Effects of combining <Emphasis Type="Italic">Beauveria bassiana</Emphasis> and <Emphasis Type="Italic">Nosema pyrausta</Emphasis> on the mortality of <Emphasis Type="Italic">Ostrinia nubilalis</Emphasis>

We tested the combined effect of the fungus Beauveria bassiana and the microsporidium Nosema pyrausta on the European corn borer larvae, Ostrinia nubilalis, in the laboratory. The first instar of O. nubilalis larvae was the most sensitive to the B. bassiana infection followed by the fifth, second, third, and fourth instar (LC₅₀s were 4.91, 6.67, 7.13, 9.15, and 6.51 × 10⁵ conidia/ml for the first to fifth instars, respectively). Mortality of each instar increases positively with concentration of conidia. When B. bassiana and N. pyrausta were used in combination, mortality increased significantly in all instars. Relative to the B. bassiana treatment alone, the B. bassiana + N. pyrausta treatment decreased the LC₅₀s by 42.16%, 37.63%, 21.60%, 27.11%, and 33.95% for the first to fifth instars, respectively. The combined effects of the two pathogens were mostly additive. However, at the two highest concentrations the pathogens interacted synergistically in the first and second instar. Individuals that survived the B. bassiana and B. bassiana + N. pyrausta treatments and developed into adults had significantly shorter lifespans and females oviposited fewer eggs than non-exposed insects. The effects on the longevity and the egg production were most pronounced at high concentration of B. bassiana conidia.     

Pathogenicity of <Emphasis Type="Italic">Beauveria bassiana</Emphasis> and <Emphasis Type="Italic">Metarhizium anisopliae</Emphasis> to the tobacco spider mite <Emphasis Type="Italic">Tetranychus evansi</Emphasis>

Seventeen isolates of Metarhizium anisopliae (Metschnikoff) Sorokin and two isolates of Beauveria bassiana (Balsamo) Vuillemin were evaluated for their pathogenicity against the tobacco spider mite, Tetranychus evansi Baker & Pritchard. In the laboratory all the fungal isolates were pathogenic to the adult female mites, causing mortality between 22.1 and 82.6%. Isolates causing more than 70% mortality were subjected to dose–response mortality bioassays. The lethal concentration causing 50% mortality (LC₅₀) values ranged between 0.7×10⁷ and 2.5×10⁷ conidia ml⁻¹. The lethal time to 50% mortality (LT₅₀) values of the most active isolates of B. bassiana and M. anisopliae strains varied between 4.6 and 5.8 days. Potted tomato plants were artificially infested with T. evansi and treated with B. bassiana isolate GPK and M. anisopliae isolate ICIPE78. Both fungal isolates reduced the population density of mites as compared to untreated controls. However, conidia formulated in oil outperformed the ones formulated in water. This study demonstrates the prospects of pathogenic fungi for the management of T. evansi.     

Response of Female <Emphasis Type="Italic">Frankliniella occidentalis</Emphasis> (Pergande) to Visual Cues and <Emphasis Type="Italic">Para-</Emphasis>anisaldehyde in a Flight Chamber

The effect of visual cue color and size, volume of para-anisaldehyde (plant-derived semiochemical), and airflow on thrips behavior were examined in a flight chamber. After 5 min more female Frankliniella occidentalis (western flower thrips) landed on sticky traps containing yellow plastic squares (100 cm²) (55.2% of those that flew landed on the trap) than blue (21%), white (4.7%), or transparent traps (2%). The percentage of thrips caught on traps increased with increasing size of the visual cues (0 and 1 cm² (4%), 4 cm² (16%), 25 cm² (44–49%), 100 cm² (60%)). Using a yellow (100 cm²) square, fewer thrips flew in the presence of 1.0 ml (47%) or 2 ml (55%) of para-anisaldehyde than of 0.5 ml (78%). However, more thrips landed on a trap with a 100 cm² yellow square when 1 ml of para-anisaldehyde (81%) was added than when 0.5 ml (55%) or 2 ml (62%) were added. Airflow (0–0.3 m/s) did not affect the percentage of thrips that flew or landed on traps. Results suggest that thrips responded to a yellow cue in the absence of UV. Further, the volume of para-anisladehyde affected the percentage that flew or landed on a trap containing a yellow cue.     

<Emphasis Type="Italic">Beauveria bassiana</Emphasis> pathogenicity to the cherry slugworm, <Emphasis Type="Italic">Caliroa cerasi</Emphasis> (Hymenoptera: Tenthredinidae) larvae

The cherry slugworm Caliroa cerasi is a significant destructive pest of sour cherries (Prunus cerasus) in Turkey. The potential of entomopathogenic fungi for controlling C. cerasi was evaluated. The effects of exposure methods and conidial concentrations (1 × 10⁶, 1.5 × 10⁶, 1 × 10⁷ and 1.5 × 10⁷ conidia/ml) on mature larvae of C. cerasi infected by Beauveria bassiana were investigated under laboratory conditions. Larvae sprayed directly with B. bassiana conidial suspensions and larvae exposed to B. bassiana-treated leaves resulted in 100% mortality within 2.90 and 2.77 days, respectively. The median lethal time (LT₅₀) and days to mortality were highest in the 1.0 × 10⁷ concentrations of conidia for both direct spray and leaf exposure. The present study suggests that B. bassiana has good potential for control of the cherry slugworm, C. cerasi.     

Isolation of <Emphasis Type="Italic">Beauveria bassiana</Emphasis> (Bals.) Vuill. (Deuteromycotina: Hyphomycetes) from the Chagas disease vector, <Emphasis Type="Italic">Triatoma infestans</Emphasis> (Hemiptera: Reduviidae) in Argentina

A survey for natural entomopathogenic fungi of the Chagas disease vector Triatoma infestans was conducted in five provinces of Argentina since 2001. Nymphs (1.5%) and adults (3.3%) infected with a strain of the fungus Beauveria bassiana were found at Dean Funes, Córdoba province, Argentina. Field collected insects that died in the laboratory were maintained in moist chambers and incubated at 22 °C. Beauveria bassiana from infected insects was cultured on SDAY media. Pathogenicity tests were conducted with a conidial suspension (1 × 10⁷ conidia/ml) of this isolate on T. infestans adults. A mortality rate of 100% was obtained at 15 days post-infection. This is the first record of natural infection of T. infestans by B. bassiana.     

Selection of entomopathogenic fungi for use in combination with sub-lethal doses of imidacloprid: perspectives for the control of the leaf-cutting ant <Emphasis Type="Italic">Atta sexdens</Emphasis><Emphasis Type="Italic">rubropilosa</Emphasis> Forel (Hymenoptera: Formicidae)

In the first part of this study, four isolates of the fungus Beauveria bassiana (Bals.) Vuillemin (LPP1, LPP2, CG05 and CG24) and one isolate of Metarhizium anisopliae (Metsch.) Sorokin (CG46) were tested against adult foragers of Atta sexdens rubropilosa. Ants were allowed to walk on filter paper discs, inside Petri dishes, previously impregnated with 1 ml of a conidia suspension (2 × 10⁷ conidia ml⁻¹), maintained at 80% RH and 26°C for 24 h and subsequently, transferred to sterile Petri dishes, maintained at 23°C, 80% RH, 24 h dark. The mean values of LT₅₀ for LPP2, LPP1, CG46, CG24 and CG05 were 3.5, 3.7, 3.8, 4.2 and 4.4 days, respectively. Control insects for all tests in this study showed less than 10% mortality. Experiments were carried out to test the toxicity of imidacloprid (IMI) to A. sexdens rubropilosa. Mortality was evaluated 10 days following a 24 h exposure to the insecticide. Percent mortality caused by 500, 200, 100 and 10 ppm IMI was 77.8, 56.7, 45.5 and 5.5 respectively. Insects treated with 10 ppm IMI were observed to have reduced locomotor activity 24 h after exposure to the insecticide. The LC₅₀ of IMI was 154.3 ppm. Subsequent tests were carried out to evaluate the combination of a sub-lethal dose of IMI (10 ppm) and infection by CG24 (1 × 10⁷ conidia ml⁻¹). Mortality due to fungal infection alone was 43.3%. Mortality of insects treated with IMI followed by exposure to the fungus was 64.3%. These results indicate that IMI significantly increases the susceptibility of ants to infection by B. bassiana CG24.     

Control of <Emphasis Type="Italic">Bemisia tabaci</Emphasis> and <Emphasis Type="Italic">Frankliniella occidentalis</Emphasis> in cucumber by <Emphasis Type="Italic">Amblyseius swirskii</Emphasis>

Bemisia tabaci Genn. (Hemiptera: Aleyrodidae) and Frankliniella occidentalis (Thysanoptera: Thripidae) are major pests in greenhouse grown cucumber crops. Recently, Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) was shown an effective biological control agent of both pests. Hence, perhaps both pests can be controlled simultaneously by this predator. However, with simultaneous infestation of both pests, synergistic effects, or interference could affect biological control and perhaps require changes in release rates of the predator. Thus, the aim of the present study was to evaluate different release rates of A. swirskii to control both pests under a worst case scenario of rapid immigration into a cucumber greenhouse. Two experiments were conducted, one simulating the influx of whiteflies alone (whitefly experiment) and the other immigration of whiteflies and thrips together (whitefly plus thrips experiment). Three treatments were compared in the whitefly experiment: (1) B. tabaci alone, (2) B. tabaci + 25 A. swirskii m⁻² and (3) B. tabaci + 75 A. swirskii m⁻². The high release rate was more effective than the low rate in controlling B. tabaci alone. The high rate was subsequently tested against B. tabaci and F. occidentalis for the whitefly and thrips experiment in which five treatments were compared: (1) B. tabaci alone, (2) F. occidentalis alone, (3) B. tabaci + 75 A. swirskii m⁻², (4) F. occidentalis + 75 A. swirskii m⁻² and (5) B. tabaci + F. occidentalis + 75 A. swirskii m⁻². This rate of A. swirskii controlled whiteflies and thrips either alone or together. Therefore, 75 A. swirskii m⁻² should be an adequate rate for controlling both pests either alone or simultaneously in cucumber greenhouses.     

Pathogenicity of hyphomycetous fungi against <Emphasis Type="Italic">Cyclocephala signaticollis</Emphasis>

Susceptibility of the white grub Cyclocephala signaticollis Burmeister (Coleoptera: Scarabaeidae: Dynastinae) larvae to seven isolates of Beauveria bassiana (Balsamo) Vuillemin, five of Metarhizium anisopliae (Metschnikoff) Sorokin and two of Paecilomyces lilacinus (Thom) Samson (Deuteromycotina: Hyphomycetes) was investigated. Among 14 fungal isolates screened the most virulent was a B. bassiana isolate (Bb 53) that caused 70% mortality of third instar larvae in 40 days after inoculation at 1 × 10⁸ conida/ml. Strains of M. anisopliae and P. lilacinus showed low efficacy or no virulence to the target host.     

Biological control of the pinewood nematode <Emphasis Type="Italic">Bursaphelenchus xylophilus</Emphasis> by application of the endoparasitic fungus <Emphasis Type="Italic">Esteya vermicola</Emphasis>

Esteya vermicola (Ophiostomataceae) is the first reported endoparasitic fungus of the pinewood nematode (PWN), Bursaphelenchus xylophilus (Nematoda: Aphelenchoidoidea). It has high in vitro infectivity. In this study, the nematocidal effect of E. vermicola in logs was investigated and evaluated. Two months after inoculation of pine wilt-killed Pinus densiflora logs with E. vermicola conidia suspensions of 3 × 10⁸ and 3 × 10⁶ ml⁻¹, the density of nematodes decreased by approximately 79% and 47%, respectively. When the fungus was sprayed on to four-year-old pine seedlings one month before PWN inoculation, the survival index of seedlings reached 0.67 compared with only 0.067 for control seedlings without fungal spraying. These results suggest that conidia spraying of E. vermicola can, to some extent, protect pine trees from wilt disease. Moreover, infected nematodes and hyphae of E. vermicola were observed in the treated wood sections.     

Synergistic action of entomopathogenic hyphomycetes and the bacteria <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis> ssp. <Emphasis Type="Italic">morrisoni</Emphasis> in the infection of Colorado potato beetle <Emphasis Type="Italic">Leptinotarsa decemlineata</Emphasis>

A synchronous coinfection of the Colorado potato beetle Leptinotarsa decemlineata (Say) with the entomopathogenic bacteria Bacillus thuringiensis ssp. morrisoni Bonnifoi & de Barjak var. tenebrionis Krieg et al. and hyphomycete Metarhizium anisopliae (Metsch.) Sorokin or Beauveria bassiana (Bals.) Vuill leads to the rapid death of 95–100% of larvae. The bacteria arrest the nutrition of insects, while the fungal spores kill the weakened larvae. The synergistic effect of two pathogens is recorded at a relatively low hyphomycete titer (1–5 × 10⁶ conidia/ml) and is evident in the mortality dynamics at all larval ages. These bacterial and fungal pathogens display no antagonism on artificial nutrient media. This microbial complex is highly efficient under natural conditions (80–90% larval mortality rate and no plant defoliation).     

Substrate influence on physiology and virulence of <Emphasis Type="Italic">Beauveria bassiana</Emphasis> acting on larvae and adults of <Emphasis Type="Italic">Tenebrio molitor</Emphasis>

Two isolates of Beauveria bassiana, wild type (wt) and its mutant type (mt) were compared in terms of growth patterns on culture plates containing media based on wheat bran, grasshopper exoskeletons, colloidal chitin or Sabouraud-dextrose agar (SDA). Germination for the mt isolate was up to 33% faster in all media. Influence of media on virulence was determined against larvae and adults of Tenebrio molitor. Mortality higher than 90% was reached for adults after 6 days using conidia from all media. For larvae, a mortality of 80% was reached after 11 days with conidia collected from SDA medium and between 15 and 35% with conidia from other media. In SDA medium, conidial yield was almost ten times higher for the mt isolate compared to the wt isolate; however, virulence traits were similar against either larvae or adults. These results may influence commercial preparations of entomopathogenic fungi based on conidia.     

Effect of inoculation method and plant growth medium on endophytic colonization of sorghum by the entomopathogenic fungus <Emphasis Type="Italic">Beauveria bassiana</Emphasis>

A study was conducted to determine the effect of inoculation method and plant growth medium on colonization of sorghum by an endophytic Beauveria bassiana. Colonization of leaves, stems, and roots by B. bassiana was assessed 20-days after application of the fungus. Although B. bassiana established as an endophyte in sorghum leaves, stems, and roots regardless of inoculation method (leaf, seed, or soil inoculation), plant growth medium (sterile soil, non-sterile soil, or vermiculite) apparently influenced colonization rates. Seed inoculation with conidia caused no stem or leaf colonization by the fungus in non-sterile soil but did result in substantial endophytic colonization in vermiculite and sterile soil. Leaf inoculation did not result in root colonization, regardless of plant growth medium. Endophytic colonization was greater in leaves and stems than roots. Endophytic colonization by B. bassiana had no adverse effects on the growth of sorghum plants. Leaf inoculation with a conidial suspension proved to be the best method to introduce B. bassiana into sorghum leaves for plants growing in either sterile or non-sterile soil. Further research should focus on the virulence of endophytic B. bassiana against sorghum stem borers.     

Effects of combining the fungi <Emphasis Type="Italic">Beauveria bassiana</Emphasis> and <Emphasis Type="Italic">Metarhiziumanisopliae</Emphasis> on the mortality of the tick <Emphasis Type="Italic">Amblyomma variegatum</Emphasis> (ixodidae) in relation to seasonal changes

The effect of formulation, fungal concentration, type and seasonal changes on the mortality of the tick Amblyomma variegatum was investigated. A previous study demonstrated high pathogenicity of strains of the fungi Beauveria bassiana and Metarhizium anisopliae against the ticks Rhipicephalus appendiculatus and Amblyomma variegatum (Kaaya et al. J Invertebr Pathol 1996; 67: 15–20). The present study was undertaken to explore possible additive or synergistic effects of the two fungi on A. variegatum. The effects of oil and water formulations at different concentrations of each fungus and combination of the two on the mortality of A. variegatum in the laboratory and in the field during the wet and dry seasons were determined and compared. The oil formulation performed better in all assays, with highest tick mortality of 92% occurring during the wet season at conidia concentration of 1 × 10¹⁰ conidia/ml of the mixed fungi compared to 49% for the water formulation at similar conidia concentration. However, at the same conidial concentration during the dry season, mortalities in the field were relatively low with the mixture of the fungi recording 24% and 17% tick mortality for the oil and water formulation respectively. The effect of infecting the ticks with a cocktail of the two fungi was inconclusive under more controlled conditions in the laboratory but field results under both wet and dry seasons indicated significant differences between the separate and mixed fungi infections. The results demonstrate a potential of cocktail formulations in the control of ticks and possibly of other arthropod pests.     

Medium Selection and Effect of Higher Oxygen Concentration Pulses on <Emphasis Type="Italic">Metarhizium anisopliae</Emphasis> var<Emphasis Type="Italic">. lepidiotum</Emphasis> Conidial Production and Quality

Rice and oat flours were analyzed as media for the production of conidia by M. anisopliae var. lepidiotum. The presence of peptone increased conidia yield regardless of the substrate used; however, the highest yield was achieved on oat flour media. The effect of oxygen on conidia production using oat-peptone medium was also studied at two levels: Normal atmosphere (21% O₂) and Oxygen-rich pulses (26% O₂). Maximum conidia production (4.25 × 10⁷ conidia cm⁻²) was achieved using 26% O₂ pulses after 156 h of culture, which was higher than 100% relative to conidial levels under normal atmosphere. Conidia yield per gram of biomass was 2.6 times higher with 26% O₂ (1.12 × 10⁷ conidia mg⁻¹). Conidia quality parameters, such as germination and hydrophobicity, did not show significant differences (P < 0.05) between those treatments. Bioassays parameters, using Tenebrio molitor adults, were analyzed for conidia obtained in both atmospheres and data were fitted to an exponential model. The specific mortality rates were 2.22 and 1.26 days⁻¹, whereas lethal times for 50% mortality were 3.90 and 4.31 days, for 26% O₂ pulses and 21% O₂ atmosphere, respectively. These results are relevant for production processes since an oxygen increase allowed superior levels of conidia by M. anisopliae without altering quality parameters and virulence toward Tenebrio molitor adults.     

Rhizosphere competent <Emphasis Type="Italic">Pantoea agglomerans</Emphasis> enhances maize (<Emphasis Type="Italic">Zea mays</Emphasis>) and chickpea (<Emphasis Type="Italic">Cicer arietinum</Emphasis> L.) growth,without altering the rhizosphere functional diversity

Plant growth promoting Pantoea agglomerans NBRISRM (NBRISRM) was able to produce 60.4 μg/ml indole acetic acid and solubilize 77.5 μg/ml tri-calcium phosphate under in vitro conditions. Addition of 2% NaCl (w/v) in the media induced the IAA production and phosphate solubilization by 11% and 7%, respectively. For evaluating the plant growth promotory effect of NBRISRM inoculation a micro plot trial was conducted using maize and chickpea as host plants. The results revealed significant increase in all growth parameters tested in NBRISRM inoculated maize and chickpea plants, which were further confirmed by higher macronutrients (N, P and K) accumulation as compared to un-inoculated controls. Throughout the growing season of maize and chickpea, rhizosphere population of NBRISRM were in the range 10⁷–10⁸ CFU/g soil and competing with 10⁷–10⁹ CFU/g soil with heterogeneous bacterial population. Functional richness, diversity, and evenness were found significantly higher in maize rhizosphere as compared to chickpea, whereas NBRISRM inoculation were not able to change it, in both crops as compared to their un-inoculated control. To the best of our knowledge this is first report where we demonstrated the effect of P. agglomerans strain for improving maize and chickpea growth without altering the functional diversity.     

Predation by <Emphasis Type="Italic">Nesidiocoris tenuis</Emphasis> on <Emphasis Type="Italic">Bemisia tabaci</Emphasis> and injury to tomato

Tomato is the most important vegetable crop in Spain. The mirid bug Nesidiocoris tenuis (Reuter) commonly appears in large numbers in protected and open-air tomato crops where little or no broad-spectrum insecticides are used. Nesidiocoris tenuis is known to be a predator of whiteflies, thrips and several other pest species. However, it is also considered a pest because it can feed on tomato plants, causing necrotic rings on stems and flowers and punctures in fruits. Our objectives were to evaluate predation by N. tenuis on sweetpotato whitefly Bemisia tabaci Gennadius under greenhouse conditions and establish its relationship to N. tenuis feeding on tomato. Two different release rates of N. tenuis were compared with an untreated control (0, 1 and 4 N. tenuis plant⁻¹) in cages of 8 m². Significant reductions of greater than 90% of the whitefly population and correspondingly high numbers of N. tenuis were observed with both release rates. Regression analysis showed that necrotic rings on foliage caused by N. tenuis were best explained by the ratio of B. tabaci nymphs:N. tenuis as predicted by the equation y = 15.086x − 0.6359.

Relative susceptibility of <Emphasis Type="Italic">Spodoptera litura</Emphasis> pupae to selected entomopathogenic fungi

The pupae of Spodoptera litura (Fab.), (Lepidoptera: Noctuidae), a polyphagous pest affecting common crops in Indian subcontinent, were treated with different concentrations of conidia of four isolates of entomopathogenic fungi belonging to three species, Metarhizium anisopliae var. anisopliae (Metschnikov) Sorokin (ARSEF 7487), Lecanicillium muscarium (Petch) Zare & W Gams (two isolates ARSEF 7037 and ARSEF 6118) and Cordyceps cardinalis Sung & Spatafora (ARSEF 7193) under laboratory conditions. Suspensions (10⁸/ml) of conidia harvested from Sabouraud dextrose agar yeast extract (SDAY) plates resulted in the highest mortality (85.8%) with M. anisopliae and the lowest mortality (57.3%) with C. cardinalis. The values of LC₅₀ and LC₉₀ suggested that M. anisopliae was the most virulent fungal strain followed by L. muscarium (ARSEF 7037). However, C. cardinalis was the least virulent species among the fungi used in the bioassay. In soil bioassays, drenching the soil with conidial suspensions of ARSEF 7487 and ARSEF 7037 (10⁸ conidia/g of soil) reduced the adult emergence from pupa by 81.3% and 72.5%, respectively, while premixing the sterile soil with conidia killed lesser number of pupae (62.9% by ARSEF 7487 and 54.6% by ARSEF 7037). Our findings suggest that M. anisopliae (ARSEF 7487) and L. muscarium (ARSEF 7037) are potent entomopathogens and could be developed into biocontrol agents against rice cutworm in IPM programs. Handling editor: Helen Roy     

Natural occurrence of soil-borne entomopathogenic fungi in the Moroccan Endemic forest of <Emphasis Type="Italic">Argania spinosa</Emphasis> and their pathogenicity to <Emphasis Type="Italic">Ceratitis capitata</Emphasis>

The occurrence and abundance of entomopathogenic fungi were analysed in 203 soil samples of the Moroccan endemic forests of Argania spinosa, the world main refuge of the Mediterranean fruit fly, Ceratitis capitata. Using the Galleria baiting method and selective media, entomopathogenic fungi were isolated from 186 of the 203 (91.62%) soil samples, with only three species found: Beauveria bassiana (Balsamo) Vuillemin, Metarhizium anisopliae (Metschnikoff) Sorokin and Paecilomyces lilacinus (Thom.) Samson. B. bassiana was the most widespread entomopathogenic fungi (90.64%) in the Argan forest whereas M. anisopliae was less common (15.27%) and P. lilacinus was very rare (1.48%). This is the first report of natural occurrence of M. anisopliae and P. lilacinus in Morocco. Furthermore, 118 Moroccan B. bassiana isolates were studied for their pathogenicity to C. capitata and thermotolerance. Most of these autochtonous B. bassiana isolates were virulent (86.44%) to Medfly pupae and tolerant (55.08%) to temperature stress at 45°C for 2 h. Only 60.17% of Moroccan B. bassiana isolates might be considered as highly entomopathogenic and will serve as a source of potential biological control agents to C. capitata. The percentage of thermotolerant and pathogenic B. bassiana to C. capitata were shown to decrease significantly at winter time characterized by low temperatures and absence of any noticeable medfly in the Argan forest. The occurrence, thermotolerance and virulence of B. bassiana isolates to C. capitata seemed to be related to the sampling periods and location. Our data are discussed with respect to fungal ecology and biocontrol potential of B. bassiana isolates in relation to their habitat.     

<Emphasis Type="Italic">Agrobacterium</Emphasis><Emphasis Type="Italic">tumefaciens</Emphasis>-mediated transformation of callus cells of <Emphasis Type="Italic">Crataegus</Emphasis><Emphasis Type="Italic">aronia</Emphasis>

A genetic transformation system has been developed for callus cells of Crataegus aronia using Agrobacterium tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with 5 mg l⁻¹ Indole-3-butyric acid (IBA) and 0.5 mg l⁻¹ 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red colored callus was obtained on MS medium supplemented with 2 mg l⁻¹ 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l⁻¹ kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l⁻¹ hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this is the first time to report an Agrobacterium-mediated transformation system in Crataegus aronia.