| Titles |
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English :
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Studies on certain pests infesting some vegetable crops in Dakahlia governorate Egypt.
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Arabic :
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دراسات علي بعض الآقات التي تصيب بعض محاصيل الخضر في محافظة الدقهليه
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| Abstract |
The present work was conduct during 1993/1994 and 1994/1995 seasons to survey some of homopterous insects (leafhopper, aphids and white flies) infesting some vegetable plants (tomato, potato, cabbage, cauliflower, squash and cucumber) in Dakahlia Governorate, Egypt. The seasonal abundance of the dominant insect species and the ability of white fly to transmit some of plant pathogenic viruses infesting tomato and potato plants were also studied. The aforementioned insects pests were collected by different methods. These were the sweeping net, planting samples, yellow sticky board and yellow pan traps. Studies showed that the sweeping net proved to be the best method to collect all the leafhopper species. The yellow sticky board traps seems to be the most attractive to leafhoppers and aphids. The yellow pan traps were also found to selective collecting leafhoppers and aphids.
The results obtained of survey can be summarized as follow.
a) The leafhoppers (Fam. Cicadellidae : Homoptera)
Empoasca decipiens (Paoli), E. decedens (Paoli), E lybica (deBerg), Orosius albicinctus (Dist), Balclutha hortensis (Lindb), Cicadulina chinai (Ghaur.), C. bipunctella zea (china) and Neolimnus aegypticaus (Mats) on tomato plants.
Empoasca decipiens, E. Lybica, Orosius albicinctus, B. hortensis, and Exitanus capicola (Stal) on potato plants.
E. decipiens, E. decedens, Orosius albicinctus, C. bipunctella zea, C, chinai, Exitanus capicola and Neolimnus aegypticaus on cabbage and cauliflower plants.
E. decipiens, E. decedens, B. hortensis and Neolimnus aegypticaus on squash and cucumber plants.
b) The aphids (Fam : Aphididae : Homoptera)
Myzus persicae (Sulz), Aphis craccivora (Kock) and Aphis gossypii (Glover) on tomato plants.
M. persicae and Aphis gossypii on potato plants.
M. persicae, Brevicoryne brassicae and Lipaphis erysimi pserdobrassicae were collected from cabbage and cauliflower plants.
M. persicae collected from cucumber plants.
c) White fly (Fam : Aleyrodidae : Homoptera)
White fly Bemisia tabaci (Genn. ) was collected from the aforementioned vegetable plants with high numbers (immature and adults stages) throughout the two seasons of investigations.
The seasonal abundance of the dominant homopterous insect species infesting aforementioned vegetable plants can be summarized as follows.
a) leafhoppers
1- Early summer plantation : Two peaks representing high population density for E. decipiens adults on tomato plants in the third week of May and July for the two peaks respectively. On potato plants one peak of E. decipiens abundance could be detected in the first week of May. On squash and cucumber plants one peak for E. decipiens,'E. decdens and B. hortensis in the second week of June and first week of July for the two crops respectively.
2- Winter plantation : Two peaks representing high population density for E. decipiens were recorded on tomato plants in the third week of December and in the beginning of March respectively. On potato plants one peak was recorded in the third week of December. On cabbage and cauliflower plants two peaks were recorded for E. decipiens and E. decdens in the second week of December and March for E. decipiens and the second week of November and February for E. decedens respectively.
b) Aphids
1- Early summer plantation : On tomato plants, two peaks representing high population density for M. persicae and A. craccivora were recorded in the third week of March and August for the two peaks respectively. On potato plants, one peak of the population density of M. persicae was recorded in the first week of April. On cucumber plants one peak was recorded at the end of April.
2- Winter plantation : On tomato plants two peaks, of M. persicae and A. craccivora could be detected in the second week of November and March for the two peaks respectively. On potato plants one peak of M. persicae was recorded in the third week of November. On cabbage and cauliflower plants two peaks of M. persicae were recorded at mid of December and February for the two peaks respectively. Brevicoryne brassicae has two peaks on cabbage plants were recorded at mid¬-December and February. On cauliflower plants two peaks of Brevicoryne brassicae, the first one was recorded at the end of November, and the second peak was recorded at mid-February. Lipaphis erystmi pseudobrassicue has one peak on cabbage and cauliflower plants occurred at the end of December.
c) White fly: Aleyrodidae : Homoptera)
1- Early summer plantation : Two peaks representing high population density for B. tabaci on tomato plants in mid-May and the end of August respectively. On potato plants one peak was recorded in mid¬May. On squash and cucumber plants two peaks of the population density were recorded in mid-May and the end of June respectively.
2- Winter plantation : Two peaks of the population density of B. tabaci were recorded on tomato plants in mid-November and the end of March respectively, on potato plants one peak was recorded at the end of November. Two peaks were obtained with high population' density for B. tabaci on cabbage and cauliflower plants in mid-November and the end of March for two peaks respectively. It is worth to mention that the peaks of population density of B. tabaci adults were always detected later 1-2 weeks than those of immature stages.
Effect of some climatic factors on population density of the dominant homopterous insects :
Effect of some climatic factors maximum & minimum temperature and relative humidity on population density of the dominant leafhoppers, aphids and white fly infesting certain vegetable plants (tomato, potato, cabbage, cauliflower, squash and cucumber) under Dakahlia Governorate conditions were studied.
The results clearly indicated that significant and insignificant correlation coefficient and partial regression were obtained between number of insects and maximum temperature, minimum temperature and relative humidity during the two investigation seasons. The statistical analysis indicate that the effect of maximum and minimum temperature came first on number of insects.
In other words, this means that thermal factors seemed to affect the population of insects followed by relative humidity.
The role of white fly in transmission some plant pathogenic viruses infected tomato and potato plants :
In the course of the transmission experiments, it demonstrated that white fly B. tabaci is actual vector, transmitting the causative agents of tomato yellow mosaic virus, tomato leaf curl virus, potato yellow virus and potato leaf curl virus.
The results of insect transmission experiments can be summarized as follow :
In case of tomato yellow mosaic virus, tomato 'leaf curl virus, and potato leaf curl virus the acquisition threshold period were 30 - 40 min., 20 - 35 min., 40 - 50 min. respectively and the incubation period in the white fly B. tabaci 21 - 24 hr., 24 - 28 hr., and 25 - 30 hr. respectively and inoculation threshold feeding period 15 - 25 min., 15 - 25 min., and 30 - 40 min. respectively and retention period of viruses in the white fly B. tabaci were 8 - 10 , 10 - 12 and 16 - 20 days respectively and the incubation periods in the host plant were 2 - 4 days, for the tomato diseases and 6 - 10 days for potato leaf curl diseases.
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| Publication year |
1997
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| Availability location |
معهد وقاية النبات - ش نادى الصيد -الدقى- جيزة
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| Availability number |
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| Organization Name |
Plant Protection Research Institute (PPRI)
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| Country |
Egypt
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| Publisher |
Name:
كليه الزراعه-جامعه الزقازيق
Place:
الزقازيق-مصر
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| Author(s) from ARC |
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| Agris Categories |
Protection of plants - General aspects
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AGROVOC
TERMS |
Aleyrodidae.
Aphidoidea.
Brevicoryne brassicae.
Cabbages.
Cauliflowers.
Cicadellidae.
Cicadulina.
Cucumbers.
Dominant species.
Empoasca.
Homoptera.
Pathogens.
Potatoes.
Squashes.
Tomatoes.
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| Publication Type |
Master Thesis
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