Effect of spiders (Arachnida: Araneae) as predators of insect pest in alfalfa crops (Medicago sativa) (Fabaceae) in Argentina

Spiders are predators that reduce insect pest populations in agroecosystems. Trials were conducted to measure the selectivity against different insect preys, the daily consumption, effect of predators alone and together with a known number of preys, and the indirect effect of predators on vegetation. For this, experimental units (1 x 1m) were used covered with a fine plastic mesh. Misumenops pallidus, Oxyopes salticus and Araneus sp. were used as generalist predators, and aphids, weevils, locusts, chrysomelids and Lepidoptera larvae as their potential preys. Among the preys offered, the spiders preferred Lepidoptera larvae compared to the other two pests groups (weevils and aphids). The maximum consumption rate was of 93.33% for Lepidoptera larvae, 25.33% for aphids and 11.67% for weevils. The Q Index values for the three species of spiders showed a positive selectivity only for defoliating larvae. O. salticus showed the highest values of consumption rates while Rachiplusia nu was the most consumed. The maximum value of consumption in 24 hours was showed by O. salticus on R. nu (C) = 2.8. The association of several species of predatory spiders increased the total number of insects captured, and also showed that the addition of spiders caused a decrease in the number of leaves damaged by the effect of lepidopterous larvae.     

红火蚁弃尸堆的食物结构

通过对红火蚁弃尸堆进行收集、整理、鉴定和分析,研究了自然条件下华南地区典型生境中红火蚁食物结构的季节性变化.结果表明:红火蚁弃尸堆中主要包括了8个目的昆虫和种子共41个种类.其中鞘翅目Coleoptera昆虫的出现频率最高,在4个生境荔枝园、苗圃、荒地、公路路边中分别为69.05%、41.7%、51.8%和66.67%;同翅目Homoptera昆虫出现频率最低,只在荒地中发现占1.20%.其余依次为膜翅目Hymenoptera(14.92%)、半翅目Hemiptera(11.96%)、种子(11.66%)、直翅目Orthoptera(2.08%)、鳞翅目Lepidoptera(0.60%)、等翅目Isoptera(0.60%)和蜻蜓目Odonata(0.60%).弃尸堆中的昆虫碎片以成虫为主,蛹和幼虫较少.不同生境弃尸堆内红火蚁觅食对象的种类虽然较为接近,但在组成与数量上存在差异,其相似度不高.弃尸堆中红火蚁觅食对象的种类和碎片数随着时间呈现明显的变动,上半年的4、5月份和下半年9、10月份红火蚁的觅食到的对象多样性丰富,这两个阶段属于觅食活跃期.     

Diet of the golden-tipped bat Kerivoula papuensis (Microchiroptera) from north-eastern New South Wales, Australia

The diet of the golden-tipped bat ( Kerivoula papuensis ) was investigated by collecting faecal samples from captured individuals in the Richmond Range State Forest, north-eastern New South Wales, Australia. Faecal analysis was used so that all captured individuals could be released after processing and banding. A total of 53 faecal pellets were collected in the summer and autumn months from 39 individuals. The major food of K. papuensis were spiders (Araneida) comprising 91.9% of the total volume of food. Other foods consumed in small quantities were Coleoptera, Lepidoptera and Diptera.     

First report of Elasmus polistis Burks (Hymenoptera: Eulophidae) recovered from Polistes versicolor (Olivier) (Hymenoptera: Vespidae) nests in Brazil

The first record of Elasmus polistis Burks in Polistes versicolor (Olivier) nests in the Rio Grande do Sul state and in Brazil is provided. A total of 173 specimens of P. versicolor and 790 specimens of E. polistis were collected from two nests from Gramado and Santa Cruz do Sul, RS, Brazil.     

Plagiorchis muris infection in Apodemus agrarius from northern Gyeonggi-do (Province) near the demilitarized zone

The small intestines of 6 species of rodents and 1 species of insectivore were examined seasonally for Plagiorchis muris infection in 3 different localities in northern Gyeonggi-do (Province), near the demilitarized zone (DMZ). A total of 1,496 animals, including 1,366 Apodemus agrarius, 54 Crocidura lasiura (insectivore), 32 Mus musculus, 28 Micronytus fortis, 9 Eothenomys regulus, 6 Micronys minutus, and 3 Cricetulus triton, were live-trapped at Yeoncheon-gun (n = 351), Paju-shi (804) and Pocheon-gun (343) at 3-mo intervals from December 2004 to September 2005. A total of 1,647 P. muris were collected from 72 (5.3%) A. agrarius. The infection rate was the highest in Pocheon-gun (8.2%), followed by Yeoncheon-gun (5.0%) and Paju-shi (4.2%). A higher infection rate was observed in A. agrarius captured during September (19.4%) than those captured during December (3.0%), June (2.6%), or April (0%). However, the worm burden was the highest in June (av. 32.1/animal), followed by September (24.7), December (4.0), and April (0). None of the other animal species were found infected with P. muris. The results reveal that A. agrarius is a natural definitive host for P. muris, and infection rates and worm burdens vary seasonally and geographically.     

New record of the tropical swallowtail moth Lyssa zampa (Butler) (Lepidoptera: Uraniidae) from mainland Japan

The tropical swallowtail moth Lyssa zampa (Butler) (Lepidoptera: Uraniidae) was recorded for the first time from mainland Japan. A male specimen of this species was captured in Amakusa, western Kyushu, on the night of 19 May 2006. An analysis of typhoon data suggests that this individual is likely to have reached the western coast of Kyushu from the Philippines, being transported over a distance of approximately 3000 km by typhoon no. 1 of 2006.     

Ecology of aquatic Lepidoptera (Crambidae: Nymphulinae) in South Carolina, USA

An ecological study was conducted in May and June of 1995 and 1996 in South Carolina to determine the factors associated with distributions of aquatic Lepidoptera (Crambidae: Nymphulinae). Larvae were found at 65 lotic and lentic sites in three ecoregions (Piedmont, Sandhills, Coastal Plain). Nine species of aquatic Lepidoptera were collected from 12 species of aquatic vascular macrophytes. One to six plant species were used as hosts, depending on the species of lepidopteran; however, the number of host plants used by a lepidopteran was significantly correlated with the lepidopteran's frequency of occurrence. Significant habitat associations were found for five species. Langessa nomophilalis (Dyar) was found under the widest range of temperature and width and occurred in both lotic and lentic habitats. Munroessa icciusalis (Walker) was found in lotic and lentic habitats and had the widest range of recorded depths. Parapoynx maculalis (Clemens) occurred at stream sites with lentic-like conditions. Parapoynx obscuralis (Grote) occupied the widest range of pH and was restricted to lotic habitats, and P. seminealis (Walker) was found in both lotic and lentic habitats. Additional species, collected at fewer than 8% of sites, included M. gyralis, P. allionealis, Synclita obliteralis, and S. tinealis. Overall, the distributions of aquatic Lepidoptera in South Carolina were nonrandom and predictable on the basis of habitat characteristics. This revised version was published online in July 2006 with corrections to the Cover Date.     

Diversity of the order Lepidoptera (Hesperioidea and Papilionoidea) from Corrientes city, Argentina

Urbanization is one of the most important threats for biodiversity. Among many different organisms, butterflies are useful indicators of environment diversity and quality. The aim of this study was to investigate the Lepidoptera from Corrientes city. Random samplings were performed at two sites: a native forest situated in Santa Catalina district and an urban area, Parque Mitre. The captures were carried out using entomological nets, at four seasons between January to October 2007. A total of 1 114 butterflies, represented by six families: Hesperiidae, Lycaenidae, Nymphalidae, Papilionidae, Pieridae and Riodinidae and 18 subfamilies were recorded. Fifty-nine genera and 75 species were identified; Anartia jatrophae jatrophae was the most abundant species at both localities. This species and Urbanus procne, Phoebis sennae marcellina, Pyrgus orcus and Dryas iulia alcionea were, among other seven, captured at all months. Highest values of abundance were registered during the warmest seasons. Santa Catalina presented the largest abundance (n = 701), richness (S = 74) and diversity (H' = 3.87). A total of 413 individuals and 52 species were identified at Parque Mitre, and Shannon diversity index was 3.58. The obtained data reveals a high species richness and similarity at both sites.     

Diet composition of post-metamorphic bullfrogs (Rana catesbeiana) in the Zhoushan archipelago, Zhejiang Province, China

Bullfrogs (Runa catesbeiana) are listed as one of the 100 worst invasive alien species in the world.They are generalist predators and thus may affect native species through predation.In previous studies,the food contents of bullfrogs were mostly examined at a single site.In the present study,the diet composition of post-metamorphic bullfrogs on eight islands (Daishan,Liuheng,Xiushan,Fodu,Taohua,Xiashi,Cezi,and Putuoshan) in the Zhoushan Archipelago,Zhejiang Province of China,were examined by using the stomach flushing method from June 30 to August 11 in 2005.A total 0f391 individual frogs were measured,including 113 adults and 278 juveniles.The analysis of the stomach contents shows that,for adult bullfrogs,the most important prey (by diet volume) overall were Decapoda,Coleoptera,Odonata,Mesogastropoda,Raniformes,and Cypriniformes.For juvenile bullfrogs,these were Decapoda,Coleoptera,Cypriniformes,Odonata,Orthoptera,Hymenoptera,Lepidoptera larvae,Mesogastropoda,and Raniformes.Moreover,the prey size and diet volume increased with the body size of both adult and juvenile bullfrogs.The diet composition of primary preys of bullfrogs was significantly different among the islands.The results indicate that bullfrogs exert different predatory influences on native fauna at different sites and that bullfrogs are generalist predators with extensive ecological impacts on native fauna.     

Multitrophic web of insects associated with <Emphasis Type="Italic">Piptadenia gonoacantha</Emphasis> (Mart.) Macbr. (Fabaceae) and their relationship with resource traits

We describe for the first time the food web of insects associated with fruits and seed of Piptadenia gonoacantha (Fabaceae), and analyze their relationships with resource traits, such as biomass and fruit area. A total of 440 fruits of P. Gonoacantha were sampled in the city of Lavras, Minas Gerais, Brazil. We found twenty-one species of insects distributed in three trophic levels. The most widely sampled species was Acanthoscelides clitellarius (Coleoptera, Chrysomelidae, Bruchinae), the main consumer species of seeds. It was also verified the presence of Lepidoptera larvae consuming both seeds and the internal fruit tissue. Other species of herbivorous insects were found in low numbers. The food web was subdivided into one sub-web of 10 parasitoid species and one hyperparasitoid species associated to A. clitellarius and another one sub-web of four parasitoid species associated with Lepidoptera. For the parasitism rates, we obtained the following: 19.11% for the total food web, 17.93% for the A. clitellarius parasitism, and 36% for the Lepidoptera parasitism. The resource traits had influence on the oviposition behavior of A. clitellarius, where fruits with larger area showed more eggs of this species. Fruits with higher biomass showed greater abundance and richness of insects as well as more interactions. Seeds with higher biomass were more often used by herbivorous insects. The larval forms of Lepidoptera caused the greatest damage in seed biomass among herbivores. Seeds with parasitoids did not show a significant difference in biomass when compared to predated seeds.     

A study of pityriasis versicolor in Bangkok (Thailand)

A total of 410 cases of pityriasis versicolor were studied in the Division of Dermatology, Department of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand, during January to December 1987. These comprised 1% of all skin disorders, while infection caused by fungus comprised 17%. Most persons infected with pityriasis versicolor were 12–21 years old (mean age 20 years) and 47% were male and 53% were female. The common sites of infection were back, arms, face and trunk. The colors of lesions found were white (83%), brown (7%), pink (6%) and ashy (4%). Both forms of M. furfur were isolated, the ovale form in 97% and the orbiculare form in 3% of cases. The colors of the lesions did not depend on the form of the organism. Mycological and immunological studies confirmed that the two forms were different stages in the complex developmental cycle of a single species.     

Advertisement-call preferences in diploid-tetraploid treefrogs (Hyla chrysoscelis and Hyla versicolor): implications for mate choice and the evolution of communication systems

Signals used for mate choice and receiver preferences are often assumed to coevolve in a lock-step fashion. However, sender-receiver coevolution can also be nonparallel: even if species differences in signals are mainly quantitative, females of some closely related species have qualitatively different preferences and underlying mechanisms. Two-alternative playback experiments using synthetic calls that differed in fine-scale temporal properties identified the receiver criteria in females of the treefrog Hyla chrysoscelis for comparison with female criteria in a cryptic tetraploid species (H. versicolor); detailed preference functions were also generated for both species based on natural patterns of variation in temporal properties. The species were similar in three respects: (1) pulses of constant frequency were as attractive as the frequency-modulated pulses typical of conspecific calls; (2) changes in preferences with temperature paralleled temperature-dependent changes in male calls; and (3) preference functions were unimodal, with weakly defined peaks estimated at values slightly higher than the estimated means in conspecific calls. There were also species differences: (1) preference function slopes were steeper in H. chrysoscelis than in H. versicolor; (2) preferences were more intensity independent in H. chrysoscelis than in H. versicolor; (3) a synergistic effect of differences in pulse rate and shape on preference strength occurred in H. versicolor but not in H. chrysoscelis; and (4) a preference for the pulse shape typical of conspecific calls was expressed at the species-typical pulse duration in H. versicolor but not in H. chrysoscelis. However, females of H. chrysoscelis did express a preference based on pulse shape when tested with longer-than-average pulses, suggesting a hypothesis that could account for some examples of nonparallel coevolution. Namely, preferences can be hidden or revealed depending on the direction of quantitative change in a signal property relative to the threshold for resolving differences in that property. The results of the experiments reported here also predict patterns of mate choice within and between contemporary populations. First, intraspecific mate choice in both species is expected to be strongly influenced by variation in temperature among calling males. Second, simultaneous differences in pulse rate and pulse shape are required for effective species discrimination by females of H. versicolor but not by females of H. chrysoscelis. Third, there is greater potential for sexual selection within populations and for discrimination against calls produced by males in other geographically remote populations in H. chrysoscelis than in H. versicolor.     

舟山群岛变态后牛蛙的食性研究

牛蛙(Ranacatesbeiana)是极其危险的外来入侵种,对当地生物类群的捕食是其主要的危害机制,但目前有关其食性的研究均只局限于一个研究地点。为了全面评估牛蛙对当地生物类群的捕食影响,2005年6月30日至8月11日期间,作者采用洗胃法对舟山群岛8个岛屿(岱山、六横、秀山、佛渡、桃花、虾峙、册子和普陀山)变态后牛蛙的食性进行了研究。共采集到变态后的牛蛙391只,包括牛蛙成体113只和亚成体278只。食性分析结果表明:(1)按食物体积计算,成年牛蛙以十足目、鞘翅目、蜻蜓目、中腹足目、蛙形目和鲤形目为主要食物,亚成体牛蛙以十足目、鞘翅目、鲤形目、蜻蜓目、直翅目、膜翅目、鳞翅目幼虫、中腹足目和蛙形目为主要食物;成体和亚成体牛蛙胃中食物的平均大小均随其体长增加而增大;(2)不同岛屿上的牛蛙在主要食物类型构成上存在差异。这表明牛蛙在不同地方对不同生物类群造成的捕食危害是不一样的,充分反映了其生态危害的广泛性。     

Diversity of insects captured by weaver spiders (Arachnida: Araneae) in the cocoa agroecosystem in Tabasco, Mexico

The aim of this work was to know the diversity of insects captured by weaver spiders in a plantation of cocoa (Theobroma cacao L.) of 6 ha in the State of Tabasco, Mexico. The study was carried out from July 2004 to June 2005 by means biweekly samples of the insects captured on the spiders webs. The total of 3,041 webs of 54 species of spiders belonging to seven families (Araneidae, Theridiidae, Tetragnathidae, Uloboridae, Pholcidae, Dyctinidae and Linyphiidae) were revised. We found 1,749 specimens belonging to 10 orders of insects, represented by 93 families, the majority of Coleoptera, Diptera and Hemiptera that constituted 74% of the identified families. The biggest number of specimens of all orders was captured by Araneidae, except of Isoptera, whose specimens were captured mainly by the family Theridiidae. The index of diversity (H'), evenness (J') and similarity (Is), applied to know the diversity of families of insects captured among families of spiders, varied from 0.00 to 3.24, 0.00 to 0.81, and 0.04 to 0.522, respectively. We conclude that there is a wide diversity of insects predated by the weaver spiders in the cocoa agroecosystem, and that there are species that can be promising for the biological control of pests.     

Predation potential of three flatworm species (Platyhelminthes: Turbellaria) on mosquitoes (Diptera: Culicidae)

We conducted a field survey for flatworms to select species as potential biological control agents against Aedes aegypti and Culex pipiens (Diptera, Culicidae) breeding in artificial containers. Laboratory experiments were performed to determine the daily predation rate, differential predation on each mosquito larval instar, selective predation on either A. aegypti or C. pipiens, and predator tolerance to water from artificial containers. Girardia anceps (Tricladida, Paludicola, Dugesiidae), Mesostoma ehrenbergii and Bothromesostoma cf. evelinae (Rhabdocoela, Typhloplanoida, Typhloplanidae) were found in temporary puddles and permanent pools. In the laboratory, they killed between 52% and 100% of immature mosquitoes coexisting in the same habitat. No preference of flatworms for mosquito preys was detected. Predation rate was related to predator size and instar of preys. Girardia anceps and B. evelinae survived after a dry period and when re-flooding occurred, they laid eggs. Tolerance to water from artificial containers was highest in G. anceps and this species could be a suitable predator to reduce mosquito populations from artificial containers using an inoculative approach.     

Ecological Life Table of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae)

An ecological life table was constructed, aiming to determine the critical stages and key mortality factors of Tuta absoluta (Lepidoptera: Gelechiidae). The total population mortality of this tomato leafminer was 92.3%. During the egg stage the mortality was 58.7%, mainly due to egg inviability. A total of 8.6% egg parasitism by Trichogramma pretiosum (Riley) (Hymenoptera: Trichogrammatidae) and 5.0% egg predation by Xylocoris sp. (Heteroptera: Anthocoridae), Cycloneda sanguinea (L.) (Coleoptera: Coccinellidae) and members of the family Phlaeothripidae (Thysanoptera) was observed. The mortality of the larval stage was 33.0%. This was considered to be the critical stage as it showed the highest apparent mortality (79.8%). Larval parasitism was low (0.1%), and was only found with Goniozus nigrifemur Ashmead (Hymenoptera: Bethylidae). Predators were responsible for 79.4% of larval mortality. Therefore, their attraction to and maintenance in the target area are important management tactics to be considered for T. absoluta control. The first and second instars were considered to be the most critical, and predation by the above mentioned species was the key mortality factor. The mortality at the pupal stage was low (0.6%) and was due to malformation.     

Food and feeding habits of black scorpionfish, <Emphasis Type="Italic">Scorpaena porcus</Emphasis> (Osteichthyes: Scorpaenidae) from the northern coast of Tunisia (Central Mediterranean)

Food and feeding habits of black scorpionfish Scorpaena porcus Linnaeus, 1758 were carried out from 715 specimens collected off Ras Jebel, city located in northern Tunisia. Diet was studied in relation to fish size, sexes and seasons. The relationship total length (TL) versus total body mass (TBM) showed a positive allometry, suggesting that S. porcus found favourable environmental parameters and available preys in its habitat. Vacuity index (VI) values were high for the total sample and also related to size classes, sexes, and seasons. Stomach contents of S. porcus revealed a very large diversity of preys; a total of 79 taxa were recorded, 3 osteichthyan, 69 crustacean, 2 annelid and 2 gastropod species, while angiosperma, alga, were rare. Crustaceans were the most abundantly found followed by osteichthyes. The troph value of S. porcus from the north-eastern coast of Tunisian reached 3.48 ± 0.58. S. porcus did not display significant changes in the diet related to sizes and/or seasons. S. porcus should be included among the carnivorous species which play a major role in regulation of marine food webs.     

Sandflies (Diptera: Psychodidae) in rural and urban environments in an endemic area of cutaneous leishmaniasis in southern Brazil

The high proportion of cases of cutaneous leishmaniasis reported amongst residents in the city of Bandeirantes, in the state of Paraná, Brazil, led the authors to investigate the phlebotomine fauna in both urban and rural environments. The sandflies were captured with automatic light traps from 07:00 pm-07:00 am fortnightly in 11 urban peridomiciles from April 2008-March 2009 and monthly in three ecotopes within four rural localities from April 2009-March 2010. In one of these latter localities, sandfly capture was conducted with white/black Shannon traps during each of three seasons: spring, summer and fall. A total of 5,729 sandflies of 17 species were captured. Nyssomyia neivai (46.7%) and Nyssomyia whitmani (35.3%) were the predominant species. In this study, 3,865 specimens were captured with automatic light traps: 22 (0.083 sandflies/trap) in the urban areas and 3,843 (26.69 sandflies/trap) in the rural areas. Ny. neivai was predominant in urban (68.2%) and rural (42.8%) areas. A total of 1,864 specimens were captured with the white/black Shannon traps and Ny. neivai (54.5%) and Ny. whitmani (31.4%) were the predominant species captured. The small numbers of sandflies captured in the urban areas suggest that the transmission of Leishmania has occurred in the rural area due to Ny. neivai and Ny. whitmani as the probable vectors.     

Diel emergence patterns of drifting chironomid (Diptera) pupal exuviae in the Aude River (Eastern Pyrenees,France)

Two diel emergence patterns (April and October 1990) of chironomids from a hyporhithral site (4th–5th order) in the Aude River are described. In April, 62 species were collected with a mean hourly richness of 31 (±4). The Orthocladiinae (91%) largely dominated the emergence. The total number of exuviae captured by one drift-net varied from 1300 to 11600 per one hour period. There was a clear bimodal pattern with peaks post dawn (07.00–09.00 hrs) and around sunset (18.00 hrs).In October, the total number of exuviae captured was much lower and varied from 150 to 540 per one hour period with post dawn (06.00–08.00 hrs) and post sunset (18.00 hrs) peaks. Nevertheless, the total species richness (65) was higher as was the mean hourly richness (37±4). The Orthocladiinae (68%) dominated less because of increases in the Tanytarsini (15%) and Chiromini (14%). A diel rhythm appeared in autumn emergence. Most of the Orthocladiinae exuviae were collected during daylight hours, whereas most of the Chironomini and Tanytarsini were sampled during darkness. A majority of the exuviae with a length below 3 mm emerged during daylight, but most of the exuviae above 5 mm length emerged during darkness. The exuviae with an intermediate length (3–5 mm) had an amodal diel emergence pattern. In spring and autumn, the majority of species had a bimodal emergence pattern either by day (Orthocladiinae) or by night (Chironominae). But the smallest species had either an unimodal (Thiennemaniella vittata) or bimodal (Neozavrelia fuldensis) daytime emergence. The diel emergence patterns of 10 of the most frequently recorded species are presented.     

About the presence of Phlebotomus sergenti Parrot, 1917 (Diptera: Psychodidae) in Eastern Sicily, Italy

The note reports the data of a three-year sand fly investigation (1997-99) carried out in Eastern Sicily (Italy) with the aim to study the distribution of Phlebotomus sergenti. The survey involved a densely inhabited area at the foot of Mount Etna and the area of Iblei mounts. A total of 9,095 sand flies, of which 63.4% males, were captured. Five species belonging to the genus Phlebotomus (P. perniciosus, P. perfiliewi, P. neglectus, P. sergenti and P. papatasi) and one to the genus Sergentomyia (S. minuta) were identified. Both the prevalence and distribution of the species were different within the two areas studied. In Mount Etna area, P. perniciosus (77.7%) was the prevalent species followed by S. minuta (19.8%), P. sergenti (2.0%), P. neglectus (0.3%) and P. papatasi (0.2%). While in Iblei mounts region S. minuta (84.5%) showed the highest prevalence, followed by P. perniciosus (14.4%), P. perfiliewi (0.9%) and P. neglectus (0.1%). Here, P. sergenti was a very rare species (< 0.02). P. sergenti was mostly associated to domestic habitats of peri-urban and urban zones located between two and 750 m a.s.l. The density values of P. sergenti, expressed as number of specimens/m2 of sticky trap, were between 0.3 and 5.5 with the highest value in the hilly collecting sites. The low observed abundance of P. sergenti does not allow to draw any prediction on the role that the species could play in the transmission of leishmaniasis in Sicily.