Resistance to starvation of Rhodnius neivai Lent, 1953 (Hemiptera: Reduviidae: Triatominae) under experimental conditions

The period of resistance to starvation and the loss of weight until death of Rhodnius neivai in all stages of development were studied. Work was based on experiments conducted under controlled laboratory conditions. One hundred specimens of each nymphal instar were observed: 50 were fed on chicken and 50 on rabbit. Adult females and males were kept together and fed on each host. All bugs were weighed weekly until death. Laid eggs were collected weekly and observed during five weeks to obtain hatchability. Resistance to starvation was similar with both hosts and increased with the evolutionary stage, excepting the 5th nymphal instar and adults. With both hosts, loss of weight was abrupt in the first week and steady in the following weeks. In adults, on the first weeks after eating, there was little or no mortality, after which mortality increased rapidly with the starving time. Reproductive output was higher in the bugs fed on rabbit. R. neivai is among the least resistant triatomine species.

Lutzomyia aldafalcaoae sp. n. a new species of Phlebotominae (Diptera: Psychodidae) from Mato Grosso do Sul, Brazil

A new sand fly species, Lutzomia aldafalcaoae is described from males collected in Vila Trindade, an urban district in Aquidauana county, State of Mato Grosso do Sul, Brazil, in October 1996. Taxonomic remarks and a description of the new species is presented.

In vitro interaction of Brazilian strains of the Nematode-trapping fungi Arthrobotrys spp. on Panagrellus sp. and Cooperia punctata

In vitro tests were carried out to verify the activity of 26 Brazilian isolates of predatory fungi of the genus Arthrobotrys on a free-living nematode (Panagrellus sp.) and on infective larvae of Cooperia punctata, a parasitic gastrointestinal nematode of cattle. The results showed that the free-living nematode Panagrellus sp. was the most preyed upon, compared to C. punctata, for all the fungal treatments. Also, variable predatory capacity was observed for different fungal isolates belonging to the same genus when applied to different nematode species.

Rhodnius robustus in Bolivia identified by its wings

Wings of a Rhodnius specimen from Alto Beni (Bolivia) was examined for identification and compared with R. stali, R. robustus, (certified Bolivian species), R. pictipes and R. prolixus (suspected Bolivian species). A projection of the unidentified wings as supplementary data into a discriminant analysis of shape revealed clear cut differences with R. stali and R. pictipes, less differences with R. prolixus, and none with R. robustus. Combining global size and shape of the wings, the unknown specimen was identified as R. robustus. Thus, this study confirmed the presence of R. robustus in Bolivia. It also highlighted the possibility of morphometrics to taxonomically interpret one individual, or even one piece of an individual, when related species data are available for comparison.

Differentiation and genetic analysis of Rhodnius prolixus and Rhodnius colombiensis by rDNA and RAPD amplification

Domiciliated Rhodnius prolixus and sylvatic R. colombiensis were analyzed in order to confirm their genetic divergence and verify the risk that the latter represents in the domiciliation process, and to provide tools for identifying the sources of possible reinfestation by triatomines in human dwellings allowing control programs to be undertaken. Comparison of random amplified polymorphic DNA amplification patterns and cluster analysis suggests reproductive discontinuity between the two species. The calculated statistical F value of 0.24 and effective migration rate of 0.6 individuals per generation are insufficient to maintain genetic homogeneity between them and confirm the absence of present genetic flow. R. colombiensis presents higher intrapopulation variability. Polymerase chain reaction of ribosomal DNA supports these findings. The low genetic flow between the two species implies that R. colombiensis do not represent an epidemiological risk for the domiciliary transmission of Trypanosoma cruzi in the Tolima Department. The lower variability of the domiciliated R. prolixus could result in greater susceptibility to the use of pesticides in control programs.

Rhodnius amazonicus Almeida, Santos & Sposina, 1973, Bona Species, Close to R. pictipes Stål, 1872 (Heteroptera, Reduviidae, Triatominae)

The discovery of two atypical specimens of Rhodnius pictipes Stål, 1872 in French Guiana and the examination of the female holotype of R. amazonicus Almeida, Santos & Sposina, 1973, the only specimen of this species so far known, lead us to propose the rehabilitation of R. amazonicus synonymized with R. pictipes. The male is described for the first time and the female redescribed. Both external characters and genitalia distinguish R. amazonicus from R. pictipes. R. amazonicus shows affinities not only with pictipes but also with R. stali Lent, Jurberg & Galvão, 1993 and R. paraensis Sherlock, Guitton & Miles, 1977. A key is provided for these four species forming, in all likelihood, a natural group, i.e. the "pictipes group".

Myxobolus absonus sp. n. (Myxozoa: Myxosporea) Parasitizing Pimelodus maculatus (Siluriformes: Pimelodidae), a South American Freshwater Fish

A new myxoporean species is described from a freshwater fish in Brazil. Myxobolus absonus sp. n. was found infecting Pimelodus maculatus captured in the river Piracicaba, State of São Paulo, Brazil. Cysts were found free in the opercular cavity. The spores are large (length-15.7 ± 1.5 µm, width-10.2 ± 0.7 µm; mean ± S.D.) and oval in shape, with the anterior end slightly pointed. The spore valves are relatively thin, smooth, and asymmetrical in a frontal view. The polar capsules are pyriform in shape, and unequal in size; the largest are 6.4 ± 0.7 µm long and 3.6 ± 0.5 µm wide, while the smallest are 4.2 ± 0.6 µm long and 2.5 ± 0.5 µm wide.

Araucnephia iberaensis n. sp., a Neotropical Black Fly with a Peculiar Distribution (Diptera-Simuliidae)

Araucnephia Wygodzinsky & Coscarón is a Neotropical black fly genus in which only one species from Central Chile is known. Another species has now been found in Corrientes province on the eastern side of the Iberá tropical swamps of Argentina, on the western border of the mountainous region of southern Brazil. This new species, A. iberaensis, is herein described and illustrated and information on its bionomics is recorded. It is an interesting species because previous to its discovery no black fly genus or subgenus from Central Chile region has been found in tropical areas, because these two regions are separated by the Monte and Pampas realms. Similarly, no Brazilian genus or subgenus has crossed the Andes mountains to Chile. A comparison with other Neotropical, Nearctic, Ethiopian (Afrotropical) and Australian Prosimuliini (sensu Crosskey & Howard) showed Araucnephia to be a valid taxon most closely related to Araucnephioides (sympatric in Chile). Araucnephia also shows great affinities with Lutzsimulium from Southeast Brazil and Argentina and Paracnephia from South Africa.

The Triatomines of Northern Peru, with Emphasis on the Ecology and Infection by Trypanosomes of Rhodnius ecuadoriensis (Triatominae)

Information on the distribution and synanthropic behaviour of triatomines is essential for Chagas disease vector control. This work summarises such information from northern Peru, and presents new data on Rhodnius ecuadoriensis - an important local vector infesting 10-35% of dwellings in some zones. Three species are strongly synanthropic and may be suitable targets for chemical control of domestic/peridomestic bug populations. Panstrongylus herreri, the main domestic vector in the area, is probably present in sylvatic ecotopes in the Marañón river system. R. ecuadoriensis and Triatoma dimidiata seem exclusively domestic; biogeographical and ecological data suggest they might have spread in association with humans in northern Peru. Confirmation of this hypothesis would result in a local eradication strategy being recommended. Presence of trypanosome natural infection was assessed in 257 R. ecuadoriensis; Trypanosoma rangeli was detected in 4% of bugs. Six further triatomine species are potential disease vectors in the region (T. carrioni, P. chinai, P. rufotuberculatus, P. geniculatus, R. pictipes, and R. robustus), whilst Eratyrus mucronatus, E. cuspidatus, Cavernicola pilosa, Hermanlentia matsunoi, and Belminus peruvianus have little or no epidemiological significance. A strong community-based entomological surveillance system and collaboration with Ecuadorian public health authorities and researchers are recommended.

Observations on the Domestic Ecology of Rhodnius ecuadoriensis (Triatominae)

Rhodnius ecuadoriensis infests peridomiciles and colonises houses in rural southern Ecuador. Six out of 84 dwellings (7%) surveyed in a rural village were infested (78 bugs/infested domicile; 279 bugs were collected in a single dwelling). Precipitin tests revealed R. ecuadoriensis fed on birds (65%), rodents (31%), marsupials (8%), and humans (15%) - mixed bloodmeals detected in 37.5% of individual samples. Trypanosoma cruzi from opossums and rodents may thus be introduced into the domestic cycle. Wasp parasitoidism was detected in 6.5% of 995 R. ecuadoriensis eggs (only in peridomestic habitats). Control strategies should integrate insecticide spraying (indoors and peridomestic), better management of poultry, and housing improvements. A possible inefficacy of Malathion is reported.

Intestinal Coccidia (Apicomplexa: Eimeriidae) of Brazilian Lizards. Eimeria carmelinoi n.sp., from Kentropyx calcarata and Acroeimeria paraensis n.sp. from Cnemidophorus lemniscatus lemniscatus (Lacertilia: Teiidae)

Eimeria carmelinoi n.sp., is described in the teiid lizard Kentropyx calcarata Spix, 1825 from north Brazil. Oocysts subspherical to spherical, averaging 21.25 x 20.15 µm. Oocyst wall smooth, colourless and devoid of striae or micropyle. No polar body or conspicuous oocystic residuum, but frequently a small number of fine granules in Brownian movement. Sporocysts, averaging 10.1 x 9 µm, are without a Stieda body. Endogenous stages characteristic of the genus: intra-cytoplasmic, within the epithelial cells of the ileum and above the host cell nucleus. A re-description is given of a parasite previously described as Eimeria cnemidophori, in the teiid lizard Cnemidophorus lemniscatus lemniscatus. A study of the endogenous stages in the ileum necessitates renaming this coccidian as Acroeimeria cnemidophori (Carini, 1941) nov.comb., and suggests that Acroeimeria pintoi Lainson & Paperna, 1999 in the teiid Ameiva ameiva is a synonym of A. cnemidophori. A further intestinal coccidian, Acroeimeria paraensis n.sp. is described in C. l. lemniscatus, frequently as a mixed infection with A. cnemidophori. Mature oocysts, averaging 24.4 x 21.8 µm, have a single-layered, smooth, colourless wall with no micropyle or striae. No polar body, but the frequent presence of a small number of fine granules exhibiting Brownian movements. Sporocysts 9 x 8, without a Stieda body. Endogenous stages epicytoplasmic, characteristic of the genus, in the upper ileum. The importance of a study of the endogenous stages of eimeriid coccidia is discussed.

Descriptions of Lutzomyia (Evandromyia) georgii n. sp. and a Synopsis of the Series infraspinosa (Diptera: Psychodidae)

Lutzomyia georgii n. sp. and the female of L. tarapacaensis in the Series infraspinosa of the subgenus Evandromyia are described, from specimens collected in rainforest in the north of the State of Pará, Brazil. The new species was taken together with five other Evandromyia species including L. infraspinosa (sensu strictu) in the same locality. L. georgii has previously been confused with both L. begonae and L. infraspinosa, whereas L. tarapacaensis would run to L. infraspinosa in recent taxonomic keys. The fact that both L. georgii and L. tarapacaensis are locally sympatric with L. infraspinosa helps to clarify the taxonomic limits of the latter species. New keys to the subgenus Evandromyia are provided.

Neyraiella distinctus n. sp. (Oxyurida, Blattophilidae) Parasite of Nymphs of Gryllodes laplatae Sauss (Orthoptera, Gryllidae) in Argentina

Neyraiella distinctus n. sp. was found parasitizing nymphs of the cricket Gryllodes laplatae Sauss in City Bell, Argentina. This species was characterized by having the excretory pore in the posterior end of the basal bulb, vulva protruding with one lip well developed in the 1/3 end of the body, anus of the female with wings, male with a single spicule without any sculpture, gubernaculum and bursa are absent, six pairs of genital papillae arranged in two preanal pairs, one adanal pair and three postanal pairs, and the tail appendage in both sexes was short and conic.

Activity and Residual Effect of Two Formulations of Lambdacyhalothrin Sprayed on Palm Leaves to Rhodnius prolixus

The insecticidal activity and residual effect of two formulations of lambdacyhalothrin were evaluated with Rhodnius prolixus;laboratory and field tests were conducted in the State of Chiapas, Mexico. The results indicate that the lethal concentrations of the active ingredient of SC (LC50 = 2.37 and LC90 = 8.5 mg, a.i./m²) were 4-8 times than those with the insecticide WP applied on R. prolixus bugs in palm leaves, a common building material for thatched roofs. Other investigators in South America recommended applying 30 mg a.i./m² in porous materials; we obtained that the products WP and SC were 3.5 and 16 times more effective on palm leaves. Regarding the evaluation of the residual effects in field spraying, there was up to 15 months persistence after the application of WP in two doses (8.6 mg a.i./m² and 3.752 mg a.i./m²) with SC. We consider R. prolixus highly susceptible to the employed pyrethroids; they could be used to control this vector in the state of Chiapas, Mexico.

Description of Pintomyia (Pifanomyia) falcaorum sp. n. (Diptera: Psychodidae: Phlebotominae), a Fossil Sand Fly from Dominican Amber

A new species of sand fly, Pintomyia (Pifanomyia) falcaorum is described from an amber originated from the northern mountain range of Dominican Republic. The male sand fly specimen is well preserved and most features used in Phlebotominae taxonomy are seen with remarkable clarity.