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Desert ecosystems are currently threatened by human activities resulting in the rapid decline of xerophytic plants and specialized fauna. In South America, the demise of cactus species already resulted in the population decline of > 30% of the iconic giant columnar cactus Trichocereus terscheckii. The increasing vulnerability of these keystone species could trigger a cascade of secondary extinctions in highly dependent organisms. Thus, necrotic cacti constitute an important habitat for desert arthropods, yet little is known on the hidden diversity of this neglected niche. We used DNA barcode techniques to survey the diversity of arthropods in a threatened cactus forest dominated by T. terscheckii in northwestern Argentina. We obtained a total of 542 mitochondrial barcode sequences, resulting in 323 Molecular Taxonomic Units (MOTUs) associated to the xerophytic forest and 21 MOTUs exclusive to the giant cactus necrosis. Our results indicated that the area is a biodiversity hotspot within the harsh Andean desert and suggests that nearly 30 species could occur in the decaying cactus, representing the highest richness of cactophilic arthropods recorded in any cactus on the continent to date (6 orders and 16 families). The community structure of cactophilic arthropods showed a phylogenetic clustering pattern, suggesting the coexistence of closely related species. Overall, our study indicates that the giant cactus necrosis sustains a particular phylogenetic diversity of desert arthropods, while demonstrating the efficacy of DNA barcodes for biodiversity assessments in complex and poorly understood ecological systems. [ABSTRACT FROM AUTHOR]

Plant resistance is a key strategy for the management of Oryzophagus oryzae (Costa Lima) (Coleoptera: Curculionidae), an important pest in South American rice paddies. The present study investigated the resistance of rice cultivars in terms of feeding and oviposition preference, growth, development, and biological performance of O. oryzae under natural conditions of field infestation during two consecutive rice seasons. There were no effects of the six cultivars on the feeding and oviposition preferences of O. oryzae as evaluated 5, 8, and 11 d After Flooding (DAF) of the plots, indicating the absence of antixenosis. Cultivars did not differ in terms of egg viability and larval density of first instars on the roots at 15 DAF. Significant differences were found 25 and 35 DAF when larval density per sample was high on 'BRS Pampa CL' (up to 24.5), intermediate on 'BRS Querência' and 'BRS Ligeirinho' (up to 16.1), and low on 'BRS Atalanta', 'BRS Firmeza', and 'Dawn' (up to 8.8). The cultivars 'BRS Atalanta', 'BRS Firmeza', and 'Dawn' caused malnutrition and inhibition of larval growth. These effects, typical of antibiosis, resulted in delayed pupation and emergence of adults; in addition, emerged females had body weight decreased strongly. The cultivars BRS Pampa CL, BRS Querência, and BRS Ligeirinho are susceptible, resulting in high larval populations and more suitable development of O. oryzae; antibiosis, as indicated for 'BRS Atalanta', 'BRS Firmeza', and 'Dawn', probably is the key mechanism of rice resistance to O. oryzae. Graphical Abstract [ABSTRACT FROM AUTHOR]

The genus Eois Hübner (Geometridae: Larentiinae) comprises 254 valid species, 217 of which were described from the Neotropics and 31 of those having their type locality in Brazil. Since this species rich genus has never been revised, and may potentially include many cryptic undescribed species, Eois embodies a problematic taxonomic scenario. The actual diversity of Eois is greatly underestimated and the Brazilian fauna is poorly known, both because of inadequate sampling and because of the potential existence of cryptic species "hidden" within some nominal taxa. In this study we investigated the diversity within a cryptic species complexes associated to the E. pallidicosta and E. odatis clades. We describe three new species Eois oya Moraes & Montebello sp. nov., Eois ewa Moraes & Stanton sp. nov., and Eois oxum Moraes & Freitas sp. nov., in an integrative taxonomy approach, using morphology, host plant use and species delimitation tools.

The genus Eois Hübner (Geometridae: Larentiinae) comprises 254 valid species, 217 of which were described from the Neotropics and 31 of those having their type locality in Brazil. Since this species rich genus has never been revised, and may potentially include many cryptic undescribed species, Eois embodies a problematic taxonomic scenario. The actual diversity of Eois is greatly underestimated and the Brazilian fauna is poorly known, both because of inadequate sampling and because of the potential existence of cryptic species "hidden" within some nominal taxa. In this study we investigated the diversity within a cryptic species complexes associated to the E. pallidicosta and E. odatis clades. We describe three new species Eois oya Moraes & Montebello sp. nov., Eois ewa Moraes & Stanton sp. nov., and Eois oxum Moraes & Freitas sp. nov., in an integrative taxonomy approach, using morphology, host plant use and species delimitation tools. [ABSTRACT FROM AUTHOR]

Insect species richness is estimated to exceed three million species, of which roughly half is herbivorous. Despite the vast number of species and varied life histories, the proportion of herbivorous species among plant-consuming organisms is lower than it could be due to constraints that impose limits to their diversification. These include ecological factors, such as vague interspecific competition; anatomical and physiological limits, such as neural limits and inability of handling a wide range of plant allelochemicals; phylogenetic constraints, like niche conservatism; and most importantly, a low level of concerted genetic variation necessary to a phyletic conversion. It is suggested that diversification ultimately depends on what we call the intrinsic trend of diversification of the insect genome. In support of the above, we survey the major types of host-specificity, the mechanisms and constraints of host specialization, possible pathways of speciation, and hypotheses concerning insect diversification. [ABSTRACT FROM AUTHOR]

Long-term studies (2012-2018) of the formation of the Rhopalosiphum padi (L.) heteroecious population (number of remigrants, oviparae and eggs in autumn, number of perished eggs, fundatrices larvae, timing of flight of emigrants in spring) on the two samples of primary host Padus avium Mill. and P. avium x P. virginiana (L.) characterized by various morpho-physiological features have been carried out. By the methods of mathematical statistics, it has been proved that this formation occurs under the significant influence of the year conditions (A), host plant characteristics (B) and these factors interaction (AB). The most visible was their highly significant impact on the number of wintering aphid eggs (A = 200.42; B = 142.6; AB = 25.612). Plant characteristics such as significantly larger leaf area from the middle part of the shoot on P. avium x P. virginiana, than on P. avium (t = 8.37; p0.01 = 2.85) was important for attracting remigrants and the prone buds on P. avium x P. virginiana - for oviposition and survival of eggs. Correlation between the period of leaf fall and number of aphid eggs on both bird-cherry samples is presented. The effect of weather conditions on R. padi and primary hosts relationships is discussed. Correlation (r = 0.76; p = 0.0048) between average temperature of October and eggs number on P. avium is given. R. fundatrices. [ABSTRACT FROM AUTHOR]

Copyright of Ecologia Mediterranea is the property of Ecologia Mediterranea and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Climate change is expected to have significant and complex impacts on ecological communities. In addition to direct effects of climate on species, there can also be indirect effects through an intermediary species, such as in host–plant interactions. Indirect effects are expected to be more pronounced in alpine environments because these ecosystems are sensitive to temperature changes and there are limited areas for migration of both species (i.e. closed systems), and because of simpler trophic interactions. We tested the hypothesis that climate change will reduce the range of an alpine butterfly (Parnassius smintheus) because of indirect effects through its host plant (Sedum sp.). To test for direct and indirect effects, we used the simulations of climate change to assess the distribution of P. smintheus with and without Sedum sp. We also compared the projected ranges of P. smintheus to four other butterfly species that are found in the alpine, but that are generalists feeding on many plant genera. We found that P. smintheus gained distributional area in climate‐only models, but these gains were significantly reduced with the inclusion of Sedum sp. and in dry‐climate scenarios which resulted in a reduction in net area. When compared to the more generalist butterfly species, P. smintheus exhibited the largest loss in suitable habitat. Our findings support the importance of including indirect effects in modelling species distributions in response to climate change. We highlight the potentially large and still neglected impacts climate change can have on the trophic structure of communities, which can lead to significant losses of biodiversity. In the future, communities will continue to favour species that are generalists as climate change induces asynchronies in the migration of species. [ABSTRACT FROM AUTHOR]

We examine the genetics, morphology and ecology of the widely distributed Megachile concinna species complex (Hymenoptera: Megachilidae), which is composed of numerous taxa of unclear taxonomic status in Africa and the Palearctic. In the Western Palearctic, three genetically distinct operational taxonomic units (OTUs) are found around the Mediterranean Sea: the western Mediterranean OTU M. pusilla, the eastern Mediterranean OTU M. anatolica and the predominantly Arabian OTU M. leucostoma. A morphological cline is present between anatolica and leucostoma in the Near East, despite a lack of mitochondrial introgression between the two; one nuclear marker suggests some gene flow between these OTUs. The contact zone between pusilla and leucostoma could not be sampled but phenotypic intergradation is also observed between these OTUs in northern Africa. In contrast, study of the contact zone between pusilla and anatolica indicates that both OTUs retain phenotypic and genomic integrity in sympatry over a contact zone spanning 1000 km. The arrangement of these three OTUs suggests a ring of interconnected populations around the Mediterranean Sea and sympatry between pusilla and anatolica at both ends of the ring in southeastern Europe. The latter two OTUs exhibit ecological differences, including phenology and host-plant preferences, which may contribute to their isolation. In addition, our results suggest that two OTUs, M. venusta and M. concinna, maintain genetic and phenotypic integrity in sympatry in parts of Africa; the latter is recognized as a valid species here. Lastly, our results indicate that two OTUs have been introduced independently into the New World, pusilla in North America and Argentina, and concinna in the Antilles. [ABSTRACT FROM AUTHOR]

The introduced beetle Ophraella communa was first found in 1996 in Japan and has rapidly expanded its distribution to include regions that encompass a wide range of latitude and altitude and are dominated by different host-plants. In this study, we investigated geographic variation in its photoperiodic response for the induction of reproductive diapause, with which the beetle adjusts its life cycle to local climate and host-plant phenology. The beetle lines were collected from 18 sites in Japan. The diapause incidence under a photoperiodic condition of 13 h light : 11 h dark (LD 13:11) and the critical day length differed among the beetle lines. Analysis with the generalized linear model showed that latitude, altitude and host-plant species ( Ambrosia artemisiifolia vs. Ambrosia trifida) had significant effects on diapause incidence under LD 13:11. These results suggest that the O. communa populations have rapidly adapted to local environmental conditions after their colonization. However, the photoperiodic response of the O. communa population in Tomakomai, the northernmost part of its distribution range in Japan, deviated significantly from the general trend. We suggest that this deviation is attributed to either: (i) that this beetle has colonized Tomakomai more recently compared to the other sites; or (ii) that the Tomakomai population has adapted to local environments in a different way from other populations. [ABSTRACT FROM AUTHOR]

Com o objetivo de estabelecer a duração do desenvolvimento pós-embrionário e dos instares, foram coletados ovos de Anteos menippe em folhas de Cassia ferruginea e levados ao laboratório para o registro das datas das ecdises. O desenvolvimento pós-embrionário durou (média ± erro-padrão) 25,7 ± 0,4 dias. O período larval (15,9 ± 0,3 dias) representou 61,7% do desenvolvimento e contou com cinco instares: L1= 2,2 ± 0,1; L2= 1,7 ± 0,2; L3= 2,0 ± 0,1; L4= 3,4 ± 0,1 e L5= 6,4 ± 0,3. Este último ínstar contou com uma fase ativa (5,4 ± 0,3 dias) e prepupa (1 dia). O período pupal foi de 9,9 ± 0,2 dias. O período de inatividade (prepupa + pupa) foi de 10,9 ± 0,2 dias representando 42,2% do desenvolvimento pós-embrionário, sendo o período ativo (larval ativo) 57,8% do desenvolvimento. A viabilidade de ovos foi de 91,6% e a sobrevivência, a partir do número de lagartas neonatas foi de 59,8%.In order to determine the duration of the post-embryonic development and its instars, eggs of Anteos menippe were collected from Cassia ferruginea leaves and were taken into the laboratory to register the dates of ecdysis. The post-embryonic development was (in days average ± standard error) 25.7 ± 0.4, the larval period 15.9 ± 0.3 represented 61.7% of the development and had five instars: L1 = 2.2 ± 0.1, L2 = 1.7 ± 0.2, L3 = 2.0 ± 0.1, L4 = 3.4 ± 0.1 and L5 = 6.4 ± 0.3. This last instar had an active phase (5.4 ± 0.3) and a prepupal phase (1 day long). The pupal period was 9.9 ± 0.2. The inactivity period (prepupa + pupa) 10.9 ± 0.2 days represented 42.2% of the post-embryonic development, and the active phase 57.8%. The egg viability was 91.6% and the survival, starting from neonate larvae, was 59.8%.

O conhecimento científico sobre a associação de Thysanoptera com plantas nativas ou cultivadas na região Neotropical é praticamente inexistente. Este trabalho objetivou identificar as espécies de tripes e as plantas por eles visitadas ou utilizadas como hospedeiras em uma unidade de conservação, o Parque Estadual de Itapuã (30°22'S 51°02'W), Viamão, Rio Grande do Sul, Brasil. Entre junho de 1999 e maio de 2001, ramos (n=1.274), flores (n=774) e touceiras de gramíneas (n=596) foram sistematicamente amostradas em 20 pontos em quatro transectos estandardizados. O total de 72 espécies de plantas pertencentes a 26 famílias foram identificadas, 60 das quais foram registradas como hospedeiras. Do total de 9.602 espécimes de tripes, 4.900 (50%) foram registrados em flores, 3.764 (39%) em ramos e 938 (10%) nas touceiras de gramíneas. Para 6.533 dos espécimes (4.480 imaturos e 2.053 adultos), foi possível identificar a planta na qual foram coletados. De uma riqueza total de 61 espécies de tripes, 35 foram registradas em flores, 36 em ramos e 14 em touceiras de gramíneas. As espécies de tripes mais abundantes e as plantas que apresentaram a mais alta diversidade de tripes são comentadas.The scientific knowledge about the association of Thysanoptera with native or cultivated plants in the Neotropical region is practically nonentity. This work aimed at identifying the thrips species and the plants visited by them or used as hosts in a Conservation Unit, the "Parque Estadual de Itapuã" (30°22'S 51°02'W), Viamão, Rio Grande do Sul, Southern Brazil. Between June 1999 and May 2001, branches (n=1,274), flowers (n=774) and grass tussocks (n=596) were systematically sampled at 20 points in four standardized transects. A total of 72 plant species belonging to 26 families were identified, 60 of those were registered as host plants. From a total of 9,602 thrips specimens, 4,900 (50%) were registered in flowers, 3,764 (39%) in branches and 938 (10%) in grass tussocks. For 6,533 of the specimens (4,480 immatures and 2,053 adults), it was possible to identify the plant on which they were collected. Of a total richness of 61 species of thrips, 35 were recorded in flowers, 36 in branches and 14 in grass tussocks. The most abundant thrips species and the plant species that showed the higher thrips diversity are commented upon.

Two new species (Hemiptera, Fulgoromorpha, Cixiidae) included in a new genus, Meenocixius gen. n., and associated with Acanthophœnix rubra (Bory) H. Wendl. (Arecaceae) are described from the island of La Réunion: M. bebourensis sp. n. and M. virescens sp. n. This genus shows several autapomorphies in its tegmina venation, very particular within the Fulgoromorpha. Borbonomyndus gen. n., is proposed for another new species, B. pandanicola sp. n. associated with Pandanus purpurascens Thouars (Pandanaceae), and B. pallidus (Synave), previously described as a member of the genus Eumyndus Synave. According to morphological and ethological data, E. bistriatus is synonymized with B. pallidus, of which three different forms are recognized. All species of Borbonomyndus are found associated with Pandanus. These two new genera are endemic to La Réunion. Without taxonomic standing, the subspecies of Brixia belouvensis are synonymyzed and restricted to four different forms. A key is proposed for the Cixiidae of La Réunion, which now includes 12 species belonging to 6 different genera: Achaemenes, Aselgeoides, Brixia, Oliarus (but we show that the species placed in this genus need to be reviewed), Borbonomyndus, and Meenocixius. Monophyly of Eumyndus, from which E. perinetensis Synave is excluded, is substantiated. Following the new interpretation, this genus is now restricted to Madagascar. The species Cubana insularis Muir, from the island of Rodrigues, is transferred to a new genus: Achaebana gen. n. Finally, cixiid endemism and their host-plant associations in the Mascarenes are discussed.

The biology of the gram blue butterfly, Euchrysops cnejus (Fabricius) (Lycaenidae: Lapidoptera) and its relationship with the phenology of host plant cowpea, Vigna unguiculata L. (Fabaceae) were studied. Eggs were reared under the laboratory conditions at 28 ± 2°C and 74 ± 3% RH. The incubation period of the eggs found to be 2.33 ± 0.51 days, larval developmental period 14.65 ± 0.51 days, pre-pupal period 0.30 ± 0.04 day and pupal period 5.66 ± 0.51 days. The species took 22.94 ± 0.55 days for development from egg to adult under the laboratory condition. The length of 1st, 2nd, 3rd and 4th instar larvae was 3.66 ± 0.40, 6.16 ± 0.51, 12.16 ± 0.51 and 15.33 ± 0.40 mm, respectively. The pre-pupal length was 9.16 ± 0.61 mm and the pupal length was 9.08 ± 0.37 mm. The host-plant occurs in the field from February to July. The butterfly appeared in March. The coincidence of the gram blue butterfly to its host-plant occurred between April and early July. The oviposition behaviour, incubation and immature stages were found to be profoundly related with host plant-phenological phases. [ABSTRACT FROM AUTHOR]

Global analyses of interspecific interactions are rapidly increasing our understanding of patterns and processes at large scales. Understanding how biodiversity assembles and functions on a global scale will increasingly require analyses of complex interactions at different ecological and phylogenetic levels. We present an analysis of host-plant associations in the sap-sucking Psylloidea (∼3,800 species) using the most comprehensive assemblage of host data for this group compiled from 66 % of published records. Psyllids are known for high levels of host specificity and host switching between related plants at local scales, but a global survey implicates historical processes that are not entirely consistent with those at local scales. In particular, saltationary host switching events appear to have been a key factor explaining the wide but patchy distribution of psyllid host-plants throughout the angiosperm phylogeny. Alternative explanations involving co-diversification with subsequent extinction seem implausible. At the seed plant family level, we compare associations for psyllids with those of their relatives the aphids, but, despite notable differences in biogeographic distributions, find few plant families (2%) that host only psyllids but not aphids, while a much larger percentage (31%) host aphids but not psyllids, and 43% of plant families distributed throughout the plant phylogeny host neither group. [ABSTRACT FROM PUBLISHER]

Apportations to the knowledge of coloration patterns of Sinopla perpunctatus Signoret are given, illustrated and discussed. A new association with a plant from the complex Chusquea culeou E. Desvaux (Poaceae: Bambusoideae), is mentioned and discussed. A review of the distribution known for this species in Argentina and Chile is included. [ABSTRACT FROM AUTHOR]

Whiteflies (Aleyrodidae) are major pests of crops in southwestern Nigeria, yet there is scanty information on diversity and distribution of these economic species. Therefore, a study of diversity and distribution of whitefly fauna was carried out in southwestern Nigeria in wet and dry seasons, between May 2007 and June 2012. Whiteflies were collected on crops and ornamental plants from 22 sampling sites, within the six states. Aleurodicus dispersus Russel (Aleurodicinae) was the most distributed species of whiteflies on crops and ornamental plants. It was recorded in all the sampling sites and on 45 different families of plants in the region. Whiteflies were most diverse in the rainforest zone than any other zone in the region. The cosmopolitan Aleurocanthus woglumi Ashby (Aleyrodinae) infested plants in the family Rutaceae more than any other species of whiteflies in the region. Citrus species was observed to host larger population of whiteflies than any other crop in the study area. Plant family, Euphorbiaceae, hosted the largest number of whiteflies (14 out of 35 whitefly species). [ABSTRACT FROM AUTHOR]

Five gall midges species (Diptera: Cecidomyiidae) are recorded for the first time in Pirenópolis (Goiás, Brazil, Cerrado biome): Contarinia gemmae, Lopesia caulinaris, L. conspicua, and L. elliptica, as well as an unidentified species of Cecidomyiidae, causative agent of marginal leaf galls. All of these species are associated with Calophyllum brasiliense (Calophyllaceae). Previous records included only Southern Brazil and now, the geographic distribution of these species is widened to the Midwest Region. [ABSTRACT FROM AUTHOR]

Seven species of Scolytodes (tribe Ctenophorini) are described as new to science: S. concavus and S. circumsetosus (from Ficus branches, La Selva), S. montanus (Monteverde), S. nudifrons (Las Cruces near San Vito), and S. triangulus (fogging sample, La Selva), all from Costa Rica, and S. ungulatus (Cerro Punta) and S. punctifrons (from Astronium graveolens, Canal Zone), both from Panama. New distributional and host plant data are given for the following species: S. amoenus (Ficus branch, La Selva, and the first record south of Mexico), S. immanis (Cerro de La Muerte), S. impressus (Xylopia branch, Peninsula de Osa), S. ochromae (Ochroma branch, La Selva), S. piceus (fogging sample, La Selva, the first low altitude record), and S. swieteniae (fogging sample, La Selva and Braulio Carrillo, the first exact locality data), all from Costa Rica, and S. nanellus (Barro Colorado Island) from Panama.

Most crop pests find a suitable host through chemical cues released from plants, but little is known about the odorscape encountered by host-seeking gravid females under natural, outdoor conditions. In this field study, the volatile organic compound (VOC) composition of maize ( Zea mays, L.), a host for the European corn borer (ECB) ( Ostrinia nubilalis Hüb.) was characterized during the oviposition flight and compared with a forest odorscape. VOCs from maize fields and the forest atmosphere were collected by solid phase microextraction and characterized by gas chromatography-mass spectrometry. The electroantennographic (EAG) response of female ECB antennae to candidate VOCs was tested. Analyses revealed clear differences between the maize field and the forest odorscapes, mainly composed of ubiquitous VOCs but in specific ratios. The maize field odorscape is more complex than the forest odorscape for maize found 18 VOCs but only eight in the forest. Both biotopes shared seven VOCs-green leaf volatiles (GLV), monoterpènes (MT) and homoterpenes. In addition, we found in the forest a distinctive sesquiterpene (SQT) identified as isoledene. The highest EAG responses were elicited by two GLVs and a MT shared by the two biotopes. SQT elicited weak EAG responses, except β-farnesene, only found in the maize field odorscape. Our results suggest that the two biotopes produce specific chemical signatures that insects may use as host cues. To the best of our knowledge this paper is the first report on the maize odorscapes under field conditions. The putative role of the VOCs in host plant detection and selection is discussed. [ABSTRACT FROM AUTHOR]

Evolutionary and biological patterns can be obscured by inadequate or ill-defined terminology. An example is the generally very specific relationship between the sap-feeding hemipteran group, psyllids, and their breeding plants, commonly called host-plants. The literature is clogged with references to so called 'hosts', which are often merely plants on which psyllids were found accidentally, and no immature development was detected. Recently the term host has also been applied by some authors to any plant on which immature or adults feed. Here we propose a terminology to clarify associated plant definitions, and we suggest restricting the use of the term host-plant to plants on which a psyllid species completes its immature to adult life cycle. For the other plant associations we suggest the terms overwintering or shelter plant (plants on which adult psyllids overwinter and on which they may feed), food plant (plants on which adult psyllids feed, but do not breed and do not spend an extended period of time) and casual plant (plants on which adult psyllids land but do not feed). [ABSTRACT FROM AUTHOR]

Precise studies on the structure and behavior of thrips can be particularly difficult, due to their small size and restless behavior. As a result, many "host-plant" records are no more than casual "finding places" with limited biological significance. Definitions of "host-plant" are complicated by situations where a plant species provides an important feeding or behavioral resource, but is not used for breeding. Similarly, failure to clearly define some structures on a thrips body, often due to inadequate technical and microscopy skills, can lead to faulty interpretation of species identities and evolutionary relationships. This article re-examines some of these problems. [ABSTRACT FROM AUTHOR]

1. Biological invasions bring together formerly isolated insect taxa and allow the study of ecological interactions between species with no coevolutionary history. Among polyphagous insects, such species may competitively exclude each other unless some form of niche partitioning allows them to coexist. 2. In the present study, we investigate whether the ability to exploit different fruits can increase the likelihood of coexistence of four species of polyphagous Tephritidae, one endemic and three successive invaders, in the island of La Réunion. In the laboratory, we studied the performances of all four species on the four most abundant fruit resources in the island, as well as the relative abundances of fly species on these four fruit species in the field. We observe no indication of niche partitioning for any of the four abundant fruits. 3. Analyses of an extensive field data series suggest that: (i) the four fly species largely overlap in fruit exploitation, once climatic effects are accounted for; (ii) however, one species ( Ceratitis capitata) can exploit rare fruit species that are not exploited by others present in the same climatic niche; and (iii) the endemic species C. catoirii, now nearly extinct in La Réunion, has no private niche with respect to either climatic range or fruit use. 4. On the whole, with the possible exception of C. capitata, the results point to a limited role of fruit diversity in encouraging coexistence among polyphagous tephritids recently brought into contact by accidental introductions. [ABSTRACT FROM AUTHOR]

In the Midwestern United States, more than 99.99% of pre-settlement oak (Quercus) savanna has been lost due to agriculture and fire suppression. Thus, the restoration of this ecosystem is imperative to secure the biodiversity, which depends on oak savanna. In this study, we characterized factors affecting the host-plant quality and nectar use of the endangered Karner blue butterfly (Lycaeides melissa samuelis Nabokov) in Ohio. Past research has shown butterfly abundance to be correlated with host-plant quantity, habitat area, and nectar plant abundance. However, there is growing recognition that host-plant quality is important at small spatial scales. We measured host-plant quality by quantifying leaf nitrogen content for the first larval brood and a PCA analysis of nitrogen and water content for the second larval brood. Additionally, observations quantified adult female foraging rates. Our results for the first brood larval stage found no significant difference in leaf nitrogen between burned, mowed, and unmanaged treatments. We used Akaike's Information Criteria (AIC) to determine that host-plant quality for the second brood was primarily explained by herbaceous vegetation density followed by canopy cover and aspect. Greater herbaceous vegetation density, greater canopy cover, and flat/north aspects were associated with higher quality host-plants. Lower host-plant nitrogen for the second brood was accompanied by a greater adult foraging rate. Management of Karner blue habitats should include restoring areas with a compatible herbaceous structure and increasing historically abundant forbs, which provide nectar to second brood Karner blues. This ecosystem-based management should positively impact many species in this rare oak savanna community. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Protection Research is the property of Institute of Plant Protection and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper we demonstrate a UV-B-mediated link between host plants, herbivores and their parasitoids, using a model system consisting of a host plant Brassica oleracea, a herbivore Plutella xylostella and its parasitoid Cotesia plutellae. Ultraviolet-B radiation (UV-B) is a potent elicitor of a variety of changes in the chemistry, morphology and physiology of plants and animals. Recent studies have demonstrated that common signals, such as jasmonic acid (JA), play important roles in the mechanisms by which plants respond to UV-B and to damage by herbivores. Plant responses elicited by UV-B radiation can affect the choices of ovipositing female insects and the fitness of their offspring. This leads to the prediction that, in plants, the changes induced as a consequence of UV damage will be similar to those elicited in response to insect damage, including knock-on effects upon the next trophic level, predators. In our trials female P. xylostella oviposited preferentially on host plants grown in depleted UV-B conditions, while their larvae preferred to feed on tissues from UV-depleted regimes over those from UV-supplemented ones. Larval feeding patterns on UV-supplemented tissues met the predictions of models which propose that induced defences in plants should disperse herbivory; feeding scars were significantly smaller and more numerous – though not significantly so – than those on host plant leaves grown in UV-depleted conditions. Most importantly, female parasitoids also showed a clear pattern of preference when given the choice between host plants and attendant larvae from the different UV regimes; however, in the case of the female parasitoids, the choice was in favour of potential hosts foraging on UV-supplemented tissues. This study demonstrates the potential for UV-B to elicit a variety of interactions between trophic levels, most likely mediated through effects upon host plant chemistry. [ABSTRACT FROM AUTHOR]

The occurrence of thrips vectors in considerable numbers enables their functioning in a dual role as vectors and as direct crop pests. The resistance of thrips to pesticides has enabled quick transmission of viruses, the transient nature of their populations being essentially responsible for the infection. The feeding behaviour of thrips contributes in a large measure towards their ability to act as vectors, enabling leaf-to-leaf transmission of the tospoviruses. The specific association of the tospoviruses and thrips vectors, particularly relating to the molecular profiles, needs increasing scrutiny to come to proper conclusions. A better understanding of the nature of virus multiplication and the pathways leading to their entry into the salivary glands and the ability of the second instar larvae to inoculate plants need further inputs. The intraspecific diversity of thrips vectors as a result of population studies from various parts of the country, would further enable a better understanding of the ability of each species to transfer the virus, besides better appreciation of the chemical ecology of thrips-host-plant interaction, not to mention the relevance of serodiagnosis in detecting disease or health. [ABSTRACT FROM AUTHOR]

The European grapevine moth, Lobesia botrana (Lepidoptera: Tortricidae), is a polyphagous insect able to develop on grapes and wild plants. We tested the hypothesis that the parasitoid Dibrachys cavus (Hymenoptera: Pteromalidae) uses the larval frass in its host search. A two-armed olfactometer was used to measure the attractiveness of L. botrana larvae, their silk, or their frass after larvae were fed on different host plants. Frass of three Lepidoptera ( L. botrana, Eupoecillia ambiguella, Sphinx ligustri) and one Orthoptera ( Chorthippus brunneus) was assayed, but only L. botrana was used to test an effect of the larval host plant (two grape cultivars and three other plant species) to D. cavus females. Larvae without frass did not attract D. cavus whatever their origin, but their frass was attractive at a dose of 2–3 days equivalent of larval frass production. The silk produced by a single larva ( L. botrana) was not attractive to D. cavus. The parasitoid was most attracted to the odor of S. ligustri; the frass of L. botrana was more attractive than that of E. ambiguella, irrespective of the species on which D. cavus had been reared. There was no difference in attractiveness of frass collected from L. botrana raised on food containing different plants. Chemical extracts using five different polarity solvents (acetone, dichloromethane, hexane, methanol, and water) differed in attractiveness to D. cavus. Water and dichloromethane were the most attractive. This suggests that a complex volatile signal made from intermediate to polar volatiles may be involved in attraction. D. cavus used frass to discriminate between different potential host species. Our results revealed that the larval food of L. botrana did not modify frass attractiveness, but that the moth species did. [ABSTRACT FROM AUTHOR]

Plant resistance is a key strategy for the management of Oryzophagus oryzae (Costa Lima) (Coleoptera: Curculionidae), an important pest in South American rice paddies. The present study investigated the resistance of rice cultivars in terms of feeding and oviposition preference, growth, development, and biological performance of O. oryzae under natural conditions of field infestation during two consecutive rice seasons. There were no effects of the six cultivars on the feeding and oviposition preferences of O. oryzae as evaluated 5, 8, and 11 d After Flooding (DAF) of the plots, indicating the absence of antixenosis. Cultivars did not differ in terms of egg viability and larval density of first instars on the roots at 15 DAF. Significant differences were found 25 and 35 DAF when larval density per sample was high on 'BRS Pampa CL' (up to 24.5), intermediate on 'BRS Querência' and 'BRS Ligeirinho' (up to 16.1), and low on 'BRS Atalanta', 'BRS Firmeza', and 'Dawn' (up to 8.8). The cultivars 'BRS Atalanta', 'BRS Firmeza', and 'Dawn' caused malnutrition and inhibition of larval growth. These effects, typical of antibiosis, resulted in delayed pupation and emergence of adults; in addition, emerged females had body weight decreased strongly. The cultivars BRS Pampa CL, BRS Querência, and BRS Ligeirinho are susceptible, resulting in high larval populations and more suitable development of O. oryzae; antibiosis, as indicated for 'BRS Atalanta', 'BRS Firmeza', and 'Dawn', probably is the key mechanism of rice resistance to O. oryzae., (© The Author(s) 2022. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)