American Congeners Research Articles

The Mexican Balsam, Impatiens mexicana Rydb: A Redescription Based on Morphological and Phylogenetic Studies, with an Update of the Current Geographical Range of the Species

Impatiens mexicana is a native balsam restricted to the cloud forests of central and southwest Mexico, which is currently known to exist in four states (Zacatecas, Veracruz, Puebla, and Oaxaca), and is probably threatened by geographic restriction. Morphological and distributional information about this species is still scarce, with only a couple of investigations since its first description in 1910, which means the phylogenetic position of this species has yet to be placed. In order to contribute to knowledge of I. mexicana, morphological and molecular studies were carried out with material collected in the localities of Hidalgo, Veracruz, and Oaxaca, during expeditions from July to October 2021 and in 2022. The specimens selected were measured, photographed, and compared with morphological information from the six American balsams. At the same time, phylogenetic studies were carried out by using two regions of the cpDNA and one of the nrDNA. We report I. mexicana for the first time in Hidalgo state, and identify new registers in the Veracruz and Oaxaca localities, thus increasing the knowledge in its geographic distribution. We also redescribe the Mexican balsam by using new and complementary traits: we note that while the species is morphologically similar to I. capensis, it is distinguished by differences in flower color, the distribution of spot patterns on the upper petal, lower sepal, and lateral petals, and geographic information such as endemic geographic distribution in Mexico’s Tropical Montane Cloud Forest (TMCF). We also carried out phylogenetic analyses by using ITS and ITS + atpb-rbcL, which showed the Mexican balsam was independent from its Asian-American congeners. Interestingly, our genetic distance analyses reveal differences of 0.01–0.16% between I. mexicana and the other North American congeners that use ITS, atpb-rbcL and trnL-F, both independently and as concatenated genes: this low divergence most likely occurred because of the recent diversification of the group. However, both future redescriptions and phylogenetic studies in American species are imperative, as this will enable better discrimination.

Full redescription and first record of Dasyhelea bifida Zilahi-Sebess (Diptera: Ceratopogonidae) from Mexico

ABSTRACT Dasyhelea bifida Zilahi-Sebess is fully redescribed, photographed and drawn from adults collected in Mexico City by Alfonso Dampf in 1944. This species is compared with the American congeners D. crassiseta Borkent and Forster, D. furva Remm and D. pollex Borkent and Forster. This is a new record of this species from Mexico.

A new species of minute litter bug of the genus Cryptostemma (Heteroptera: Dipsocoromorpha: Dipsocoridae) from Basse-Terre (Guadeloupe Islands)

Summary A new species of the genus Cryptostemma Herrich-Schaeffer, 1835, C. karukeraensis n. sp., was collected in several localities of the island of Basse-Terre (Guadeloupe), by prospecting the particular micro-habitats specific to the Dipsocoridae. Males and females (macropterous) and 5th instar nymphs are described and illustrated, in particular details of the pregenital abdomen, and the highly asymmetric and modified genitalia in the male. Among its American congeners, the new species shows morphological similarities with C. haywardi Wygodzinsky described from Argentina, but differs in male and female genital characters. The standard barcode DNA sequence (COI) is given for this new species, which is the third known dipsocoromorphan representative from Guadeloupe, after Ceratocombus bifenestratus Poppius, 1910 (Ceratocombidae) and Schizoptera elegans Poppius, 1910 (Schizopteridae).

Exotic tree species have consistently lower herbivore load in a cross-Atlantic tree biodiversity experiment.

It is commonly expected that exotic plants experience reduced herbivory, but experimental evidence for such enemy release is still controversial. One reason for conflicting results might be that community context has rarely been accounted for, although the surrounding plant diversity may moderate enemy release. Here, we tested the effects of focal tree origin and surrounding tree diversity on herbivore abundance and leaf damage in a cross-Atlantic tree-diversity experiment in Canada and Germany. We evaluated six European tree species paired with six North American congeners in both their native and exotic range, expecting lower herbivory for the exotic tree species in each pair at each site. Such reciprocal experiments have long been called for, but have not been realized thus far. In addition to a thorough evaluation of overall enemy release effects, we tested whether enemy release effects changed with the surrounding tree diversity. Herbivore abundance was indeed consistently lower on exotics across all six tree genera (12 comparisons). This effect of exotic status was independent of the continent, phylogenetic relatedness, and surrounding tree diversity. In contrast, leaf damage associated with generalist leaf chewers was consistently higher on North American tree species. Interestingly, several species of European weevils were the most abundant leaf chewers on both continents and the dominant herbivores at the Canadian site. Thus, most observed leaf damage is likely to reflect the effect of generalist herbivores that feed heavily on plant species with which they have not evolved. At the German site, sap suckers were the dominant herbivores and showed a pattern consistent with enemy release. Taken together, the consistently lower herbivory on exotics on both continents is not purely a pattern of enemy release in the strictest sense, but to some degree additionally reflects the susceptibility of native plants to invasive herbivores. In conclusion, our cross-Atlantic study is consistent with the idea that nonnative trees have generally reduced herbivory, regardless of tree community diversity and species identity, but for different reasons depending on the dominant herbivore guild.

An interesting new species of Conocephalus (Orthoptera: Tettigoniidae: Conocephalinae) from Argentina

Conocephalus cinnamonifrons sp. nov. is distinguished by a cinnamon brown head and a distinctly upcurved ovipositor from South American congeners with usually green heads and practically straight ovipositors. The short-winged species lives in wetlands near the coast of the Río de la Plata, and has also been recorded from Entre Ríos Province. The calling song of the male shows a distinctive pattern of long syllable trains alternating with short sequences of a few isolated syllables, quite different to the songs of the syntopically occurring C. doryphorus and C. longipes. Some ecological aspects are briefly discussed.

A New Species of Bothriocephalus (Cestoda: Bothriocephalidae) from Lepomis spp. (Actinopterygii: Centrarchidae) in North America

Based on morphological and molecular data, a new species of tapeworm, Bothriocephalus kupermani n. sp., is described from pumpkinseed, Lepomis gibbosus (Linnaeus, 1758) (type host), and green sunfish, L. cyanellus Rafinesque, 1819 (Actinopterygii: Centrarchidae) in the United States. The new species differs from its North American congeners mainly in the shape of its scolex, which is almost rectangular in dorsoventral and lateral views (nearly parallel margins in the bothrial region), with shallow, wide bothria, and by an extensive field of vitelline follicles that are also variably present, albeit more sparsely, medially in the cortex of the ovarian and uterine areas. This tapeworm appears to be typically associated with Lepomis sunfishes. Examination of museum specimens of Bothriocephalus species from Lepomis spp. indicates that the tapeworm also parasitizes bluegill, Lepomis macrochirus, longear sunfish, Lepomis megalotis, and that previous records of Bothriocephalus cuspidatus and Bothriocephalus claviceps in these fishes are of the new species, B. kupermani.

Phylogenetic Position of a New Trisetacus Mite Species (Nalepellidae) Destroying Seeds of North American Junipers and New Hypotheses on Basal Divergence of Eriophyoidea.

Simple SummaryEriophyoid mites are microscopic herbivores associated with higher plants. Some of them are serious pests due to their ability to vector viruses and cause other damage to host plants. Mites of the genus Trisetacus are widespread parasites of conifers. They usually live in buds, cones, and rarely within needles of Pinaceae (pine family) and Cupressaceae (cypress family). We discovered a new species, Trisetacus indelis n. sp., severely damaging seeds of three North American junipers in the western USA. This species possesses two morphologically different forms of females and has two deletion mutations in the gene cytochrome oxidase subunit I (Cox1). Such mutations are rare in eriophyoids and were previously detected only in two pestiferous species from palms and hazelnut. Our molecular-phylogenetic analyses determine the closest known relatives of the new species and suggest that Old and New World Trisetacus independently transitioned to living in seeds of junipers. Additionally we show that reconstruction of the phylogeny of Eriophyoidea based on one gene, Cox1, produces a poorly-resolved but biologically consistent tree topology to hypothesize the evolution of Eriophyoidea. Overall, our study improves our understanding of the diversity of conifer-inhabiting mites and indicates further needs in investigating the phylogeny of Eriophyoidea.Eriophyoid mites of the genus Trisetacus Keifer are widespread parasites of conifers. A new oligophagous species, T. indelis n. sp., was discovered severely damaging seeds of North American junipers (Juniperus osteosperma, J. occidentalis, and J. californica) in the western USA. It has two codon deletions in the mitochondrial gene Cox1 rarely detected in Eriophyoidea and includes distinct morphological dimorphism of females. A phylogenetic analysis based on amino acid alignment of translated Cox1 sequences using a large set of out-groups (a) determined that two North American congeners, T. batonrougei and T. neoquadrisetus, were the closest known relatives of T. indelis n. sp., and (b) indicated that Old and New World seed-inhabiting Trisetacus from junipers do not form a distinct clade, suggesting a possible independent transition to living in seeds of junipers in America and Eurasia by Trisetacus spp. Our analysis produced a new topology consistent with a scenario assuming gradual reduction of prodorsal shield setation in Eriophyoidea and an ancient switch from gymnosperms to other hosts. Additionally, our analysis did not support monophyly of Trisetacus; recovered a new host-specific, moderately supported clade comprising Trisetacus and Nalepellinae (Nalepella + Setoptus) associated with Pinaceae; and questioned the monophyly of Trisetacus associated with Cupressaceae.

Redescription of Myotis atacamensis (Chiroptera: Vespertilionidae) with neotype designation

Myotis atacamensis (Lataste, 1892) was described based on three syntypes from San Pedro de Atacama, Chile. The type series is lost. The original description was based on few external and cranial characters, and the diagnosis became obsolete and useless considering the current diversity of South American Myotis. Based on 12 specimens of M. atacamensis from southern Peru and northern Chile, we provide a morphological comparison with its South American congeners, designate a neotype, and provide a new diagnosis.

Metabolic and Transcriptional Profiling of Fraxinus chinensis var. rhynchophylla Unravels Possible Constitutive Resistance against Agrilus planipennis

The emerald ash borer (EAB, Agrilus planipennis), an ash-tree wood-boring beetle, has caused widespread mortality of ash. Asian ash, which coevolved with EAB, is considered more resistant than its North American and European congeners. Although some compounds and proteins related to resistance to EAB have been identified, the underlying ash resistance mechanism to EAB still needs further study. The Asian ash species, Fraxinus chinensis var. rhynchophylla, is highly resistant to EAB. In this study, metabolic and transcriptional profiling of the phloem of this species was investigated, and differentially expressed metabolites and genes were analyzed by comparing them with those of the susceptible F. pennsylvanica. Four hundred and twenty-eight metabolites were detected in both species, and several coumarins and lignans, which were exclusive to F. chinensis var. rhynchophylla, were identified. Compared with susceptible F. pennsylvanica, genes related to phenylpropanoid biosynthesis, ethylene (ET), and jasmonic acid (JA) biosynthesis and signaling in F. chinensis var. rhynchophylla were found to be up-regulated. It was hypothesized that coumarins, lignans, and ET and JA signaling might contribute to greater resistance to EAB in F. chinensis var. rhynchophylla. This study suggests candidate metabolites and genes for biomarker development in future ash-breeding programs.

Cranial Morphology of the Flat-Headed Bat Myotis planiceps (Chiroptera: Vespertilionidae) in the Context of American Myotis

Myotis planiceps is an insectivorous species with a distinctive flat-headed morphology among Myotis species. Its distribution is restricted to the northeastern Mexico highlands, and uses trees of Yucca carnerosana to roost. The particular ecological and morphological characteristics of this species make it a likely resource-use specialist. We evaluated the morphological specialization of M. planiceps as compared with thirteen American congeners belonging to different dietary categories, using a geometric morphometric protocol and multivariate statistical analyses. We estimated morphological differences across dietary categories, including M. planiceps as a separate group, and evaluated the effect of cranial size and diet on variations in cranial morphology. We found a significant differentiation of this species in all the cranial shape characters, with soft insectivores as the dietary group closest to M. planiceps. Additionally, diet explained similar percentages of shape variance in cranial and mandibular characters, and the highest interaction between diet and cranial size was recorded in the braincase. In general, the smallest sizes and thinner skulls were observed in soft insectivores. Our findings do not support a significant relationship between skull shape characters, described by the first principal component, and hardness of food items, but we found a significant association with the mandible shape. No phylogenetic structure was observed in the residual variance of these models. We found trends of change in cranial morphology associated with specialized habitats, the mandibular characters being more contrasting in the fishing bat M. vivesi, and the braincase morphology being more contrasting in M. planiceps, a species that lives in restricted habitats and probably feeds on soft insects.

Genomic assessment of the Phyllodactylus tuberculosus complex (Reptilia: Phyllodactylidae) in America

AbstractLeaf‐toed geckos (Phyllodactylus) exhibit much cryptic diversity, at least in North America. However, the origins of Central American taxa and their relationships with North American congeners remain unknown. The P. tuberculosus species complex is ideal for evolutionary and biogeographic studies because its geographic distribution extends from northern Mexico to Costa Rica. We analyse ~2,500 nuclear loci obtained by the GBS genomic technique to test hypotheses of genetic isolation among taxa and estimate times of divergence using a relaxed molecular clock model, which constitutes the first hypothesis for the diversification of North and Central American phyllodactylids. Phylogenetic analysis recovers three main clades within polyphyletic P. tuberculosus: tuberculosus, magnus and saxatilis. ABBA‐BABA tests show moderate to low levels of gene flow within the latter two clades and yet genetic isolation in Central American lineages. The relaxed molecular clock model dates the age of the MRCA between the Central American and North American lineages to the beginning of the Paleocene (65 mya), suggesting an ancestral distribution in the proto‐Mexican region and the Chortis Block.

Influence of canopy openness, ungulate exclosure, and low-intensity fire for improved oak regeneration in temperate Europe.

Failed oak regeneration is widely reported in temperate forests and has been linked in part to changed disturbance regimes and land‐use. We investigated if the North American fire–oak hypothesis could be applicable to temperate European oaks (Quercus robur, Quercus petraea) using a replicated field experiment with contrasting canopy openness, protection against ungulate browsing (fencing/no fencing), and low‐intensity surface fire (burn/no burn). Survival, relative height growth (RGRH), browsing damage on naturally regenerated oaks (≤300 cm tall), and changes in competing woody vegetation were monitored over three years. Greater light availability in canopy gaps increased oak RGRH (p = .034) and tended to increase survival (p = .092). There was also a trend that protection from browsing positively affected RGRH (p = .058) and survival (p = .059). Burning reduced survival (p < .001), nonetheless, survival rates were relatively high across treatment combinations at the end of the experiment (54%–92%). Most oaks receiving fire were top‐killed and survived by producing new sprouts; therefore, RGRH in burned plots became strongly negative the first year. Thereafter, RGRH was greater in burned plots (p = .002). Burning altered the patterns of ungulate browsing frequency on oaks. Overall, browsing frequency was greater during winter; however, in recently burned plots summer browsing was prominent. Burning did not change relative density of oaks, but it had a clear effect on competing woody vegetation as it reduced the number of individuals (p < .001) and their heights (p < .001). Our results suggest that young, temperate European oaks may respond similarly to fire as their North American congeners. However, disturbance from a single low‐intensity fire may not be sufficient to ensure a persistent competitive advantage—multiple fires and canopy thinning to increase light availability may be needed. Further research investigating long‐term fire effects on oaks of various ages, species‐specific response of competitors and implications for biodiversity conservation is needed.

Eight new Lepadellidae (Rotifera, Monogononta) from the Congo bring to levelendemism in Africa's rotifers.

While patterns in diversity and biogeography of macroscopic organisms may be fairly well-documented, this is much less the case for microscopic organisms, for which mechanisms working at entirely different scales may be relevant. Data deficiency remains a major obstacle to the study of these mechanisms, and this situation is exacerbated in regions for which accessibility is not self-evident. We here report on the Lepadellidae rotifers in zooplankton samples collected during the Boyekoli ebale Congo 2010 expedition and a subsequent visit to Yangambi, DR Congo in June 2012. The material contained eight hitherto unknown species amongst 33 Lepadellidae taxa. This remarkable result illustrates a previously unknown and largely endemic microfauna of the Congo Basin and refutes the "African anomaly" hypothesis on the purported poverty of the Central African rotifer fauna. We describe the new species, viz. Colurella asymmetrica n. sp., Lepadella hanneloreae n. sp., L. jingruae n. sp., L. weijiai n. sp., L.wilungulai n. sp., L. yangambi n. sp., Squatinella curviseta n. sp. and S. longipila n. sp., and comment on the diversity and biogeographical relationships of this fauna. Two of the new species appear to have a South American congener as their closest relative, potentially constituting two more examples of rare African-South American vicariant species-pairs in Rotifera.

Growth of Lonicera caerulea across Fertility and Moisture Conditions: Comparisons with Lonicera villosa and Invasive Congeners

Several species of honeysuckle from Europe and Asia have proved to be invasive in North America, with substantial impacts on native ecosystems. Although shrubby honeysuckles of Eurasian origin have appeared on banned plant lists in North America and other parts of the world, cultivars of the edible blue honeysuckle (Lonicera caerulea L.) derived from Eurasian germplasm and marketed as honeyberry, Haskap, or sweetberry honeysuckle have recently been widely developed for agricultural use in North America, with little scrutiny of invasive potential in North America despite its documented invasion of the Scandinavian Peninsula in northern Europe. To gain insight into differences in growth strategies among congeners, we compared the growth of Eurasian L. caerulea with that of a closely related congener in North America [Lonicera villosa (Michx.) R. &amp; S.] and two known invasive congeners from Eurasia (Lonicera tatarica L. and Lonicera xylosteum L.). In Expt. 1, L. villosa, L. caerulea, and L. tatarica were grown in #1 nursery containers after top-dressing with Osmocote Pro 17–5–11 4-month controlled-release fertilizer (CRF) at rates of 5, 10, 15, 20, and 25 g CRF/container. Across all fertilizer treatments, L. caerulea outperformed L. villosa by a factor of two for root and shoot dry weights, although L. tatarica produced more growth than either of the others and was more responsive to increasing CRF. However, L. caerulea more strongly resembled L. tatarica in form, producing leaves of greater individual size and producing significantly taller primary stems than L. villosa, evidence for prioritization of competitive growth. In Expt. 2, plants of the same taxa plus L. xylosteum were grown communally in #20 nursery containers, followed by a period in which each container was subjected to regular irrigation, withheld irrigation (dry treatment), or inundation (flooded treatment). Plant growth differed substantially among taxa, but moisture treatments did not affect growth significantly. As in Expt. 1, plants of L. caerulea in Expt. 2 produced greater dry biomass than plants of L. villosa and resembled the invasive Eurasian honeysuckles more strongly in size and form. We conclude Eurasian L. caerulea is distinct in growth rate and morphology from North American L. villosa. In light of these findings, the ecology and competitive ability of Eurasian L. caerulea may not be well predicted by ecological observations of its closely related North American congener.

Phegopteris excelsior (Thelypteridaceae): A New Species of North American Tetraploid Beech Fern

Since the 1970s, an apomictic tetraploid beech fern (genus Phegopteris (C. Presl) Fée) has been known in northeastern North America. Previously published isozyme data suggest that this lineage is of allopolyploid origin involving long beech fern (P. connectilis (Michx.) Watt.) but not broad beech fern (P. hexagonoptera (Michx.) Fée), as originally hypothesized. Its second progenitor remains unknown. We performed a principal components analysis of the apomict and its North American congeners to elucidate morphological differences between them. We recognize the apomictic tetraploid at specific rank as P. excelsior N. R. Patel &amp; A. V. Gilman and provide an illustration, a range map, a list of exsiccatae, and a key to Phegopteris species of North America.

A new fossil species of Pycnomerus Erichson (Coleoptera: Zopheridae) from Baltic amber, and a replacement name for a Recent North American congener.

Based on a well-preserved specimen from Eocene Baltic amber, the second fossil species belonging to the genus Pycnomerus Erichson (Coleoptera: Zopheridae: Zopherinae), P. agtsteinicus Bukejs, Alekseev McKellar sp. nov. is described and illustrated using synchrotron X-ray micro-CT observations. The new species adds to the sparse fossil record of Pycnomerus, which consists of the Baltic amber discoveries, and only four subfossil records in sediments that are less than one million years old. As part of this work, the new replacement name Pycnomerus lordi Bukejs, Alekseev McKellar nom. nov. is also established for the extant species Pycnomerus sulcicollis LeConte, 1863 [non Pycnomerus sulcicollis (Germar, 1824)].

Fulfilling the taxonomic consequence after DNA Barcoding: Carychiumpanamaense sp. n. (Eupulmonata, Ellobioidea, Carychiidae) from Panama is described using computed tomographic (CT) imaging.

Five years ago, the Panamanian evolutionary lineage (EL) C12 was uncovered along with four other ELs in an integrative phylogenetic investigation of worldwide Carychiidae. Since EL C12 lacked shell material post-molecular analysis to serve as a museum voucher, it remained undescribed. Now, after recent collection efforts of C12 and the congener, Carychiumzarzaae Jochum & Weigand, 2017 at their original Panamanian sites, C12 is morphologically described and formally assigned the name, Carychiumpanamaense Jochum, sp. n. In sync with recent taxonomic treatment of the genus, computed tomography (CT) is used in this work to differentiate shells of C.panamaensesp. n. from geographically-proximal, Caribbean, North and Central American congeners. Recent material of topotypic Carychiumjardineanum (Chitty, 1853) and undamaged C.zarzaae were additionally CT-scanned and assessed in the comparative analyses.

Redescription of Trichomycterus striatus (Meek Hildebrand, 1913) (Siluriformes: Trichomycteridae), with notes on its geographic distribution.

Trichomycterus striatus is herein redescribed, based on examination of the types and recently collected specimens, and its geographic distribution is updated. This species can be diagnosed from all other northeastern South American congeners by its variable coloration pattern consisting of a yellowish to light brown background with a black lateral band and/or small dark brown spots on sides or uniformly light brown and by the following combination of characters: teeth conical arranged in three to four irregular rows in both jaws; anterior section of infraorbital canal (sensory pores i1 and i3) present; sensory pores s6 paired, 11-23 opercular odontodes; 27-44 interopercular odontodes; seven to eight pectoral-fin branched rays; 36-37 free vertebrae; 12-14 ribs; cleithrum pierced by several foramina; and caudal fin truncate to rounded. Trichomycterus striatus occurs from southern Costa Rica [from the Pirrís (herein reported for the first time), Térraba and Coto River basins] to eastern Panama (in most of the main river basins in both the Pacific and Atlantic versants), being the sole representative of the family in lower Central American waters.

Fates of angiosperm species following long-distance dispersal: Examples from American amphitropical Polemoniaceae.

Following establishment after long-distance dispersal, species may experience stasis, accumulate changes leading to new species identity, diversify into multiple species, interact with related species to form novel species, and even become extirpated. We examined each species of temperate Polemoniaceae in South America via the literature and new analyses to better understand the fates of species in this family after their dispersal from North America. We reviewed literature for the 15 species of Polemoniaceae in South America amphitropically disjunct from their relatives in North America. We conducted DNA sequence analyses to infer relationships, timing of dispersal, and processes involved since dispersal in Microsteris gracilis, three Gilia, two Giliastrum, and three Collomia. Analyses included construction of haplotype networks and phylogenetic trees using maximum likelihood and Bayesian inference. For all species examined in detail, origins in South America are compatible with dispersal via epizoochory from ca. 0.092-19.46 million years ago. Most species in South America are unique relative to their North American congeners, yet few have radiated into two or more species. Relative stasis, divergence, and hybridization with, and without, allopolyploid formation have occurred postdispersal in Polemoniaceae, as well as extirpation following at least brief establishment. Polemoniaceae that have established in South America share many features likely inherited from their North American progenitors, but some traits may have arisen in situ in specific taxa, such as cleistogamy, self-incompatibility, and the annual habit, evidencing the rich nature of diversification processes.

Variation in Sterilization byDeladenus proximuson the Native Woodwasp,Sirex nigricornis, in Arkansas

Discovery of a potentially destructive non-native woodwasp, Sirex noctilio F. (Hymenoptera: Siricidae), in pine forests of eastern North America has elicited interest in appropriate management options. A parasitic nematode, Deladenus siricidicola Bedding (Tylenchida: Neotylenchidae), was introduced as a biological control agent in the Southern Hemisphere where it has been successful in some areas and unsuccessful in others. The North American congener (D. proximus Bedding) parasitizes native Sirex woodwasps and has potential as a biological control agent of S. noctilio due to its ability to utilize the invasive woodwasp as a novel host. However, basic biology and ecology of these native nematodes are largely unknown. Sirex nigricornis females were collected from three geographic locations in Arkansas in 2009 and 2010, dissected, and examined for the presence of D. proximus. Nematodes were found within S. nigricornis collected from all locations and years. Parasitism negatively affected woodwasp body size. We found high variation in percent of eggs infected with nematodes during both years of trapping. Research is needed to investigate potential mechanisms behind this variation of parasitism.