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At least 19 recordsLinked to original sources
PubMed2000

Performance of yeast-baited traps with Triatoma sordida, Triatoma brasiliensis, Triatoma pseudomaculata, and Panstrongylus megistus in laboratory assays.

The effectiveness of a trap for triatomines baited with yeast cultures has been previously demonstrated for Triatoma infestans in laboratory assays. We report here results from laboratory assays testing yeast traps for Triatoma sordida, Triatoma brasiliensis, Triatoma pseudomaculata, and Panstrongylus megistus. All assays were conducted in an open experimental arena 100 cm x 100 cm, with two traps placed at opposite sides of the arena. One of the traps contained a yeast culture, and the other trap contained a saccharose solution as a control. Two series of experiments were done, one without a refuge for the insects and one with a refuge. The results obtained clearly demonstrated that the yeast-baited traps were effective in the laboratory in capturing both T. sordida and P. megistus. For T. sordida, yeast-baited traps captured significantly more bugs than did the control traps (t test P value = 0.03). For P. megistus, when a refuge was provided during the assay, yeast-baited traps also captured significantly more bugs than did the control traps (t test P value = 0.006). In the experiments with T. brasiliensis and T. pseudomaculata, both traps captured some insects, but the yeast traps captured many fewer bugs than was true with the T. sordida and P. megistus bugs. These results indicate that, in the laboratory, yeast traps can capture considerable numbers of T. sordida and P. megistus in one night. We discuss the potential use of yeast traps for detecting and capturing both triatomine species.

Animals↗
PubMed2000

Comparison of feeding behaviour of Triatoma infestans, Triatoma brasiliensis and Triatoma pseudomaculata in different hosts by electronic monitoring of the cibarial pump.

Feeding behaviour of Triatoma infestans, T. brasiliensis and T. pseudomaculata on pigeons and mice was compared by electronic monitoring of the cibarial pump. The methodology developed permits the study detailed of triatomine feeding behaviour using an artificial feeder as well as on live hosts. T. infestans was the species that fed most rapidly on the two hosts tested (28.03+/-1.6 mg/min for pigeon and 21.33+/-1.7 mg/min for mouse), followed by T. brasiliensis (17.09+/-1.4 mg/min and 13.1+/-1.5 mg/min for pigeon and mouse, respectively) and T. pseudomaculata, (5.23+/-0.6 mg/min and 4.09+/-0.4 mg/min for pigeon and mouse, respectively). The quantity of liquid ingested per stroke of the cibarial pump was 100.7+/-4.1 nl for T. infestans, 69.1+/-2.7 nl for T. brasiliensis and 26.8+/-1.5 nl for T. pseudomaculata. The rate of engorgement in pigeons tended to be greater than that obtained for mice in the three species studied. In the experiments carried out using mice, probing times tended to be longer and interruptions during the meal more prolonged. This reinforces the idea that feeding on mice is more difficult than on pigeons, requiring more contact time to obtain the similar quantity of blood.

Journal Article↗
PubMed1983

Experimental parasitization of eggs of Triatoma maculata (Erichson) by the oriental microhymenopteran, Gryon triatomae Masner and comment on the susceptibility of other neotropical triatomines.

The oriental microhymenopteran wasp, Gryon triatomae Masner, 1975 was reared in eggs of triatomine bugs, including vectors of Chagas' disease. In particular, G. triatomae was maintained for 31 generations in eggs of Triatoma maculata (Erichson). Only one parasite develops in each bug egg and 30 to 40 days are required for completion of development at 24 +/- 1 degrees C. Mean parasitization rate of 7484 eggs of T. maculata, in 54 rearings, was 34.7% with a range from zero to the highest rate of 86.7%. Mated females produce predominantly female progeny (mean sex ratio, 1 male:6.7 females). Unmated females produce parthenogenetic males. The wasp reproduces in fertile eggs, from those recently laid to those with well-advanced bug embryos. Infertile eggs are not usually parasitized. Both sexes survive for one to two weeks unfed, but for several weeks (up to 16 for females) if fed (on honey). Frequent ovipositions may reduce survival. Successful parasitization by females persisted for about three weeks but declined subsequently. Abortions of developing Gryon were usually 10% or less. Brief comparison with other neotropical triatomine species indicates that eggs of Triatoma spp. are susceptible to G. triatomae; Panstrongylus spp. seem relatively poor hosts, and there is little or no parasitization of Rhodnius spp.

Animals↗
PubMed1999

The effect of azadirachtin on Blastocrithidia triatomae and Trypanosoma cruzi in Triatoma infestans (Insecta, Hemiptera).

The effect of azadirachtin on Blastocrithidia triatomae and Trypanosoma cruzi, which colonise the intestinal tract of the blood-sucking bug Triatoma infestans, was investigated. In established infections of controls without azadirachtin treatment, the small intestine of fifth-instar T. infestans contained up to 7 x l0(6) B. triatomae and the rectum 3 x 10(6). In comparison to this homoxenous flagellate, the population densities of T. cruzi in the respective regions were 99.3 and 76% lower. Treatment with azadirachtin (1 microg ml(-1)) via a blood meal and a concurrent infection with B. triatomae resulted in an increase of the population density (3 weeks p.i.), caused mainly by the mastigote stages in the rectum. In an established B. triatomae infection (12 weeks p.i.), feeding of azadirachtin did not affect the population density and composition. In an optimal T. cruzi-vector system, i.e. parasite and bug originate from the same locality, the treatment with azadirachtin at 20 weeks p.i. strongly reduced the population density in the small intestine of all bugs up to 100 days after treatment, but only in a minor percentage of the bugs in the rectum. Trypanosoma (cruzi incubated for up to 24 h in faeces of azadirachtin-treated bugs were not affected, indicating that the rectum of these bugs contained no toxic substances. The importance of these findings is that investigations of the mechanisms of action of azadirachtin offer a possibility to identify vector-derived compounds, which are necessary for the development of T. cruzi, thereby, giving us a possible new strategy to combat Chagas' disease.

Animals↗
PubMed2000

Peridomestic distribution of Triatoma garciabesi and Triatoma guasayana in north-west Argentina.

The Reduviid bugs Triatoma garciabesi Carcavallo et al. (Hemiptera: Reduviidae: Triatominae), previously known as T. sordida Ståhl in the semi-arid chaco region, and T. guasayana Wygodzinsky & Abalos, vectors of Trypanosoma cruzi Chagas (Kinetoplastida: Trypanosomatidae), were found to occupy wide but different ranges of ecotopes in the peridomestic environment. At Amamá and nearby rural villages in north-western Argentina, a combined total of 1233 specimens were collected from 325/2314 (14%) sites surveyed at 6-monthly intervals from November 1994 to November 1996. Triatoma garciabesi and T. guasayana displayed a significantly different distribution among peridomestic ecotopes. Triatoma garciabesi predominated over T. guasayana in the prevalence of infested sites, the number of colonies and the number of bugs collected. For T. garciabesi, the predominant ecotopes most likely to yield T. garciabesi repeatedly were the rugged bark of Prosopis alba or P. nigra (Fabaceae) trees, where chickens roosted, and chicken coops. For T. guasayana the main ecotopes were goat or sheep corrals, piled materials and orchard fences. Triatoma garciabesi and T. guasayana were collected concurrently from the same site on 9/2314 (0.4%) occasions, and on different dates at the same site on 12 (0.5%) occasions. The observed low frequency of mixed populations (< 1%) was not significantly different from that expected from a hypothesis of independence. Triatoma garciabesi clearly outnumbered T. guasayana in four of the nine mixed populations, none of which persisted as such. Neither T. garciabesi nor T. guasayana colonized human habitations, even in the absence of T. infestans (formerly the predominant domestic vector of T. cruzi in this area), a situation that apparently has not changed in the last 50 years in northern Argentina.

Animals↗
PubMed1983

Parasitization by the microhymenopteran Gryon triatomae Masner of eggs of Triatoma maculata (Erichson) in holes and mazes of artificial walls.

Oriental parasitoid wasps, Gryon triatomae, were confined for several weeks in transparent tanks (400 X 180 X 200 mm) with eggs of the neotropical triatomine bug Triatoma maculata. The eggs were lodged in moulded holes (about 50 mm deep and 15 mm diameter) of polystyrene blocks, to simulate walls. The blocks were arranged with the holes either vertical or horizontal; openings of the holes were either 5 mm or 15 mm diameter. One wall included three mazes of linked holes, each maze with one entrance. Eggs were also accessible in an open petri-dish and on top of one wall. Some eggs in the walls and the maze block were in holes sealed off from access by wasps to provide controls, in order to assess fertility of the eggs, since this favours parasitization. This was satisfactory at 82.2% and 88.5% in two tanks studied. Parasitization rates were 32% of 50 eggs exposed to one female G. triatomae, with one male wasp, in one tank, and in the other 55.9% of 136 eggs exposed to 14 female wasps, with five males. In both tanks, eggs in the open petri-dish, in accessible vertical and horizontal holes and on top of walls were parasitized, but parasitization of eggs in the mazes occurred only in the tank with 14 female Gryon and then as far as the last, 18th, hole of the longest maze, a linear penetration by a searching wasp of about 270 mm; the distance travelled could be considerably greater. Late wasp oviposition after protracted questing may have caused the observed 15.8% abortion rate of G. triatomae. The few wasps seen by night were at rest, but at daybreak many more emerged from the walls and flew actively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

The effect of Blastocrithidia triatomae (Trypanosomatidae) on the midgut of the reduviid bug Triatoma infestans.

The pathogenic flagellate Blastocrithidia triatomae disrupts the digestion of Triatoma infestans; the midgut ultrastructure of bugs infected with the flagellate and of uninfected bugs is compared. Third or fourth instar larvae were dissected either unfed or 1 week after feeding. In all uninfected bugs extracellular membrane layers (e.m.l.) covered the apical microvillar border of the epithelial cells. Some midgut regions of bugs infected with B. triatomae appeared normal but often adjacent cells showed pathological effects. In affected cells the e.m.l. and the microvilli and finally the cells themselves were reduced or destroyed. Correlated with these observations of pathogenicity the method of attachment of parasites changed. When the e.m.l. were present only rarely were flagella found, but on extracellular membrane-free cells B. triatomae attached by flagellar enlargement to the microvillar border or, if this was reduced, to the apical host cell membrane. No hemidesmosome-like plaques were found at the attachment site. Although some flagella were inserted into the apical region of the cells no intracellular flagellates were observed.

Animals↗
PubMed1989

Cultivation of Blastocrithidia triatomae (Trypanosomatidae) on a cell line of its host Triatoma infestans (Reduviidae).

Blastocrithidia triatomae parasitizes vectors of Chagas' disease and is very difficult to cultivate in conventional media. However, co-cultivation with a cell line of its host Triatoma infestans (TI-32; in Schneider's Drosophila medium supplemented with 20% foetal calf serum and 10% tryptose phosphate broth) led to vigorous growth at 24 or 28 degrees C without an adaptation phase. More than 60 primary cultures were initiated successfully without any failures. Subcultures could be started immediately at weekly intervals. The doubling time was similar in both the primary cultures (41 h) and the 33rd subculture (39 h). The importance of the reduviid cells for B. triatomae became clear after removal of the insect cells, when multiplication of epimastigotes stopped and mainly cysts were formed. Cysts produced in vitro were infective for reduviids. Scanning electron microscopy showed that B. triatomae attached to the host cells, inserted its flagellum into them and destroyed them.

Animals↗
PubMedDate not supplied

[Biological susceptibility of Triatoma sordida and Triatoma infestans to deltamethrin and lambdacyhalothrin under field conditions].

The biological susceptibility of Triatoma sordida and Triatoma infestans to deltamethrin and lambdacyhalothrin was evaluated in three homogeneous groups of houses in the municipality of Posse, Goiás. Each group of houses was treated according to one of the following protocols: deltamethrin 5% wetted powder at 25 mg a.i./m2; deltamethrin 5% concentrated suspension at 25 mg a.i./m2; and lambdacyhalothrin 10% wetted powder at 30 mg a.i./m2. Monitoring of susceptibility to the insecticides was done after 90, 210, 270 and 360 days after the spraying. Each test consisted of an exposure of 10 third-instar nymphs of each species for every house. The insects were kept in contact with the sprayed wall for a period of 72 hours in plastic containers developed by WHO for studies with adult mosquitos. Thirty days after the exposure the death numbers were scored. Results demonstrate persistent activity of the three insecticides for up to a year after spraying and equal biological susceptibilities for both Triatoma sordida and Triatoma infestans to each formulation.

Animals↗
PubMed1987

Differences in binding of lectin-gold conjugates by Trypanosoma cruzi and Blastocrithidia triatomae (Trypanosomatidae) in the intestine of Triatoma infestans (Reduviidae).

Two species of trypanosomatid flagellates, Trypanosoma cruzi and Blastocrithidia triatomae which develop in the intestine of Triatoma infestans, were incubated with lectin-gold conjugates to demonstrate sugar components of the cell surface with the electron microscope. T. cruzi, strain "Chile 5" (zymodeme 1), bound SBA-gold, revealing N-acetyl-galactosamine and/or galactose residues. WGA-BSA-gold, specific for N-acetylglucosamine, did not bind to the surface of this flagellate. On the other hand, N-acetyl-glucosamine bound WGA-BSA-gold on the cell membrane of epimastigotes and cysts of B. triatomae, whereas SBA-gold was not bound by flagellates which were attached to the midgut epithelium and the rectum cuticle. Among other criteria, these differences in lectin binding may facilitate the discrimination of the two parasite species in the vector of Chagas' disease.

Animals↗
PubMed1990

Membrane feeding for infection of the reduviid bug Triatoma infestans with Blastocrithidia triatomae (Trypanosomatidae) and pathogenic effects of the flagellate.

To investigate the pathogenic effects of the trypanosome Blastocrithidia triatomae on Triatoma infestans, a method for direct infection by in vitro feeding was developed. After isolation of B. triatomae cysts from infected dead bugs, a suspension of cysts was disinfected with Desogen and Chloramin T, then mixed with sterile blood, spread on a sterile, parallel-grooved glass plate or a hammered aluminium plate and covered with a thin, sterile silicone membrane. The blood and plate were warmed to 36 degrees-38 degrees C by a heating plate. For investigation of the pathological effects, first instars of T. infestans were allowed to feed through the membrane on a mixture containing 10(6) cyst stages/cm3 blood. Development of about 30% of the third and fourth instar larvae was retarded as compared with that in uninfected control groups, and mortality rates increased in fourth and/or fifth instar larvae. Whereas total mortality rates of about 5% occurred in control groups, about 85% of the larvae died in the infected groups. These effects are very similar to those obtained in previous studies with coprophagic infections.

Animals↗
PubMed1988

Influence of Blastocrithidia triatomae (Trypanosomatidae) on the reduviid bug Triatoma infestans: alterations in the Malpighian tubules.

To investigate the cellular basis of our recent observation that the trypanosome Blastocrithidia triatomae disturbs excretion in Triatoma infestans, we compared the morphology and ultrastructure of Malpighian tubules in infected and noninfected bugs. Tubules of bugs infected 3-4 months before dissection did not show any morphological alterations in either the upper or lower regions. In fifth instars with a long lasting infection (9-10 months) and a correspondingly retarded larval development, the tracheal system supplying the Malpighian tubules was reduced and alterations were conspicuous in the upper region, where the tubules were slightly widened, sometimes having parts with conspicuous swellings. The cells were filled with white concretions and a strong autofluorescence was evident by fluorescence microscopy. Transmission electron microscopy demonstrated an increase in the number of these concretions, even after short infection periods. In the extremely swollen parts of the tubules there was a reduction in basal cell interdigitations, mitochondria, and microvilli. B. triatomae (but also gram-negative bacteria) occurred only in these swollen parts.

Animals↗
PubMed1990

The effect of Blastocrithidia triatomae (Trypanosomatidae) on the reduviid bug Triatoma infestans: influence of group size.

Developmental time and mortality in uninfected larvae of the reduviid bug Triatoma infestans and in those infected by feeding a mixture of blood and cysts of the homoxenous trypanosomatid Blastocrithidia triatomae were compared. Larvae were maintained isolated in 77-cm3 (area 9.6 cm2) beakers or in groups of 20, 30, 40, and 50 bugs per 1-liter beaker (area 722 cm2). In uninfected groups, only a minor proportion of isolated bugs showed delayed development, but in groups infected with B. triatomae, additionally, a retardation in groups of 50 larvae occurred. Infected bugs needed more time to complete development in fourth and fifth instar than did uninfected bugs. Mean mortality rates of about 10% in uninfected groups were unaffected by group size. Mortality rates in most groups of infected bugs were about 50%, but in groups consisting of 50 larvae a statistically significant higher mortality rate of 75% was observed. This indicates a subpathological overcrowding stress, increased by the synergistic action of the flagellate.

Animals↗
PubMed1986

Studies of kissing bug-sensitive patients: evidence for the lack of cross-reactivity between Triatoma protracta and Triatoma rubida salivary gland extracts.

In the southern and western sections of the United States, bites from the reduviid bug, commonly known as the kissing bug, genus Triatoma, may induce serious life-threatening allergic reactions. This study was undertaken to identify the allergens responsible for patient sensitization and to determine the extent of cross-reactivity of these allergens. The Triatoma spp. most commonly encountered in California and Arizona, T. protracta and T. rubida, were obtained, maintained in the laboratory, and dissected to prepare extracts for testing. Extracts were prepared from T. protracta and T. rubida for study by RAST, lymphocyte transformation, leukocyte histamine release, and RAST inhibition. Sera and cells were collected from patients who had generalized reactions to Triatoma bites. Our results indicate that T. protracta and T. rubida antigens to which patients are sensitized are present in extracts that contain saliva and that human responses are specific for T. protracta or T. rubida, i.e., allergic cross-reactivity could not be demonstrated.

Adolescent↗
PubMed1989

Parasite/host-interrelationships of the trypanosomatids Trypanosoma cruzi and Blastocrithidia triatomae and the reduviid bug Triatoma infestans: influence of starvation of the bug.

We have investigated the effects of Trypanosoma cruzi and Blastocrithidia triatomae on the life span of starved second/third (L2/3), third/fourth (L3/4), and fourth/fifth instars (L4/5) of Triatoma infestans, which had been infected in the first instar and fed last in the second, third or fourth instar respectively. The intestines and sometimes also the flagellate populations of dead bugs were examined. In uninfected L2/3 a higher relative humidity prolonged the life span. With a maximal survival of 14 months, uninfected L3/4 were the most resistant to starvation, followed by L4/5 and then L2/3. Trypanosoma cruzi reduced the life span of starved L3/4 and L4/5 by only 14% and 17%, respectively. Infection with B. triatomae reduced life spans by 51% (L2/3), 55% (L3/4) and 32% (L4/5). The intestines of dead infected bugs were more likely to contain incompletely-digested blood remnants than those of uninfected bugs; living flagellates occurred in all parts of the intestine, and often the rectal lumen contained more dead flagellates than were found on the rectal wall.

Animals↗
PubMed1988

Pathological effects of Blastocrithidia triatomae (Trypanosomatidae) on the reduviid bugs Triatoma sordida, T. pallidipennis and Dipetalogaster maxima after coprophagic infection.

Developmental time and mortality in nymphs of the reduviid bugs Triatoma sordida (Stål), Triatoma pallidipennis (Stål) and Dipetalogaster maxima (Uhler) were studied in uninfected groups and in those infected with Blastocrithidia triatomae Cerisola et al. (Trypanosomatidae). In T.sordida and T.pallidipennis, major vectors of Chagas' disease in Brazil and Mexico respectively, infection with B.triatomae was associated with slight developmental retardations in the final instars, and increased mortality in the pre-adult instar. These effects were less evident in T.pallidipennis, but in this species a total infection rate of only 5-15% was achieved, compared with about 45% in T.sordida. In contrast, D.maxima was strongly affected by B.triatomae: nymphal development was retarded and complete mortality occurred in some groups exposed to infection, although not all bugs were infected.

Animals↗
PubMed1990

Developmental time and mortality of the reduviid bug Triatoma infestans with differential exposure to coprophagic infections with Blastocrithidia triatomae (Trypanosomatidae).

Developmental time and survival in larvae of the reduviid bug Triatoma infestans were studied in uninfected groups and in those exposed to a coprophagic infection with Blastocrithidia triatomae. Addition to young uninfected larvae of (a) different numbers of infected bugs, (b) infected and uninfected bugs, and (c) fresh or dry infectious feces were compared. Retardation of development was evident in groups given infected larvae or fresh feces. Mortality rates were correlated with infection rates and were higher in groups given more infected bugs, independent of the presence of uninfected bugs. Therefore, bugs did not discriminate between feces from infected and uninfected bugs, or they did not reject infectious feces. Dry feces had to be redissolved with fresh feces before infection was possible.

Animals↗