الفهرس 
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Abstract
Leaf miners are significant and dangerous plant pests that attack a variety of fruits, vegetables, field crops, and weeds. Inside leaf tissue, insect larvae feed, reduce photosynthesis, and create entrance routes for plant infections. As a result, it was proposed that the current work encompass the following topics:
-1Survey of leaf miners infesting certain fruit, crops, vegetables, field crops and weeds and their parasitoids.
-2Study of seasonal changes and population density of P. mixta and study the relation between these populations with some weather factors and their parasitoids in Beni-Suef governorate.
-3Survey of parasitoids of the sugar beet leaf miner, P. mixta.
-4Role of those parasitoids in suppressing the population of P. mixta.
-5Study of seasonal changes and population density of T. absoluta and study the relation between these populations with some weather factors and their parasitoids in Beni-Suef governorate.
-6Survey of parasitoids of tomato leaf miner, T. absoluta.
-7Role of those parasitoids in suppressing the population of T. absoluta.
-8Study effect of biological and chemical compounds on T. absoluta.
The obtained results were summarized as follows.
1.Leaf miners and their parasitoids survey:
During the current investigation, 15 species of leaf miners were recorded and identified as follows: Agromyza nana, Agromyza nigrella, Liriomyza brassicae, L. bryoniae, L. helianthi, L. sativae, L. Trifolli, Melanagromyra albocilia, M. phaseoli, Pegomiya mixta, P. horticola, Phytomyza cunctans, Pseudonapomyza spicata, Tylomyza pinguis and Tuta absoluta. These identified leaf miners were parasitized by 11 species of hymenopteran parasitoids.
2. Relation between seasonal changes, population density of leaf miners and their parasitoids:
A. Sugar beet miner, Pegomya mixta:
A.1. Fluctuation in the population density:
During the first season of planting, The first and second samples had zero population density and the sample taken on October 19, 2014 had the lowest relative population density (36 individuals per 100 leaves). The sample taken on February 8, 2015 had the highest relative population density (209 individuals per 100 leaves). On the other hand, three larval population peaks were discovered. The population of P. mixta began extremely weakly on November 9, during the second plantation of the first season, with 2 individuals/100 leaves. The sample taken on March 15, 2015 has the highest relative population density (208 individuals per 100 leaves). On the second plantation, P. mixta showed four peaks. The samples taken on the 18th and 25th of October 2014 had the lowest relative population density during the first plantation of the second season (2015/2016). (3 individuals per 100 leaves in both samples). The sample of 14th February 2015 has the highest relative population density (354 individuals per 100 leaves). P. mixta revealed 3 peaks. The sample taken on November 8, 2014, had the lowest relative population density during the second plantation of the season (2 individuals per 100 leaves). The sample from February 28, 2016 has the highest relative population density (390 individuals per 100 leaves). During the second plantation, P. mixta showed three peaks.
A.2. Survey of parasitoids:
Only one species of hymenopterous parasitoids was recovered from the sample of P. mixta collected from sugar beet leaves during the two seasons (2014/2015) and (2015/2016). This species identified as Opius nitidulator (Braconidae).
A.3. Rate of parasitism:
Parasitoid of P. mixta was recorded almost all year around with percentage ranged between 3-72% during the first season (2014/2015) and between 3-98% during the second season (2015/2016). During the first plantation in the first season (2014/2015), the percentage of parasitism showed five peaks on the larvae and pupae of P. mixta. During second plantation in the first season (2014/2015), the percentage of parasitism ranged between 7-72% with six peaks on the larvae and pupae of P. mixta. During first plantation in the second season (2015/2016), percentage of parasitism had five peaks on P. mixta larvae and pupae. During the second plantation in the second season (2015/2016), percentage of parasitism ranged between 3-73% with also, six peaks on P. mixta.
B- The tomato leaf miner Tuta absoluta:
B.1. Fluctuation in the population density of tomato leaf miner T. absoluta:
The population density of the tomato leaf miner, T. absoluta as indicated by the weekly counts of leaf miner per 25 compound leaves during two seasons. During first plantation in the first season (2014/2015), infestation started after one month from plantation on 3rd August with 4 individuals/25 leaves. This pest had 5 peaks. The number of larvae has increased gradually to reach to the first peak in 7th September with 19 individuals/25 leaves with max. temperature 33.6℃, min. temperature 22.3℃ and average humidity 63.79%. During second plantation in the first season, the population of T. absoluta started very weak in the 12th April with 8 individuals/25 leaves. T. absoluta had five peaks during second plantation. During first plantation in the second season (2015/2016), this pest had 5 peaks. During second plantation in the second season, T. absoluta had five peaks.
B.2. Survey of parasitoids:
The sample of T. absoluta collected from tomato leaves during the two seasons (2014/2015) and (2015/2016) of investigation gave rise the following species of parasitoids: Three species of hymenopterous parasitoids were reared from tomato leaf miner Bracon sp. (Braconidae), Pteromalus sp. (Petromalidae), Eulophus sp. (Eulophidae).
B.3. Rate of parasitism:
T. absoluta parasitoids were presented almost all year around, the proportion of parasitism on T. absoluta was between 1-41% during the first season (2014/2015) and between 1-51% during the second season (2015/2016). During first plantation in the first season (2014/2015), percentage of parasitism had six peaks on T. absoluta. During second plantation in the first season (2014/2015), percentage of parasitism ranged between 1-35% and showed four peaks. During first plantation in the second season (2015/2016), percentage of parasitism had six peaks on T. absoluta. During second plantation in the second season (2015/2016), percentage of parasitism ranged between 6-51% with also four peaks.
3. Study effect of biological and chemical compounds on T. absoluta:
The efficacy of Dipel 2x 6.4% SC (Bacillus thuringiensis), Lannate 90% SC (Methomyl), Avaunt 15% SC (indoxacarb), Radiant 12% SC (spinetoram) and Tracer 24% SC (spinosad) against T. absoluta in two seasons. The results showed that Dipel 2x 6.4% SC (Bacillus thuringiensis) was the most efficient in reducing T. absoluta infestation. These findings suggested that biopesticides could be employed as effective alternatives to chemical insecticides.