One of the important Integrated Pest Management Strategies (IPM) against economic pests in Egypt is the use of biological control methods.The use of entomopathogenic bacteria is one of these methods. The authors achieved four isolates of bacteria from the naturally infected P. gossypiella in cotton fields at Assuit and Kafr El-Sheikh Governorates, Egypt. Isolates were characterized based on morphological properties. Morphological analyses were carried out based on Bergey's Manual of Systematic Bacteriology. The identification of the isolated bacteria was confirmed by using Biolog-System as, Staphyloccus sciuri, Micrococcus luteus, Brevibacterium lines & Brevibacterium casei. In addition, their larvicidal effect was evaluated. The results revealed that, S. sciuri and M. luteus were the most effective against 1 st instar larvae of PBW. Furthermore, their latent effect caused the lowest pupation % resulted from treated PBW larvae. S. sciuri was the most promising bacterial isolate to be developed as a biological control agent against P.gossypiella. The antagonists of bacterial strain against the mycelial growth of the pathogenic fungi (Rhizoctonia solani, Fusarium solani and Macrophomia phaseolina), was experimently tested to evaluate growth reduction of all pathogenic fungi.

The Egyptian cotton variety Giza 90 was planted in a wire green house (4 sides and rough of wire 0.1mm mesh) and the recommended agronomic practices were followed during 2013 and 2014 cotton seasons. The cotton bolls 20-25 days of age were tagged and artificially infected with newly hatched larvae of Pink Bollworm (PBW), Pectinophora gossypiella and followed daily during cotton season as well as during late season. The present results revealed that the PBW ability infestation% (= infestation severity) and infestation % are affected significantly by ambient temperature °C and relative humidity (R.H. %) at the first half hour of infestation at the infestation date. Also, PBW larval instars were photographed inside the cotton bolls samples as well as determination thermal requirements of all PBW stages under the natural conditions In addition, present results recorded the average of head capsule width for the four instars of larvae. It ranged between (0.17±0.002 mm) to (1.30±0.23 mm) for the first and fourth larval instars, respectively. Statistical analysis proved significant negative correlation between temperature and all instars duration (r =-0.77576,-0.89575,-0.99905 and-0.98433) .In contrary there was significant positive correlation between temperature and rate development of all instars (r = 0.96, 0.94, 0.98 and 0.94) for (the first, second, third and fourth instars, respectively). Also, PBW heat unites requirements for larval instars and total larval stage under natural fluctuated temperature was estimated according to Campbell and Mackaure (1975). The developmental zero (to) for successive instars recorded (15.17&15.12&15.11and 15.5), °C respectively. While it recorded 15.22 °C for the larval stage under field conditions. Furthermore, development rates, durations as well as thermal requirements of larvae, pupae, pre-oviposition, and incubation period under field conditions were evaluated according to (Zalom1983). DD , s values for the respective stages were (149-153), (238.5-248.7), (44.6-56.7) and (54.6-73). The emergence of adult moths (91%) took place after 22-23 days from the egg hatchability, with the sex ratio (1.5♀: 1♂). The pre-oviposition period and the incubation period of eggs on cotton Varity Giza 90 recorded (3-4 days) & (4-5 days), respectively, during cotton season. General results showed that one generation of PBW recorded 30-31 days with 485-502 DD , s through period from 20 th July to 3 rd September 2014.

Interaction between cotton variety and temperature Earia insulana (Boisd.) (Lepidoptera: Noctuidae) larvae and/or pupae (cocoons) were collected from five different cotton varieties (Giza 45, Giza 86, Giza 87, Giza 88, and Giza 92) have been grown in Sakha, Kafr El-Sheikh-Governorate at the end of cotton season 2014. Some biological aspects of these populations were investigated under laboratory conditions at three constant temperatures (25, 27 and 30˚C). The present results concluded that, the tested temperatures had main effect on stages durations, survival, adult emergence percentages, sex ratio, and fecundity of field SBW strain. Regardless the variety of cotton general trend of results indicated that, the highest, moderate and lowest percentage of emerged moths were recorded at 25ºC, 30ºC and 27ºC, respectively. In addition, sex ratio were almost 1:1 but tend to females at 25ºC while in reverse to male at 30ºC. At 27ºC sex ratio was 2♀: 1♂. Moreover, the fecundity of developed female from tested varieties recorded its highest values at 25ºC and sharply decreased at 27ºC. While, at 30ºC, the emerged female lost its fecundity except females of Giza 45 deposited 169.0 eggs / female. Furthermore, the tested temperature may be reliable for one developed stage of spiny bollworm and not reliable for another of same population. Also, cotton variety had highly significant effect on the studied biological aspects on its pest SBW, as well as, the interaction between cotton variety and temperature. Regardless temperature, duration of larval stage was 29 & 25.0 days on cotton varieties Giza 45 and Giza 87 at 25ºC, respectively. Although, the respective duration of generation in both cases acquire 50 days and 39.1 days, the reproductive capacity of SBW of Giza 45 equal ten times of that when fed on Giza 87. In addition, the larval mortality was higher in population of Giza 87. Depending on the aforementioned conclusion, cotton variety Giza 45 is more susceptible to SBW infestation. The authors arranged the susceptibility of tested cotton varieties to SBW infestation in descending order as follow: Giza 45, Giza 88, Giza 87, Giza 92 and Giza 86. These composite relations need to further vision to study the insect ecology, biology, physiology and economic damage. However, the use of less susceptible cultivars can be considered as a part of IPM control program.

The healthy appearance PBW larvae were placed individually in sterilized glass tubes (2x7cm) plugged with cotton wool under room conditions and observed 2 times/ week. Infected larvae with baculuviruses (NPV & GV) were collected. Present study clarified and discussed the pathogenicity of baculuviruses against PBW resting larvae in many views (appearance, histology and biochemistry). Results indicated that, the activation of PBW chitinase (CHT) at the resting period enhances the insecticidal activity of latent baculuviruses. So that the baculuviruses overcome apoptosis and prevent ecdysis of PBW resting larvae. And the scanning electron microscope and histology micrographs revealed the appearances of this infection as external scleroticzation, shrinking, swelling and internal degradation of P. gossypiella organs Furthermore, the biochemical analysis revealed decrease activity of larval chitinase with increase activity of both Nacetylglucosamine (NAG) and phenoloxidase. However, the utilizing of these epizootic baculuviruses as microbial control agents still need more studies of insect immune, insecticidal evaluation, molecular biology and environmental safety.