EFFICIENCY OF PREPARED BAITS OF LONE OR/AND ADMIXED FOUR BOTANICAL OILS ON THE VIABILITY OF SUCCESSIVE RAISED GENERATIONS OF AGROTIS IPSILON (HUFNAGEL) (INSECTA: LEPIDOPTERA: NOCTUIDAE) AFTER TREATING THE PARENT ONES.

The present study is initiated to determine the toxic and delayed effects of four botanical oils on the greasy cutworm A. ipsilon, aiming to attain an alternative environmentally safe and effective phytochemicals against the insect-pest. Four botanical oils (camphor, red basil, menthol and rose oil) were added at rates of 0.5 and 1.0% (v/w). The tested oils were added alone, and/or admixed at proportional rate of 1:1 in the prepared baits against the exposed 4th instar till the 6th instar larvae of the insect. The study was run under the laboratory higrothermic conditions of 25±2°C and 65±5% R.H. The results showed that the tested baits of camphor, red basil and menthol oils at concentration rates of 0.5 and 1.0% (v/w) adversely affected the inspected parameters of fitness components of the treated individuals of parent (p) generation. They gave more or less fewer numbers of weak unviable adult-moths, which were either sterile or they laid few numbers of infertile eggs and died before the induction of (F1) progeny. That failure could be elucidated by the rapid occurrence of drastic effects on the biological performance of both the influenced sexes of adult-moths along the period of parent's development. Finally it ended by the inhibited induction of (F1) progeny. A delayed effect of the prepared baits of rose oil at 0.5 and 1.0% (v/w), was assessed on the following raised F1, F2, F3 and F4 generations after parent's treatment. The delayed effect was detected as less efficient latent effect on each of these consequently raised generations; characterized by the gradual decrease of the number of alive immatures and adult-moths. The effect was recorded as gradual increase of dead and malformed individuals and adult-moths. In addition to the gradual decrease of deposited and/or hatched eggs up to the 4th generation, which ended by the complete failure of the development. That failure could be also attributed to the cumulated effects of the induced recessive lethal genes in both the influenced sexes during the periods of raised F1, F2 and F3 generations. The recessive lethal genes caused drastic unprofitable effects that appeared at the beginning of the 4th generation that failed. Also, the tested baits (0.5 and 1.0%, v/w) of each of admixed camphor, red basil and menthol oil with rose oil (1:1), greatly affected the developmental parameters of the treated insects. The highest efficient toxicity and an adverse biological performance of the admixed camphor and/or red basil oils with rose oil at 0.5 and 1.0 (v/w), and menthol/rose oil at 0.5% (v/w) on the treated parent generation were detected. The previous treatment gave unviable sterile adults, which died before the induction of (F1) progeny. That recorded failure of (F1) proves the fastest toxic efficiency and a drastic biological performance which were entirely unable to induce (F1) progeny. The tested bait of mixed menthol/rose oils (1.0%, v/w), showed significant reduction in all studied parameters of F1 and F2 fitness components. The tested bait raised sterile unviable adult-moths of (F2) generation which furtherly ended by the distinct failure of (F2) development. This effect may be caused by the cumulative effects of the induced recessive lethal genes in both of the affected sexes through the developmental period of (F1) generation after (P) one treatment, inducing apparent drastic effects, which were revealed at the beginning of (F2) generation. Remarkably, the inspected faster or slower occurred toxicity and drastic biological performance of these admixed botanical oils, may be referred to the synergistic action for most of the evaluated mixtures or/and the additive one for menthol/rose oil (1.0%), which needs further investigation.

Efficiency of guva and lemon grass fine dusts on the potato tuber moth Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae).

The present study was initiated to elucidate the effect of potato tubers treatment using fine dusts of Psidium guajava, Cymbopogon citratus, talc powder and their progressive dilutions(w/w) on the fitness components of raised generations of the potato tuber moth (PTM), Phthorimaea operculella. Results showed a direct as well as cumulative delayed effect of the tested plants fine dusts, either alone or admixed with talc powder in progressive dilutions from 5% up to 50% w/w on the viability of developing immatures and potentiality of adult moths. The revealed effects of each of the tested crude plant fine dusts or talc powder alone and/or their progressive dilutions (w/w) could be explained briefly as gradual significant shortening of life span of both sexes, prolongation of larval duration, reduction in number of raised pupae, increase of malformed ones, sharp decrease in the rate of emerged moths, deposited eggs, and developing of immatures; According to lower used dilutions of each tested plant fine dust from 5% to 20%, the complete inhibition of reproductive potential of both adult sexes, the going on metamorphic development of deposited eggs and/or raised immatures of the following generation, after the treatment of parent one, had been revealed the following distinct failure of: a) F1 development after former treatment of parent generation with the higher concentrations of 30-50% of both tested plant fine dusts and the lower prepared dilutions (10% and 20% (w/w)) of both the tested Psidium guajava and (20% (w/w)) Cymbopogom citratus plant fine dusts, resulted in fewer number of the emerged moths that were unviable, weak, sterile and died before induction the F1 progeny, b) F2 development due to the former treatment of the parents with talc powder, Psidium guajava fine dusts alone or its prepared dilutions of (5% (w/w)) and Cymbopogom citratus dilution of (10%(w/w)) gave unviable weak and sterile moths unable to induce the F2 progeny, c) F3 development post former treatment of the parent generations with Cymbopogom citratus dilution of 5% (w/w) induced unviable sterile moths and died after emergence and d) F4 development owing to the former parent treatment with Cymbopogon citratus fine dust alone; The complete failure of each of the above mentioned generations could be attributed to the cumulative effect of induced recessive lethal genes in both sexes along the extended period of each of these following generations, post former treatment of parent one, causing apparent undesirable effects, that appeared at the beginning of each of them.

A novel approach for the management of the chalkbrood disease infesting honeybee Apis mellifera L. (Hymenoptera: Apidae) colonies in Egypt.

Except for, very few articles regarding the influence of some organic acids on the causative pathogen, Ascosphaera apis Maassen, no other studies pertaining to the management of the chalkbrood disease were performed, so far in Egypt. Laboratory investigations indicated that the fungicides, i.e (Galben C 46%, Radomil gold pluse WP 42.5% and Daconil 2787) at their recommended rates did not exert any effect on the mycelical growth of the fungus. Therefore, these fungicides were completely excluded from the subsequent apiary trials. As to the Mycostatin, it was found clearly that this mycostatic compound was effective at the rates of 50.000 and 100.000 IU. Regarding the essential oils (ceder, clove, peppermint, parsley, black cumin, garden rocket, and ricin), ceder oil surpassed the other oils and materials in controlling the subject disease. It is peculiar that no studies on the efficacy of ceder are available in the literature, so the present work using ceder oil is recorded for the first time worldwide. Thymol substance at the rate of 2% showed also a great success in managing the CHB disease. Baised on the obtained results, the promising materials in controlling the disease could be arranged according to their efficacy in a descending order as follows: ceder oil>thymol>mycostatin and oxalic acid, so these highly effective materials were again tested under the apiary conditions. Outdoors (apiary) studies revealed that ceder oil 4% gave 100% reduction in mummies numbers. Reductions in number of fallen mummies ranged from 63.22 to 96.94, 18.93 to 81.74, and 10.11 to 68.16%, on average, for thymol, mycostatin, and oxalic acid, respectively. From the practical point of view, thymol could be recommended for controlling the CHB disease, as it is the cheapest material and proved to increase the brood nest as well. In addition, thymol has other uses in the field of apiculture.

Assessment of losses in honey yield due to the chalkbrood disease, with reference to the determination of its economic injury levels in Egypt.

In Egypt, the chalk brood (CHB) disease caused by the fungus, Ascosphaera apis Maassen started again infesting the honeybee, Apis melifera L (Hymenoptera: Apidae) colonies after a cessation pause of seven to nine years. For the first time, an attempt has been made to look into the problem of the CHB disease from the view point of assessing losses in both clover (Trifolium alexandrinum) and chinus (Chinus molus) honey yields. In this regard, two techniques were adopted. Under the natural conditions of the experimental apiary (first technique), loss in clover honey was 18.412 +/- 0.663%, on average, whereas the average loss in chinus honey was 18.332 +/- 1.536%. In the second technique of loss appraisal (artificial infection). The tested honeybee colonies were artificially infected with four sources of A. apis infection, I.e. black mummies, white mummies, pollen grains and water, in addition to controls to create the so-called "different levels of infection". The mean percentages of losses in clover honey were 30.06 +/- 1.807, 27.95 +/- 1.062; 21.13 +/- 0.987; 16.96 +/- 0.672 and 0.00 +/- 0.00 for black mummies, white mummies, pollen grains, water and control, respectively. Taking into account the relationship between number of resulted mummies in each source of infection and % loss in clover honey, it could be concluded that as the resulted mummies increased, the corresponding clover honey yield decreased in each source of infection. It was noticed that the % loss in clover honey differed as the used technique differed. For example, the percentage loss in clover honey produced from colonies exposed to the natural conditions was relatively less than that of the artificially infected ones. This has been discussed in the text. However, the causative pathogen of CHB disease resulted in serious decrease in honey production. Loss appraisal is a perquisite step for the determination of the economic injury levels (EILs). By regressing % loss in clover honey yield against the total number of fallen mummies, the linear equation was worked out to be: Y = 0.242 + 0.040 x (r2 = 0.99, F = 62408.865). Depending on the total costs of controlling CHB disease, the EIL values were 31.875 and 11.250 mummies/colony for cedar oil and thymol granules, subsequently. As to the chinus honey the corresponding EILs were 18.940 and 6.683 mummies/colony for cedar oil and thymol granules, in respect, as a result of adopting the regression formula: Y = -6.762 + 0.101 X. As for the clover honey (artificial infection) the EIL values were 39.844 and 14.063 mummies/ colony in case of using cedar oil and thymol grains, subsequently. These values were worked out using the formula Y = 5.871 + 0.032 X. From the practical point of view, apiarists should not use thymol or cedar oil as fallen mummies don't reach the suggested EILs values to minimize control costs as much as possible.

Effect of sequential applications of foliar nutrients, biofertilizers and sowing dates on the incidence of corn stem borers in Egypt.

In this study either early sown (May 1st) or lately sown (June 2nd) corn plants were treated with Phosphorin & Rhizobactrin as biofertilizers and sprayed with six selected foliar nutrients, i.e. Polymex; Greenzit SP100, Greenzit NPK, Potasin-F, Copper sulphate and Ascorbic acid; in mono-, bi-, and/or tri-sequential applications. Such practices were conducted to show their beneficial effects compared with the chemical treatment in checking the incidence of the stem borers and hence increasing the corn yield. The obtained results could be summarized in the following chief points: (a) the lately sown biofertilized plants showed somewhat higher levels of infestation than the early planted ones., (b) in general, spraying the biofertilized corn plants in both sowing dates with the tested foliar nutrients, significantly decreased the rate of the stem borers infestation than the untreated plants of control., (c) the foliar sprays of Greenzit NPK alone, bi- or tri-sequential applications of Potasin-F, Polymex, Ascorbic acid and Copper sulphate achieved considerable success in reducing larval numbers of the borers species. For example, in case of using the bi-sequential nutrients (Polymex/Ascorbic acid) the numbers were 1.2, 1.5 and 1.2 larvae/5 plants, whereas the numbers were 1.3, 1.0 and 0.7 larvae/5 plants as a result, of the tri-sequential applications (Potasin-F/Ascorbic acid/Polymex) for the pink stem borer, Sesamia cretica, (Led.), the purple lined borer, Chilo agamemnon, (Bels.), and the European corn borer Ostrinia nubilalis (Hb.), in respect, vs. 4.8, 4.5 and 2.9 larvae/5 plants for the same stem borers, respectively, in case of the untreated corn plants. In addition, the other trisequential applications (Polymex/ascorbic acid/Copper sulphate), (Potasin-F/Copper sulphate/ascorbic acid) and (Potasin-F/Copper sulphate/Polymex) reduced the stem borers infestation; (d) from the view point of the interaction effects of sowing dates and the tested foliar nutrients, it was found that the tri-sequential sprayings (Potasin-F/Copper sulphate/Polymex) and/or (Potasin-F/Copper sulphate/Ascorbic acid) have lowered the rate of the stem borers infestation to 3.3 and 3.3 and 5.7 and 4.3 larvae/5 plants for the tri-applications in the 1st and 2nd sowing dates, respectively. Such reductions in the levels of infestation led to an increase in the grain yield up to 6.9 and 7.2 and 5.4 and 5.8 ton/fed, for the early and lately sown corn plants, in respect, and (e) All the foliar nutrients, with no exception, proved to be efficient in managing the stem borers infestation as compared with the insecticide treatment using Polytrin. Although the chemical application had lowered the level of infestation to 2.3 and 5.7 larvae/5 plants in the 1st and 2nd sowing dates as compared with 9.7 and 14.7 larvae/5 untreated plants for the same sowing dates, lesser grain yield of 5.6 and 4.4 ton/fed. was obtained in the first and second dates of planting, successively, in comparison to the grain yield resulted from the tri-applications of Potasin-F/Copper sulphate with either Polymex or Ascorbic acid. The abovementioned results assured the profitable effects of using foliar nutrients as well as the biofertilizers for attaining healthy corn plants, which would be capable of tolerating the injury inflicted by the studied stem borers and compensating for the harmful effects of insects infestation, so high grain yields could be obtained than those of the untreated and/or the insecticide treated plants.