The effect of six plant essential oils against three stored grain insects, Sitophilus oryzae, Rhizopertha dominica and Tribolium castaneum were studied under laboratory conditions. The tested oils are namely, fennel oil (Foeniculum vulgare), caraway oil (Carum carvi), cinnamon oil (Cinnamomum verum), citronella oil (Cymbopogon winterianus), nutmeg oil (Myristica fragrans) and black cumin oil (Nigella sativa). The result showed that increasing of the oil concentration and exposure times significantly increased the mortality percentage.Generally, the toxicity of essential oils at all tested concentrations increased with the increasing of exposure time. So, the results indicated that toxicity of all tested essential oil against the three stored grain insects at the high concentration was recorded high mortality faster than low concentration.The tested essential oils significantly decreased the different haemocyte counts in tested insects, cinnamon oil markedly increased the haemocyte surface areas in the tested insects especially the surface area of oenocytoides in T. castaneum.The recorded results indicate that the essential oils of fennel, caraway, cinnamon and citronella could be applicable to the management of S. oryzae, R. dominica and T. castaneum adults.

No abstract

In Egypt, parasitic weed species, Orobanche crenata Forsk is one of the major constraints to the production of faba bean, which is considered the most important food legume in the country. The broomrape fly, Phytomyza orobanchia Kaltenbach (Diptera, Agromyzidae) is particularly suitable for biological control since it is oligophagous feeding in the larval stage, only on Orobanche species. The objective of the present study is to estimate the number of annual generations of P. orobanchia, using growing degree-days (GDD) in Alexandria region, Egypt. Results revealed that development of Phytomyza immature stages (from egg deposition to adult emergence) required 103.5, 90.0, 79.5, and 93.5 DD through 31, 20, 18, and 16 days for the investigated four generations, respectively. Percentage of infested Orobanche capsules positively increased with increasing accumulated degree-days. A linear model for predicting infested capsules with P. orobanchia through knowing DD was estimated. The constructed model may be used also in predicting Orobanche capsule infestation with P. orobanchia. Results also indicated that estimating the degree-days will help in predicting the occurrence of the first egg laid for P. orobanchia in O. crenata flowers in the field for the first generation and subsequent generations. Knowledge of the Phytomyza activity will provide a prediction for adult emergence and subsequent egg laying and potential damage by larvae according to infestation percent of Orobanche capsules through the successive generations. This may help the biological control programs to justify the required numbers of Phytomyza and adequate time for releases to obtain the maximum destruction of Orobanche seeds.

Onion maggot (Delia antiqua M) is an economically important pest of Allium crops throughout the world; thus, management of this pest is required to achieve economic returns. Accordingly, this study aimed to select some clones of garlic resistant to infestation with onion maggot through the implementation three cycles of clonal selection program within some improved garlic clones derived from Balady cultivar. Afterwards, the developed clones and their original population were evaluated in a randomized complete block design with three replicates. Thus, this study was conducted during four successive winter seasons of 2016/2017 to 2019/2020. The obtained results showed, clearly, significant differences among garlic selected clones, as well as their original population in their response to Delia antiqua M. and their bulb characteristics. Where, the selected clones varied between resistant and ability of infestation by onion maggot that was between 0.00% and 22.45%, with classification into five groups by cluster analysis: HR (highly resistant), R (resistant), MR (moderately resistant), MS (moderately susceptible) and S (susceptible). Among the 16 selected clones three clones were HR; and six clones were R to onion maggot. Moreover, improvement percentage for the same character using clonal selection program was between 48.97% to 100%, which reflected that clonal selection could be an effective way to improve onion maggot resistance. Also, utilization of these improved clones will promise in minimize environmental pollution.

Tomato is the most susceptible hosts to many insect pests and broomrape, which causes significant yield losses. The present study was carried out with the purpose to know which infestation density of Egyptian broomrape (Phelipanche aegyptiaca Pomel) was affected on efficiency the bio-agent, Phytomyza orobanchia Kaltenbach (Diptera: Agromyzidae) in the area grown with tomato crop, which was affected at the same time by tomato leaf miner, Tuta absoluta (Meyrick) (Gelechiidae: Lepidoptera) under natural conditions during two successive years (2019 and 2020) at El-Beheira governorate, Egypt. Three randomized fields cultivated with tomato crop in summer were selected during 2019 and 2020. Infestation density with Ph. aegyptiaca was divided into three levels, Low (1 -10 shoots / plant), Medium (11 -25 shoots / plant) and High (≥ 25 shoots / plant). Number of pupae in capsules, number of pupae in stems, total number of pupae in shoots and the percentage of pupae in capsules were determined per Ph. aegyptiaca shoot. Highest effectiveness of P. orobanchia (36.0%) was recorded in low infestation density with Ph. aegyptiaca, while with medium and high infestation density with Ph. aegyptiaca only 23.5% and 18.6%, respectively in second year 2020. No significant difference was found between low and medium infestation density with Ph. aegyptiaca in the total number of P. orobanchia pupae per shoot. At the beginning of fruiting stage of tomato crop, leaves and fruits were taken from the randomly selected tomato plants according to infestation density with Ph. aegyptiaca flourishes, to estimate the infestation percent by leaf miner (Tuta absoluta) throughout the two year (2019-2020). In addition to, percentage of parasitism by egg parasitoids of the genus Trichogramma on tomato leaf miner was determined. According to infestation density with Ph. aegyptiaca, tomato yield was calculated. At the end of this study, under the medium infestation density of Egyptian broomrape the infestation percent by T. absoluta was (16.67%) synchronized with high percentage of its parasitoid, Trichogramma spp. (63.2%) with high yield of tomato (820 gm/ plant) compared with control (without infestation with Ph. aegyptiaca).Obtained data may provide information for improving effective of P. orobanchia in biological control program of Ph. aegyptiaca in the frame of integrated pest management (IPM) of T. absoluta in tomato fields. However, combining Egyptian broomrape (Ph. aegyptiaca) and T. absoluta in IPM program will contribute to management efficacy as well as avoid used each control methods separately for each pest. Further research is needed to choose the timing in combining between these pests to use IPM, taking into consideration efficacy, cost and environmental aspects.