Two species of pink stem borers cause serious damage on their hosts in Iran. Chemical control of them caused pest resurgence. Their egg parasitoid was distinguished as Platytelenomus hylas Nixon (Hym.: Scelionidae). Studies on rearing and releasing of this parasitoid, for biocontrol purpose, indicated that the wasps have a high spescialization and for multiplication it is necessary to use their natural hosts. In this investigation two semi-artificial and three natural diets (Sorghum, Corn and Sugarcane stems) for rearing in Laboratory conditions were used. On each diet mean of larval period, pupation percentage, means of male and female pupal weight, mean of pupal period and percentage of emerged adult were evaluated. Finally fertility rate of emerging adults from each diet were compared by CRD experiment. In vivo rearing of species of the stem borers have no success on semi-artificial diets whereas rearing on natural hosts were more efficiently. Survival rate and quality of Scretica fed on sorghum were higher than S.nonagrioides botanephaga whereas individual of the latter could be reared more successfully on corn. Comparison of food effect on adult fertility indicated that food quality have no effect on fertility of S cretica whereas individuals of the latter that reared on corn and sorghum in 5% probability level have a significant difference with sugarcane and moths have laid more eggs.

Background and Objectives The sugarcane stem borers, Sesamia cretica Lederer and S. nonagrioides Lefever are the most important pests of sugarcane in Iran causing heavy losses in cane and considerable reduction in sugar yield. The egg parasitoid wasp, Telenomus busseolae Gahan is the most remarkable natural enemy of Sesamia spp. in Khuzestan province, Iran that plays an important role in regulating the populations of sugarcane stem borers. Temperature is an effective abiotic factor that influences the development of natural enemies. The present study aimed to investigate the temperature-dependent development of T. busseolae on S. cretica. Material and Methods The development rates and thermal constant of the immature stages of T. busseolae on S. cretica eggs were studied at seven constant temperatures (15, 18, 20, 25, 30, 35, and 37ºC), a photoperiod of 16L:8L, and 65%±5% RH. Fresh egg masses of S. cretica were exposed to the newly mated female of T. busseolae for 6 h. Afterwards, the parasitized eggs were kept at different temperatures. The parasitized eggs were checked daily until adult emergence. Development rate was modeled as a function of temperature using two mathematical models, including common and Ikemoto and Takai linear models. The linear models were analyzed using the SAS software. Results The results of regression analysis showed that the immature developmental period of T. busseolae decreased with elevating temperature from 18ºC to 35ºC. In 15ºC and 37ºC, no development rate was found for T. busseolae. Immature development time declined from 45 to 11 days and 46 to 12 days in male and female parasitoids, respectively. The percent of adult emergence was not affected by temperature. However, two linear models provided a satisfactory relationship between immature development rate and temperature. Based on statistical criteria, Ikemoto and Takai linear model estimated thermal constant and temperature threshold more precisely. For male and female parasitoids, the thermal constant was 250 and 255 degree-days and the low-temperature threshold was 12.44ºC and 12.5ºC on S. cretica eggs, respectively. Conclusion In the current study, the thermal requirement of T. busseolae on S, cretica was estimated for the first one. Information regarding the thermal requirement of T. busseolae can be useful for the rearing and application of this parasitoid in the biological control of sugarcane stem borers. This finding could be used to predict the number of T. busseolae generations and the best time for parasitoid release in sugarcane fields.

The corn stem borer Sesamia cretica Led. (Lepidoptera. Noctuidae) is one of the most important corn pests in Iran. Chemical control of this pest is rather difficult due to larval living inside the corn stem. As the role of nutrients is critical in plant resistance to pests, adequate crop fertilization can be a good preventive measure to control this pest. Phosphorus (P) is one of the essential elements required for plant’ s performance, otherwise its limitation can impose severe consequences on cellular function and the growth rate. In the current study, the effect of different phosphorus fertilizer formulations was conducted on the corn stem borer infestation in a randomized block design of field conditions. Stem borer infestations were evaluated by the number of dead hearts and the percentage of infested stalks. The establishment of larvae under the greenhouse conditions were investigated. Results showed that the lowest and highest dead hearts were related to the application of P slow release fertilizer treatment with 1. 15 % and the control treatment with 4. 53 %. A significant decrease in infestation was observed when the slow-release phosphorus treatment by 10% stem compared to control and other treatments. Minimal and maximal percentages of larval establishment were observed in slow-release phosphorus treatment with 10% larvae and control with 57. 5% larvae per plant respectively. Based on the results of this research, application of slow-release phosphorus fertilizer in corn stem borer management is recommended.

Stem borer moth, Sesamia cretica Lederer, causes major damage on sugarcane. Sex Pheromone ofS. cretica was synthesized in the chemical laboratory of Iranian Research Institute of Plant Protection. Efficacy of the synthesized pheromone with 3 types imported pheromone ofS. cretica from Russell, Econex & Silvanderson companies were tested at the fields of Sugar cane Agro-Industrial Company of Ahvaz during 2014. Also, attractiveness of the synthesized pheromone was investigated with funnel and delta traps.The results showed significant differences among treatments (p<0.01). The synthetic pheromone with doses of 0.5, 1 and 2 mg had more attractant (5±0.91, 2.75±0.45 and 3.75±0.85 mean±SE, respectively) in comparison with the imported pheromones that had no moth capture. Analysis of the imported pheromones by mass spectroscopy devices indicated these pheromones contain only two molecules including (Z) -9-tetradecen-1-ol and (Z) -9-tetradecen-1-ylacetate. None of the imported pheromones had third molecule (Z) -11-hexadecen-1-ol, and for this reason they had no attraction for S. cretica in the field experiments. Funnel traps with doses of 1 and 2 mg had the most trapping (12.25±2.68 and 11.25±2.80, respectively). Delta trap treatments with doses of 1and 2 mg had less capture (0.00±0.00 and 0.25±0.25). Therefore, we can conclude that proper formulation forS. cretica sex pheromone with three molecules and a funnel trap is the most suitable shape for trappingS. cretica.

The sugarcane stem borer, Sesamia cretica Lederer, is one of the most economically important pests of sugarcane in Khuzestan province, southwest Iran. The egg parasitoidTelenomus busseolae Gahan significantly affect S. cretica population in the field. Host age is an important factor of host acceptance and suitability for egg parasitoids. We examined the ability of T. busseolaeto parasitize and develop in S. cretica eggs of different ages. In a no choice laboratory experiment, we measured the effect of host age (12, 36, or 60 h old) on parasitism rate and offspring fitness characteristics such as survival, development time, sex ratio, size, and progeny longevity and fecundity. Results revealed that the suitability of host eggs decreased as host age increased. Exposure of parasitoids to 12h old eggs resulted in higher percentage parasitism, higher acceptance, higher survival and larger body size of parasitoid progeny. Progeny that emerged from 12h old eggs had also higher longevity and fecundity than those emerged from other host ages tested.

Demographic parameters of the pink stem borer, Sesamia cretica Lederer (Lepidoptera: Noctuidae) were estimatedon its two main host plants, maize and sugarcane. The present studywas conducted under laboratory conditions at 27±1oC, 50±10% Relative Humidity (RH %), and a photoperiod of 0: 24 (L: D) hour for the larval stage and 16: 8 (L: D) hour for the other life stages. The raw data were analyzed based on the age-stage, two-sex life table theory. For estimating the SE of the population parameters, the bootstrap technique was applied. Total pre-adult developmental periods of the pink stem borer were51.95 and 39.51 days on maize and sugarcane, respectively. The oviposition periods were 5.03 and 5.38 days and fecunditywas 118.04 and 142.88 eggs on maize and sugarcane, respectively. Peaks of reproductive value occurred at ages 49 and 38days when reared on maize and sugarcane, respectively.The net Reproductive rate R 0, intrinsic rates of increase r and finite rate of increase  l of S. cretica were 53.58 offspring, 0.0937 day-1 and 1.0983 day-1 on sugarcane and 39.54 offspring, 0.0672 day-1 and 1.0695 day-1 on maize, respectively. Themean generation Time (T) of the pink stem borer was 42.41 and 54.57 days on sugarcane and maize, respectively. There was significant difference between demographic parameters of S. cretica on maize and sugarcane. The results showed that there was higher reproductive performance and population growth of S. cretica on sugarcane than on maize.