The newly introduced castor bean whitefly (CBW) Trialeurodes ricini (Misra) has become an important pest which is widely spread all over Egypt. Biochemical studies were conducted to distinguish the different T . ricini biotypes and to determine the biotype economic threshold based on its ability to transmit plant viruses. Forty-five samples of T. ricini adults were collected from castor bean (Ricinus comrnunis) at different geographical locations representing the Egyptian Delta and Nile valley governorates. Esterase banding patterns were investigated to evaluate the extent of variation among the tested populations of the castor bean whitefly. Electrophoresis of homogenates of individual T. ricini females showed that there are five different biotypes (C,-CJ. The predominant biotype (C, type) was found in about 80% of the tested locations. In transmission studies, the polymerase chain reaction (PCR) was used to detect geminiviruses in nucleic acid extracted from the different castor bean whitefly biotypes. PCR revealed that the five biotypes of T . ricini are viruliferous. To evaluate the efficiency of the predominant T . ricini biotype for transmitting the tomato yellow leaf curl virus (TYLCV), acquisition and inoculation access periods were determined. PCR indicated that 50% of whitefly adults collected from castor bean, acquired the virus after 10 h exposure to TYLCV infected tomato. Experimentally, the rate of transmission increased as the inoculation access period was lengthened and reached a maximum after 4 h. The obtained symptomatological results were also confirmed by PCR.

Four experiments were conducted at Embaba, Giza Governorate by planting beans four times during 2011, 2012 and 2013 to assess the annual variation in population of Melanagromyza phaseoli attacking bean plants Phaseolus vulgaris (L.) in relation to certain climatic factors, synchronization of plant age with insect counts, generation numbers, and injury on plants. Obtained results cleared that adults and larvae of this fly attack plants as soon as seedlings emergence in all growing seasons. In spring 2011, adult females reached highest counts 1.17, 1.17 and 1.1 individual/ sweep at 12 th April, 10 th May and 7 th June, respectively. Their larvae reached highest 2.2 and 15.33 larvae/leaf at 26 th April and 31 st May. The highest tunnels number during season was 26.87 tunnel/leaf. In summer 2011, larvae reached highest counts 1.4, 29 and 2.3 larvae/leaf at 5 th July, 23 rd August and 20 th September at temperature 27.17, 29.84 and 27.97°C and relative humidity 54.14, 54.57 and 57.71%, respectively. During summer 2012, both adults and larvae reached its highest three times, larvae were 1.9, 4.87 and 7.2 larvae/leaf. Tunnels number was 11.07/leaf in highest case. Leaf miner population was rather low during winter 2012/2013. Capabilities of insect to produce progeny and to injure plants were discussed. Insect produced three generations/ growing season. Temperature and relative humidity revealed their presence inside the optimum range for the insect activity. Plant age had positive relationship with larvae counts in spring and summer seasons. Management program must be directed against insect during period 39-74 day of plant age.

Bermuda grass, Cynodon dactylon (L.) extracts were tested on cotton leaf worm, Spodoptera littorals (Boisd.). Five solvents were used in preparing of these extracts, (i.e., methanol, petroleum ether, acetone, diethyl ether and distilled water). Distilled water was used as polar solvent. The results showed that extracts of non polar solvents were more effective than water. Methanol extract resulted in highest number of giant larvae. Methanol and diethyl ether extracts resulted in the highest number of deformed pupae. Acetone extract caused highest number of mortalities, followed by diethyl ether and methanol extracts. Methanol extract proved to be the most efficient on fertility of S. littorals. All extracts had a slight effect on the larval and pupal stages duration compared with control. Larval and pupal weights were affected in the same manner also. It was concluded that all extracts caused a disturbance in hormonal balance in the larvae.