Neotropical Entomology

Published by Springer Nature

Online ISSN: 1678-8052


Print ISSN: 1519-566X


Fig. 60. Probable distribución del género Cephalocoema. 
The Genus Cephalocoema Serville, 1839 (Orthoptera: Proscopiidae, Tetanorhynchini)
  • Article
  • Full-text available

June 2007


328 Reads

The genus Cephalocoema Serville, 1,839 is revised by the study of its type-species and additional ones. New species are described and synonymies are made. Each species is studied in its morphological features and genital characters, both male and female. Type localities are marked in Biogeographical regions map, which let us to get a pattern of distribution related with the habitat preferences of each species, for the whole genus.

Fig. 1. Laranda uai sp. nov.: dorsal view of male holotype. 
Fig. 2. Laranda uai sp. nov.: dorsal view of male nymph.
Fig. 3. Laranda uai sp. nov. Male genitalia on A) dorsal, B) ventral, C) lateral and D) posterior views. E. Subgenital plate. Arrow on ventral projection of pseudepiphallic paramere (B). Abbreviations: Ps. P.: pseudepiphallic paramere; Ps. L.: pseudepiphallic lobe; Ps. M. P.: pseudepiphallic median process; r: rami; Ect. Arc: ectophallic arc; Ect. F.: ectophallic fold; Ect. Ap.: ectophallic apodeme; End. Ap.: endophallic apodeme.
Fig. 4. Laranda uai sp. nov. Female copulatory papilla on A) dorsal, B) ventral and C) lateral views. D) Supra-anal plate. E) Subgenital plate. F) Maxillary palpi. Superior scale bar: A, B, C; inferior: D, E, F.
Fig. 5. Geographic distribution of Laranda Walker, 1869 species in South and Southeast of Brazil. Legend: 1-L. major; 2-L. castanea; 3-L. uai sp. nov.; 4-L. tibialis; 5-L. singularis; 6-L. meridionalis (Modifi ed to IBGE 2004).
A new species of Laranda Walker 1869 (Orthoptera : Grylloidea, Phalangopsidae) from Remnant patches of the Brazilian Atlantic Forest

September 2008


115 Reads

The genus Laranda has six described species and is confined to South and Southeast of Brazil. We describe a new species and discuss the biology and distribution of the genus. The new species can be distinguished from its known congeners by the following characteristics: absence of yellow spots on pronotum and base of posterior tibiae; female copulatory papilla: sclerotization in dorsal view forming opposing acute angles, apical lobes narrow and small; male genitalia: pseudepiphallic median process short and wide; pseudepiphallic paramere with apex incurved and ectophallic fold surpassing apex of the parameres. The genus is distributed within the Atlantic Forest biome; the new species is found on tree trunks, as well as on forest leaf litter.

Fig. 1. P. minuta. A, cephalic capsule in the first instar; B, mandible in the first instar; C, cephalic capsule in the fourth instar; D, mandible in the fourth instar. 
Fig. 4. Pupa of P. minuta. A, ventral view; B, terminal abdomen segments of the female; C, terminal abdomen segments of the male. 
Fig. 5. P. minuta. Blotches on upper leaf surface of white clover. 
Figure 4 of 4
Morphology and biology of Porphyrosela minuta Clarke 1953 (Lepidoptera : Gracillariidae, Lithocolletinae) in Uruguay

July 2007


374 Reads

Porphyrosela minuta Clarke is a gracillariid that causes damage on white clover (Trifolium repens) in Uruguay. In this article, the eggs, all the larval instars, the pupa and the external morphological characteristics of the adult are described. Information about the insect's biology under laboratory and field conditions is presented. The eggs are laid singly on the upper surface of the leaflets. The larvae make extensive mines that appear as white blotches. The larvae develop through five instars and do not remain exposed during their development. At 25 degrees C the life cycle lasted 16.2 days, made up of 3.0 for eggs, 8.8 for larvae and 4.4 for pupae. Females began laying on the first night, and during an oviposition period that varied between five and 12 days deposited an average of 71.8 eggs. It is a multivoltine species and seven to nine generations occur between November and the end of March.

The effect of the glyphosate, 2,4-D, atrazine e nicosulfuron herbicides upon the Edaphic collembola (Arthropoda: Ellipura) in a no tillage system

March 2007


197 Reads

The use of herbicides is a common and intensive practice in no tillage systems. The herbicides can influence, directly or indirectly, the population of edaphic arthropods. Collembola is a group that functions as a bio-indicator of soil conditions. The degree of abundance and diversity of Collembola provides the level of soil disturbance provoked by agricultural practices. This experiment was designed to compare the influence of herbicides on the population fluctuation of Collembola in a no-till soil preparation system. The work was conducted in a non irrigated no-till area at the Núcleo Experimental de Ciências Agrárias of the Universidade Federal de Mato Grosso do Sul (UFMS), Campus de Dourados, in soil planted with corn as a surface covering, during the period of December, 2002 to December, 2003. The data were analyzed according to a completely randomized model, in a split plot design. The plots received four types of herbicides: glyphosate, atrazine, 2,4-D and nicosulfuron. A fifth plot did not receive any herbicide (control), for a total of five treatment types. The sub plots were represented by their collection times (10, 20, 30 and 40 days after the herbicide applications). Both the type of herbicide and the time of data sampling influenced the Collembola population fluctuaction. The treatments with atrazine and 2,4-D caused the most reduction of the population of Collembola, depending on the time of application.

[Human myiasis in Bahía Blanca, Argentina. Period 2000 / 2005]

August 2007


51 Reads

Myiasis is the infestation of live human and vertebrate animals with dipterous larvae which, at least for a short period, feed on the host's dead or living tissue, liquid body-substance, or ingested food. The objective of this study was to identify the flies producing myiasis in Bahía Blanca city, Argentina, from 01/03/2000 to 31/05/2005. Seventeen clinical cases were studied. The larvae obtained from lesions were forwarded from laboratories and from public and private hospitals. Part of the larvae were fixed in alcohol 70 masculine and processed according to the Mazza & Jörg technique (1939). The other part continued growing in flasks with meat in laboratory conditions to obtain the adults. The etiological agents of myiasis were identified by observing the diagnostic characteristics of the larvae III and of the adults, and by using taxonomic keys. Myiasis was produced by Cochlyiomia hominivorax (Coquerel) in thirteen of the cases and by Phaenicia sericata (= Lucila sericata) (Meigen) (Diptera: Calliphoridae) in the other four. The cases were traumatic and aural myiasis and happened from December to March. The ages of patients were four to eighty-six years and 76.5% of the cases occurred in male patients. Given the aggressiveness of these larvae, mainly C. hominivorax, in causing human myiasis, the importance of specific and quick diagnosis and of adequate treatment must be acknowledged.

Figs 1-5 First metaphase of 1) Diophanes scaberrimus; 2) Leptotettix humaita; 3) Bliastes viridifrons; 4) Leptotettix crassicerci; and 5) Diophanes amazonensis. For each species, the chromosomes were organized in decreasing order of size from left to right, with the X at the right end. Scale bar = 10 m 
Cytogenetics Studies in Brazilian Species of Pseudophyllinae (Orthoptera: Tettigoniidae): 2n(male)=35 and FN=35 the Probable Basic and Ancestral Karyotype of the Family Tettigoniidae

August 2010


63 Reads

The karyotypes of five species of Brazilian Pseudophyllinae belonging to four tribes were here studied. The data available in the literature altogether with those obtained with species in here studied allowed us to infer that 2n(♂)=35 is the highest chromosome number found in the family Tettigoniidae and that it is present in species belonging to Pseudophyllinae, Zaprochilinae and in one species of Tettigoniinae. In spite of that all five species exhibit secondary karyotypes arisen surely by a mechanism of chromosomal rearrangement of centric fusion, tandem fusion and centric inversion types from those with 2n(♂)=35 and FN=35, they share some common traits. The X chromosome is submetacentric (FN=36), heteropicnotic during the first prophase, the largest of the set but its size is rather variable among the species and the sex chromosomal mechanism is of the XO( ♂ ), XX( ♀ ) type. The chromosomal rearrangements involved in the karyotype evolution of the Pseudophyllinae and its relationship with those of the family Tettigoniidae are discussed and we propose that the basic and the ancestral karyotype of the Tettigoniidae is formed by 2n(♂)=35, FN=35 and not by 2n(♂)=31, FN= 31, as usually accepted.

Fig 1 Chrono M.  
Table 3 Mean defecation time (min) of different instars of Triatoma infestans, T. sordida, T. guasayana.
Table 5 Mean quantity of blood ingested (mg) for each instar of Triatoma infestans, T. sordida and T. guasayana.
Vectorial Capacity of Triatoma guasayana (Wygodzinsky & Abalos) (Hemiptera: Reduviidae) Compared with Two other Species of Epidemic Importance

September 2010


101 Reads

Triatoma guasayana (Wygodzinsky & Abalos) is a peridomestic triatomine with epidemiological importance in Bolivia, that may play an important role in the transmission of Trypanosoma cruzi (Chagas). In this study, two parameters of vectorial capacity were evaluated: the interval of feeding-defecation time and metacyclogenesis, in adult males and females and nymphal instars II to V of T. guasayana with comparisons with Triatoma infestans (Klug) and T. sordida (Stal). The results showed a close relationship between ingestion of blood and beginning of defecation. Values were negative in T. infestans, and T. sordida for instars II, III, IV, and V and also males and females but were positive in female T. sordida. Triatoma guasayana showed only negative values for instar II. Adults and nymphs began defecation as soon as they had finished feeding and required an average of 29.8 min. The analysis of metacyclogenesis showed that T. guasayana was superior to T. infestans and T. sordida. However, the vectorial effectiveness of T. guasayana was significantly affected regarding the percentage of metacyclic trypomastigotes during instars III to V and showed a progressive increase. Females had higher proportions despite their ingestion being half that of T. infestans. The different instars of T. guasayana had a higher parasitic load than those of T. sordida and, although ingestion was 1/3 of that of female T. infestans, there was a progressive increase in metacyclic trypomastigotes in the different nymphal stages of T. guasayana that decreased in adults.

Fig. 1. Chilicola ( Hylaeosoma ) muruimuinane sp. nov. , Holotipo macho (arriba) y paratipo hembra (abajo) en vista lateral. 
Fig. 2. Chilicola ( Hylaeosoma ) muruimuinane sp. nov. Hembra, tarsómero basal de la pata anterior con proceso apical claramente curvo y sin pelo (indicado por la fl echa). 
Figs. 3-5. Chilicola (Hylaeosoma) muruimuinane sp. nov. Macho. Vista dorsal (mitad izquierda) y ventral (mitad derecha) del S7 (3), S8 (4), y cápsula genital (5).
Abejas Chilicola (Hylaeosoma) Ashmead (Colletidae: Xeromelissinae) del Grupo megalostigma: una Especie Nueva de Colombia y Clave para las especies

May 2013


298 Reads

We describe a new species of Chilicola (Hylaeosoma) of the megalostigma group from southern Colombia and present an identification key to species. Chilicola muruimuinane sp. nov. resembles Chilicola yanezae Hinojosa-Díaz & Michener, 2005, from Mexico, but it differs from it in its body color, shape of basal tarsomeres of female fore legs, and characters of the seventh and eighth sterna of the male.

Fig 3 Population density of Brevicoryne brassicae collected in cabbage, from August to December 2007. Different letters indicate significant differences by using the Tukey multiple comparisons test (P<0.05). 
Fig 4 Relationship between the size of the mummified Brevicoryne brassicae aphids and the size of the hyperparasitoid Alloxysta fuscicornis collected in cabbage leaves, from August to December 2007 (b≠0; F028.158; P<0.001). 
Figure 3 of 3
Biotic and Abiotic Factors Affecting Brevicoryne brassicae (L.) (Hemiptera: Aphididae) and the Associated Hyperparasitoid Alloxysta fuscicornis Hartig (Hymenoptera: Figitidae) Morphologies

August 2012


120 Reads

This study investigates the influence of biotic and abiotic factors associated with the morphological development of Brevicoryne brassicae (Linnaeus) and the associated hyperparasitoid Alloxysta fuscicornis (Hartig). The experiment involved the examination of whether aphid size was influenced by their vertical distribution and density on the host plant, as well as whether variations in hyperparasitoid size and symmetry were correlated with those of their aphid hosts. An aphid multivariate size index was obtained using principal component analysis, while symmetry was evaluated in terms of fluctuating asymmetry (FA). Samples were collected in 2007 on cabbage plants cultivated at an experimental farm located in Uberlândia, Minas Gerais, Brazil (18°56'54″ S; 48°12'46″ W). The results demonstrated that the size of B. brassicae was negatively associated with temperature, but not with its vertical distribution on the host plant. Temperature was also negatively correlated with hyperparasitoid size. During warmer periods, females produced large quantities of small-sized offspring, whereas an opposite pattern, i.e. the production of fewer offspring of larger size took place during colder periods. This type of adjustment involving trade-offs between physiological and morphological mechanisms, as well as individual interaction with abiotic environmental factors, such as temperature, can be considered an adaptive plastic response in order to increase the chances of survival at a given locality. The encountered relationship between aphid and hyperparasitoid sizes may be an after effect of their indirectly biotic interaction. Hyperparasitoid FA was dependent on the width of the mummified aphids. However, the hypothesis that temperature and vertical distribution on the host plant might influence FA was not confirmed.

Old Fragments of Forest Inside an Urban Area Are Able to Keep Orchid Bee (Hymenoptera: Apidae: Euglossini) Assemblages? The Case of a Brazilian Historical City

July 2013


394 Reads



M C Dutra




Retention of habitat fragments within the urban matrix can provide critical resources for the maintenance of regional biodiversity while still providing socio-economic value. Euglossini bees are important components in a community as they are important pollinators for economically valuable plants as well as hundreds of orchid species. However, some species are very sensitive to environmental impacts like urbanization. This study presents the role of antique urban fragments in a historical city in Brazil and compares it with a conservation area on the aspects of orchid bee assemblage, such as richness, composition, and abundance. Four fragments inside the city of Ouro Preto and three inside Parque Estadual do Itacolomi (PEIT) were sampled for Euglossini bees. Sorensen similarity index was used to compare community composition. The Mantel test was applied to verify the hypothesis that an urban center is a barrier for the mobility of the individuals. Fourteen Euglossini species from the region were registered. Close to 75% of the sampled bees were collected from the PEIT sampling areas. The fragments presented differences in Euglossini richness and abundance. A majority of the sampled fragments were dominated by the Eulaema cingulata Fabricius, Eulaema nigrita Lepeletier, and Euglossa securigera Dressler species. We found differences on community composition between the fragments localized in PEIT and those located in the urban center. The data suggest that there is a possible flux of individuals between the sampled fragments. The various small forest fragments in Ouro Preto, primarily in backyards, may also serve as stepping stones between sampled fragments.

Presence-absence sampling plan for Oligonychus yothersi (McGregor) (Acari : Tetranychidae) on mate-tea orchard

July 2007


99 Reads

Mite infestations to the culture of mate-tea frequently causes losses by the premature fall of the leaves. So, it is necessary to monitor the population of these arthropods, and to adopt management strategies for their control. The objective of this research was to evaluate the trustworthiness of presence-absence sampling for Oligonychus yothersi (McGregor) on mate-tea orchard. This study was conducted in Cascavel, Paraná State, from April 2001 to July 2000, in a mate-tea tree commercial plantation. Biweekly sampling of 240 leaves were collected in different parts of 10 plants, and the number of mites was counted. The aggregation pattern was determined through the coefficients a and b of Taylor's power law. The proportion of infested leaves and the number of required samples were estimated through mathematical model. The mite O. yothersi presented aggregate distribution. The proportion of infested leaves calculated by means of mathematical model showed to be a trustworthy parameter to estimate the population density of the mite. The number of required samples was small, making feasible the practical application of the presence-absence sampling method for O. yothersi in the culture of mate-tea.

Table 2 Overall diversity indices in Monte Zerpa and El Baho.
of species in the samples in Monte Zerpa and El Baho (collected in baited traps along altitudinal transects), species with more than 10 % in the sample are highlighted in bold.
The Presence–Absence Situation and Its Impact on the Assemblage Structure and Interspecific Relations of Pronophilina Butterflies in the Venezuelan Andes (Lepidoptera: Nymphalidae)

June 2012


104 Reads

Assemblage structure and altitudinal patterns of Pronophilina, a species-rich group of Andean butterflies, are compared in El Baho and Monte Zerpa, two closely situated and ecologically similar Andean localities. Their faunas differ only by the absence of Pedaliodes ornata Grose-Smith in El Baho. There are, however, important structural differences between the two Pronophilina assemblages. Whereas there are five co-dominant species in Monte Zerpa, including P. ornata, Pedaliodes minabilis Pyrcz is the only dominant with more than half of all the individuals in the sample in El Baho. The absence of P. ornata in El Baho is investigated from historical, geographic, and ecological perspectives exploring the factors responsible for its possible extinction including climate change, mass dying out of host plants, and competitive exclusion. Although competitive exclusion between P. ornata and P. minabilis is a plausible mechanism, considered that their ecological niches overlap, which suggests a limiting influence on each other’s populations, the object of competition was not identified, and the reason of the absence of P. ornata in El Baho could not be established. The role of spatial interference related to imperfect sexual behavioral isolation is evaluated in maintaining the parapatric altitudinal distributions of three pairs of phenotypically similar and related species of Pedaliodes, Corades, and Lymanopoda. Electronic supplementary material The online version of this article (doi:10.1007/s13744-012-0031-2) contains supplementary material, which is available to authorized users.

Selection of Isolates of Entomopathogenic Fungi for Controlling Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) and their Compatibility with Insecticides Used in Tomato Crop

December 2010


523 Reads

The activity of Metarhizium anisopliae and Beauveria bassiana towards eggs and larvae of Tuta absoluta (Meyrick) was evaluated. Our data showed that the isolates were pathogenic to both developmental stages tested and the eggs were more susceptible than the 1st instars. The isolates URPE-6 and URPE-19 of M. anisopliae were more pathogenic to eggs and larvae, respectively. The compatibility of these two isolates with the insecticides chlorfenapyr, spinosad, indoxacarb, abamectin, and neem were evaluated. Spinosad and indoxacarb were compatible with the two M. anisopliae isolates in all tested concentrations. At the average recommended concentration, chlorfenapyr was compatible to URPE-6 and abamectin to UFPE-19. The use of entomopathogenic fungi associated with compatible insecticides may be a useful alternative to control T. absoluta.

Fig 1 Curvas de supervivencia de hembras de Trichogrammatoidea bactrae expuestas a diferentes hospederos y sustratos. S/C: huevos de Sitotroga cerealella sobre cartulina; S/T: huevos de S. cerealella sobre tomate; T/T: huevos de Tuta absoluta sobre tomate.  
Biological Studies on Trichogrammatoidea bactrae Nagaraja (Hymenoptera: Trichogrammatidae), Egg Parasitoid of Tuta absoluta Meyrick (Lepidoptera: Gelechiidae)

August 2010


179 Reads

The tomato moth, Tuta absoluta Meyrick, is one of the most important tomato pests in South America. In Argentina, management strategies include only chemical control. In this work, the parasitoid wasp Trichogrammatoidea bactrae Nagaraja was evaluated as a potential natural enemy against this pest. Biological and population parameters were estimated by developing a life table under laboratory conditions at 25 ± 1ºC, 14:10 photoperiod and 60 ± 10% RH. Three cohorts of 26-30 T. bactrae females each were placed with one of the three following treatments: 1 - Sitotroga cerealella (Olivier) eggs on a piece of cardboard; 2 - S. cerealella eggs on a piece of tomato leaf, and 3- T. absoluta eggs on a piece on tomato leaf. The following parameters were estimated for each cohort: survival (egg to adult), longevity, fecundity and oviposition period of females, sex proportion of the F1, net rate of reproduction (Ro), mean generation time (T) and intrinsic rate of population increase (r m). Survival of the T. bactrae immatures was higher than 90% on both, S. cerealella and T. absoluta eggs. The female survival curves corresponded to type III and showed no significant differences among treatments. The three cohorts did not show significant differences between sex ratio, female longevity, oviposition period, fecundity and the population parameters studied. These results indicate that T. bactrae would be a potential biological control agent of T. absoluta.

Effects of Tomato Genotypes and Aqueous Extracts of Melia azedarach Leaves and Azadirachta indica Seeds on Tula absoluta (Meyrick) (Lepidoptera: Gelechiidae)

October 2010


138 Reads

Insecticide plants are an important tool among the new alternatives for pest control in IPM systems because they reduce the use of synthetic insecticides, preserving human health and the environment. We investigated the effects of aqueous extracts of Melia azedarach leaves and Azadirachta indica seeds and three tomato genotypes, 'Santa Clara', 'IPA-5'--Solanum lycopersicum (=Lycopersicon esculentum Mill), and LA444-1--S. peruvianum (=L. peruvianum), on the development, reproduction and longevity of the tomato pinworm Tuta absoluta (Meyrick), under laboratory conditions. The trials were set up in a completely randomized design, with nine treatments [three genotypes x two extracts (M. azedarach and A. indica) and control]. The replication consisted on five tubes, each with three newly hatched larvae, totalizing 90 individuals per treatment. The larvae were fed with tomato leaves treated with aqueous extracts at 0.1% concentration or distilled water (control) and daily observed until adults' emergence. Larval and pupal development and mortality, pupal weight, longevity and fecundity were evaluated. The accession LA444-1 negatively affected the development and reproduction of T. absoluta; the tomato pinworm had similar development and reproduction on 'IPA-5' and 'Santa Clara' (the susceptible control). The association of resistant tomato genotypes and extracts of M. azedarach leaves and neem seeds did not result in synergistic or antagonistic effects on T. absoluta.

Neochrysocharis formosa (Westwood) (Hymenoptera: Eulophidae), a Newly Recorded Parasitoid of the Tomato Moth, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), in Argentina

June 2011


572 Reads

We report the first record of Neochrysocharis formosa (Westwood) parasitizing larvae of the tomato moth, Tuta absoluta (Meyrick), in tomato crops in Northern Buenos Aires Province, Argentina. Tomato moth larvae were sampled during four consecutive growing cycles, between 2003 and 2005, in 10 sites. Neochrysocharis formosa was present only in organic outdoor and protected crops, and predominantly during the late season. Parasitism rates varied from 1.5% to 5%. The finding of this species is a new record for Argentina and South America, and T. absoluta is a new host record.

CROP PROTECTION Effect of Two Solanaceous Plants on Developmental and Population Parameters of the Tomato Leaf Miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae)

September 2006


310 Reads

Tuta absoluta (Meyrick) is an important tomato pest that also feeds on other host-plants from the Solanceae family. We studied the effect of two cultivated plants, tomato (Lycopersicum esculentum Mill.) and potato Solanum tuberosum L. on the development and populational parameters of T. absoluta related with host-plant suitability. Larval developmental time, pupal weight, mean fecundity and an index of host-plant quality (IPQ = pupal weight / frass weight) were estimated. Age-specific survivorship and fecundity life tables were constructed in the laboratory to evaluate the following populational parameters: net reproductive rate (Ro), intrinsic rate of increase (r) and generation time (T). Larval developmental time was shorter and pupal weight was higher (P < 0.0001) for larvae reared on tomato (P < 0.0001). Mean fecundity was not significantly different on both plants (P = 0.07) and food quality of host-plant was higher for tomato (P = 0.02). Mean population parameters on tomato were: Ro = 48.92; T = 27.98, r = 0.14; and on potato: Ro = 14.43; T = 32.35, r = 0.08. Although results showed that tomato was a more suitable host-plant and had a better nutritional quality than potato, when T. absoluta fed on potato the potential population increase requires attention. Under appropriate climatic conditions, spatial and temporal coincidence between crop and pest, T. absoluta could become a pest for the potato crop.

Optimization of a Trap for Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) and Trials to Determine the Effectiveness of Mass Trapping

June 2013


2,588 Reads

Management of the South American tomato leafminer, Tuta absoluta Meyrick, with insecticides has led to the widespread development of insect resistance. Mass trapping using traps baited with the female-produced sex pheromone is an attractive alternative for the management of this pest. The current study evaluated several commercial trap designs for capture of T. absoluta. Based on its small size and ease of handling, the most effective trap is a small plastic container with entry windows cut on the sides filled with motor oil over water. These traps are most effective when placed near ground level. Tests of septa containing 0.1 or 0.2 mg of the pheromone (95:5) E4, Z8-14Ac/E4,Z8,Z11-14Ac were slightly more attractive than septa loaded with 0.5, 1.0, or 2 mg during the first week of use, but the latter three loadings were slightly more attractive than the first two loadings after 9 weeks. Ideal trap baits were loaded with 0.5 mg of pheromone. Higher numbers of T. absoluta were captured near upwind borders of tomato fields suggesting that treatments against T. absoluta should be concentrated near upwind parts of fields. Comparisons of conventional insecticide treatment versus mass trapping to manage T. absoluta damage in three different test sites showed that even when initial captures in monitoring traps were high (>35 males trap(-1) day(-1)), mass trapping at 48 traps/ha reduced leaf damage more efficiently than conventional insecticide treatment. Based on the typical insecticide recommendations against T. absoluta, mass trapping is an economically viable alternative.

Fig. 3. Adultos deformados de T. absoluta em folíolos de tomateiro tratados com moléculas (0,1%) isoladas de T. pallida. TRIT-1 (24-metilenocicloarta-3-ol), LIM (gedunina), EST-1 (24-metileno-3,22-diidroxicolesterol), TRIT-2 (24-metilenocicloarta-3-26- diol), EST-2 (24-metilenocolesterol), EST-3 (24-metileno-3,4,22-triidroxicolesterol) e TRIT-3 (cicloarta-23-eno-3,25-diol). Dados originais; para análise estatística foram transformados em log de x+0,5. n.s. não signifi cativo.  
Bioactivity of Trichilia pallida Swartz (Meliaceae) Derived Molecules on Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae)

December 2008


81 Reads

Dichloromethane (DIC) leaf and fruit extracts of Trichiliapallida Swartz were obtained for the isolation and identification of molecules with insecticidal activity against the tomato leafminer, Tuta absoluta (Meyrick). DIC leaf extracts of T. pallida yielded six compounds, the triterpenes 24-methylenecycloarta-3beta-ol (TRIT-1), 24-methylenecycloarta-3beta-26-diol (TRIT-2) and cycloarta-23-eno-3beta,25-diol (TRIT-3), the sterols 24-methylene-3,22-dihydroxycholesterol (EST-1), 24-methylenecholesterol (EST-2) and 24-methylene-3beta,4beta,22-trihydroxycholesterol (EST-3), while the fruit extract yielded the limonoid gedunine (LIM). These molecules were dissolved in acetone and sprayed at 0.1% on tomato leaflets infested with newly-hatched larvae. Larval mortality at day 5 and 9 after infestation, larval and pupal developmental time and survival, pupal weight and adult malformation were evaluated. TRIT-1, EST-1 and LIM were the most effective against T. absoluta due to larval development arrestment and reduced larval survivorship.

Fig 1 Geographic location of the Araya Peninsula, State of Sucre, Venezuela. The map shows the location of sampling stations (A, B, and C) and transects (geometric symbols) within the aridity gradient (gray area). The dotted line indicates the precipitation change suggested by Thielen (2003). The gray values are UTM geographic coordinates (zone 20). 
Fig 2 Relationship between ant species richness and longitudinal variation (aridity gradient) in Araya Peninsula, State of Sucre, Venezuela. Each point represents the total richness values of ant species (a) and genera (b). The line is a best fit regression model. The acronyms C2 indicates the values recorded in the second transect of sampling station C. 
Fig 3 Relationship between the species adjusted abundance and longitudinal variation (aridity gradient) in Araya Peninsula, State of Sucre, Venezuela. Each point represents the adjusted abundance values of species in traps. The line corresponds to the regression model that best fit the data (quadratic polynomial regression). The acronym C2 indicates the AA values recorded in the second transect of sampling station C. 
Fig 4 Mantel correlograms for the ant assemblages and longitudinal variation (aridity gradient) in Araya Peninsula, State of Sucre, Venezuela. Correlograms represent the spatial association pattern between ant composition and the geographical location of pitfall traps. The filled boxes represent the Mantel coefficient values that differ from the expected by chance (p<0.05), the empty boxes represent the not significant Mantel statistic values (p>0.05). 
Fig 5 TWINSPAN classification analysis for the ant assemblage in Araya Peninsula, State of Sucre, Venezuela. a Classification of 49 species and 150 samples (pitfall traps), the values in boxes indicate the number of sample units (SU) per division, percentages indicate the contribution of samples from each transect, and the names in italics are the indicator species for each final SU, b Geographical representation of the TWINSPAN results within the peninsula, dotted black lines represent the division dichotomies and the shades of grays indicate the SU variation along the gradient. 
Patterns of Ant (Hymenoptera: Formicidae) Richness and Relative Abundance along an Aridity Gradient in Western Venezuela

April 2013


586 Reads

In xeric ecosystems, ant diversity response to aridity varies with rainfall magnitude and gradient extension. At a local scale and with low precipitation regimes, increased aridity leads to a reduction of species richness and an increased relative abundance for some ant species. In order to test this pattern in tropical environments, ant richness and relative abundance variation were evaluated along 35 km of an aridity gradient in the Araya Peninsula, state of Sucre, Venezuela. Three sampling stations comprising five transects each were set up. Pitfall traps and direct collecting from vegetation were assessed per transect. Overall, 52 species, 23 genera, and 7 subfamilies of ants were recorded in the peninsula. The total number of species and genera recorded by both sampling stations and transects decreased linearly with increasing aridity. Total relative abundance was highest in the most arid portion of the peninsula, with Crematogaster rochai (Forel) and Camponotus conspicuus zonatus (Emery) (Hymenoptera: Formicidae) being the numerically dominant species. Spatial and multivariate analyses revealed significant changes in ant composition every 11 km of distance, and showed a decrease of ant diversity with the increase of harsh conditions in the gradient. Here, we discuss how local geographic and topographic features of Araya originate the aridity gradient and so affect the microhabitat conditions for the ant fauna. Electronic supplementary material The online version of this article (doi:10.1007/s13744-012-0096-y) contains supplementary material, which is available to authorized users.

Richness and Abundance of Ichneumonidae in a Fragmented Tropical Rain Forest

June 2013


151 Reads

Because of the magnitude of land use currently occurring in tropical regions, the local loss of animal species due to habitat fragmentation has been widely studied, particularly in the case of vertebrates. Many invertebrate groups and the ichneumonid wasps in particular, however, have been poorly studied in this context, despite the fact that they are one of the most species-rich groups and play an important role as regulators of other insect populations. Here, we recorded the taxonomic composition of ichneumonid parasitoids and assessed their species richness, abundance, similarity, and dominance in the Los Tuxtlas tropical rain forest, Mexico. We compared two forest types: a continuous forest (640 ha) and a forest fragment (19 ha). We sampled ichneumonids using four malaise traps in both forest types during the dry (September-October) and rainy (March-April) seasons. A total of 104 individuals of Ichneumonidae belonging to 11 subfamilies, 18 genera, and 42 species were collected in the continuous forest and 11 subfamilies, 15 genera, and 24 species were collected in the forest fragment. Species richness, abundance, and diversity of ichneumonids were greater in the continuous forest than in the forest fragment. We did not detect differences between seasons. Species rank/abundance curves showed that the ichneumonid community between the forest types was different. Species similarity between forest types was low. The most dominant species in continuous forest was Neotheronia sp., whereas in the forest fragment, it was Orthocentrus sp. Changes in the ichneumonid wasp community may compromise important tropical ecosystem processes.

Comparison of the number of S. cathosiota caterpillars parasitized by Braconidae among cerrado areas of the Distrito Federal with different fi re regimes: FAL = accidentally burned in 1987 and 1994; IBGE = experimental biennial August fi res since 1990. (A) Among areas, total censuses periods; (B) Among areas, same censuses periods; (C) Same area, between years at same months. 
Temporal and spatial variation of Stenoma cathosiota Meyrick (Lepidoptera : Elachistidae) caterpillar abundance in the cerrado of Brasilia, Brazil

November 2007


72 Reads

The caterpillars of Stenoma cathosiota Meyrick feed on Roupala montana Aubl. (Proteaceae) in the cerrado of the Distrito Federal, Brazil. They construct shelters by joining leaves of the plant where they feed and pupate. The caterpillars are parasitized by a wasp (Hymenoptera: Brachonidae), which emerges from the pupae. Caterpillar abundance and parasitism frequency were associated in an area of frequently burned cerrado (biennial fire) and in another area that burns sporadically (1987 and 1994). For S. cathosiota, the variation among years in a single area, with sporadic fires, was greater than the variation among areas with different fire regimes. Caterpillar abundance among years was significantly different in the area that burns sporadically (chi2 = 24.06; df. = 1; P = 0.000). However, there were no significant differences on caterpillar abundance between areas for the same period (chi2 = 3.45; df. = 1; P = 0.063). Parasitism frequency was high, reaching 29% of the collected caterpillars, and did not differ among areas. The great temporal variation in abundance of lepidopteran caterpillars in the cerrado makes it difficult to determine the effects that fire exerts over this fauna.

Fig 1 Average abundance of Collembola specimens collected from the understory in 12 sampling areas in the FLONA-SFP, from September 2003 to August 2004. Vegetation physiognomies: (NF = mixed ombrophyllous forest; AP = Araucaria spp. plantation; PP = Pinus spp. plantation; EP = Eucalyptus spp. plantation). Different letters indicate signifi cant differences. Bars indicate the standard error. NF AP PP EP  
Fig 2 Average richness of Collembola morphospecies collected from the understory in 12 sampling areas in the FLONA-SFP, from September 2003 to August 2004. Vegetation physiognomies: (NF = mixed ombrophyllous forest; AP = Araucaria spp. plantation; PP = Pinus spp. plantation; EP = Eucalyptus spp. plantation). Different letters indicate signifi cant differences. Bars indicate the standard error.  
Fig 3 Correspondence Analysis between Collembola morphospecies described by habitat types (ARV = tree; ARB = shrub; LIA = liana; PTE = fern). Only morphspecies correlated to ordination axes are shown (T1 = Tomoceridae; E1, E2, E4 and E6 = Entomobryidae sp.1, sp.2, sp. 4 and sp.6; S2 and S3 = Sminthuridaesp.2 and sp.3).  
Fig 4 Cluster analysis dendrogram of four physiognomies in southern Brazil mixed ombrophyllous forest based on understory springtail abundances. The analysis was based on chord distance between vegetation physiognomies and UPGMA grouping criterion. Indicated resulting groups were signifi cant after bootstrap resampling (1,000 iteractions). NF = mixed ombrophyllous forest; AP = Araucaria spp. plantation; PP = Pinus spp. plantation; EP = Eucalyptus spp. plantation.  
Effects of Understory Structure on the Abundance, Richness and Diversity of Collembola (Arthropoda) in Southern Brazil

May 2009


109 Reads

The purpose of this study was to investigate the effects of different landscape structures on the understory Collembola community. Four different forest physiognomies were compared: Pinus spp. plantation, Eucalyptus spp. plantation, Araucaria angustifolia plantation, and a remaining native Araucaria forest. Three areas containing two sampling units (25 mx2 m each) were selected in each forest physiognomy. Understory Collembola collection was done with a 1x1 m canvas sheet held horizontally below the vegetation, which was beaten with a 1 m long stick, seasonally from September 2003 to August 2004. We evaluated the influence of forest physiognomies on the abundance, richness and diversity of Collembola communities. It was also verified if the habitat structure of each physiognomy was associated with the composition of the Collembola community. A total number of 4,111 individuals were collected belonging to the families Entomobrydae and Tomocerida (Entomobryomorpha), and Sminthuridae (Symphypleona), and divided in 12 morphospecies. Pinus plantation presented the highest richness, abundance and diversity of Collembola and it was associated to diverse understory vegetation. The abundance of Entomobrydae and Sminthuridae was associated to the presence of bushes, while Tomoceridae abundance was associated to the presence of trees. The habitat structure, measured through understory vegetation density and composition, plays an important role on the determination of the structure and composition of the Collembola community.

Collection sites for Brevipalpus spp. mites and citrus species composition in each location.
Species Composition and Abundance of Brevipalpus spp. on Different Citrus Species in Mexican Orchards

August 2013


168 Reads

We studied the abundance of Brevipalpus spp. in citrus orchards in the Mexican states of Yucatan, Quintana Roo and Campeche. Mites were collected from 100 trees containing a mixture of citrus species where sweet orange was always the main species. Eight collections were made at each location from February 2010 to February 2011. Mites from the genus Brevipalpus were separated from other mites surveyed and their abundance and relationships with the different citrus species were quantified throughout the collection period. A subsample of 25% of the total Brevipalpus mites collected were identified to species level and the interaction of mite species and citrus species were described. Brevipalpus spp. were present on all collection dates and their relative abundance was similar on all citrus species studies. The smallest number of mites collected was during the rainy season. Brevipalpus phoenicis (Geijskes) and Brevipalpus californicus (Banks) were the only two species present and they were found in all locations except Campeche, where only B. phoenicis was present. Yucatan and Campeche are at greater risk of leprosis virus transmission than Quintana Roo because the main vector, B. phoenicis, was more abundant than B. californicus. The implications of our results for the design of more accurate sampling and control methods for Brevipalpus spp. are discussed.

Top-cited authors