ABSTRACT
Tick salivary glands produce and secrete a variety of compounds that modulate host responses and ensure a successful blood meal. Despite great progress made in the identification of ticks salivary compounds in recent years, there is still a paucity of information concerning salivary molecules of Neotropical argasid ticks. Among this group of ticks, considering the number of human cases of parasitism, including severe syndromes and hospitalization, Ornithodoros brasiliensis can be considered one of the major Neotropical argasid species with impact in public health. Here, we describe the transcriptome analysis of O. brasiliensis salivary glands (ObSG). The transcriptome yielded ~14,957 putative contigs. A total of 368 contigs were attributed to secreted proteins (SP), which represent approximately 2.5% of transcripts but ~53% expression coverage transcripts per million. Lipocalins are the major protein family among the most expressed SP, accounting for ~16% of the secretory transcripts and 51% of secretory protein abundance. The most expressed transcript is an ortholog of TSGP4 (tick salivary gland protein 4), a lipocalin first identified in Ornithodoros kalahariensis that functions as a leukotriene C4 scavenger. A total of 55 lipocalin transcripts were identified in ObSG. Other transcripts potentially involved in tick-host interaction included as: basic/acid tail secretory proteins (second most abundant expressed group), serine protease inhibitors (including Kunitz inhibitors), 5' nucleotidases (tick apyrases), phospholipase A2, 7 disulfide bond domain, cystatins, and tick antimicrobial peptides. Another abundant group of proteins in ObSG is metalloproteases. Analysis of these major protein groups suggests that several duplication events after speciation were responsible for the abundance of redundant compounds in tick salivary glands. A full mitochondrial genome could be assembled from the transcriptome data and confirmed the close genetic identity of the tick strain sampled in the current study, to a tick strain previously implicated in tick toxicoses. This study provides novel information on the molecular composition of ObSG, a Brazilian endemic tick associated with several human cases of parasitism. These results could be helpful in the understanding of clinical findings observed in bitten patients, and also, could provide more information on the evolution of Neotropical argasids.
ABSTRACT
The potential of the parasitoid Psyllaephagus bliteus Riek for the biological control of the eucalyptus pest Glycaspis brimblecombei Moore (Hemiptera: Aphalaridae) nymphs is high. This research sought to analyze the courtship, male competition, and mating behavior of P. bliteus at the proportions of 1:1 and 2:1 males to female in a Petri dish (5 cm diameter), and to describe the ovary histology of virgin and mated females of this parasitoid. At 1:1, males touch the antennae and thorax-abdomen of females during courtship, but females avoid mate attempts before they are 48 h old. At 2:1, the competition between male parasitoids inhibits mating. The histology of ovaries of virgin and mated P. bliteus females is similar, with two well-defined germarium and vitellarium regions, with oocytes at different developmental stages, including mature ones rich in yolk and with eggshell. A clearer understanding of the reproductive behavior and histology of P. bliteus aids in the use of this parasitoid for the biological control of G. brimblecombei.
Subject(s)
Hymenoptera/anatomy & histology , Hymenoptera/physiology , Sexual Behavior, Animal , Animals , Courtship , Female , Hemiptera/growth & development , Hemiptera/parasitology , Host-Parasite Interactions , Insect Control , Male , Nymph/parasitology , Ovary/anatomy & histology , Pest Control, BiologicalABSTRACT
The active locomotion of ticks is directly associated with the epidemiology of tick-borne diseases, as it has important implications for the interaction of ticks with their hosts and their dispersion in the environment. In an attempt to elucidate the factors involved in the dispersion of Amblyomma sculptum, the present work aimed to characterize different aspects of the active locomotion of A. sculptum nymphs under laboratory conditions. To this end, nymphs were placed on a string at a 70° inclination and their walking activity was recorded daily along with their survival period. During their lifetime, ticks walked an average of 110 m. Their locomotion was not in a straight line and nymphs changed direction 142 times throughout their lifetimes. The mean distance walked per experimental day was 1.8 m, while the average walking distance before changing direction was 52 cm. The distance walked per experimental day reduced over time. The survival of ticks was affected by walking; resting nymphs survived for over 6 months, while the survival of those that walked daily was reduced to approximately 62 days. The results showed that A. sculptum nymphs were able to cover distances of over 100 m throughout their lifetimes, but they walked short distances at a time and constantly changed direction. This behavior indicates that ticks are not able to disperse over long distances by means of active locomotion.
Subject(s)
Amblyomma/physiology , Amblyomma/growth & development , Animals , Locomotion , Longevity , Nymph/growth & development , Nymph/physiologyABSTRACT
Here we describe the final instar larvae of Acanthagrion truncatum Selys, 1876, the 16th described for the genus. We compare the diagnostic characters of A. truncatum with other species of the Group II. Although very similar to other Acanthagrion, the larvae of A. truncatum can be separated from other congeners from having the following character combination: cephalic lobes bulging and rounded, seven antennomeres, 2+1 or 2 premental setae, and nodus at 0.60-0.62 of total length of the lamella.
Subject(s)
Odonata , Animals , LarvaABSTRACT
Miroculis Edmunds represents one of the most species-rich genera amongst Neotropical leptophlebiids comprising 25 valid species, with 18 of them reported from Brazil. Although several species have been described throughout the years, the taxonomy of Miroculis has focused mainly on male imagos, with other semaphoronts often unknown. Here, Miroculis (Miroculis) niltoi sp. nov. is described based on nymphs and imagos from Chapada Diamantina's Complex, Northeast Brazil. Male imagos of M. (M.) niltoi sp. nov. can be distinguished by the styliger plate being medially cleft with a well-sclerotized ventrally-directed process at the posteromedial margin, while female imagos can be distinguished by the egg guide being well-developed, reaching sternum IX, and sternum IX about as long as wide, with a shallow apical cleft. Together with Miroculis (Miroculis) samba Costa, Almeida Salles and Miroculis (Miroculis) wolverine Costa, Almeida Salles, M. (M.) niltoi sp. nov. represents species within Miroculis with male imago exhibiting both extremely long penes and styliger plate. Now, Miroculis comprises 26 valid species, with 19 of them reported from Brazil.
Subject(s)
Ephemeroptera , Heteroptera , Animals , Brazil , Female , Male , NymphABSTRACT
The study of immature stages in Pentatomidae contributes to the knowledge in several areas, mainly systematics, ecology and agriculture. In faunistic inventories, nymphs comprise a significant part of the specimens collected, which often cannot be identified due to lack of knowledge about the immature. Here, we describe the external morphology of eggs and nymphal stages of Runibia perspicua (Fabricius, 1798). The egg is barrel-shaped with the surface of chorium covered by spines, forming polygonal markings interconnected by sheets, similar as observed in some species of Carpocorini. In all the nymphal instars the abdomen is characterized by having rounded reddish spots and an orange/yellow longitudinal macula in the middle of each abdominal tergite, from abdominal segment II to VII. The first instar is the most distinctive, standing out mainly by the head and thorax totally brown. From the second instar the head and thorax acquire pale color with irregular brown spots. The labium presents significant variations in size along the ontogenetic development showing a non-isometric pattern, when compared to the total length of the body. Illustrations and photographs of all the immature stages and the detailed morphology of some structures in SEM are provided.
Subject(s)
Hemiptera , Heteroptera , Animals , Color , Ecology , Nymph , OvumABSTRACT
Franciscagrion longispinum Machado Bedê larvae were collected in the São Francisco river historical springs at the Serra da Canastra National Park, Brazil. Here, we describe and illustrate the final instar larvae of this rare and endemic species.
Subject(s)
Odonata , Animals , Brazil , Larva , Natural Springs , RiversABSTRACT
The lack of nymph-adult associations limits our knowledge of the ecology, history and sensitivity of aquatic insects. In this study, the new species, Anacroneuria suerre sp. nov is described from Costa Rica based on the male, female, and nymphal stages. We briefly discuss the use of Plecoptera in ecotoxicological studies.
Subject(s)
Lepidoptera , Animals , Costa Rica , Ecology , Female , Insecta , Male , NymphABSTRACT
16. Tick-borne rickettsiosis is becoming a common emergent disease in many tropical countries, and the rapid detection of this disease could reduce the impact on wild life and public health. Pools of larvae and nymphs, and individual adult ticks are used for detection of Rickettsia species (Rickettsiaceae), but the number of larvae and nymphs in the pools likely affect the probability of detection of Rickettsia spp. We tested whether the number of larvae or nymphs of Amblyomma (Ixodidae) included in the pools affected the probability of detection. The number of larvae in each pool did not affect the probability of detecting Rickettsia spp., but the probability of detection increased rapidly with the number of nymphs. In this study, 20 nymphs are enough to approach a probability of 1 of detecting Rickettsia.
20. La rickettsiosis transmitida por garrapatas es una enfermedad emergente cada vez más común en muchos países tropicales, por lo que su rápida detección podría reducir su impacto negativo en la salud humana. Grupos (pozos) de larvas y ninfas de garrapatas, así como individuos adultos son usados para detectar la presencia de diferentes especies de Rickettsia. Sin embargo, el número de larvas y ninfas incluidos en estos grupos probablemente afecta la detección de Rickettsia spp. Nosotros probamos si el número de larvas o ninfas incluidas en estos grupos afecta la probabilidad de detección. Encontramos que el número de larvas incluidas en cada grupo no afectó la probabilidad de detección de Rickettsia spp., pero la probabilidad de detección aumenta rápidamente con el número de ninfas incluidas en los grupos. En este estudio, 20 ninfas por grupo fueron suficientes para tener una probabilidad cercana a 1 de detectar Rickettsia.
ABSTRACT
The last nymphal instars of Anacroneuria planicollis Klapálek, 1923 and A. quetzali Gutiérrez-Fonseca and Springer, 2015 are described from the Caldera River, Chiriquí Province, Panamá. The adult female of A. quetzali is associated for the first time and described also from the Caldera River, Chiriquí Province, Panamá.
Subject(s)
Insecta , Animals , Female , Neoptera , Nymph , Panama , RiversABSTRACT
Recent expeditions to the Serra da Canastra and Chapada dos Guimarães National Parks in Brazil resulted in the collection of larvae of Argia mollis Hagen in Selys, 1865 and A. smithiana Calvert, 1909. Thus, here we describe the last instar larvae of these two Argia species from the Brazilian Cerrado.
Subject(s)
Odonata , Animals , Brazil , Expeditions , Larva , Parks, RecreationalABSTRACT
Specimens of the perlid stonefly Anacroneuria flintorum from different regions of the Brazilian Atlantic Forest along the Atlantic coast of Brazil were studied. In this paper, the nymph of A. flintorum is described based on reared specimens and molecular associations. Additionally, we provide new locality records and comments about variation of the species.
Subject(s)
Lepidoptera , Animals , Brazil , Forests , Insecta , NymphABSTRACT
Resumen Plecoptera es un grupo basal de insectos acuáticos, también conocidos como "moscas de piedra". Con el objetivo de contribuir al conocimiento taxonómico y ecológico del género Anacroneuria, se realizaron recolectas de ninfas en la parte alta y media del río Caldera, en la provincia de Chiriquí. Para esto se hicieron giras de campo una vez al mes de enero a diciembre de 2015. En siete estaciones de muestreo, se recolectaron ninfas en rocas y hojarasca sumergida, de forma manual con pinzas entomológicas y con red triangular, para su posterior cría en sistemas de acuarios en el laboratorio. Se recolectaron 485 ninfas, con la emergencia de 138 adultos. Cinco especies de Anacroneuria: Anacroneuria annulipalpis, A. benedettoi, A. planicollis, A. quetzali, A. marca y dos especies no identificadas fueron determinadas a través de la crianza de ninfas en laboratorio. El rango de distribución de A. benedettoi fue extendido a la provincia de Chiriquí. El primer registro de A. quetzalipara Panamá es comentado. Se aporta datos de distribución altitudinal, variabilidad estacional y requerimientos ambientales. Se recomienda ampliar los estudios sobre las asociaciones de ninfas con las formas adultas en otras áreas de Panamá y del Neotrópico, así como incrementar el conocimiento sobre la biología y ecología de este grupo.
Abstract Plecoptera order is a basal group of aquatic insects, also known as stonefly. In order to contribute to the taxonomic and ecological knowledge of the genus Anacroneuria, nymphs were collected in the upper and low parts of the Caldera River, in the Chiriquí province. For this, field trips were carried out once a month, from January to December of 2015. A total of seven stations were sampled, and nymphs were collected on rocks and submerged leaf litter, manually with entomological tweezers, and with a triangular net; nymphs were later transported and reared in aquarium systems in the laboratory, and their growth was followed. A total of 485 nymphs were collected, with the emergence of 138 adults. Five species of Anacroneuria: Anacroneuriaannulipalpis, A. benedettoi, A. planicollis, A. quetzali, A. marca and two unknown species were obtained after nymphs rearing. The distribution range of A. benedettoi was extended to the Chiriqui province. The first record for A. quetzaliin Panamá is commented. In addition, data of altitudinal distribution, seasonal variability and environment requirements were mentioned. We recommend to expand studies on Plecoptera nymph associations with adult forms in other areas of Panama and the Neotropics, as well as to increase the knowledge about their biology and ecology. Rev. Biol. Trop. 66(1): 164-177. Epub 2018 March 01.
ABSTRACT
In arachnids, pedipalps are highly variable appendages that may be used in feeding, courtship, defense, and agonistic encounters. In cosmetid harvestmen, adults have pedipalps that feature flattened femora, spoon-shaped tibiae, and robust tarsal claws. In contrast, the pedipalps of nymphs are elongate with cylindrical podomeres and are adorned with delicate pretarsi. In this study, we used scanning electron microscopy to examine the distribution of cuticular structures (e.g., sensilla chaetica, pores) on the elements of the pedipalps of adults and nymphs of three species of cosmetid harvestmen. Our results indicate that there is considerable ontogenetic variation in the morphology of the trochanter, femur, patella, tibia, and tarsus. The pretarsus of the nymph has a ventral patch of setae that is absent from the adult tarsal claw. We observed this structure on all three cosmetid species as well as on the pedipalps of an additional seven morphospecies of nymphs collected in Belize and Costa Rica. This structure may represent a previously unrecognized autapomorphy for Cosmetidae. Examinations of the pedipalps of antepenultimate nymphs of additional gonyleptoidean harvestmen representing the families Ampycidae, Cranaidae, Manaosbiidae, and Stygnidae revealed the occurrence of unusual, plumose tarsal setae, but no setal patches on the tarsal claw.
Subject(s)
Arachnida/anatomy & histology , Sense Organs/anatomy & histology , Animals , Arachnida/ultrastructure , Belize , Bone and Bones/anatomy & histology , Bone and Bones/ultrastructure , Extremities/anatomy & histology , Female , Larva/anatomy & histology , Larva/ultrastructure , Male , Organ Size , Patella/ultrastructure , Sense Organs/ultrastructure , Sensilla/anatomy & histology , Sensilla/ultrastructure , Sex CharacteristicsABSTRACT
Laboratory and field studies were conducted with nymphs and adults of the Neotropical stink bug Runibia perspicua (F.) to evaluate their biology on plants. Total nymph mortality was ca. 13% on immature fruits of Brunfelsia australis Benth. (IFBA) and 90% on raw shelled peanuts, Arachis hypogaea L. (RSP); no nymphs survived on immature pods of green bean, Phaseolus vulgaris L., or on immature fruits of privet, Ligustrum lucidum Ait. Nymph developmental time was ca. 36 on IFBA and 55 days on RSP. Body weight was significantly greater when nymphs were raised isolated compared to those raised in groups. Adult feeding activity was greater than third instars on IFBA. Adult longevity on IFBA + cherry tomato, Solanum lycopersicum L. fruit, reached ca. 150 days. On IFBA, fecundity was 2.5 egg masses/female and 48.3 eggs/female; 25.6% of the eggs hatched. Adults did not reproduce on tomato. Body weight gain did not increase significantly for both sexes during the first four weeks of adult life on IFBA. In the field, plants of B. australis were surveyed in Passo Fundo, RS (28°15'S; 52°24'W). The majority of egg masses were deposited on the lower (abaxial) surface of leaves. Nymphs aggregated on immature fruits, and adults were seldom found on the plants. These are the first data on the performance of R. perspicua on B. australis indicating that this plant species is suitable to the bug's biology.
Subject(s)
Herbivory , Heteroptera/physiology , Solanaceae , Animals , Body Weight , Brazil , Fabaceae , Female , Fertility , Fruit , Longevity , Male , Nymph/physiology , Ovum/physiology , ReproductionABSTRACT
The bronze bug, Thaumastocoris peregrinus Carpintero & Dellape (Heteroptera: Thaumastocoridae), is an exotic emerging pest in Eucalyptus commercial forests in South America, Africa and southern Europe. Information on the chemical communication system and reproductive ecology of this insect is scant, and it may be relevant for designing management strategies for eucalypt plantations. Adults and nymphs usually aggregate in the field, possibly by means of chemical signals. Males emit large amounts of 3-methyl-2-butenyl butyrate, which attracts conspecific adult males but not females. The ecological role of this putative male aggregation pheromone remains unknown. Here, we report olfactometer bioassays showing that late-instar male nymphs are also attracted to synthetic 3-methyl-2-butenyl butyrate and to adult male volatile extracts, which contain this compound as the major component. As previously shown for adult females, nymphs that moulted into females were not attracted to either volatile stimulus. The intra-gender attraction of nymphs and adults may be related to the exploitation of food resources, or as a reproductive strategy for newly emerged males. Further studies on the reproductive behaviour and mating system of T. peregrinus will contribute to understanding the ecological significance of male-male, adult-nymph attraction, as well as the practical applications that may result from these findings.
Subject(s)
Behavior, Animal , Heteroptera/physiology , Nymph/physiology , Pheromones/physiology , Animals , Eucalyptus , Female , Male , Reproduction , South AmericaABSTRACT
Triatoma infestans Klug (Hemiptera: Reduviidae) is the main vector of Chagas disease in Latin America. This insect has been controlled with pyrethroids since the 1980s, although the emergence of resistance to deltamethrin has decreased control success in some areas of the Gran Chaco ecoregion. The response of T. infestans to deltamethrin was evaluated per developmental stage. In addition, we evaluated the possible stage-dependent expression of deltamethrin resistance. The bioassays were conducted by topical application of the insecticide in acetone. The drop size, age at the time of exposure, and mortality measuring time were standardized per stage. The lethal dose of deltamethrin moderately increased with the developmental stage. The resistance to deltamethrin was expressed in every instar, and was the highest in the fourth- and fifth-instar nymphs. While increasing, weight plays a relevant role in lethal dose stage dependency, a number of contributing factors such as degradative metabolism are probably involved in the variability of insecticide effect and resistance described for different T. infestans developmental stages. Possible explanations for these differences and their implications on resistance management and chemical control are discussed.
Subject(s)
Pest Control , Triatominae , Chagas Disease , Vector Control of Diseases , Growth and Development , Toxicity , Insect Repellents , Insecticides , NymphABSTRACT
BACKGROUND: Until recently, Amblyomma cajennense (Fabricius, 1787) was considered to represent a single tick species in the New World. Recent studies have split this taxon into six species. While the A. cajennense species complex or A. cajennense (sensu lato) (s.l.) is currently represented by two species in Brazil, A. cajennense (sensu stricto) (s.s.) and Amblyomma sculptum Berlese, 1888, their geographical distribution is poorly known. METHODS: The distribution of the A. cajennense (s.l.) in Brazil was determined by morphological examination of all lots of A. cajennense (s.l.) in two large tick collections of Brazil, and by collecting new material during three field expeditions in the possible transition areas between the distribution ranges of A. cajennense (s.s.) and A. sculptum. Phylogenetic analysis inferred from the ITS2 rRNA gene was used to validate morphological results. Morphological description of the nymphal stage of A. cajennense (s.s.) is provided based on laboratory-reared specimens. RESULTS: From the tick collections, a total 12,512 adult ticks were examined and identified as 312 A. cajennense (s.s.), 6,252 A. sculptum and 5,948 A. cajennense (s.l.). A total of 1,746 ticks from 77 localities were collected during field expeditions, and were identified as 249 A. cajennense (s.s.), 443 A. sculptum, and 1,054 A. cajennense (s.l.) [these A. cajennense (s.l.) ticks were considered to be males of either A. cajennense (s.s.) or A. sculptum]. At least 23 localities contained the presence of both A. cajennense (s.s.) and A. sculptum in sympatry. DNA sequences of the ITS2 gene of 50 ticks from 30 localities confirmed the results of the morphological analyses. The nymph of A. cajennense (s.s.) is morphologically very similar to A. sculptum. CONCLUSION: Our results confirmed that A. cajennense (s.l.) is currently represented in Brazil by only two species, A. cajennense (s.s.) and A. sculptum. While these species have distinct distribution areas in the country, they are found in sympatry in some transition areas. The current distribution of A. cajennense (s.l.) has important implications to public health, since in Brazil A. sculptum is the most important vector of the bacterium Rickettsia rickettsii, the etiological agent of Brazilian spotted fever.
Subject(s)
Ixodidae/anatomy & histology , Ixodidae/growth & development , Phylogeography , Animals , Brazil , Cluster Analysis , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , Nymph/anatomy & histology , Phylogeny , Sequence Analysis, DNAABSTRACT
Identifying the tick species that successfully feed on humans would increase knowledge of the epidemiology of several tick-borne diseases. These species salivate into the host, increasing the risk of pathogen transmission. However, there is a lack of data in the literature regarding the ticks that prefer to feed on humans. Herein, we describe the successful feeding of Amblyomma coelebs Neumann nymphs on two of the authors after accidental tick bites occurred during field surveys in two preserved areas of Mato Grosso do Sul, Brazil. One of the host-parasite interactions was closely monitored, and the tick development, gross host skin alterations, and related sensations are presented.
Subject(s)
Ixodidae , Skin/pathology , Tick Bites/pathology , Animals , Feeding Behavior , Humans , NymphABSTRACT
Descriptions of the last three nymphal instars of the water boatman Sigara (Aphelosigara) tucma Bachmann (Hemiptera: Heteroptera: Corixidae) are provided, for the first time, for specimens collected in northern Argentina; the egg is redescribed. Adults and nymphs were collected in the field. The eggs were obtained by dissection from females. The immature stages were fixed for microscopic examination and illustration and were described with an emphasis on morphometry and chaetotaxy of selected structures. The last three nymphal instars of S. tucma can be easily recognized by the body and head lengths and widths; the number of transverse sulcations of the rostrum; the chaetotaxy of trochanters, protibiotarsus, midlegs, metatibia, and metatarsus; and the grade of development of the wing pads. The eggs of the genus Sigara can be distinguished by the size and the chorionic surface. The chaetotaxy of the mesonotum, metafemur, and metatibia distinguish groups of species belonging to the last nymphal instar of the genus Sigara. A key to the last three nymphal instars of the species of Sigara from Argentina is provided.