Abstract in English:In social insects, the typical mode of colony foundation occurs when a single queen is inseminated by a male and establishes a new colony, although we can find interspecific and intraspecific variations in queen number and queen-mating frequencies in a single colony. This study aimed to verify the queen number in Pachycondyla striata (Smith) colonies and to evaluate the level of aggressiveness among workers. We collected 14 colonies of P. striata. The behaviors of individuals from five multiple-queen colonies maintained in laboratory were studied by the method of scan sampling. In order to evaluate aggressiveness, dyadic encounters among heterocolonial and homocolonial workers were performed. The results showed that colonies of P. striata can have two or more mated queens (polygynous colonies) besides to monogynous ones (colony containing one queen). Because in polygynous colonies the number of workers was relatively low, such colonies could represent colonies in the foundation phase that characterize a pleometrosis state. In fact, ovarian development analysis from queens showed that the number of queens in the colonies seemed to be unstable. Despite a few cases of oophagy (egg cannibalism), social hierarchy among queens is unclear in comparison to other Pachycondyla species. In addition, aggressiveness increased with distance among nests. Nearby colonies (less than 1 m apart) showed a low level of aggressiveness, suggesting the presence of polydomy, that is, a unique colony can occupy multiple nests. Polygyny associated to polydomy in founding colonies may confer benefits on growth and dispersion of colonies in the studied environments.
Abstract in English:A total of 1,177 lice of four species were collected from 124 kelp gulls (Larus dominicanus) and 137 lice of the same four species from 60 Franklin's gulls (Larus pipixcan). The louse Saemundssonia lari (O Fabricius) (Phthiraptera: Philopteridae) was the most numerous on both gull species, with infestation rates of 4.9 on kelp gulls and 1.8 on Franklin's gulls. The second most abundant louse was Quadraceps punctatus (Burmeister), with a high infestation rate but low prevalence on kelp gulls; those parameters were much lower among lice from Franklin's gulls. The composition and community structure of the lice were similar on both host species, but not their infestation rates. In addition, the feather mite Zachvatkinia larica Mironov (Acari: Avenzoariidae) is recorded from kelp gulls and Franklin's gulls for the first time, while the gamasid mite Larinyssus sp. is recorded from kelp gulls, also for the first time. The population parameters of all species of ectoparasites are discussed.
Abstract in English:This study analyses the role of body size and symmetry in the sexual selection and courtship behavior of Dysdercus maurus Distant. Sexual conflicts signaled by coercive mating, female resistance, and pre-copulation fights illustrate the mating system. Male-female struggles were observed in all mating attempts. Females tried to reject males by pushing or running and even by vigorously shaking their bodies, in attempts to dislodge the male from their dorsum. In spite of sexual conflicts during courtship, females actively chose their mates based on morphological and behavioral traits. Larger males with more symmetrical tibiae and longer tarsi that are better copula imposers were more successful in sexual competition. Evidence is presented that sexual conflict and female mate choice should not be mutually excluded.
Abstract in English:Among the pests of cassava, the shoot fly, Neosilba perezi (Romero & Ruppell), is one of the most prevalent. It attacks mainly the terminal shoots and causes infested plants to produce lateral shoots. Reports on this species are rare or inexistent; thus, the purpose of this study was to assess three different areas for N. perezi infestation. The survey began in March 2008 and finished in February 2009. Fortnightly analyses were performed starting 45 days after planting, calculating the rate of infestation by N. perezi larvae in each study area. The areas were correlated separately for each parameter: fortnightly mean temperature, fortnightly mean rainfall, and plant age. The N. perezi larvae occurrence rate was higher in area 1 - which presented the highest population peaks in autumn and winter. There was only a single population peak in area 2, in winter; and area 3 presented the weakest population peak among the three, in November. The shoot fly population dynamics in the studied region is separately correlated to temperature, rainfall and plant age: temperatures above 23ºC, relatively high rainfall and older plants seem to have a negative effect on populations of this insect.
Abstract in English:Greenidea ficicola Takahashi and Greenidea psidii van der Goot (Aphididae: Greenideinae) are Asian aphid species newly introduced in Brazil associated with Moraceae and Myrtaceae. The feeding behavior of G. ficicola and G. psidii was investigated on their respective host plants, Ficus benjamina (Moraceae) and Psidium guajava (Myrtaceae), using the Electrical Penetration Graph (EPG). Fifteen females of each aphid species were monitored during 24h using a DC-EPG GIGA-4 monitor. The time spent in phloem phase (waveforms E1 and E2) was 13.6% of the total recording time for G. ficicola and 0.8% for G. psidii. The average time in the pathway phase (waveforms C and pd) represented 50% of the total time for both species. Aphids spent more time in non-penetration and stylet pathway activities than in the phloem phase or actual feeding. The principal component analysis (PCA) showed that the two species formed different groups in relation to EPG parameters, despite some overlapping. The probing patterns with multiple penetrations of short duration in the sieve elements for both species may indicate apparent unsuitability for sustained feeding on their respective host plants. These results suggest that these two exotic species are in the process of adaptation to their host plants in their new environment and/or the plants may present either chemical or physical barriers against these insects.
Abstract in English:We provide the first information on the morphology of the immature stages (egg, larva, and pupa), oviposition and larval behavior, and host plant, for the Brazilian crescent butterfly Ortilia liriope (Cramer), based on material from Santarém Municipality, Pará State, Northern Brazil. Females of O. liriope lay eggs in clusters. After hatching, larvae eat the exochorion and remain gregarious in all but the final instar. The host plant recorded in the study site is Justicia sp. (Acanthaceae). Despite the scarcity of data on the immature stages of Neotropical Melitaeini, we can already say that some morphological and behavioral traits observed in the immature stages of O. liriope are also present in all known genera in this tribe.
Abstract in English:Neoblattella mista sp. nov. is described and illustrated based on male genitalia and morphological characters of a single specimen collected in the town of Coari, State of Amazonas, Brazil. By studying the literature on the genus, we determined that N. mista sp. nov. differs from the other four known complexes in the morphology of its genital structures, including the supra-anal plate, subgenital plate, right and left phallomeres, median genital sclerite and tergal modification in the abdomen, and is placed in the new "mista complex".
Abstract in English:Cicindis Bruch is a monospecific genus of carabid beetles endemic to Argentina. In this contribution, Cicindis horni Bruch is re-described, with addition of new morphological features of male internal sac, female genital tract and elytral closure. New information on the species' habitat and distribution is also provided. The phylogenetic placement and relationships of Cicindis within the family Carabidae are discussed on the basis of a cladistic analysis. Terminal taxa included representatives of all subfamilies of Carabidae and supertribes of Carabinae, with a major sampling of those taxa considered to be closely related to Cicindini by previous authors. The phylogenetic analysis shows the basal position of Cicindis in a clade that includes Ozaeninae, Omophronini, Scaritinae and Conjuncta. A close relationship of Cicindis with Ozaenini + Metriini is supported by the particular closure of the procoxa and the ventral position of the oviduct with respect to the spermatheca.
Abstract in English:The lac insect genus Tachardiella Cockerell is reviewed and 17 species are recognized, including one new species. The adult female of Tachardiella palobrea Kondo & Gullan sp. n. is described and illustrated based on material collected in Argentina on 'brea', Parkinsonia praecox (Fabaceae). The adult female of Tachardiella argentina (Dominguez) is redescribed and a lectotype is designated based on newly discovered syntype material in the Bohart Museum of Entomology, University of California, Davis (BME). Diagnoses and notes are provided for the other species of Tachardiella studied and a lectotype is designated for Tachardiella ferrisi Chamberlin. A taxonomic key to separate all known species of lac insects in the New World is provided.
Abstract in English:Microbial insecticides for cockroach control, such as those containing entomopathogenic fungi, may be an alternative to reduce contamination by chemicals in housing and food storage environments. Virulence of isolate ESALQ1037 belonging to the Metarhizium anisopliae complex against nymphs and adults of Blattella germanica (L.), and its infectivity following exposure of insects to a contaminated surface or to M. anisopliae-bait were determined under laboratory conditions. Estimated LD50 15 d following topical inoculation was 2.69 x 10(5) conidia per adult, whereas for nymphs the maximum mortality was lower than 50%. Baits amended with M. anisopliae conidia had no repellent effect on targets; adult mortality was inferior to 25%, and nymphs were not susceptible. All conidia found in the digestive tract of M. anisopliae-bait fed cockroaches were unviable, and bait-treated insects that succumbed to fungal infection showed a typical mycelial growth on mouthparts and front legs, but not on the hind body parts. As opposed to baits, the use of a M. anisopliae powdery formulation for surface treatment was effective in attaining high mortality rates of B. germanica. Both nymphs and adults were infected when this delivery strategy was used, and mycelia growth occurred all over the body surface. Our results suggest that the development of powders or similar formulations of M. anisopliae to control B. germanica may provide faster and better results than some of the strategies based on baits currently available.
Abstract in English:Botanical compounds with insecticidal and acaricidal activities have been used in pest management with different levels of success. Toxicity of ethanolic extracts obtained from wild oregano (Lippia origanoides) and gliricidia (Gliricidia sepium) to Tetranychus cinnabarinus (Boisduval) were evaluated. Mite population was collected from black bean plants growing in Urachiche Municipality, Yaracuy State, Venezuela. Ethanolic extracts of wild oregano and gliricidia leaves were evaluated at different concentrations (5, 10, 15, and 20%) using the leaf disk immersion technique. The presence of alkaloids, flavonoids, phenols and tannins, essential oils and saponins was verified in the plant material used in our study. Tetranychus cinnabarinus oviposition decreased at a rate of 43.7% or 57% when 5% oregano or gliricidia extracts were used, respectively. Also, 10% oregano or gliricidia extracts caused 42.2% or 72.5% of mortality to T. cinnabarinus, respectively. Ethanolic extracts showed acaricidal effects on T. cinnabarinus, as evidenced by maximum mortality (96.6% and 100% caused by wild oregano and gliricidia, respectively) when used at a concentration of 20%. Our results showed that gliricidia and wild oregano are promising for the management of T. cinnabarinus, although their field efficacy remains to be evaluated.
Abstract in English:The antibiotic and antixenotic resistance of six commonly produced potato cultivars in Iran including Aozonia, Agria, Cosima, Cosmos, Kondor and Savalan to the green peach aphid, Myzus persicae Sulzer, were investigated under laboratory conditions at 20 ± 2ºC, 65 ± 5% RH and 16:8h (L:D) in 2009. Antibiosis experiments showed significant differences in the developmental time, nymphal survivorship, fecundity, adult longevity of the green peach aphid among the potato cultivars. Intrinsic rate of natural increase (r m) for apterous aphids varied significantly with the potato cultivars on which the aphids were reared. This value ranged from 0.225 to 0.293 females/female/day, which was lowest on Cosmos and highest on Aozonia. Additionally, the estimated net reproductive rate (R0) and finite rate of increase (λ) for apterous aphids were the lowest on Cosmos. For the antixenosis experiment, no significant difference was found in aphid's preference to the potato cultivars. However, Aozonia was preferred more than the other five cultivars by the apterous aphids. Therefore, our results demonstrated that among the investigated cultivars the Cosmos cultivar is moderately resistant to the green peach aphid.
Abstract in English:Changes in the agroecosystem with the increase of green cane harvesting in Brazil affected the insect populations associated to this crop, and secondary pests like the spittlebug Mahanarva fimbriolata Stål, became much more important. Many studies have demonstrated the active role played by silicon in plant defense against herbivory. The objective of this study was to evaluate the effects of silicon applications on the biology of the spittlebug reared on two resistant (SP79-1011 and SP80-1816) and one susceptible (SP81-3250) sugarcane cultivars. Sugarcane plants were grown under greenhouse conditions and submitted to different treatments: with and without silicon fertilizer in two different soil type (sandy and clay soil). The newly hatched nymphs were transferred to sugarcane roots and placed into boxes with lids, to keep a moistened and dark environment favoring their growth and maintenance of the root system, providing food access to the developing nymphs. After emergence, adult males and females were placed in cages for mating and oviposition. The silicon absorbed and accumulated in the plant caused an increase in nymphal mortality, and depending on the sugarcane cultivar tested this element also provided an increase in the duration of the nymphal stage and a decrease in the longevity of males and females. 'SP79-1011' presented the highest silicon content in leaves, and M. fimbriolata had the highest nymph mortality and the shortest female longevity. The pre-oviposition period, fecundity and egg viability were not affected by the silicon content in plants or the cultivar used.
Abstract in English:Myiases are infestations with dipteran larvae in both necrosed and living tissues, the food source of these insects. These illnesses occur in warm humid climates, and are most frequent in developing countries. We assessed the epidemiological aspects and the influence of climate on the occurrence of myiases and the bioagents in patients admitted to the federal Hospital do Andaraí in Rio de Janeiro from February 2007 to 2008. The influence of abiotic factors (temperature, humidity, and rainfall) on the incidence of myiases was investigated by using the Pearson's correlation test. Of the 40 patients studied, the prevalence of myiases was higher in adults, particularly in the 40 to 65 year-old (37.5%) African descent males (57.5%). Most of the injuries were caused by trauma (62.5%). Some patients made use of licit (50%) and illicit drugs (17.2%). The occurrence of myiases was not affected by the abiotic factors investigated. The cases reported here were treated in only one hospital, indicating that the disease is relatively common. The most frequent bioagent was Cochliomyia hominivorax (Coquerel), but Cochliomyia macellaria (Fabricius), Chrysomya albiceps (Wiedemann) and Dermatobia hominis (Wiedemann) (Diptera: Calliphoridae) were also detected causing myiases. Chrysomya albiceps is an exotic etiologic agent of myiases.
Abstract in English:The rupicola series was proposed initially for Evandromyia rupicola (Martins et al) and Evandromyia correalimai (Martins et al), and recently extended with the inclusion of Evandromyia gaucha Andrade-Filho et al and Evandromyia grimaldii Andrade-Filho et al. The female of E. rupicola is here described and illustrated for the first time and its male is redescribed and drawn on the basis of specimens captured in forest on the coast of the state of São Paulo, Brazil. The head and genitalia of both sexes of E. correalimai are also illustrated. The distinctive traits among females of the four species and of males of E. rupicola, E. correalimai and E. grimaldii, and the distribution range of these species are commented.
Abstract in English:The association among Anastrepha species, braconid parasitoids and host fruits in southern Bahia is recorded. Doryctobracon areolatus (Szépligeti) was associated with A. serpentina (Wied.) in Pouteria caimito, A. bahiensis Lima in Helicostylis tomentosa, A. sororcula Zucchi in Eugenia uniflora, and A. obliqua (Macquart) in Spondias purpurea. Anatrepha obliqua was unique in fruits of Averrhoa carambola, but associated with D. areolatus, Asobara anastrephae (Muesebeck) and Utetes anastrephae (Viereck). In Achras sapota, A. serpentina was associated with A. anastrephae and D. areolatus, while in Psidium guajava, A. fraterculus (Wied.) and A. sororcula were associated with D. areolatus and U. anastrephae.
Abstract in English:Spintherophyta semiaurata (Klug) is reported for the first time damaging flowers of strawberry (Fragaria x ananassa) in the municipality of São José dos Pinhais, State of Parana, Brazil.
Abstract in English:The presence of the red palm mite, Raoiella indica Hirst, is reported for the first time in Brazil. This invasive mite was found in July 2009 infesting coconut palms and bananas in urban areas of Boa Vista, State of Roraima, in northern Brazil. Comments on the possible pathways of R. indica into the country, present and potential impact of its introduction and mitigating measures to prevent or to delay the mite spread in Brazil are presented.
Abstract in English: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.