populations of the moth in native areas appeared to be regulated by the assemblage of parasitoids. Phenological associations between host stages and parasitoids, susceptible stage(s) of the host for each parasitoid, and stage‐specific parasitism were studied. The egg larval parasitoid Ageniaspis fuscicollis (Dalman) had highest parasitism of first instar larvae (24%), with 14% parasitism of other larval stages. Dolichogenidea delecta (Haliday) was recovered from all larval instars with the highest parasitism rate of second instar larvae (20.1%), followed by 19.9% parasitism of mid‐larval hosts. Herpestomus brunicornis Gravenhorst was reared from second instar larvae through to pupal collection, and had the highest parasitism rate (29.9%) at the pupal stage. The larval pupal parasitoid Zenillia dolosa (Meigen) was recovered from mid‐larval to pupal stages with the highest parasitism rate (5.5%) occurring in third to fourth instar larvae. The host stages for developing A. fuscicollis completely overlap with those of D. delecta, and with those of H. brunicornis to some degree. A statistically significant negative correlation exists between A. fuscicollis and these dominant parasitoids, indicating competitive interaction within the host.     

Nematode parasitism in a northern European drosophilid community

Many factors may influence the structure of invertebrate communities. Among these is the presence of parasites which attack some or all members of a guild and potentially promote coexistence of competitor species. We assessed the prevalence of nematode (Allantonematidae) parasitism in Dutch woodland drosophilids (Diptera). Nematodes were found in 6 of the 18 drosophilid species sampled (percentage parasitism in parentheses): Drosophila phalerata (16%), D. kuntzei (5.1%), D. immigrans (0.5%), D. testacea (1.2%) and D. transversa (2.8%) were all parasitized by Howardula aoronymphium and D. subobscura (3%) was parasitized by Parazitylenchus diplogenus. This is the first report of nematode parasitism of D. immigrans and D. transversa. There were no important seasonal trends in percentage parasitism. We explored the consequences of nematode parasitism for individual drosophilids. Nematodes did not exert an important influence on the wing length (adult body size) of the drosophilids we sampled, but egg loads (fecundities) of female D. phalerata, D. subobscura and D. kuntzei were reduced by nematode parasitism. Parasitism rates were positively correlated with relative host abundance, in Dutch and other communities, suggesting that species diversity is promoted by a disproportionately high parasitism of more common host species.     

Intraspecific nest parasitism in the European starling Sturnus vulgaris

Biochemical genetic markers were used along with conventional methods (abnormal laying sequence/clutch size, unusual egg shape/pigmentation) to identify intraspecific nest parasitism at two British nestbox colonies of the European starling. Between 11 and 37% of first clutches were parasitized during 1977–1979. Parasitic females probably comprised all of the following categories: (1) paired females contesting a nestbox occupied by another pair; (2) previously paired females who had laid a clutch but had been unsuccessful; (3) unpaired females who had copulated with males that already had a mate and nest site; and (4) ‘professional’ nest parasites who distributed at lest some of their eggs in one or more nests other than their own. Although parasitized nests had higher clutch sizes, parasitism led to fewer host young fledging per egg laid, mainly through the eviction of eggs and subsequent nest desertion. Number of parasitic young fledged per egg laid was highest when eggs were laid synchronously with the host, when host clutches were larger, or a smaller number of parasite eggs were added to a nest, thus favouring parasites that distribute their eggs amongst a number of nests. A greater pressure on nest sites may have accounted for the higher levels of parasitism at the Aberdeen colony and for the greater number of parasite eggs laid in a nest. Although most parasitic female starlings appeared to be much less successful than non-parasitic ones, nest parasitism in the starling might evolve directly when one or more of the following advantages are present. (1) There are no constraints on the number of eggs a female may lay but there are constraints on the number of young she may feed adequately. (2) Female survival is increased by having fewer or no eggs/young to care for. (3) Current feeding conditions favour the survival of more young than would be produced by the most common clutch size. Intraspecific nest parasitism is considered to be a first stage in the evolution of interspecific nest parasitism.     

Intrinsic competition between two oligophagous parasitoids, Sturmiopsis parasitica and Cotesia sesamiae, attacking the same life stages of lepidopteran cereal stemborers

Host acceptability and suitability of four cereal stemborers (Lepidoptera) commonly occurring in eastern Africa, Sesamia calamistis Hampson, Busseola fusca (Fuller) (both Noctuidae), Chilo partellus Swinhoe (Crambidae), and Eldana saccharina Walker (Pyralidae), for a West African strain of Sturmiopsis parasitica (Curran) (Diptera: Tachinidae) were assessed. In addition, the outcome of multi-parasitism was studied using a local strain of the endoparasitic Cotesia sesamiae Cameron (Hymenoptera: Braconidae) as the competing parasitoid. Various parasitism sequences and time intervals between parasitism were chosen. Parasitism increased linearly with the number of planidia used per larvae and was 80% with eight planidia. All species were accepted for larviposition, but suitability varied greatly; parasitism was 75.2, 37.9, 34.8, and 23.8% with S. calamistis , B. fusca , E. saccharina , and Ch. partellus , respectively. Sturmiopsis parasitica outcompeted Co. sesamiae irrespective of the time interval between parasitism, and whether it was the first or second species to parasitize. This was mainly due to a longer egg-to-cocoon development time and a high cocoon-to-adult mortality in Co. sesamiae . The implications of these results for expanding the geographic range of the West African strain of the tachinid in Africa are discussed.     

Profitable self-superparasitism in an infanticidal parasitoid when conspecifics are present: self-superparasitism deters later attackers from probing for infanticide

Abstract.  1. To reveal the profitability of self-superparasitism when conspecifics are present, the total combined fitness returns from the first and second ovipositions under triple parasitism were compared with fitness returns from the first oviposition under double parasitism, using the small brown hopper Laodelphax striatellus and its semi-solitary infanticidal parasitoid Echthrodelphax fairchildii .
2. The total combined survival rate of the first and second comers under triple parasitism with oviposition intervals of 1/24 h (where 1 and 24 h represent the first-to-second and second-to-third oviposition intervals respectively) was nearly double the survival rate of the first comer under double parasitism with a 25-h oviposition interval, although there was no difference between these triple and double parasitisms in terms of head width and developmental time. Under the conditions of other oviposition intervals, self-superparasitism produced null (1/1- and 24/24-h intervals) or negative fitness returns (24/1-h intervals). This suggests that self-superparasitism on hosts that were self-parasitised 1 h previously is profitable when conspecifics are present.
3. When the female parasitoid laid an egg on a host harbouring the earlier comer(s) on the non-oviposition side, she often probed the non-oviposition side for infanticide, i.e. killing the first offspring. When the first and second comers were on different sides, the probing frequency at the third oviposition in triple parasitism with 1/24-h oviposition intervals was lower than that at the second oviposition in double parasitism with a 25-h oviposition interval. This difference was responsible for the above difference in survival rate between the triple and double parasitisms.     

Delayed development of the whitefly (Bemisia tabaci) and increased parasitism by Encarsia bimaculata in response to sublethal doses of piperonyl butoxide

Abstract Effects of sublethal piperonyl butoxide (PB) on parasitization of Bemisia tabaci (Gennadius ) (Hemiptera: Aleyrodidae) by Encarsia bimaculata Heraty et Polaszek (Hymenoptera: Aphelinidae) were evaluated both in cage and greenhouse experiments. When first, second and third instar B. tabaci nymphs were treated with PB, all but the first instar were significantly prolonged. Data indicated that sublethal PB could improve E. bimaculata parasitism rates without influencing parasitoid eclosion rates. Prolonged development increased rates of parasitism by E. bimaculata, from 17.6% to 24.7% in cages, presumably by increasing the duration of host exposure. Sublethal PB combined with E. bimaculata as an integrated approach to control B. tabaci was evaluated using life table parameters under greenhouse conditions. Indices of population trend (I) calculated from life tables were estimated at 4.6 for B. tabaci exposed to PB and parasitoids compared to 14.1 with parasitoids alone and 23.5 in untreated controls. The results showed that after PB was sprayed and parasitoids introduced, development of B. tabaci was delayed and the peak of each stage was postponed. The older nymphal stage had highest mortality, primarily due to mortality caused by parasitism by E. bimaculata.     

Mode of development and interspecific avian brood parasitism

Avian interspecific brood parasites differ considerably in theircommitment to parasitism; 87 species are obligate brood parasites,whereas 35 species are known to be facultative brood parasites.This variation is strongly related to mode of development. Obligateparasitism is found almost exclusively in altricial species,whereas facultative interspecific parasitism is predominantin precocial birds. We propose that the association betweenmode of development and form of parasitism reflects a fundamentaldifference between altricial and precocial birds in the relativebenefits of emancipation from parental care after laying. Weargue that altricial brood parasites obtain such a large increasein realized fecundity by avoiding the costs of parental carethat obligate parasitism is favored over facultative parasitism.In contrast, precocial brood parasites gain relatively littlein terms of increased fecundity via obligate parasitism, andmuch of this increase could potentially be gained by facultativeparasitism. Thus, obligate interspecific brood parasitism willnot be favored in precocial birds. Three factors influence thisdifference between altricial and precocial species: (1) altricialbirds have relatively more energy and nutrients with which tolay additional eggs, (2) altricial birds can produce more eggsfor the same amount of energy and nutrients, and (3) altricialbirds realize a greater relative gain in fecundity for eachadditional egg laid. We suggest further that facultative interspecificparasitism in birds may originate simply through a carry overof intraspecific parasitism; 29 of 33 facultative interspecificparasites also parasitize conspecifics. Facultative parasitismof other species would provide a greater range of potentialhost nests and could be maintained as an evolutionarily stableend point by the same mechanisms that maintain intraspecificbrood parasitism. [Behav Ecol 1991;2:309–318]     

The selection of pupation sites by the stalk-eyed fly Diopsis thoracica (Diptera: Diopsidae) and pupal parasitism in some rice cultivars

Six rice cultivars (lines (TKM6, OS6, ADNY 11, IR28, Rexero and IR579-48-1) were used to determine the pupation sites of Diopsis thoracica and their effects on pupal parasitism. There was a general preference for pupation on the first three outer leaf sheaths. Preference was also observed for healthy tillers compared with damaged ones, except in OS6 where there was no significant difference between pupation on healthy and damaged tillers. Pupae on the first two outer leaf sheaths were heavily parasitised by the eulophid Tetrastichus (Neotrichoporoides) sp. (Hymenoptera). The level of parasitism ranged from 17·6% in OS6 to 58·8% in Rexero, with an overall mean of 38·9% for the entire experimental plot. The number of parasites per pupa ranged from 0·5 in OS6 to 3·0 in Rexero, with an overall mean of 1·37. There was a strong relationship between (a) parasitism (%) (r = 0·68); (b) number of parasites per pupa per variety (r = 0·90) and pupal length. The relationship between parasitism (%) and parasite density was very strong (r = 0·89), but a marginal improvement in relationship was obtained when parasitism (%) was correlated with log parasite density (r = 0·94), thus possibly suggesting weak interaction between the parasites.     

Intraspecific nest parasitism in the Spotless Starling Sturnus unicolor

Intraspecific nest parasitism in two colonies of Spotless Starling Sturnus unicolor breeding in nestboxes was studied in central Spain from 1991 to 1994. Nests were monitored regularly and three criteria were used to detect nest parasitism: the appearance of more than one egg per day during the laying period of the host; the appearance of an egg after the start of incubation; eggs with unusual shape or pigmentation. The proportion of parasitized nests in first clutches (37%) was twice that of intermediate (19%) or second (20%) clutches in colony B, whereas parasitism occurred in first (35%) and intermediate (12%) but not in second clutches in colony A. Most clutches (52–70%) were parasitized during the host's laying period and received one parasitic egg. In 10% of the parasitized clutches in colony B, one of the host's eggs disappeared on the day the parasitic egg was added, suggesting that the parasitic female removed this egg. Although parasitism increased clutch size significantly, it led to a decrease in host breeding success, mainly through the removal of eggs and the loss of host nestlings and the survival of parasitic chicks. Observations suggested that parasitic females were young individuals without their own nests and/or those whose breeding attempt had been disrupted while laying in their own nest.     

Do parasitic flies attack mites? Evidence in Baltic amber

We provide the first evidence of a small-headed fly planidium (first instar larva; Diptera: Acroceridae) associated with a whirligig mite (Acari: Acariformes: Prostigmata: Anystina: Anystidae) in Baltic amber. This fossil is surprising as parasitic nematodes are the only metazoans known to successfully attack acariform mites, and Acroceridae are believed to be host-restricted parasitoids of spiders. The fossil corroborates a previously published, but widely dismissed, paper that first reported parasitism of parasitengone mites by acrocerid planidia. The possible natural history implications of this find are discussed.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 93 , 9–13.     

Classical Biological Control of the Citrus Blackfly <Emphasis Type="Italic">Aleurocanthus Woglumi</Emphasis> by <Emphasis Type="Italic">Amitus Hesperidum</Emphasis> in Trinidad

The citrus blackfly Aleurocanthus woglumi Ashby (Homoptera: Aleyrodidae), a native of South East Asia, was first reported in Trinidad in 1998. As part of a classical biological control programme against the pest, releases of Amitus hesperidum Silvestri (Hymenoptera: Platygasteridae) were made in Trinidad from June to August 2000. Field studies were conducted on three commercial citrus farms, two large estates ( >500 ha) and one small orchard (<50 ha) where releases were initially made. Adult blackfly and Amitus populations were monitored weekly with yellow sticky traps. Immature blackfly and parasitism rates were monitored monthly by field sampling. During the study period, citrus blackfly populations declined by more than 98% at all sites while parasitism increased to 60–90%. There were, however, differences between locations, with control at Cumuto being reached within 4 months, at Todd’s Road between 6 and 7 months and at La Gloria about 13 months. This was consistent with the parasitism rates recorded. Although Encarsia perplexa Huang and Polaszek (Hymenoptera: Aphelinidae) was also introduced, it would seem that A. hesperidum was capable of bringing down and maintaining citrus blackfly populations at acceptable levels by itself.     

Closing the mitochondrial circle on paraphyly of the Monogenea (Platyhelminthes) infers evolution in the diet of parasitic flatworms

Relationships between the three classes of Neodermata (parasitic Platyhelminthes) are much debated and restrict our understanding of the evolution of parasitism and contingent adaptations. The historic view of a sister relationship between Cestoda and Monogenea (Cercomeromorphae; larvae bearing posterior hooks) has been dismissed and the weight of evidence against monogenean monophyly has mounted. We present the nucleotide sequence of the complete mitochondrial (mt) genome of Benedenia seriolae (Monogenea: Monopisthocotylea: Capsalidae), the first complete non-gyrodactylid monopisthocotylean mt genome to be reported. We also include nucleotide sequence data for some mt protein coding genes for a second capsalid, Neobenedenia sp. Analyses of the new mt genomes with all available platyhelminth mt genomes provide new phylogenetic hypotheses, which strongly influence perspectives on the evolution of diet in the Neodermata. Our analyses do not support monogenean monophyly but confirm that the Digenea and Cestoda are each monophyletic and sister groups. Epithelial feeding monopisthocotyleans on fish hosts are basal in the Neodermata and represent the first shift to parasitism from free-living ancestors. The next evolutionary step in parasitism was a dietary change from epithelium to blood. The common ancestor of Digenea + Cestoda was monogenean-like and most likely sanguinivorous. From this ancestral condition, adult digeneans and cestodes independently evolved dietary specialisations to suit their diverse microhabitats in their final vertebrate hosts. These improved perspectives on relationships fundamentally enhance our understanding of the evolution of parasitism in the Neodermata and in particular, the evolution of diet.