mohammadreza attaran

In some Trichogramma species, parthenogenesis is mostly induced by intracellular symbiotic Wolbachia bacteria. Populations of this egg parasitoid wasp that produce more female progeny can potentially have higher fitness. After finding a thelytokous Wolbachia-infected native strain of Trichogramma brassicae, a study was conducted to evaluate its parasitism rate and foraging efficiency in the greenhouse and field conditions. Treatments included a Wolbachia-associated thelytokous T. brassicae strain (A), an uninfected natural bisexual population (B), and an antibiotic-cured bisexual population (CB). Results of the equal female wasps’ releases revealed no significant difference among the three populations regarding their dispersal ability, mean parasitized eggs (PE) and parasitized bait cards (PBC) per female on forage corn (SC704) in greenhouse condition. However, when equal wasp individuals were released (e.g. 100 individual wasps including males in the bisexual populations), the number of mean parasitized egg batches by asexual line (7.57 PBC) was significantly higher compared with that in B and CB bisexual populations (4.50 and 4.97 PBC, respectively). Similarly, in the corn field condition, the highest number of parasitized bait cards and parasitized egg numbers belonged to asexual wasp (A) (1.94±0.21 PBC and 7.26±1.2 PE/female) compared with those in B (1.56±0.39 PBC and 5.46±1.99 PE/female), and CB (1.6±0.3 PBC and 5.82 ± 1.96 PE/female) bisexual populations. In general, it can be concluded that the use of an asexual Wolbachia- associated line of T. brassicae can increase the efficiency of this biological control agent at the field level in addition to reducing mass production costs.

The study of the thematic trends of articles published in Persian in the field of plant pests and categorizes them based on specified fields to determine their issue and evaluate them based on the priorities and requirements.

This research is a qualitative research based on content analysis and a descriptive-analytical approach has been used to describe and evaluate the content of the target community's articles. The research population consisted of all articles (2028 articles) published in seven prestigious scientific journals from 2008 to 2017. The articles were categorized and coded according to the subjects (6 subjects) and features of the authors (the first or the rest authors). Then, the obtained data were sorted and analyzed by means of software Excel, and tables and charts were prepared

From the point of view of number abundance, the articles with the laboratory subject were ranked first, the molecular subject the last (sixth) and the applied field the fifth. About 30% of the first authors were from the Research, Training and Promotion Organization of the Agriculture and 70% from universities.

The topic selection and design of the research were more based on the article preparation.

The carob moth Ectomyelois ceratoniae (Lep.: Pyralidae) is the most important pest of pomegranate in Iran which annually causes considerable damages. Trichogramma wasps are one of the main factors in biological control of this pest, which can be used effectively to reduce damage. In this research, biological parameters of three species ofTrichogrammatids viz. T. brassicae, T. emryophagum and T. pintoi were evaluated on the carob moth, (E. ceratoniae) eggs under the laboratory conditions. The results showed that reproductive period, post-reproductive period and adult life span for T. brassicae reared on the carob moth were 7.8, 0.9, 8.7 days, respectively. These parameters for T. embryophagum were 8.2, 1.00, 9.2 days and for T. pintoi were 7.4, 1.1, 8.5 days, respectively. The studied species lacked pre-reproductive period. The results also showed that gross reproductive rate (GRR), intrinsic rate of natural increase (rm), mean generation time (T) and finite rate of population increase (λ) for T. brassicae reared on the carob moth were 38.021 (eggs), 0.286 (day-1), 12.659 (days), 1.330(day-1), respectively. The above calculated parameters for T. embryophagum reared on the same host were 39.247 (eggs), 0.311 (day-1), 11.659 (days), and 1.365 (day-1), and for T. pintoi they were 28.626 (eggs), 0.262 (day-1), 12.558 (days), and 1.300 (day-1), respectively, that was significantly different. It can be concluded that efficiency of T. embryophagum species compared with two other species, T. brassicae and T. pintoi on the carob moth eggs was higher. Therefore, it is recommended to use this species in integrated pest management program.

In order to select a suitable species of the trichogrammatid wasps for biological control of the codling moth، some of the trichogramatid wasps were collected and identified from the apple orchards located in north east of Tehran province by direct sampling on the codling moth eggs and using egg traps. Furthermore، laboratory experiments were carried out according to completely randomized design for evaluation of fecundity and longevity of the collected wasps at temperatures 22، 24، and 26°C by using the eggs of Sitotroga cerealla as factitous host. Moreover، host acceptance of the codling moth eggs by the wasps was examined statistically after five generation rearing on factitious host. Three species of the trichogrammatid wasps، Trichogramma brassicae، T. pintoi، and T. embryophagum، were collected and identified from the studied apple orchards located in Damavand and Rodehen region. According to the obtained results، fecundity of the evaluated wasps at temperatures 24 and 26°C were higher statistically than temperature 22°C. The highest values of the fecundity of T. pintoi and T. embryophagum were 30. 96 and 26. 46 eggs/female at studied time interval، respectively. In order to examine host acceptance level of the wasps، the percentage of the host eggs parasitism were determined as 73. 64% and 17. 70%، by T. embryophagum and T. pintoi، respectively. Considering all the obtained results، collected native strain of T. embryophagum was introduced as a suitable choice for extension of the biological control program aginst the codling moth in apple orchards located in study region.

The codling moth, Cydia pomonella, is the most important pest insect in apple orchards. Efficacy of a native strain of the egg parasitoid wasp, Trichogramma embryophagum, was statistically compared with chemical control and check treatments in an apple orchard. The best times for releasing the parasitoid wasps were determined by using a forecasting model based on estimation of Growing Degree Hours (GDH). Codling moth biofix was determined by using pheromone traps, and environmental temperature in the apple orchard was recorded hourly for estimation of GDH. Based on the recorded temperatures and by using phenological forecasting model, the best times for releasing egg parasitoid wasps were determined. The wasps were released five times for two generations of the codling moth. The results of the efficacy test, showed that there was no statistically difference between chemical and biological control treatments using Tukey range test (P

Trichogramma wasps (Hym., Trichogrammatidae) are frequently used as egg parasitoid and biological control agent of lepidopteran pests. These haplodiploid wasps display two reproductive modes, including thelytoky and arrhenotoky. The thelytoky (unisexuality) are often associated with the presence of endosymbiotic Wolbachia bacteria (α-proteobacteria). The use of thelytokous parasitoids has long been considered as a way to enhance the biocontrol efficacy. In this study a series of experiments were conducted to compare the behavioral aspects, dispersal potential and parasitism of thelytokous (BW+) and bisexual (B) Trichogramma brassicae strains (Baboulsar ecotype) at 25◦C in laboratory conditions. By using Y-tube olfactometer, it was observed that the Wolbachia infection in the Baboulsar strain (mixed population) neither affected the wasp's response to volatile odors of honey water solution and factitious host eggs nor did it interfere with female wasp's sex pheromone emission. Greenhouse release tests on corn plants, resulted in non significant differences between the strains taking the number of parasitized eggs per one female wasp into consideration. However, based on releasing 100 wasps (male and female in the case of bisexual), the number of egg masses parasitized by thelytokous T. brassicae (6.01) was significantly higher than B strain (2.88). Therefore, this thelytokous line of Trichogramma might be superior to bisexual conspecifics under more natural conditions and hence have a higher potential in pest control.