Mortality of Plutella xylostella (Lepidoptera, Plutellidae) by parasitoids in the Province of Santa Fe, Argentina

Mortality of Plutella xylostella (Lepidoptera, Plutellidae) by parasitoids in the Province of Santa Fe, Argentina. Plutella xylostella (Linnaeus, 1758) (Lepidoptera, Plutellidae) larvae cause severe economic damage on cabbage, Brassica oleracea L. variety capitata (Brassicaceae), in the horticultural fields in the Province of Santa Fe, Argentina. Overuse of broad spectrum insecticides affects the action of natural enemies of this insect on cabbage. The objectives of this work were to identify the parasitoids of P. xylostella and to determine their influence on larva and pupa mortality. Weekly collections of larvae and pupae were randomly conducted in cabbage crops during spring 2006 and 2007. The immature forms collected were classified according to their developmental stage: L1 and L2 (Ls = small larvae), L3 (Lm = medium larvae), L4 (Ll = large larvae), pre-pupae and pupae (P). Each individual was observed daily in the laboratory until the adult pest or parasitoid emergence. We identified parasitoids, the number of instar and the percentage of mortality of P. xylostella for each species of parasitoid. Parasitoids recorded were: Diadegma insulare (Cresson, 1875) (Hymenoptera, Ichneumonidae), Oomyzus sokolowskii (Kurdjumov, 1912) (Hymenoptera, Eulophidae), Cotesia plutellae (Kurdjumov, 1912) (Hymenoptera, Braconidae) and an unidentified species of Chalcididae (Hymenoptera). Besides parasitoids, an unidentified entomopathogenic fungus was also recorded in 2006 and 2007. In 2006, the most successful parasitoids were D. insulare and O. sokolowskii, while in 2007 only D. insulare exerted a satisfactory control and it attacked the early instars of the pest.

Relationships between host plant architecture and gall abundance and survival

The plant architecture hypothesis predicts that variation in host plant architecture influences insect herbivore community structure, dynamics and performance. In this study we evaluated the effects of Macairea radula (Melastomataceae) architecture on the abundance of galls induced by a moth (Lepidoptera: Gelechiidae). Plant architecture and gall abundance were directly recorded on 58 arbitrarily chosen M. radula host plants in the rainy season of 2006 in an area of Cerrado vegetation, southeastern Brazil. Plant height, dry biomass, number of branches, number of shoots and leaf abundance were used as predicting variables of gall abundance and larval survival. Gall abundance correlated positively with host plant biomass and branch number. Otherwise, no correlation (p > 0.05) was found between gall abundance with shoot number or with the number of leaves/plant. From a total of 124 galls analyzed, 67.7% survived, 14.5% were attacked by parasitoids, while 17.7% died due to unknown causes. Larvae that survived or were parasitized were not influenced by architectural complexity of the host plant. Our results partially corroborate the plant architecture hypothesis, but since parasitism was not related to plant architecture it is argued that bottom-up effects may be more important than top-down effects in controlling the population dynamics of the galling lepidopteran. Because galling insects often decrease plant fitness, the potential of galling insects in selecting for less architectural complex plants is discussed.

A new case constructing adelid moth from Chile (Lepidoptera)

A new case constructing adelid moth from Chile (Lepidoptera). The adult and larva of Ceromitia tubulifolia sp. nov. are described and illustrated. The larvae seem to be associated with sclerophyllous forest of central Chile. The larvae make a protective case from of a piece of leaf. The name phylloikos is proposed for this form of larval case. A review of the morphology and bionomics of this species are provided.

First record of folivory on a newly documented host plant for the little known geometrid moth Eupithecia yubitzae Vargas & Parra (Lepidoptera, Geometridae) in northern Chile

The native tree Schinus molle (Anacardiacae) is reported for the first time as a host plant for larvae of the little known geometrid moth Eupithecia yubitzae Vargas & Parra (Lepidoptera, Geometridae) in the Atacama Desert of northern Chile, based on morphology and DNA barcodes. This discovery importantly expands the host range of E. yubitzae, as previous records were restricted to Fabaceae trees. Larvae were previously known as florivorous, while these were found to be folivorous on S. molle. Furthermore, host-associated cryptic larval polychromatism was detected, as larvae collected on S. molle were found to be mostly pale green, contrasting with the dark yellow ground color of the larvae typically collected on fabaceous host plants.

Biologia da Arsenura xanthopus (Walker, 1855) ( Lepidoptera - Adelocephalidae ), praga do «Açoita-Cavalo» (Luehea spp.) e notas sôbre seus inimigos naturais

Biology of Arsenura xanthopus (Walker, 1855) (Lep., Adelocephalidae), a pest of Luehea spp. (Tiliaceae), and notes on its natural enemies. In the beginning of 1950, one of the Authors made some observations about the biology of Arsenura xanthopus (Walker), in Piracicaba, State of S. Paulo, Brazil. From 1951 to 1953, both Authors continued the observations on such an important Adelocephalidae, the caterpillars of which represent a serious pest of Luehea spp. leaves. Actually, in some occasions, the caterpillars can destroy completely the leaves of the trees. The species is efficientely controlled by two natural enemies: an egg parasite (Tetrastichus sp., Hym., Eulophidae) and a fly attacking the last instar caterpillar (Winthemia tricolor (van der Wulp), Dip., Tachinidae). Tetrastichus sp. can destroy 100% of the eggs and the fly, 70 to 100% of the caterpillars. Indeed, facts as such are very interesting because we rarely know of a case of so complete a control of a pest by an insect. A. xanthopus had not yet been mentioned in our literature. Actually neither the systematic bibliography nor the economic one has treated of this species. However, a few other species of Arsenura are already known as living on Luehea spp. According to the Authors' observations, W. tricolor was also unknown by the Brazilian entomological literature. Arsenura xanthopus (Walker, 1855) After giving the sinonimy and a few historical data concerning the species, and its geographical distribution, the Authors discuss its placing in the genus Arsenura Duncan or Rhescyntis Huebner, finishing by considering Arsenura xanthopus as a valid name. The Authors put the species in the family Adelocephalidae, as it has been made by several entomologists. The host plant The species of Tiliaceae plants belonging to the genus Luehea are called "açoita-cavalo" and are well known for the usefulness of their largely utilized wood. The genus comprises exclusively American plants, including about 25 species distributed throughout the Latin America. Luehea divaricata Mart, is the best known species and the most commonly cultivated. Biology of Arsenura xanthopus Our observations show that the species passes by 6 larval stages. Eggs and egg-postures, all the 6 instars of the caterpillars as well as the chrysalid are described. The pupal period is the longest of the cycle, taking from 146 to 256 days. Data on the eclosion and habits of the caterpillars are also presented. A redescription of the adult is also given. Our specimens agreed with BOUVIER's description, except in the dimension between the extremities of the extended wings, which is a little shorter (107 mm according to BOUVlErVs paper against from 80 to 100mm in our individuals). Winthemia tricolor (van der Wulp, 1890) Historical data, geographical distribution and host are first related. W. tricolor had as yet a single known host-; Ar^-senura armida (Cramer). This chapter also contains some observations on the biolcn gy of the fly and on its behaviour when trying to lay eggs on the caterpillars' skin. The female of W. tricolor lays from 1 to 33 eggs on the skin of the last instar caterpillar. The mam region of the body where the eggs are laid are the membranous legs. Eggs are also very numerous oh the ventral surface of the thorax and abdomen. The. preference for such regions is easily cleared up considering the position assumed by the caterpillar when fixed motionless in a branch. In such an occasion, the fly approaches, the victim, puts the ovipositor out and lays the eggs on different parts of the body, mainly on the mentioned regions, which are much more easily reached. The eggs of the fly are firmly attached to the host's skin, being almost impossible to detach them, without having them broken. The minute larvae of the fly enter the body of, the host when it transforms into chrysalid. Chrysalids recentely formed and collected in nature f requentely show a few small larvae walking on its skin and looking for an adequate place to get into the body. A few larvae die by remaining in the skin of the caterpillar which is pushed away to some distance by the active movements of the chrysalid recentely formed. From 1 to 10 larvae completely grown may emerge from the attacked chrysalid about 8 days after their penetrating into the caterpillars' body and soon begin to look for an adequate substratum where they can transform themselves into pupae. In natural conditions, the metamorphosis occurs in the soil. The flies appear within 15 days. Tetrastichus sp. This microhymenoptera is economically the most interesting parasite, being commonly able to destroy the whole pos^ ture of the moth. Indeed, some days after the beginning of the infestation of the trees, it is almost impossible to obtain postures completely free of parasites. The active wasp introduces the ovipositor into the egg of the moth, laying its egg inside, from 80 to 120 seconds after having introduced it. A single adult wasp emerges from each egg. Sarcophaga lambens Wiedemann, 1830 During the observations carried out, the Authors obtained 10 flies from a chysalid that were recognized as belonging to the species above. S. lambens is a widely distributed Sarcophagidae, having a long list of hosts. It is commonly obtained from weak or died invertebrates, having no importance as one of their natural enemies. Sinonimy, list of hosts and distribution are presented in this paper. Control of Arsenura xanthopus A test has been carefully made in the laboratory just to find out the best insecticide for controlling A. xanthopus caterpillars. Four different products were experimented (DDT, Pa-rathion, BHC and Fenatox), the best results having been obtained with DDT at 0,25%. However, the Authors believe in spite of the initial damages of the trees, that the application of an insecticide may be harmful by destroying the natural agents of control. A biological desiquilibrium may in this way take place. The introduction of the parasites studied (Tetrastichus sp. and Winthemia tricolor) seems to be the most desirable measure to fight A. xanthopus.

The three phases of the ensemble forecasting of niche models: geographic range and shifts in climatically suitable areas of Utetheisa ornatrix (Lepidoptera, Arctiidae)

Species' geographic ranges are usually considered as basic units in macroecology and biogeography, yet it is still difficult to measure them accurately for many reasons. About 20 years ago, researchers started using local data on species' occurrences to estimate broad scale ranges, thereby establishing the niche modeling approach. However, there are still many problems in model evaluation and application, and one of the solutions is to find a consensus solution among models derived from different mathematical and statistical models for niche modeling, climatic projections and variable combination, all of which are sources of uncertainty during niche modeling. In this paper, we discuss this approach of ensemble forecasting and propose that it can be divided into three phases with increasing levels of complexity. Phase I is the simple combination of maps to achieve a consensual and hopefully conservative solution. In Phase II, differences among the maps used are described by multivariate analyses, and Phase III consists of the quantitative evaluation of the relative magnitude of uncertainties from different sources and their mapping. To illustrate these developments, we analyzed the occurrence data of the tiger moth, Utetheisa ornatrix (Lepidoptera, Arctiidae), a Neotropical moth species, and modeled its geographic range in current and future climates.

Age and multiple mating effects on reproductive success of Grapholita molesta (Busck) (Lepidoptera, Tortricidae)

The reproductive success of the oriental peach moth was evaluated in four experiments: 1) assessment of the mating duration, fecundity, fertility and longevity of females paired with virgin and immediately mated males; 2) mating duration, spermatophore size, fecundity, fertility and longevity in females paired with virgin and up to four times mated males; 3) receptivity of females to additional copulations after mating with virgin or mated males, and the effects of this behavior in female fecundity, fertility and longevity; 4) influence of insects age in the reproductive output. Males (33%) could copulate immediately after a previous copula. They were fertile until the fourth mating, but only in the first copula they transferred the longest (1.43 ± 0.10 mm) and widest (0.83 ± 0.11 mm) spermatophore, presenting the fastest mating duration (34.8 ± 2.62 min). A high proportion of females copulated by non-virgin males (84%) was receptive to other copulas, in comparison to those copulated by virgin males (32.4%). However, the fecundity, fertility, and longevity were similar among females that copulate once or more. The age was the most important factor affecting reproductive variables, where one and three day old insects had a significant higher fecundity, fertility and presented a shorter mating duration in comparison with older individuals. Results pointed out that the reproductive capacity of Grapholita molesta changes a little with respect to the analyzed factors, highlighting the elevated biotic potential of the species.

First host plant records for Iridopsis hausmanni Vargas (Lepidoptera, Geometridae) in the coastal valleys of northern Chile

First host plant records for Iridopsis hausmanni Vargas (Lepidoptera, Geometridae) in the coastal valleys of northern Chile. The trees Haplorhus peruviana Engl. and Schinus molle L. (Anacardiaceae) are mentioned as the first host plant records for the little known native moth Iridopsis hausmanni Vargas, 2007 (Lepidoptera, Geometridae, Ennominae) in the coastal valleys of the northern Chilean Atacama Desert. This is also the first record of Anacardiaceae as host plant for a Neotropical species of Iridopsis Warren, 1894.

An unusual food plant for Cydia pomonella (Linnaeus) (Lepidoptera, Tortricidae) in Mexico

An unusual food plant for Cydia pomonella (Linnaeus) (Lepidoptera, Tortricidae) in Mexico. Larvae of Cydia pomonella (Linnaeus, 1758) were discovered on floral cones of Magnolia schiedeana (Schltdl, 1864) near the natural reserve of La Martinica, Veracruz, México. Magnolia represents an unusual host for this moth species, which is known throughout the world as the "codling moth", a serious pest of fruits of Rosaceae, especially apples. The larvae were identified using taxonomic keys, and identification was corroborated using molecular markers. Further sampling resulted in no additional larvae, hence, the observation was probably that of an ovipositional error by the female, and M. schiedeana is not at risk of attack by this important moth pest.

A morphological reappraisal of the immature stages and life history of Elachista synethes Meyrick (Lepidoptera, Elachistidae), an Australian leaf miner alien to Chile

ABSTRACT Elachista synethes was recently recognized as an alien species in northern Chile, where its larvae mine the rescue grass Bromus catharticus (Poaceae). In order to provide the necessary information to allow field detection of E. synethes during early ontogeny, we conducted a morphological reappraisal of the immature stages of this leaf-miner moth, based on light and scanning electron microscopy, including the first descriptions of the egg and the first-instar larva. This is the first report of the existence of an apodal early larva for a species of Elachista Treitschke. The legs and prolegs are absent in the first two instars, but are well developed in the last two. Additional observations on the life history are also provided, including a description of the mine.

Mating disruption with low density diffusers for the management of oriental fruit moths (Lepidoptera: Tortricidae) in apple orchards under subtropical climate in southern Brazil

The oriental fruit moth, Grapholita molesta Busck, and fruit flies, Anastrepha fraterculus L., are the important apple pests under Subtropical climate in Southern Brazil, and control is normally accomplished with insecticides. An alternative strategy for the control of G. molesta is mating disruption, through the use of pheromones. Mating disruption strategies using a low density of dispensers (20) per hectare were tested in comparison with conventional pesticides for control of G. molesta in commercial Gala apple orchards in Fraiburgo, SC, for a period of five years. The average field efficiency period of mating disruption formulation over five years was 113 days. In this period the mating interruption index on mating disruption plots was 84.8% over five years. Damage to Gala apples by oriental moth larvae was low (<0.1%) in mating disruption plots but did not differ from conventional plots, except in the third year. The use of mating disruption allowed for an average reduction of 5.2 insecticide treatments per year in Gala orchards during field efficiency period. It was necessary to apply 1.0 and 1.2 applications of insecticide to control of G. molesta and A. fraterculus, respectively. Mating disruption with a low density of diffusers proved to be an effective alternative to conventional methods for control of G. molesta in Gala apple orchards in subtropical climate in southern Brazil.

Resistência de variedades de algodão ao curuquerê do algodoeiro Alabama argillacea Hubner (lepidoptera: noctuidae)

Este trabalho teve como objetivo verificar a ocorrência das formas de resistência, tais como: a não preferência para oviposição, a não preferência para alimentação e a antibiose, em variedades de algodoeiro (Gossypium hirsutum L.), à Alabama argillacea (Hubner, 1818), em experimentos de laboratório (27 ± 2 ºC, 70 ± 10% de U.R. e fotofase de 14 horas). Para avaliar a não preferência para oviposição e para a alimentação em teste com chance de escolha, adotou-se o delineamento em blocos casualizados e, no teste sem chance, o inteiramente casualizado. Para avaliar a antibiose, foram fornecidas às larvas, diariamente, folhas das variedades DeltaOpal, NuOpal, FMT 701, FMX 910 e 20 FMX 996. Durante este processo, verificou-se a duração de cada fase do inseto, avaliando-se a massa de larvas aos dez dias de idade, massa de pupas com 24 horas, período larval, pré-pupal e pupal, longevidade de adultos, viabilidade total e fecundidade. As variedades NuOpal e FMT 701 apresentam resistência do tipo não preferência para alimentação. As variedades NuOpal, FMT 701 e FMX 910 apresentam resistência do tipo antibiose em relação a A. argillacea.

Disposição espacial e injúrias da lagarta-do-cartucho Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) em milho

O conhecimento dos padrões de dispersão populacional de Spodoptera frugiperda (J. E. Smith), a mais importante praga do milho, no Brasil, é fundamental para o estabelecimento de técnicas eficientes de monitoramento e manejo. Este trabalho objetivou conhecer a distribuição espacial da praga na cultura. A distribuição espacial foi avaliada em cinco campos experimentais, de um hectare cada, divididos em 100 unidades experimentais, onde se avaliaram de cinco a dez plantas por parcela. Foi testado o ajuste das frequências observadas às esperadas, de acordo com as distribuições de Poisson, Binomial Negativa e Binomial Positiva. Spodoptera frugiperda ocorreu em elevados índices populacionais na área amostral, com correlação significativa entre a nota de injúria 3 e o número de lagartas médias, o que também ocorreu para o número de plantas infestadas com pelo menos uma lagarta média. Não houve correlação significativa entre a nota de injúria 3 e lagartas pequenas. O modelo que melhor se aproximou dos dados de distribuição da oviposição foi a Binomial Positiva, enquanto a disposição espacial de lagartas, atacando a espiga, foi descrita como aleatória. O modelo de distribuição Binomial Positiva foi o que melhor representou a distribuição espacial da população de plantas infestadas; a distribuição das lagartas de tamanho médio teve padrão de distribuição agregada.

Preferência de Cotesia flavipes (Cameron, 1891) (Hymenoptera: Braconidae) por lagartas de Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) alimentadas com diferentes cultivares de cana-de-açúcar

O objetivo desta pesquisa foi avaliar a preferência do parasitoide Cotesia flavipes (Hymenoptera: Braconidae) por lagartas de Diatraea saccharalis (Lepidoptera: Crambidae), alimentadas com diferentes cultivares de cana-de-açúcar. O experimento foi conduzido em laboratório, em duas condições de alimentação, uma envolvendo lagartas de D. saccharalis, alimentadas em dieta artificial, e, a outra, com lagartas alimentadas em dieta artificial e mantidas temporariamente nos toletes dos cultivares de cana-de-açúcar. Os cultivares utilizados foram: SP80-1842 e SP81-3250, resistentes, e RB855536, suscetível à D. saccharalis. A preferência para oviposição das fêmeas de C. flavipes foi avaliada em testes com e sem chance de escolha, em delineamento inteiramente casualizado, com quatro tratamentos e 15 repetições. Lagartas de D. saccharalis com 19 dias de idade foram oferecidas para fêmeas de C. flavipes, acasaladas e com 24 horas de idade, em ambos os testes. No teste com chance de escolha, utilizou-se um olfatômetro, o qual constou de quatro compartimentos, em cujo centro liberaram-se quatro fêmeas de C. flavipes, enquanto, no teste sem chance de escolha, foram utilizadas placas de Petri, no interior das quais se colocou uma lagarta de D. saccharalis, oriunda das duas condições de alimentação. Nestes testes, foi observada a percentagem de parasitismo e, continua-mente, o comportamento da primeira escolha de fêmeas de C. flavipes, em intervalos de zero a um, um a três, três a cinco, cinco a oito e de oito a dez minutos após as liberações. Lagartas de D. saccharalis, oriundas da alimentação em dieta artificial com colmos triturados dos cultivares, foram igualmente preferidas para atratividade de fêmeas do parasitoide C. flavipes. A percentagem de parasitismo de lagartas de D. saccharalis, criadas com dietas artificiais com colmos dos cultivares SP80-1042 e RB855536, foi igualmente parasitadas por C. flavipes.

Deterrência alimentar em Ascia monuste orseis Godart (Lepidoptera: Pieridae) induzida por soluções homeopáticas

A couve, Brassica oleracea var. acephala, destaca-se entre as plantas hortícolas como sendo frequentemente atacada por pragas, dentre as quais o curuquerê da couve, Ascia monuste orseis (Godart, 1819) (Lepidoptera: Pieridae). O controle desse inseto tem sido feito com inseticidas. Na agricultura orgânica, o uso dos referidos produtos é proibido e já existem alguns casos em que agricultores estão substituindo-o, por outras alternativas menos danosas ao meio ambiente, como as soluções homeopáticas, substâncias apontadas como ferramentas para Agroecologia. Este trabalho teve por objetivo verificar se soluções homeopáticas proporcionam mecanismos de antibiose, como deterrência alimentar, em Ascia monuste orseis, em couve 'manteiga cv. Santo Antônio' e se podem ser utilizadas no controle de pragas. As soluções testadas foram: - Sulphur 12CH; Phosphorus 5CH; Magnesia carbonica 30CH; Ruta 5CH. A testemunha foi água destilada + álcool de cereais 70% 5CH. Para o preparo de cada solução, foram retirados 0,2 ml de cada preparado homeopático, adicionados a 200 ml de água destilada pulverizados nas folhas e nos solo dos vasos. As características analisadas foram peso de lagartas no início e no final do 4° instar; peso seco de pupa (biomassa incorporada), comprimento de lagarta no 4° instar, duração do ciclo ovo-adulto, percentagem de emergência de adultos, comprimento alar, fecundidade das fêmeas e valor nutritivo das couves tratadas. Sulphur 12CH pode ser recomendado como método alternativo eficiente no controle de A. monuste orseis. Todas as soluções homeopáticas, com exceção do Phosphorus 5CH, promoveram deterrência alimentar, mecanismo de antibiose, interferindo no ciclo biológico de A. monuste orseis.