Endophytic Colonisation of Solanum lycopersicum and Phaseolus vulgaris by Fungal Endophytes Promotes Seedlings Growth and Hampers the Reproductive Traits, Development, and Survival of the Greenhouse Whitefly, Trialeurodes vaporariorum

In the scope of mitigating the negative impacts of pesticide use and managing greenhouse whiteflies, Trialeurodes vaporariorum sustainably, 16 endophytic fungal isolates from five different genera (Beauveria, Trichoderma, Hypocrea, Bionectria, and Fusarium) were screened for their ability to colonise two preferred host plant species, namely, tomato (Solanum lycopersicum L.) and French bean (Phaseolus vulgaris L.), through seed inoculation. Seven and nine isolates were endophytic to P. vulgaris and S. lycopersicum, respectively, where significant differences in the endophytic colonisation rates were observed among the fungal isolates in P. vulgaris and its plant parts, with a significant interaction between the isolates and plant parts in S. lycopersicum. Hypocrea lixii F3ST1, Trichoderma asperellum M2RT4, Trichoderma atroviride F5S21, and T. harzianum KF2R41 successfully colonised all the plant parts of both hosts and therefore were selected and further evaluated for their endophytic persistence, effect on plant growth, and pathogenicity to T. vaporariorum adults and F1 progeny. The four endophytes remained in both host plants for the 5-week assessment with varied colonisation rates related to the strong interaction with the time, isolates, and plant parts in both hosts. The effect of the same endophytes on the different host growth parameters varied in P. vulgaris and S. lycopersicum, with T. asperellum M2RT4 not boosting the growth in both host plants while T. atroviride F5S21 resulted in enhanced shoot biomass in S. lycopersicum. T. atroviride F5S21 and T. harzianum KF2R41 inoculated S. lycopersicum plants and H. lixii F3ST1, T. asperellum M2RT4, and T. harzianum KF2R41 inoculated P. vulgaris plants had significantly lower oviposition, while nymph development in both hosts was significantly prolonged in all the endophytically–colonised plants. The endophytes H. lixii F3ST1 and T. asperellum M2RT4 significantly reduced the longevity/survival of the exposed T. vaporariorum adults and the progeny in both S. lycopersicum and P. vulgaris. The findings demonstrate the attributes of the various endophytes in host plant growth promotion as well as their effects on the life-history parameters of T. vaporariorum and could consequently be developed as potential endophytic fungal-based biopesticides for the sustainable management of the pest in S. lycopersicum and P. vulgaris cropping systems.

Compostos secundàrios de anona na proteçâo de plantas contra pests / Secondary compounds of anona in plant protection against pests

En tiempos remotos las culturas antiguas utilizaron los compuestos secundarios de las plantas para el manejo de las plagas de los cultivos. Actualmente surge la necesidad de rescatar estos conocimientos como una alternativa al uso de plaguicidas sintéticos. Las anonáceas presentan principios activos que causan repelencia, disuasión de la alimentación, disuasión de la oviposición y reguladores de crecimiento en los insectos, esta actividad se debe principalmente a la presencia de las acetogeninas. En este sentido, se aplicaron concentraciones de 0.000001, 0.00001, 0.0001, 0.001, 0.01, 0.1 y 1.0% con cuatro repeticiones de extractos crudos de anona amarilla Annona lutescens extraídos con metanol, etanol, diclorometano y hexano, para determinar su efecto repelente en adultos de mosca Trialeurodes vaporariorum comparados con los testigo químico y absoluto. La unidad de muestreo consistió en introducir 20 adultos en un vaso transparente de 1 L, conteniendo una hoja de tomate tratada con el extracto y dosis respectiva colocado en un frasco gotero de 10 mL con agua de la llave, los datos de moscas posadas se tomaron a las 3, 6, 12, 24, 48 y 72 h y por diferencia se calculó los no posados, obteniendo como resultado que las siete concentraciones de los cuatro extractos crudos de anona causaron de 75.7 a 93.0% de repelencia de los adultos de mosca blanca de las 3 a las 72 h después de la aplicación. Por otro lado, desde el inicio hasta el final de las observaciones los extractos crudos de anona causaron mayor repelencia que el producto químico. Esto hace sugerir el uso del extracto de anona en el manejo de adultos de mosca blanca.

Mogućnosti suzbijanja cvjetnog štitastog moljca prirodnim neprijateljima i botaničkim insekticidima

Cvjetni štitasti moljac, Trialeurodes vaporariorum (Westwood, 1856), ekonomski je najznačajniji štetnik na kulturama koje se uzgajaju u zaštićenim prostorima, posebice rajčice. Javlja se svake godine i uzrokuje direktne i indirektne štete, te prenosi biljne viruse. Brojnost populacije i visina šteta su u izravnoj korelaciji, odnosno veće štete nastaju pri brojnijoj populaciji. Praćenje i pravovremeno uočavanje ovog štetnika ima veliki značaj za uspjeh primjene mjera suzbijanja. Cvjetni štitasti moljac prati se žutim ljepljivim pločama i vizualnim pregledima naličja listova. Već pri uočavanju jedne odrasle jedinke potrebno je pristupiti suzbijanju kako bi se spriječilo prenamnožavanje i daljnje širenje. Kemijske mjere najčešći su način suzbijanja moljca. No, uslijed učestalog korištenja insekticida, posebice insekticida istog mehanizma djelovanja, pojavio se problem rezistentnosti ovog štetnika na brojne djelatne tvari iz različitih kemijskih grupa. Stoga se u integriranoj zaštiti prednost daje agrotehničkim, mehaničkim, fizikalnim i biološkim mjerama koje ne dovode do pojave rezistentnosti i prihvatljivije su za okoliš. Biološke mjere uključuju korištenje različitih makrobioloških i mikrobioloških preparata, naturalita i botaničkih insekticida. Entomofagne osice uspješno se koriste u suzbijanju cvjetnog štitastog moljca. Vrlo je važna njihova pravovremena primjena, jer su najviše učinkovite pri nižim populacijama štetnika. Sve veća pozornost pridaje se botaničkim insekticidima kao ekološki povoljnijoj zamjeni za kemijske insekticide. Prirodnog su porijekla, a mnogi od njih imaju insekticidno djelovanje te bi se mogli primjenjivati u suzbijanju cvjetnog štitastog moljca i na taj način omogućiti uspješnu zaštitu kultura koje ovaj štetnik napada.

Compatibility of the fungus Lecanicillium muscarium and the predatory mite Amblyseius swirskii for their combined application against the greenhouse whitefly Trialeurodes vaporariorum

The present study evaluated effects of the fungus Lecanicillium muscarium (Ascomycota: Hypocreales) and an organic extract from its mycelium on the greenhouse whitefly Trialeurodes vaporariorum (Hemiptera: Aleyrodidae) and its predator, mite Amblyseius swirskii (Acari: Phytoseiidae). Mites were exposed to fungal spores or organic extract prepared from L. muscarium mycelium. No negative effect was shown on the predator feeding on T. vaporariorum nymphs treated with fungal conidia at a concentration of 5 × 107 spores/ml; by day six the number of mite eggs and nymphs was 18.7 % higher than on leaves treated with Tween 80. In contrast, treatment of leaves with a 0.5 % alcohol extract derived from L. muscarium mycelium caused 35 % mortality of A. swirskii adults by day two. In a trial conducted in a commercial greenhouse on rose plants, the application of L. muscarium conidia followed by the release of A. swirskii suppressed T. vaporariorum more effectively than each of the control agents applied separately.

INVASIVE PESTS DETECTED IN SOME GREENHOUSES OF EREVAN CITY

The following invasive species: Toxoptera aurantii Boyer de Fonscolombe, Toxoptera citricida Kirkaldy, Macrosiphoniteella sanborni Latr, Toxoptera , Macrosiphoniella Del Guercio), Trialeurodes vaporariorum Westwood (Aleyrodidae West., Trialeurodes Cockerell), Tetranychus viennensis Zacher (Tetranychidae Donn, Tetranychus Dufour), and Cenopalpus mespili Lufour. et Mitrofanov (Tenuipalpidae Sayed, Cenopalpus Pritchard & Baker) were identified during studying of the pest fauna of three greenhouse complexes ("Grig Garden", "Green Paradise" and "Avan") in Yerevan which are specialized on the cultivation of ornamental plants. Insecticide and acaricide resistant lines of Tetranychus viennensis and Macrosiphum rosae were found in two greenhouse complexes.