Thrips from the genus Frankliniella (Thysanoptera, Thripidae) are phytophagous on crops and wild plants. Some of them cause slight economic damage, however, others including F. occidentalis and F. intonsa are responsible for considerable losses in crop production. Moreover, they constitute a double threat for host plants by not only feeding on them but also vectoring viruses, some of which are on the quarantined list of the European Plant Protection Organization. The rapid detection and differentiation between more and less harmful Frankliniella species is, therefore, important in order to combat the pests at the time of their appearance. In this study, we have undertaken to develop a method of detecting F. occidentalis, F. intonsa, F. pallida, and F. tenuicornis. The protocol is based on PCR amplification of ITS1 rDNA fragments of these insects using universal primers pair giving products of slightly distinct length for studied insects. Restriction enzymes digestion which is easy to interpret, allows for visible differentiation of all these Frankliniella species. The method was shown to be species-specific and sensitive. Even single specimens in either the larvae or adult stage could be distinguished.
The mangosteen international standard for export requires fruit free from scar. This was the most constraining issue for the Indonesian export of mangosteen. Thrips are pests which cause scars on mangosteen fruits. Hence, there is an inevitable need to control the thrips population. This research was aimed at identifying the thrips pest that causes scars on the mangosteen fruit. This project was also aimed at studying the effects of using yellow fluorescent sticky trap (YST), and the combination treatment: YST and intensive orchard care (YST+IOC) on the percentage and intensity of fruit scars caused by thrips. The research was conducted at a farm with a polycultured mangosteen orchard in Lima Puluh Kota, West Sumatra, Indonesia. It was conducted during the two fruit seasons from September 2006 to February 2007, and from October 2007 to February 2008. The results showed that there were two species of thrips pests that are associated with the mangosteen: Scirtothrips dorsalis (Hood) and Selenothrips rubrocintus Giard. All of the treatments gave significant differences in decreasing the percentage and intensity of scars. These differences were significantly different compared to the control group in the first year as well as in second year. The combined treatment of YST+IOC proved to have the best results in reducing the percentage (41.19% and 43.96%) and intensity of scars (32.14% and 15.81%) in the first year as well as in the second year, respectively.
The studies were carried out in Wielkopolska region (western Poland) in oat and winter rye cultures. Density and species structure of Thysanoptera were studied. Average density of adult Thysanoptera on oat reached 371.4 individuals/m2, and was higher than on rye, where it reached 107.5 individuals/m2. Limothrips cerealium Haliday was a dominant species on oat as well as on winter rye.
The work has determined the species composition of thrips and their occurrence of winter rye in the chosen soil-climatic regions of Poland. The occurrence of several species of thrips has been noted on winter rye, with Haplothrips aculeatus Fabricius as the dominant one. Limothrips cerealium Holiday has extended its occurrence in the western direction of Poland. Thrips on winter rye occurred most amply in the south-western region.
The objective of this study was to determine the abundance and species composition of thrips collected from ears of Triticum durum Desf. in relation to plant protection intensity. The experiment was set up at the Experimental Research Station of Wrocław University of Environmental and Life Sciences, at Pawłowice (51°09’ N; 17°06’ E), Poland, in 2006-2008. It was conducted on durum wheat plants at three different levels of plant protection intensity and on common winter wheat plants. The samples of thrips were collected from the ears of the plants at the milk maturity stage of the grain. During three years of the research, eight species of thrips were identified from Triticum durum. Most often the eudominants were Haplothrips aculeatus, Limothrips cerealium and L. denticornis. We have demonstrated that there was no statistically significant effect of the plant protection intensity on the thrips abundance. The host species, on the other hand, did not affect the species composition of the studied insects.
Among the thrips species feeding on pea plants, the most numerous were: Thrips fuscipennis – occurring on green parts of plants and flowers, Frankliniella intonsa – occurring on flowers and a polyphagous species Thrips tabaci. These species were observed on pea plants from the first decade of May to the end of harvest.The greatest number of thrips was recorded in the first decade of June. Among the recoded species Aeolothrips intermedius was also numerous. This species is a zoophagous however, its larvae can prick and suck plant tissues, especially flowers.
The wettable powder was prepared on the basis of aerial conidia of two isolates of the entomopathognic fungus, Beauveria bassiana. Viability and pathogenicity of conidia products were evaluated against the second-instar larva of Thrips tabaci in four cases; Conidial-product Maintained in Refrigerator (CMR), Conidial-product Maintained in Laboratory (CML), New Formulated Conidia (NFC) and New Conidia without formulation (NC). Analysis of corrected seven-day total mortality data revealed that there were significant differences among these product-cases in their pathogenicity to thrips larvae. Recorded mortality rates for CMR, CML, NFC and NC showed that the pathogenicity of CML was lower compared to three other cases for both isolates. In the next step, inorganic salts (MgCl2, NH4PO4, KH2PO4, MgSO4 and NaCl) were added at a rate of 0.1 M into the both CMR and CML products. Bioassay results indicated that caused total mortality of thrips larvae increased with adding of salts. Our results showed that applied carriers and salts have positively effected preserving of conidia viability and pathogenicity to the second-instar larva of the onion thrips.
The new fossil thrips Uzelothrips eocenicus P. Nel and A. Nel sp. nov. (Thysanoptera: Uzelothripidae) is described from two lowermost Eocene amber−preserved specimens (one macropterous and one apterous). The family Uzelothripidae is only known so far from a single extant species, Uzelothrips scabrosus. The fossils differ from the extant species only by the antennal segments III and IV, which appear distinctly separated instead of being fused as in the in the extant U. scabrosus. Dark−coloured hyphae and conidia of the Dothideomycetes (Ascomycota) which are likely to belong to the sooty moulds (Capnodiales) are attached to the apterous fossil specimen. We consider this arthropod−fungus association not to be accidental since these fungi are also found in extant specimens of these uzelothripids, suggesting very specific long−term interactions and strong habitat specificity.
The western flower thrips, Frankliniella occidentalis (Pergande) attacks a large number of crop plants. The current insecticides have caused resistance in insects and have caused outbreaks of thrips. In many instances, alternative methods of insect management and natural products, offer adequate pest control and pose fewer hazards. Several species of minute pirate bugs of the genus Orius play a significant role in the biological control of a large number of thrips species, such as F. occidentalis. In this study, the insecticidal activity of four ethanolic plant extracts (Cercis siliquastrum L., Calendula officinalis L., Peganum harmala L., Melia azedarach L.) in integration with Orius horvathi (Reuter) were evaluated for controlling F. occidentalis. The present research aimed to find plant extracts with a good impact on F. occidentalis but which have fewer side effects on O. horvathi. The results showed that P. harmala extract can be considered compatible with the natural enemy for controlling thrips. When the predatory bugs O. horvathi, were released three days after P. harmala extract spraying, the integration was more effective. While the P. harmala plant extract plays an important role in thrips control, it is necessary to consider the specified time interval between the application of the P. harmala plant extract and the release of the O. horvathi predatory bugs. The ethanolic extract of M. azedarach caused a balance between the pest population and the natural enemy. This result is very important in an Integrated Pest Management (IPM) program because this ethanolic extract of M. azedarach had lower side effects on the natural enemy. This means that an integration of plant derived chemicals and the natural enemy, O. horvathi, can effectively control thrips.
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