Effect of larval selection with two bioinsecticides on susceptibility levels and reproductive capacity ofAedes aegypti (L.)

Two bacterial insecticides,Bacillus thuringiensis H-14 andB. sphaericus 1593 were evaluated for larvicidal potency against mosquito larvae ofAedes aegypti. LC₅₀ values showed thatB.thuringiensis H-14 (4×10⁵ spores/ml) had a higher pathogenicity against fourth larval instars ofA. aegypti thanB. sphaericus (3.1×10⁶ spores/ml) by about 7.75 times. Larval selection with LC₉₀ of both pathogens for 8 successive generations caused a decrease in the susceptibility levels of selected strains ofA. aegypti as compared with the original strain. Moreover, the results indicated that the effect of larval selection with the above bioinsecticides led to an obvious reduction in the egg production and hatchability of eggs produced by mosquito adults that developed from surviving larvae.     

Sustained-release formulations ofBacillus thuringiensis serotype H-14 and plastic formulations of Abate for long-term control of mosquito larvae

The larvicidal activity of sustained-release formulations ofBacillus thuringiensis H-14 (Bactimos briquets) and controlledrelease plastic formulations of Abate against mosquito larvae ofAedes aegypti (L.) has been evaluated. The test formulations provided continuous effective control with 90–100% larval mortality for several weeks. The presence of suspended soil constituents was associated with a lowering of larval mortality and tended to reduce the durations of effective control of Bactimos and Abate plastic pellets against mosquito larvae by about 1.8 and 2.2 times, respectively. Treatments with such formulations did not appear to prevent hatch of eggs which oviposited after application, but all newly hatched larvae failed to develop beyond the second instar.     

Pilot-Versuch zur Bekämpfung von Stechmückenlarven im Freiland mit einem UV-behandelten Präparat von Bacillus thuringiensis var. israelensis

Preparations derived from sporulated cultures ofBacillus thuringiensis var.israelensis were used in a small field trial for control of mosquito larvae (Aedes cantans, Aedes rusticus, Culiseta morsitans). In the test two liquid formulations (suspension) were compared: (1) a native preparation containing living spores and toxic crystals, and (2) a preparation in which the spores have been inactivated to a high degree (99.99%) by ultraviolet rays. The efficacy of both preparations against mosquito larvae showed no difference: doses of 10⁴ to 10⁵ spore equvalents/ml, induced 100% mortality of the target insects. But no harmful effect on non-target organisms (especially water arthropods with exception of Chironomidae larvae) could be observed. To minimize the contamination of surface water with living spores, the use of UV-inactivated preparations ofB. t. var.israelensis is indicated for mosquito control.     

Über kombinierte Wirkungen eines Juvenoids (Altosid) und eines Bacillus-thuringiensis-Präparats (Bactimos) auf Larven der Stechmücken Culex pipiens molestus Forsk. und Theobaldia longiareolata Macq. (Dipt., Culicidae)

Exposing second and fourth instar larvae ofCulex pipiens molestus for 24 h to Altosid increased their tolerance to Bactimos. The interaction was apparent in fourth instar larvae treatment especially at the higher concentrations. Exposure bactimos to Altosid for 72 hours decreased its efficacy against the fourth instar larvae ofCulex pipiens molestus. The LT₅₀ values were significantly lower in larvae treated with Bactimos only than that treated with Altosid and Bactimos. Altosid briquets increased significantly the tolerance ofTheobaldia longiareolata larvae toBacillus thuringiensis var.israelensis at all concentrations tested. Generally, pretreatment mosquito larvae with Altosid followed by Bactimos, increased the tolerance of larvae to the bacterium, this may be due to the toxic effect of Altosid on the bacterium or to the changes in the physiological status of the treated larvae to tolerate the effect of bacterium. On the light of these studies, Altosid exhibited detrimental effect on the efficacy ofB. thuringiensis var.israelensis againstC. pipiens molestus andT. longiareolata larvae. Therefore, interactions between Altosid and Bactimos could not fit the integrated control of mosquitoes.     

Zur Wirkung von Bacillus thuringiensis var. israelensis auf die Larven der Stechmücke Culex pipiens molestus

Laboratory infectivity tests were undertaken to investigate the pathogenicity of “Bactimos” (a new commerical bacterial biocide) aginst different instar larvae ofCulex pipiens molestus. The biocide “Bactimos”,Bacillus thuringiensis var.israelensis, was confirmed as pathogenic for mosquito larvae ofC. pipiens molestus. At dosage of 0.000125 mg/250 ml water, mortalities of 25, 98, and 97% were recorded for the 1st, 2nd and 3rd instar larvae after 24 hrs, respectively. Dosage of 0.008 mg/250 ml water proved to kill all types of instar larvae (100% mortality) after 24 hours. Water volumes ranging from 100 to 800 ml, containing 0.005 mg “Bactimos” per each were found to kill the 2nd and 4th instar larvae (90–100% mortality) with no significant differences. In conclusion, it is quite evident that the commerical bacterialbiocide “Bactimos” should be recommended as biomortality agent against mosquito larvae in Upper Egypt.     

Über die Fähigkeit vonBracon brevicornis Wesm. (Hym., Braconidae), zwischen nicht infizierten und von Bakterien infizierten Raupen vonSesamia cretica Led. (Lep., Noctuidae) zu unterscheiden

Sesamia cretica larvae infected with the bacterium,Serratia marcescens orBacillus thuringiensis were exposed toBracon brevicornis females, separately and in combination with non-infected larvae in the laboratory. Host larvae were exposed to the parasitoid under two manipulations “the larvae still alive or dead completely”. Bracon brevicornis females could not absolutely discriminate between healthy and moribund larvae (due toB. t. orS. m.) when those larvae exposed in a live appearance separately or jointly. However, they could discriminate between dead larvae (due to parasitoid's venom) and dead larvae due to Bacteria (B. t. orS. m.).     

Produktion von Präparaten auf der Basis von Bacillus thuringiensis var. israelensis mit UV-inaktivierten Sporen zur biologischen Bekämpfung von Mückenlarven

Zusammenfassung Zur Bekämpfung von Stechmücken-Larven geeignete Präparate vonBacillus thuringiensis var.israelensis (B. t. i. = Serotyp H₁₄) enthalten Sporen und parasporale Toxinkristalle. Um die Belastung von Oberflächenwasser mit aktiven Sporen bei einer solchen Bekämpfung möglichst gering zu halten, wurden Untersuchungen durchgeführt mit dem Ziel, die Keimzahl des Biopräparates zu reduzieren. Bei Versuchen mit einem UV-Entkeimungsgerät für Trinkwasser wurde eine 99,99%ige Inaktivierung der Sporen erzielt. Im Biotest bewirkte das bestrahlte Präparat nahezu den gleichen Effekt gegenüber Mückenlarven wie die nichtbestrahlte Suspension. Bei der Anwendung dieses neuenB. t. i.-Präparates in der kalkulierten Aufwandmenge in Oberflächenwasser wird nicht einmal die Toleranzgrenze für die Trinkwasser-Qualität überschritten. Das bedeutet, daß der Einsatz eines UV-behandeltenB. t. i.-Präparates zur Mückenbekämpfung hygienisch unbedenklich ist.

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Production of preparations based on Bacillus thuringiensis var. israelensis with UV-inactivated spores for biological control of mosquito larvae

Preparations ofBacillus thuringiensis var.israelensis (B. t. i.= serotype H₁₄) contain spores and toxic parasporal crystals. To minimize the loading of surface water with active spores in connection with mosquito control, studies were carried out to reduce the germination index of the spores using an UV equipment for sterilization of drinking water. With this method an inactivation rate of 99.99% could be obtained. In our biotest with mosquito larvae the irradiated preparation induced the same effect as the non treated one. For use ofB. t. i. in the calculated dosage in surface water the tolerance limit for drinking water will not be exceeded. Therefore, application of an UV-treatedB. t. i.-preparation for mosquito control should not be hampered by safety considerations.

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Mit 2 Abbildungen und 2 Tabellen

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Arbeitsgruppe Prof. Dr.H. W. Ludwig und Dr.W. Schnetter.     

Insecticidal activity and antifeedant effect of a new type biocide GCSC-BtA against Plutella xylostella L. (Lep., Plutellidae)

Insecticidal activity and antifeedant effect of a new type biocide GCSC-BtA and its two reactants Bacillus thuringiensis (B.t.) crystal and Abamectin against third instar larvae of Plutella xylostella L. (Lep., Plutellidae) were investigated using bioassays. GCSC-BtA showed significantly higher toxicity to P. xylostella with LC₅₀ of 0.021 mg/ml than B.t. crystal with 0.060 mg/ml and Abamectin with 0.139 mg/ml in leaf-dip bioassay. Net leaf-dip test gave LC₅₀s of 0.073, 0.071 and 0.670 mg/ml for GCSC-BtA, B.t. crystal and Abamectin, respectively. The significant differences of the biocide toxicities between leaf-dip and net leaf-dip methods showed the potential of net leaf-dip method for separating ingestion and contact poisons. Variation in toxicity of the biocide and two reactants in net leaf-dip method and in mortality in topical application bioassay showed that GCSC-BtA possessed a combination of strong stomach as well as contact poison property higher than B.t. or Abamectin. GCSC-BtA indicated no fumigant and systemic toxicities, which the two reactants lacked. In the antifeedant bioassay, GCSC-BtA acted as a strong antifeedant to the larvae of P. xylostella. Leaf consumption by the larvae after GCSC-BtA treatment was 0.04–0.60 mm² with a concentration range of 0.04–4.00 mg/ml, which was lower than 0.26–1.02 and 0.04–6.47 mm² for B.t. crystal and Abamectin, respectively. DC₅₀ (concentration resulting in a deterrence index of 50%) value for GCSC-BtA was 0.089 mg/ml, which was also significantly lower than 0.275 and 0.736 mg/ml for B.t. crystal and Abamectin, respectively.     

Zur Wirkung von Precocen 2 und Fenarimol auf die Kohlblattlaus,Brevicoryne brassicae (L.) und ihren ParasitoidenDiaeretiella rapae (M'Intosh)

The anti-hormone compounds, precocene-2 (anti-juvenile hormone) and fenarimol (anti-ecdysone) were evaluated against the green cabbbage aphid,Brevicoryne brassicae (L.) alone and for their compatibility with the endoparasiteDiaeretiella rapae (M'Intosh). The results revealed that precocene-2 provided more than 90% control ofB. brassicae acted on larvae within 72 h after the treatment, while fenarimol was less effective. Moreover, either precocene-2 or fenarimol extremely reduced the reproductive potentiality ofB. brassicae surviving adults. Both anti-hormone compounds demonstrated compatibility withD. rapae, a parasitoid ofB. brassicae. No considerable difference was detected when parasite emergence was compared from treated and untreated individuals.     

A potential lignan botanical insecticide from Phryma leptostachya against Aedes aegypti: laboratory selection,metabolic mechanism,and resistance risk assessment

The development of resistance to mosquitocides highlights the need for new insecticides that can be incorporated into a rational resistance management strategy. Botanical insecticides that are highly effective and safe to non-target organisms have recently gained attention. Haedoxan A (HA) is a lignan isolated from Phryma leptostachya L. that exhibits high activity against mosquito larvae. In the present study, we subjected Waco mosquitoes, a susceptible Aedes aegypti (L.) line, to selection with HA to investigate the insecticidal properties of HA and the mechanisms underlying the development of HA resistance. The resistance ratio achieved by third instar larvae from the HA-resistant (HAR) line at G₁₉ was 20.354-fold higher than that of the Waco line. Synergist tests showed that the HAR line developed resistance mainly via enhanced cytochrome P450-dependent monooxygenase activity. The realized heritability of resistance to HA in Ae. aegypti was 0.159. Resistance risk assessment indicated that 18 generations of Ae. aegypti are required for a tenfold increase in the LC₅₀ in real-world HA application. Moreover, HA had very low cross-resistance with imidacloprid and chlorpyrifos in the HAR line compared with the Waco line. Therefore, HA shows promise as a botanical insecticide for mosquito control.

     

Efficiency of the mixed biocide GCSC-BtA against vegetable pests of different arthropod orders in the south-eastern China

The present paper deals with the efficiency of the mixed biocide GCSC-BtA against vegetable pests of five orders of arthropod insects in the south-eastern China, i.?e., diamondback moth, Plutella xylostella (L.); green peach aphid, Myzus persicae (Sulzer); yellow-fanded flea beetle, Phyllotreta vittata Fabricius; vegetable leaf miner, Phytomyza nigricornis Macquart; and vegetable spider mite, Tetranychus neocaledonicus Andre. The results show that the mixed biocide GCSC-BtA has a higher efficacy of control against all of the five pests than the commercial biocide B.t. and insecticide Diazinon. GCSC-BtA gave a higher mortality value of 92.18?% against P. xylostella as compared to the biocide B.t. with a value of 64.70?% and Diazinon with a value of 50.00?%. Similar mortalities were obtained with the other four pests regarding the efficacy of the three products tested against them. The concentration-mortality regression equations were calculated by the probit analysis, from which the average mortalities were calculated. The values calculated for GCSC-BtA were 81.13?% for P. xylostella, 75?% for M. persicae and T. neocaledonicus, 69.23?% for P. vittata, and 61.03?% for P. nigricornis as compared to those caused by Diazinon: 33.33?%, 27.42?%, 66.31?%, 44.54?%, 19.65?% for P. xylostella, M. persicae, P. vittata, P. nigricornis, and T. neocaledonicus, respectively. Based on LC₅₀, P. xylostella was most susceptible to GCSC-BtA with a LC₅₀ value of 0.3445, followed by B.t. with a value of 0.8404 and Diazinon with a value of 1.3160. The LC₅₀ value of GCSC-BtA for M. persicae was 0.4660 which was about three times less than that of Diazinon. LC₅₀ value of GCSC-BtA for P. vittata was 0.3954 which was about the same as that of Diazinon. P. nigricornis and T. neocaledonicus were also much more susceptible to GCSC-BtA than to B.t. and Diazinon. It is concluded that GCSC-BtA kills more target pests than B.t. and is more effective than Diazinon in controlling the vegetable pests.     

Conjugation of δ-endotoxin from <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis> with abamectin of <Emphasis Type="Italic">Streptomyces avermitilis</Emphasis> as a new type of biocide,GCSC-BtA,for control of agricultural insect pests

Conjugation of δ-endotoxin from Bacillus thuringiensis with abamectin, a toxin of Streptomyces avermitilis, was carried out to form a new type of biocide, GCSC-BtA based on “Germany-China Scientific Cooperation” research, for the control of agricultural insect pests. The strategy for biochemical linkage was designed by conjugating an amino group in B.t. protoxin with a carboxyl group in carboxylated abamectin under the treatment of conjugator EDC [1-Ethyl-3-(3-dimethylaminopropyl carbodiimide Hydrochloride)]. The formation of B.t. protoxin was processed by solubilizing B.t. crystal in 25?mM dithiothreitol (DTT) at 37?°C for 2?h. The carboxylated abamectin was formed by carboxylating the NaH-activated abamectin with 10?mg/ml butyric anhydride at 111?°C in a water-circumfluent condensation device for 2?h. The conjugating reaction, consisting of 5?mg/ml B.t. protoxin, 10?mg/ml carboxylated abamectin and 19.17?mg/ml EDC, was successfully conducted at room temperature for 24?h. Significant differences were found between pure abamectin, carboxylated abamectin and the conjugated BtA by means of UV-photo absorptions recorded at wavelengths 354, 438, 518, 600?nm (P?<?0.01). LT₅₀ of the conjugated GCSC-BtA to the 3^rd instar larvae of Plutella xylostella (L.) (Lep., Plutellidae) was 35.27 μg a.i./ml, about 62?% and 76?% of that caused by the B.t. protoxin and the caxboxylated abamectin, respectively. The conjugated GCSC-BtA caused 87.14?% mortalities in larvae of P. xylostella, 93.75?% in adult Myzus persicae (Sulzer) (Hom., Aphididae) and 89.33?% in adult Phyllotreta vittata Fabricius (Col., Chrysomelidae) as compared to 48.33?% by the B.t. crystal only in P. xylostella. The symptoms caused by conjugated GCSC-BtA in the 3^rd instar of P. xylostella were black color in the head part and white-yellow in the abdomen of dead larvae, which differed from the black color or the white-yellow all along the body caused by either the B.t. crystal or the abamectin, respectively. It was concluded that the conjugated GCSC-BtA biocide had a broader host spectrum and a faster killing speed than either the B.t. crystal or abamectin alone for the control of agricultural pests.     

Toxic effects of limonene againstCulex quinquefasciatus Say larvae and its interference with oviposition

Limonene, a major constituent of citrus essential oil isolated from abraded fresh peels of bitter orangeCitrus aurantium L., was tested for its toxicity against early 4th instar larvae ofCulex quinquefasciatus Say. The response of treated larvae was concentration-dependent and LC₉₀s were 53.80 and 32.52 ppm after 24 and 48 h of treatment respectively. Limonene treated water was less favorable for oviposition by females ofCx. quinquefasciatus.     

Toxicity and repellence of Taiwanese indigenous djulis, Chenopodium formosaneum, against Aedes albopictus (Diptera: Culicidae) and Forcipomyia taiwana (Diptera: Ceratopogonidae)

The biological activity of djulis (Chenopodium formosaneum) extracts was evaluated against mosquitoes and biting midges. Djulis extracts were relatively nontoxic to Aedes albopictus larvae. However, they showed interesting repellence against adult mosquitoes as estimated by the median effective dosages (ED₅₀). ED₅₀ values for djulis extracts against mosquito adults in descending order were: seed extracted with methanol (0.83 %), seed extracted with dichloromethane (0.66 %), leaf extracted with methanol (0.50 %), and leaf extracted with dichloromethane (0.40 %). Field tests also suggested that djulis methanol extracts were effective at about a 1 % level against biting midges (Forcipomyia taiwana). A total of 15 and 20 compounds accounting for 88.8 and 79.9 % in the seed and leaf extract, respectively were identified by gas chromatography coupled to mass spectrometry (GC–MS). Among these, 9, 12-octadecadienoyl chloride, (Z, Z) was found in both as well as being the major constituent in the leaf extract (35.7 %). Further studies on the repellent property of the extracts against mosquitoes and biting midges are warranted.     

Bioactivities of caffeic acid methyl ester (methyl-(E)-3-(3,4-dihydroxyphenyl)prop-2-enoate): a hydroxycinnamic acid derivative from Solanum melongena L. fruits

Feeding deterrent and growth inhibitory effects of caffeic acid methyl ester (CME) isolated from the fruit extract of eggplant, Solanum melongena L. along with two known phenolic acids, caffeic acid (CA) and chlorogenic acid (CG) and azadirachtin (taken as active control), were evaluated against Spodoptera litura Fab. and Achaea janata L. (Lep., Noctuidae). The structure of CME was determined on the basis of extensive spectroscopic (UV, FTIR, ¹H, and ¹³C NMR) data analysis. CME has exhibited strong feeding deterrent activity against S. litura and A. janata larvae with ED₅₀ values of 52.02 and 41.02 μg/cm² leaf area, respectively. CA and CG were relatively less effective compounds when compared with CME. The results also revealed that the isolated compound CME caused marked larval growth inhibition in S. litura and A. janata larvae after 7 days of feeding on a treated diet. The effect on growth of larvae was concomitant with the reduced feeding and digestibility of ingested food. So the activities of digestive proteases within the midgut of larvae were examined using specific substrates to understand the digestive physiology in the larval guts. The bulk of the activity was associated with serine proteases comprising trypsin-, chymotrypsin-, and elastase-like enzymes, which decreased in diets containing CME, whereas, interestingly increased with CG. From the results, we conclude that CME isolated from S. melongena fruit extract shows feeding deterrent and larval development inhibitory activities that may prove useful in the management of S. litura and A. janata larvae.     

Evaluation of nine strains ofBacillus thuringiensis Berliner against the giant looper,Boarmia (Ascotis) selenaria Schiffermüller (Lepidoptera,Geometridae)

Nine isolates ofBacillus thuringiensis Berliner belonging to var.kenyae, var.aizawai and var.entomocidus, were bioassayed against 1st instar larvae ofBoarmia (Ascotis) selenaria Schiffermüller and compared withB. thuringiensis var.kurstaki, HD-1-S-1980. None were found to have a higher potency than HD-1-S-1980, which is used for commercial control of young larvae of this pest in avocado plantations in Israel.     

Parasitoids of Saperda populnea (L.) (Coleoptera: Cerambycidae) on aspen (Populus tremula L.) in Bulgaria

The parasitoids of Saperda populnea (L.) (Col.: Cerambycidae) were studied in Bulgaria during the period 1997?–?2001. Galls with pest larvae were collected from young aspen trees at eight locations (Sofia, Kokaliane, Plana, Churek, Gorni Lom, Gintzi, Dolno Kamartzi and Klisura) and examined under laboratory conditions. Four species were reared from 1118 galls containing overwintering pest larvae: Iphiaulax impostor (Scop.) (Hym.: Braconidae), Dolichomitus populneus (Ratz.), Schreineria populnea (Gir.) (Hym.: Ichneumonidae) and Billaea irrorata (Meig.) (Dipt.: Tachinidae). All of the parasitoids were solitary. Schreineria populnea was found as a new parasitoid of the host in Bulgaria. B. irrorata emerged mainly from late-stage S. populnea larvae; the remaining species from both early- and mid-stage larvae. In the parasitoid complex of S. populnea, the most numerous were B. irrorata (59.8?%) and D. populneus (29.4?%). The percentage of host larval parasitism varied from 2.4 to 33.3, with an average of 9.7?%. B. irrorata was the most important in reducing the pest number. The average mortality of S. populnea caused by the tachinid was 5.8?%, and the highest mortality observed in individual study was 20.2?%.     

The potential of resynthesized lines to provide resistance traits against rape stem weevil in oilseed rape

The rape stem weevil, Ceutorhynchus napi Gyll., is a serious pest of winter oilseed rape (Brassica napus L.) crops in Europe that causes stem distortion, severe disruption of stem growth, and significant yield loss. No resistance has been identified in current B. napus breeding material. Resynthesized lines of oilseed rape can be used to introduce genetic material from the parent species Brassica oleracea L. and B. rapa L. The susceptibility to C. napi of five resynthesized lines and three cultivars of oilseed rape was compared in a multi-choice field plot experiment. Morphological stem traits and stem levels of glucosinolates, carbon, and nitrogen were assessed as potential mediators of resistance. Eggs and larvae of C. napi in stems were counted weekly from the beginning of oviposition to larval maturation and stem pith degeneration in response to oviposition was assessed. Egg counts per stem were negatively dependent on stem length and positively dependent on the levels of five glucosinolates, glucobrassicanapin, glucoalyssin, glucobrassicin, neoglucobrassicin, and gluconasturtiin. The resynthesized line S30 was significantly more resistant to C. napi than the commercial cultivar Sollux, having fewer eggs and larvae. This resistance appeared to be largely antixenotic, due to the combination of a long stem and a paucity of the five key glucosinolates. We propose that resynthesized lines such as S30 should be used to introduce genes determining traits such as long stem length and glucosinolate profile into breeding programs to enhance resistance against C. napi in oilseed rape.     

Über Eignung und Reaktion überwinternder und aktiver Raupen von Sesamia cretica Led. (Lepid., Noctuidae) in bezug auf den Parasitoiden Bracon brevicornis Wesm. (Hymen., Braconidae)

Laboratory studies were undertaken to determine the differential response and suitability of 2 types of host larvae ofSesamia cretica (hibernating and active) to the development of the braconid,B. brevicornis. The parasitoid was able to immobilize the 2 forms of larvae. However, hibernating larvae were significantly less sensitive to the parasitoid's venom than active larvae. Parasitoid parents (specially females) which associated with hibernating larvae were significantly longer-lived than those kept with active larvae. Life cycle period of the parasitoid did not affect with any of the 2 types of larvae. However, numbers of each of cocoons and emerged adults/larva were significantly higher in case of hibernating than in case of active larvae. Moreover, the produced adults from hibernating larvae were significantly larger in their size. Therefore the hibernating host larvae will serve better for mass colonization of this braconid.     

Oviposition preference and larval performance of Aeolesthes sarta (Coleoptera: Cerambycidae) in six hardwood tree species

Sarta longhorned beetle (SLB), Aeolesthes sarta Solsky, is an economically important pest of fruit and shade trees in central and east Asia. Choice, no-choice, and larval insertion experiments were conducted to determine SLB oviposition preference and larval host suitability on six hardwood tree species including Ulmus carpinifolia Borkh., Ulmus carpinifolia var. umbraculifera Rehd., Platanus orientalis L., Populus alba L., Salix alba L., and Fraxinus rotundifolia Miller subsp. persica (Boiss.), under laboratory conditions. In the choice and no-choice experiments, significantly greater numbers of eggs and living larvae, and greater mass of living larvae were found on U. carpinifolia and U. carpinifolia var. umbraculifera compared to those on the other tree species. In the choice experiment, oviposition did not occur on F. rotundifolia subsp. persica. There were a few eggs on P. alba but no living larvae. The mean mass of living larvae was lowest on P. orientalis. In addition, in the no-choice experiment significantly fewer numbers and mass of living larvae were found in P. alba and F. rotundifolia subsp. persica. In the larval insertion experiment, more larvae survived on U. carpinifolia and U. carpinifolia var. umbraculifera compared to the other trees. Larvae recovered from U. carpinifolia and U. carpinifolia var. umbraculifera weighed significantly more than larvae from the other trees. These results suggest that U. carpinifolia and U. carpinifolia var. umbraculifera are the most preferred and suitable hosts for SLB adults and larvae. Salix alba is an acceptable host for adult oviposition and a potentially suitable host for larval development. Platanus orientalis and P. alba are less suitable, and F. rotundifolia subsp. persica appeared to be unsuitable as a host for SLB.