Flowering Dynamics and Pollinator Visitation of Oilseed Echium (Echium plantagineum)

Echium (Echium plantagineum L.) is an alternative oilseed crop in summer-wet temperate regions that provides floral resources to pollinators. Its seed oil is rich in omega-3 fatty acids, such as stearidonic acid, which is desired highly by the cosmetic industry. Seeds were sown in field plots over three years in western Minnesota in spring (early-sown) or early summer (late-sown), and flower abundance, pollinator visitation, and seed yields were studied. Initial flowering commenced 41 to 55 d after sowing, and anthesis duration (first flowering to harvest) was 34 to 70 d. Late sowing dates delayed anthesis, but increased the intensity of visitation by pollinators. Cumulative flower densities ranged from 1 to 4.5 billion ha⁻¹. Flowers attracted numerous honey bees (Apis mellifera L.), as many as 35 per minute of observation, which represented about 50% of all insect visitors. Early-sown echium produced seed yields up to 750 kg ha⁻¹, which were 2–29 times higher than those of late-sown echium. Early sowing of echium in Minnesota provides abundant floral resources for pollinators for up to two months and simultaneously produces seed yields whose profits rival those of corn (Zea mays L.).     

Fine structure of a mandibular stretch receptor in Thrips physapus L. (Thysanoptera,Insecta)

Summary Only one non-ciliary proprioceptor is developed on the mandible of Thrips. It consists of two bipolar, multiterminal sense cells, the dendrites of which form a strand extended between the tentorium and the back mandibular margin. The dendritic terminals are embedded in an electron-dense, homogeneous matrix, which obviously represents the stimulus transmitting structure. The strand is stretched, if the mandible is moved forwards and upwards. In Thrips, the system of proprioceptors monitoring the mandibular movement is reduced extensively compared with other pterygote insects. This is linked up with the far-reaching reduction of the mobility of the mandible itself.This study is dedicated to Mrs. Signe Ulmer, in memory of her winning nature, her invaluable assistance, and her disciplineSupported by a grant from the Deutsche Forschungsgemeinschaft (Ho 826/2-2)     

First Record of Elixothrips brevisetis (Bagnall) (Thysanoptera: Thripidae) in Brazil

Elixothrips brevisetis (Bagnall), a species exotic to Brazil, is first recorded in the country. Individuals were collected on banana fruits (Musa sp.) (Musaceae) in July 2010 in the municipality of Luís Alves, state of Santa Catarina, causing rusting on the fruit peel in several bunches of bananas.     

Thrips (Thysanoptera) identification using artificial neural networks

We studied the use of a supervised artificial neural network (ANN) model for semi-automated identification of 18 common European species of Thysanoptera from four genera: Aeolothrips Haliday (Aeolothripidae), Chirothrips Haliday, Dendrothrips Uzel, and Limothrips Haliday (all Thripidae). As input data, we entered 17 continuous morphometric and two qualitative two-state characters measured or determined on different parts of the thrips body (head, pronotum, forewing and ovipositor) and the sex. Our experimental data set included 498 thrips specimens. A relatively simple ANN architecture (multilayer perceptrons with a single hidden layer) enabled a 97% correct simultaneous identification of both males and females of all the 18 species in an independent test. This high reliability of classification is promising for a wider application of ANN in the practice of Thysanoptera identification.     

A New Method for Mounting Thrips (Thysanoptera) on Slides

Entomologists that frequently work with thrips often find mounting of their material by well known methods too complicated and slow. A new method is described here that is the shortest possible, and is still very reliable and safe in everyday work.     

Species of the genus Thrips from India (Thysanoptera)

Abstract. The species of Thrips Linnaeus from the Indian region are revised, and a key is provided to the thirty-three valid species, including eight new species and one new subspecies, Eight species customarily included in Taenio-thrips Amyot & Serville are here included in Thrips and six species are newly placed in synonymy: Thrips hawaiiensis (Morgan) (= Thrips exilicornis Hood from Africa); Thrips palmi Karny (= leucadophilus Priesner from Sudan); Thrips brunneus Anan. & Jaga. ( =speratus zur Strassen from South West Africa); Thrips tabaci Lind.(= kallarensis (Anan.) from India); Thrips sumatrensis Priesner (= lucaenae Moulton from Guam); Thrips simplex (Morison) (= Taeniothrips quinani Moulton from South Africa). Isoneurothrips Bagnall is regarded as a synonym of Thrips , and Isothrips is treated as a synonym rather than as a sub-genus. Two nominal species, beharensis (Ram. & Marg.) and rostratus (Ram. & Marg.) are considered unrecognizable at present.     

A Second Species of the Genus Australothrips Bagnall (Thysanoptera: Thripidae)

A second member of the Australian endemic genus Australothrips Bagnall (Thripidae: Panchaetothripinae) is described. This species, Australothrips aliceae , was found at sites near Darwin, Northern Territory on the leaves of Calytrix brownii (Myrtaceae). It is of systematic interest because it approaches in structure the members of the palaeotropical genus Phibalothrips Hood that live only on grasses.     

Resistance to Thrips palmi (Thysanoptera: Thripidae) in beans

Resistance in beans, Phaseolus vulgaris L., to the melon thrips Thrips palmi Karny was studied under field conditions at two sites in Colombia. Genotypes were rated for resistance on the basis of visual damage scores, bean production ratings (a visual estimate of pod and seed set), and grain yields. Of 1,138 genotypes tested, only 60 (5.3%) were rated as resistant. Repeated testing allowed us to identify potential sources of resistance in five germplasm accessions (G 02402, G 02852, G 03177, G 03569, and G 04055), one commercial variety ('Brunca'), six elite breeding lines (A 216, DOR 714, EMP 486, FEB 115, FEB 161, and FEB 162), 41 recombinant inbred lines derived from the BAT 881 x G 21212 cross, and seven recombinant inbred lines derived from a cross between DOR 364 and BAT 477. Resistance was not associated with maturity, growth habit, pubescence, and seed color or seed size. In general, correlations between visual damage scores and bean production ratings and between damage scores and yield were high and significant meaning that selection on damage rating is useful to identify genotypes that may have tolerance as a mechanism of resistance. The continuous distribution of damage scores of 139 recombinant inbred lines suggested that the inheritance of resistance to the melon thrips might be quantitative. Overall, resistance levels in beans can be considered as moderate, because none of the genotypes tested received damage scores of <3 on a 1-9 scale and none was ever rated as highly resistant in terms of bean production ratings.     

Polymorphic microsatellite markers in Thrips hawaiiensis (Thysanoptera: Thripidae)

Thrips hawaiiensis (Morgan, 1913) is an important insect pest of fruits and vegetables. At present, it is primarily distributed in tropical and subtropical area. For a better understanding of the genetic makeup and migration patterns of T. hawaiiensis throughout the world, we isolated 11 novel polymorphic microsatellite loci from an enriched genomic library based on a biotin/streptavidin capture protocol. Genetic parameters were estimated on 80 individual thrips from two natural populations. The results showed that all 11 loci were highly polymorphic; the number of alleles ranged from six to 37, and nine loci demonstrated polymorphic information content (PIC) > 0.5. The observed (H _O) and expected (H _E) heterozygosities ranged from 0.350 to 0.925 and 0.307 to 0.952, respectively. Furthermore, only four locus/population combinations significantly deviated from Hardy–Weinberg equilibrium (HWE). These microsatellite markers have potential utility in population structure and gene flow studies of this species.     

Metabolic profiling in Echium plantagineum: presence of bioactive pyrrolizidine alkaloids and napthoquinones from accessions across southeastern Australia

Geographically distinct populations of Paterson’s curse (Echium plantagineum L., Boragineacea), found near roadsides across New South Wales and Victoria, Australia were surveyed along 3 distinct longitudinal transects in spring of 2011 for presence of pyrrolizidine alkaloids and naphthoquinones in sampled plants. Composite samples of shoots and roots were collected from each of 45 sites; shoot extracts were subjected to solid phase extraction and LC-ESI/MS for determination of pyrrolizidine alkaloids (PAs) and related N-oxides (PANOs), while root periderm extracts were analysed for naphthoquinone content spectrophotometrically and by LC-ESI/MS. Metabolic profiling of 12 possible PAs and PANOs showed their consistent appearance in all shoot extracts, with lepthamine N-oxide, echimidine-N oxide and echumine N-oxide predominant. The three major PANOs were significantly higher in northern sampling locations than those further south. Root extracts contained shikonin and several related naphthoquinones, as well as two of the major PANOs found in the leaves. Naphthoquinones were highest in the northwest corner of the sampled region. The patterns of abundance of secondary metabolites in E. plantagienum suggest that climate change might result in greater production of defensive compounds by E. plantagineum, making this weed increasingly toxic to livestock.     

Analysis of the thrips fauna (Thysanoptera) on flowers of herbs

Studies of Thysanoptera were realized at the Agricultural Experimental Station in Mydlniki near Cracow over the years 2003-2005. This research work covers the observations of the species composition of thrips and the periods of the occurrence of the particulars species of thrips and their numerousness. The thrips were collected from flowers of Valeriana officinalis L., Hypericum perforatum L. and Levisticum officinale Koch. Following thrips species dominated samples collected directly from plants: Frankliniella intonsa (Trybom), Thrips fuscipennis Haliday, Thrips tabaci Lindeman and Thrips major Uzel. The greatest number of thrips was noticed during flowering period on Valeriana officinalis L., and Hypericum perforatum L.     

Rapid Development of Adaptive,Climate-Driven Clinal Variation in Seed Mass in the Invasive Annual Forb Echium plantagineum L.

We examined adaptive clinal variation in seed mass among populations of an invasive annual species, Echium plantagineum, in response to climatic selection. We collected seeds from 34 field populations from a 1,000 km long temperature and rainfall gradient across the species'' introduced range in south-eastern Australia. Seeds were germinated, grown to reproductive age under common glasshouse conditions, and progeny seeds were harvested and weighed. Analyses showed that seed mass was significantly related to climatic factors, with populations sourced from hotter, more arid sites producing heavier seeds than populations from cooler and wetter sites. Seed mass was not related to edaphic factors. We also found that seed mass was significantly related to both longitude and latitude with each degree of longitude west and latitude north increasing seed mass by around 2.5% and 4% on average. There was little evidence that within-population or between-population variation in seed mass varied in a systematic manner across the study region. Our findings provide compelling evidence for development of a strong cline in seed mass across the geographic range of a widespread and highly successful invasive annual forb. Since large seed mass is known to provide reproductive assurance for plants in arid environments, our results support the hypothesis that the fitness and range potential of invasive species can increase as a result of genetic divergence of populations along broad climatic gradients. In E. plantagineum population-level differentiation has occurred in 150 years or less, indicating that the adaptation process can be rapid.     

Population dynamics of banded thrips (Aeolothrips intermedius Bagnall, Thysanoptera, Aeolothripidae) and its potential prey Thysanoptera species on white clover

In 2002, the occurrence of banded thrips (Aeolothrips intermedius Bagnall) and some other Thysanoptera species on white clover (Trifolium repens L.) was monitored at two locations in the continental part of Slovenia. White clover presents in many countries important intercrop in integrated vegetable production. Light blue sticky boards were placed on grasslands (one parcel on each location) with high percentage of white clover. Sticky boards were changed in about 10-days intervals from the end of April till the beginning of October. Number of caught individuals on the boards was counted. They were classified in three different groups: 1. Aeolothrips intermedius, 2. representatives of Haplothrips, Odontothrips and Frankliniella genera, 3. representatives of Thrips genus. We stated that, compared with the other Thysanoptera species in the open, predatory thrips occurs in lower number. Predatory species Aeolothrips intermedius was the most numerous during the flowering of white clover. It was established that other Thysanoptera species (the most of them are facultative phytophagous species) were more numerous also in the periods of less favourable weather conditions and during the non-flowering growing stages of white clover. Based on the results of present research we concluded that A. intermedius has a potential to control onion thrips (Thrips tabaci Lindeman), especially in July and August, when in the open both species occur in high numbers.     

The Thrips orientalis group from South-east Asia and Australia: some species identities and relationships (Thysanoptera, Thripidae)

Abstract  A thrips associated in Thailand with the flowers of Paederia foetida , a rubiaceous weed in Florida that is a threat to Australia, is here recognised as Thrips morindae Priesner, a species previously considered a synonym of T. javanicus Priesner. Systematic relationships of these species with others in South-east Asia and the Australasian region are discussed. Two new species-groups are designated: the T. obscuratus group of six species from New Zealand and New Caledonia, and the T. orientalis group of 12 South-east Asian species that are associated with scented white flowers such as Gardenia . Four species of this second group are recorded from tropical Australia.     

A Trichodorus (Triplonchida: Trichodoridae) Nematode from Thrips (Thysanoptera: Panchaetothripinae)

A thrips insect Caliothrips sp. (Thysanoptera: Panchaetothripinae) from persimmon fruit (Ebenaceae: Diospyros sp.) from an unknown origin, possibly Asia, was intercepted in a passenger bag in November 2012 at the Peace Arch Border Crossing from Canada to Blaine, WA, by a USDA-APHIS-PPQ port inspector. Nematodes were attached to the abdomen of the female insect and sent to us in saline. Seven nematodes (five females, two males) were measured and these and others were processed for permanent slides. An adult female and a female juvenile were prepared for PCR. Morphologically these nematodes belonged to the Trichodorus sparsus group, and the 28S rDNA D2-D3 sequence showed greatest similarity to Trichodorus paragiennensis (94%) and T. giennensis (93%), with greatest morphological similarity to the latter species. Among other morphological differences, the innermost uterus width is wider than in related species. Trichodorus spp. are normally found in soil, so this is the first population seen in the atypical habitat of an insect. Morphological and molecular characteristics of Trichodorus sp. are presented, but a putative new species name is not currently advisable because of relatively poor condition of specimens. Ecological associations are also discussed.     

Transmission of capsicum chlorosis virus by Thrips palmi (Thysanoptera: Thripidae)

Applied Entomology and Zoology - Transmission efficiencies of capsicum chlorosis virus (CaCV) were investigated for four thrips species (Thysanoptera: Thripidae), Frankliniella occidentalis...