Cry1C rice doesn't affect the ecological fitness of rice brown planthopper, Nilaparvata lugens either under RDV stress or not.

The potential risks of Bt rice on non-target arthropods (NTAs) should be evaluated and defined before commercial production. Recently, effects of Bt rice on NTAs under abiotic and biotic stress conditions attracted much attention. Here we reported the effects of Bt rice T1C-19 (Cry1C rice) on the non-target herbivore, Nilaparvata lugens (rice brown planthopper, BPH) with or without RDV (rice dwarf virus) infection conditions. BPH showed no feeding and oviposition preference between Bt rice T1C-19 and its non-Bt parental rice Minghui 63 (MH63), as well as between RDV-infected and RDV-free rice plants. Meanwhile, rice type, RDV infection status, and their interaction had little impacts on the survival, development and fecundity of BPH. By comparison with non-Bt control, Bt rice T1C-19 with or without RDV infection had no significant effects on the life-table parameters of BPH including rm, R0, T, DT and λ. Thus, it could be concluded that Bt rice T1C-19 doesn't affect the ecological fitness of BPH either under RDV stress or not.

Sublethal and transgenerational effects of sulfoxaflor on the demography and feeding behaviour of the mirid bug Apolygus lucorum.

Sulfoxaflor, the first commercially available sulfoximine insecticide, has been used for the control of sap-feeding insect pests such as plant bugs and aphids on a variety of crops. However, its sublethal effects on the mirid bug Apolygus lucorum, one of the key insect pests of Bt cotton and fruit trees in China, have not been fully examined. Here, we evaluated the demography and feeding behaviour of A. lucorum exposed to sulfoxaflor. The leaf-dipping bioassay showed that the LC10 and LC30 of sulfoxaflor against 3rd-instar nymphs of this insect were 1.23 and 8.37 mg L-1, respectively. The LC10 significantly extended the nymphal duration and decreased the oviposition period by 5.29 days and female fecundity by 56.99% in the parent generation (F0). The longer duration of egg, 5th-instar nymphs, preadult, and male adult longevity were observed in the F1 generation (F1) at LC10. At the LC30, the duration of egg and 1st-instar nymph, female adult longevity, and oviposition period of the F1 were significantly shorter, while the nymphal duration in the F0 and duration of 5th-instar nymphs, preadult survival rate, and male adult longevity in the F1 significantly increased. The net reproductive rate (R0), intrinsic rate of increase (r), and finite rate of increase (λ) in the F1 were not significantly affected by these two concentrations, whereas the mean generation time (T) was lower at the LC30. Additionally, the probe counts and cells mixture feeding time were markedly lengthened by the LC10 and LC30, respectively, when A. lucorum nymphs exposed to sulfoxaflor fed on Bt cotton plants without insecticides. These results clearly indicate that sulfoxaflor causes sublethal effects on A. lucorum and the transgenerational effects depend on the tested concentrations.

Direct and indirect effects of predation and parasitism on the Anopheles gambiae mosquito.

BACKGROUND: A good understanding of mosquito ecology is imperative for integrated vector control of malaria. In breeding sites, Anopheles larvae are concurrently exposed to predators and parasites. However, to our knowledge, there is no study on combined effects of predators and parasites on development and survival of larvae and their carry-over effects on adult survivorship and susceptibility to further parasite infection. METHODS: This study focused on effects of the nymphs of the dragonfly Pantala flavescens and the parasitic fungus Beauveria bassiana on Anopheles gambiae, to determine: predation efficacy of nymphs against An. gambiae larvae; development rate of An. gambiae larvae in the presence of one, two or four constrained nymphs; efficacy of B. bassiana against An. gambiae larvae at doses of 3, 6 and 12 mg; and survival of adult mosquitoes exposed to B. bassiana, following pre-exposure to a constrained predator and/or parasite at the larval stage. The experiments consisted of survival bioassays quantified as pupation day, or dead larvae and/or adults. RESULTS: Nymphs had an average predation efficacy of 88.3% (95% CI: 87.5-89.1) at 24 hours, against An. gambiae larvae. The presence of one or two nymphs reduced development time of larvae by 0.65 and 0.35 days, respectively. However, development time of larvae exposed to four nymphs was similar to the control larvae. Larvae exposed to 3, 6 and 12 mg of B. bassiana were 2.0, 2.5 and 3.5 times more likely to die, respectively, compared to control larvae. Adults not pre-exposed, those pre-exposed to predator, parasite, or both were 45.8, 67.4, 50.9 and 112.0 times more likely to die, respectively, compared to control that were unexposed to predator or parasite, at larval and adult stage. CONCLUSIONS: This study shows that both predator and parasite can reduce larval population of An. gambiae, and presence of predator cues decreases development time in breeding sites, as well as, increases the susceptibility of emerging adult to fungus. Predator and parasite both have an additive effect on survival of adults exposed to B. bassiana. Field studies are required for an in-depth understanding of predator and parasite influence on mosquito development time, survival and susceptibility in nature.

Severe infection caused by nymphs of Armillifer armillatus (Pentastomida, Porocephalidae) in a leopard, Panthera pardus, in the Kruger National Park, South Africa.

The necropsy of an adult male leopard, Panthera pardus, shot in the Kruger National Park, revealed the presence of large numbers of Armillifer armillatus nymphs in the intestine, liver, spleen, mesentery, peritoneal fold, mediastinum and lungs. The animal had been observed to be blind in the right eye and severely debilitated. The infection with A. armillatus clearly contributed to its emaciation and anaemia. Armillifer armillatus is a parasite of snakes, using mammals that form part of the snakes' prey as intermediate hosts. It is also one of the pentastomids with the highest zoonotic potential in Africa. It is unclear if the leopard's partial blindness and injuries of its extremities forced it to forego larger prey items for easier prey, such as snakes, and this in turn led to exposure to this unusual parasite, or if he had simply developed a preference for snakes. The incidental finding of A. armillatus in a large carnivore emphasises the importance of necropsies in expanding our knowledge on wildlife diseases.

Phenology, seasonal abundance and stage-structure of spittlebug (Hemiptera: Aphrophoridae) populations in olive groves in Italy.

Spittlebugs (Hemiptera: Aphrophoridae) are the dominant xylem-sap feeders in the Mediterranean area and the only proven vectors of Xylella fastidiosa ST53, the causal agent of the olive dieback epidemic in Apulia, Italy. We have investigated the structured population phenology, abundance and seasonal movement between crops and wild plant species of both the nymphal and adult stages of different spittlebug species in olive groves. Field surveys were conducted during the 2016-2018 period in four olive orchards located in coastal and inland areas in the Apulia and Liguria regions in Italy. The nymphal population in the herbaceous cover was estimated using quadrat samplings. Adults were collected through sweep nets on three different vegetational components: herbaceous cover, olive canopy and wild woody plants. Philaenus spumarius was the most abundant species; its nymphs were collected from early March and reached a peak around mid-April, when the 4th instar was prevalent. Spittlebug adults were collected from late April until late autumn. P. spumarius adults were abundant on the herbaceous cover and olive trees in late spring, and they then dispersed to wild woody hosts during the summer and returned to the olive groves in autumn when searching for oviposition sites in the herbaceous cover. A relatively high abundance of P. spumarius was observed on olive trees during summer in the Liguria Region. The present work provides a large amount of data on the life cycle of spittlebugs within an olive agroecosystem that can be used to design effective control programmes against these vectors in infected areas and to assess the risk of the establishment and spread of X. fastidiosa to Xylella-free areas.

When Do We Eat? The Clock is Ticking.

Ticks are simultaneously fascinating and disgusting. Anyone who has removed a bloated blood-filled tick from themselves or a pet understands the "yuck" factor they arouse. But ticks are also fascinating from a physiological perspective. Ticks are the ultimate sit-and-wait predators. Female ixodid ticks (hard ticks) consume a single meal during each life stage (larva, nymph and adult), which means only three lifetime meals over a 1- to 3-year lifespan. Most males do not feed as adults, so they only feed twice. Thus, prolonged starvation is a quintessential aspect of tick life history. Although ticks have been widely studied for their importance as disease vectors, the vast majority of research has focused on tick-host interactions. Ixodid ticks spend the overwhelming majority of their lives off their hosts, but little is known about these periods. A new study begins to fill in some of these knowledge gaps. In this issue of Molecular Ecology, Rosendale, Dunlevy, Marshall, and Benoit examine physiological, behavioural and transcriptomic changes occurring during long-term starvation of the American dog tick, Dermacentor variabilis. Their work provides insights into how ticks are able to go so long between meals and how they prepare for their next meal.

EPG combined with micro-CT and video recording reveals new insights on the feeding behavior of Philaenus spumarius.

The meadow spittlebug Philaenus spumarius plays a key role in the transmission of the bacterium Xylella fastidiosa to olive in Apulia (South Italy). Currently, available data on P. spumarius feeding behavior is limited, and a real-time observation of the different steps involved in stylet insertion, exploratory probes, and ingestion, has never been carried out. Therefore, we performed an EPG-assisted characterization of P. spumarius female feeding behavior on olive, in order to detect and analyze the main EPG waveforms describing their amplitude, frequency, voltage level, and electrical origin of the traces during stylet penetration in plant tissues. Thereafter, each of the main waveforms was correlated with specific biological activities, through video recording and analysis of excretion by adults and excretion/secretion by nymphs. Furthermore, the specific stylet tips position within the plant tissues during each of the waveforms observed was assessed by microcomputer tomography (micro-CT). Additional EPG-recordings were carried out with males of P. spumarius on olive, in order to assess possible sex-related differences. P. spumarius feeding behavior can be described by five main distinct waveforms: C (pathway), Xc (xylem contact/pre-ingestion), Xi (xylem sap ingestion), R (resting), N (interruption within xylem phase). Compared to males, females require shorter time to begin the first probe, and their Xi phase is significantly longer. Furthermore, considering the single waveform events, males on olive exhibit longer np and R compared to females.

Metabolic alterations in the nymphal instars of Diaphorina citri induced by Candidatus Liberibacter asiaticus, the putative pathogen of huanglongbing.

Currently, huanglongbing is the most damaging disease of citrus causing huge economic losses. The disease is caused by the Gram-negative bacterium Candidatus Liberibacter asiaticus (CLas). The pathogen is transmitted in a persistent propagative circulative manner within its vector, the Asian citrus psyllid, Diaphorina citri. Exploring the metabolic alteration in the vector may lead to a better understanding of the nutritional needs of CLas and to designing an artificial medium for culturing the pathogen. It has been shown that the nymphal stages have a greater role in transmission mainly because they feed on plants more actively than adults. In this study, we carried out an untargeted comparative metabolomic analysis for healthy and CLas-infected 4th / 5th instar nymphs. The metabolic analysis was performed using trimethylsilylation and methyl chloroformate derivatization followed by Gas Chromatography-Mass Spectrometry (GC-MS). Overall, the changes in the nymph metabolism due to the infection with CLas were more pronounced than in adults, as we previously published. Nymphs reared on CLas-infected Valencia sweet orange were higher in many metabolites, mainly those of the TCA cycle, C16 and C18 fatty acids, glucose, sucrose, L-proline, L-serine, pyroglutamic acid, saccharic acid, threonic acid and myo-inositol than those reared on healthy plants. In contrast, CLas-infected nymphs were lower in putrescine, glycine, L -phenylalanine, L -tyrosine, L -valine, and chiro-inositol. The information provided from this study may contribute in acceleration of the availability of CLas in culture and consequent screening of antibacterial compounds to discover a definitive solution for huanglongbing.

Unexpected Infection with Armillifer Parasites.

Visceral pentastomiasis is usually found incidentally during surgery. We describe a case of visceral pentastomiasis discovered during inguinoscrotal hernia surgery for a man from Benin, Africa. Because surgical removal of nymphs is needed for symptomatic patients only, this patient's asymptomatic pentastomiasis was not treated and he recovered from surgery uneventfully.

The specific host plant DNA detection suggests a potential migration of Apolygus lucorum from cotton to mungbean fields.

The polyphagous mirid bug Apolygus lucorum (Heteroptera: Miridae) has more than 200 species of host plants and is an insect pest of important agricultural crops, including cotton (Gossypium hirsutum) and mungbean (Vigna radiata). Previous field trials have shown that A. lucorum adults prefer mungbean to cotton plants, indicating the considerable potential of mungbean as a trap crop in cotton fields. However, direct evidence supporting the migration of A. lucorum adults from cotton to mungbean is lacking. We developed a DNA-based polymerase chain reaction (PCR) approach to reveal the movement of A. lucorum between neighboring mungbean and cotton fields. Two pairs of PCR primers specific to cotton or mungbean were designed to target the trnL-trnF region of chloroplast DNA. Significant differences in the detectability half-life (DS50) were observed between these two host plants, and the mean for cotton (8.26 h) was approximately two times longer than that of mungbean (4.38 h), requiring weighted mean calculations to compare the detectability of plant DNA in the guts of field-collected bugs. In field trials, cotton DNA was detected in the guts of the adult A. lucorum individuals collected in mungbean plots, and the cotton DNA detection rate decreased successively from 5 to 15 m away from the mungbean-cotton midline. In addition to the specific detection of cotton- and mungbean-fed bugs, both cotton and mungbean DNA were simultaneously detected within the guts of single individuals caught from mungbean fields. This study successfully established a tool for molecular gut-content analyses and clearly demonstrated the movement of A. lucorum adults from cotton to neighboring mungbean fields, providing new insights into understanding the feeding characteristics and landscape-level ecology of A. lucorum under natural conditions.

No impact of transgenic cry1C rice on the rove beetle Paederus fuscipes, a generalist predator of brown planthopper Nilaparvata lugens.

T1C-19 is newly developed transgenic rice active against lepidopteran pests, and expresses a synthesized cry1C gene driven by the maize ubiquitin promoter. The brown planthopper, Nilaparvata lugens, is a major non-target pest of rice, and the rove beetle (Paederus fuscipes) is a generalist predator of N. lugens nymphs. As P. fuscipes may be exposed to the Cry1C protein through preying on N. lugens, it is essential to assess the potential effects of transgenic cry1C rice on this predator. In this study, two experiments (a direct feeding experiment and a tritrophic experiment) were conducted to evaluate the ecological risk of cry1C rice to P. fuscipes. No significant negative effects were observed in the development, survival, female ratio and body weight of P. fuscipes in both treatments of direct exposure to elevated doses of Cry1C protein and prey-mediated exposure to realistic doses of the protein. This indicated that cry1C rice had no detrimental effects on P. fuscipes. This work represents the first study of an assessment continuum for the effects of transgenic cry1C rice on P. fuscipes. Use of the rove beetle as an indicator species to assess potential effects of genetically modified crops on non-target arthropods is feasible.

Prevalence and morphopathological characteristics of linguatulosis in one-humped camel (Camelus dromedarius) in Yazd, Iran.

Linguatula serrata is a cosmopolitan zoonotic parasite. Its adult form inhabit the nasal and respiratory passages of canids as the definitive hosts while its immature stages localize in the mesenteric lymph nodes or in other organs of herbivorous intermediate hosts. We examined the liver, mesenteric, and mediastinal lymph nodes of 272 camels slaughtered at the slaughterhouse of Yazd, Iran. Forty-one out of 272 camels (15.1 %) were infected with nymphs of L. serrata. Twenty-four out of 166 males (14.45 %) and 17 out of 106 females (16 %) were positive. The livers of five camels, which also had nymphs in their lymph nodes, were infected with the larval stage of this parasite. The infection rate increased with age and was highly significant, while sex did not play a significant role in the prevalence of this parasitic infection. The infected lymph nodes were grossly enlarged, edematous, and consisted of hemorrhagic and necrotic lesions. Histopathologically, the architecture of the infected lymph nodes was degraded, necrotic, and sectioned migrating stages of L. serrata were clearly visible. In some lymph nodes, parasitic granulomatous lymphadenitis with necrosis and in some cases, degenerated parasite in central area was observed. High prevalence of infection in camels suggests possibility of similar high rate of infection in other animals of this region. In view of the consumption of raw or undercooked visceral organs of camel by humans of this region, the importance of careful inspection at slaughterhouse needs to be emphasized.

Large scale spatial risk and comparative prevalence of Borrelia miyamotoi and Borrelia burgdorferi sensu lato in Ixodes pacificus.

Borrelia miyamotoi is a newly described emerging pathogen transmitted to people by Ixodes species ticks and found in temperate regions of North America, Europe, and Asia. There is limited understanding of large scale entomological risk patterns of B. miyamotoi and of Borreila burgdorferi sensu stricto (ss), the agent of Lyme disease, in western North America. In this study, B. miyamotoi, a relapsing fever spirochete, was detected in adult (n=70) and nymphal (n=36) Ixodes pacificus ticks collected from 24 of 48 California counties that were surveyed over a 13 year period. Statewide prevalence of B. burgdorferi sensu lato (sl), which includes B. burgdorferi ss, and B. miyamotoi were similar in adult I. pacificus (0.6% and 0.8%, respectively). In contrast, the prevalence of B. burgdorferi sl was almost 2.5 times higher than B. miyamotoi in nymphal I. pacificus (3.2% versus 1.4%). These results suggest similar risk of exposure to B. burgdorferi sl and B. miyamotoi from adult I. pacificus tick bites in California, but a higher risk of contracting B. burgdorferi sl than B. miyamotoi from nymphal tick bites. While regional risk of exposure to these two spirochetes varies, the highest risk for both species is found in north and central coastal California and the Sierra Nevada foothill region, and the lowest risk is in southern California; nevertheless, tick-bite avoidance measures should be implemented in all regions of California. This is the first study to comprehensively evaluate entomologic risk for B. miyamotoi and B. burgdorferi for both adult and nymphal I. pacificus, an important human biting tick in western North America.

[Seasonal changes in the physiological age of Ixodes ricinus (Acari: Ixodidae) imagoes on the Stavropol Elevation].

Ixodes ricinus imagoes were caught using a flannel flag in the April to October of 2011 to 2013. There were two seasons when these stages were numerous, namely: spring and autumn. The physiological age of 506 hungry I. ricinus imagoes was determined from their outward signs: the shape of their rear body, the surface of the cuticle, and visibility of the internals through the latter. The change in the age composition suggests that an autumn imago cohort consists of specimens that emerged from nymphs in summer.

Ticks (Acari: Ixodidae) parasitizing humans in an Atlantic rainforest reserve of Southeastern Brazil with notes on host suitability.

While conducting projects on ticks from deer and on tick ecology in animal trails in an Atlantic rainforest reserve in Southeastern Brazil, researchers of our group were bitten by ticks several times. Some of these episodes were recorded. Three species of adult ticks attached to humans: Amblyomma brasiliense Aragão, Amblyomma incisum Neumann, and Amblyomma ovale Koch. Eight nymphal attachments with engorgement on humans were recorded. From these, six molted to adults of A. incisum, one to an adult of A. brasiliense, and one had an anomalous molting, therefore the adult tick could not be properly identified. Local reactions to tick attachment varied among individual hosts from almost imperceptible to intense. Especially itching, but hyperemia and swelling as well, were prominent features of the reaction. Overall it can be affirmed that human beings can be a physiologically suitable host species for ticks in the Atlantic rainforest and that itching was an important if not the major component of the resistance to tick bite.

Estudio comparativo de la sensibilidad y mortalidad de las ninfas III y IV de triatoma infestans usadas en el xenodiagnóstico de pacientes chagásicos crónicos / Comparative study on sensivity and mortality of triatoma infestans nymphs III and IV used in the xenodiagnosis of chronic chagasic patients

Triatoma infestans nymphs have shown a good sensitivity for detecting trypanosoma cruzi in the bood stream of infected hosts when are used in the xenodiagnosis (XD). This method, with its natural limitations, using seven nymphs III of T. infestans, has been routinely utilized with a satisfactory yield. With the aim of an eventual improving of the yield of XD (with 7 nymphs), two series of 54 XD boxes each, containing a total of 378 nymphs III and 378 nymphs IV respectively, were applied one of each during three consecutive days to nine chronic chagasic patients. Each of the nymphs was weighted before an after the application of the boxes, and the intestinal content of them was examined 30, 60 and 90 days later. The main comparative results obtained with nymphs III and IV of T. infestans were: blood ingestion 40 versus 107 mg (2,7 higher), positivity of insects 35,8 percent versus 50,6 percent (15,8 percent higher), positivity of XD boxes (7 nymphs each) 46,3 percent versus 55,6 percent (9,3 percent higher), and mortality rates 28,6 percent versus 12,2 percent (16,4 percent lower). All these results demonstrate that nymphs IV of T. infestans, because their higher capacity of ingesting blood and higher tolerance to examination manipulations, are more suitable for been used in XD

[Preliminary studies of the occurrence of allergenic mites in coal dust in the mines of the Upper Silesia]. / Wstepne badania nad wystepowaniem roztoczy alergogennych w pyle weglowym w kopalniach Górnego Slaska.

The study was conducted in four coal mines located in Upper Silesia. A total of 40 specimens were found: 20 from the genus Tarsonemus (Tarsonemidae, Tarsonemida); 9 from the family Pygmephoridae (Tarsonemida); two males of Tyrophagus putrescentiae (Acaridae, Acaridida) and one tritonymph--Tyrophagus sp.; two unidentified larvae (Acaridae, Acaridida); one specimen of Oppia clavipectinata (Oppidae, Oribatida) and 5 other mites from this order. T. putrescentiae and species from the genus Tarsonemus are considered as allergenic mites which may cause sensitization in humans.