Journal of Applied Entomologist

Impact of ecological conditions on population dynamic of Phenacoccus solenopsis Tinsley and associated predators in sweet potato fields ELBeheira Governorate, Egypt

2024-06-12T18:01:21+00:00

The mealy bug, Phenacoccus solenopsis and the two spotted spider mite, Tetranychus urticae are a highly polyphagous sap sucking pests, without a hibernation period, as both are active all the year round. They are destructive pests of important vegetables and field crops. The present study was carried out at Rasheed region, Beheira Governorate during 2021 and 2022 seasons, to monitor the population fluctuations of mealybug and its predators; Coccinella undecimpunctata L., Chrysoperla carnea Steph, Scymnus spp. and Hippodamia tredecimpunctata in the first season, the infestation of P. solenopsis started on sweet potato plants at low numbers, the population increased gradually to reach its highest peak during 30^th July (115.00 individual). This peak was followed by a relatively high population of the three predators, C. undecimpunctata (4.00 individual), Ch. carnea (8.00 individ.), Scymnus sp. (3.00 individ.) and H. tredecimpunctata (2.25 individ.). The second peak of the pest was detected on 21^st Aug. (259.05 individual), synchronized with the peaks of the four, predators. During 2022, the first incidence of the mealybug was recorded on 30^th July (114.97individ.). This peak was associated with the peaks of the four predators. The second peak of P. solenopsis was observed on 28^th Aug. (196.50 individ.), it coincided with the peaks of the four predators. The infestation of P. solenopsis and T. urticae and their predators were highly significantly correlated with weather factors (Min.°c. and RH).

Taxonomic Redescription of genus Thriptera Solier, 1836 (Coleoptera: Pimelliinae, Tenebrionidae) in Egypt

2024-06-19T15:01:55+00:00

This study was planned to identify, redescription and determine the recent taxonomic status of genus Thriptera Solier in Egypt. The gathered information indicated that genus Thriptera is represented in Egypt by 4 species. Their diagnostic characters, illustrated habits of adults and illustration of male genetalia were given.

Monitoring and assessment of mustard aphid, Lipaphis erysismi in North-Western Haryana with yellow sticky trap

2024-06-20T15:45:14+00:00

Production of rapeseed-mustard (Brassica sp.) is severely hampered by aphid infestation in India, specifically Lipaphis erysimi (Kalt.). Impact of weather on the occurrence and multiplication of mustard aphids is very crucial and should be taken into consideration when developing an aphid management plan. Keeping this in view, an experiment was conducted at Oilseeds Section, Department of Genetics and Plant Breeding, CCS HAU, Hisar using yellow chrome painted smeared with transparent grease of 1kg tin box, five in number, height maintained at 30-45 cm above the crop canopy. Maximum numbers of aphid catches were recorded in 10th and 11th standard week. Sunshine hour seems to favour the presence of aphid in significant positive association in both the crop season 2020-21 and 2021-22. Maximum and minimum of temperature of exhibited positive correlation to the numbers of aphid. Presence of numbers of aphid cane be in surrounding mustard field can decide the volume of infestation in forthcoming period through the catch of aphid via yellow chrome smeared tin box to be vigil to manage it.

Comparative effectiveness between entomopathogens and conventional insecticide against Spodoptera frugiperda larvae and accompanying alteration in some enzymatic activities

2024-06-27T17:36:23+00:00

Background: The Spodoptera frugiperda (J. E. Smith) fall armyworm (Lepidoptera: Noctuidae) is a dangerous insect pest of an excessive number of crops., with larvae attacking the plants at all growth stages.

Materials: Protecto (Bacillus thuringiensis), Biossiana (Beauveria bassiana) and BioMeta (Metarhizium anisopliae), compared to abamectin (traditional insecticides), were assessed against S. Frugiperda in maize field. The enzymatic activities of the larvae were determined 48 hours after exposure to the tested pesticides.

Results: Under laboratory condition, the entomopathogenic bacteria was more effective against fall armyworm (2^nd instar) than entomopathogenic fungi, with total mortalities of 96.67 and 93.33% due to Biometa and Biossiana, respectively. Opposite results were obtained in case of 4^thinstar larvae, with total mortalities of 53.33 and 50% due to Biossiana and Biometa, respectively. In maize fields, abamectin was the most potent compound in reducing fall armyworm larval population (94.48% reduction) three days post-treatments, followed by Biometa (78.19% reduction), while the least one was Protecto (43.53% reduction). Five and seven days post treatments, the highest reductions (94.66 and 94.84%, respectively) were recorded in abamectin treatment, followed by Biometa (79.38% and 80.56% reduction, respectively). On the other hand, 10 days after treatments, Biossiana treatment induced the highest reduction (77.90%), followed by abamectin (75.41%). Overall average larval reductions, proved that abamectin induced the highest value (89.87%), followed by Biossiana (59.47%) and Biometa (57.91%) while Protecto resulted in the lowest reduction (32.56%) The correspondent total protein ratios were 0.68, 0.06, 0.90, 0.69. In addition, the highest lipid peroxide activity was highest in S. frugiperda larvae treated with Protecto (724.40) and abamectin (376.90), but lowest in case of treating the larvae by Biometa (179.52) and Biossiana (158.22). Protecto, Biometa and abamectin applications induced higher acetylcholine esterase activity in the 4^th instar larvae compared with larvae treated with Biossiana. The lowest activity of chitinase was detected in case of Biossiana treatment. The chitinase activity was 15.59 in abamectin, and 20.78 in Protecto treatments.