Histopathological and Ultrastructure changes in the embryonic development of Schistocerca gregaria (Forskal) (Orthoptera: Acrididae) induced by Lufenuron(CSI) and Rice Bran Extract (Waste product).

Abstract

Background: Waste product compound of rice bran and lufenuron are considered safe compounds to the human and to the environment. They can be used to control Schistocerca gregaria. Objective: The aim of the present study is to examine the ultrastructural changes and histopathological alteration in the Schistocerca gregaria embryogenesis induced by selected waste product compound of rice bran (Oryza sativa) and a chitin synthesis inhibitor (lufenuron). Materials and Methods: Histological and ultrastructure study of normal and affected eggs of Schistocerca gregaria were conducted to demonstrate the effects of lufenuron and rice bran extract on the embryogenesis. Cleavages started about 5 hrs post oviposition (pop) and continue to divide until formation of cellular blastodrem by 1 day pop. By 2 days pop germ band is formed, differentiated into ectoderm and mesoderm. At 3 days pop segmentation of germ band into mouthpart and three thoracic segments occur. Antenna was observed at 3 days pop. Fore and midgut were detected by 5 days pop. Hindgut was also observed by 5 days pop. By 4 days pop, eyes and brain appeared. Brain appeared as two ganglionic masses separated by oesophagus, which by 5 days pop appears as 2 large interconnect cerebral lobes enwrapped by neurilemma. Histological section of affected eggs showed great effects on brain, alimentary canals and compound eyes. Results: Ultrastructure study of newly deposited eggs showed that, the chorion consists of several easily distinguishable layers and in 30-hour-old eggs, cleavage nuclei of different shapes could be observed. The nuclei of the blastoderm cell have spindle shape and have condensed chromatin, which attaches to nuclear membrane. Electron micrograph of lufenuron-affected eggs revealed abnormal chorion and cleavage nuclei. In rice bran affected eggs, disintegrated blastoderm that failed to arranged and sever malformed nuclei were seen. Vaculation and lysis of cell components leaving cavities within the ooplasm were detected in both treatments. Conclusion: The tested compounds induced serious changes to the embryos of Schistocerca gregaria as revealed by the histological and ultrastructure studies.

Latent Histopathological Effects of Lufenuron and Rice Bran Extract on Schistocerca Gregaria (Forskal) (Orthoptera: Acrididae)

“…Also rice bran extract caused compression and loss in the brain morphic nature, and poorly developed compound eyes (F.2b). These observations are in agreement with the findings of the brain and compound eyes damage in newly hatched nymphs of S. gregaria due to lufenuron treatment reported by (Abdel Rahman, 2017), also, rice bran extract and lufenuron exhibited disruption in the histological formation of the brain and compound eyes during embryonic development in the desert locust (Mahdy et al, 2020). Similar observations showed by different plant extracts as azadirachtin on S. gregaria eggs caused poorly developed brain and compound eyes of newly hatching (Ghazawy et al, 2010), abnormal brain cells of desert locust nymphs treated with Cestrum leaf powder were observed by Ben Hamouda et al (2011).…”

“…The present study revealed that The tested compounds have latent histopathological effects where they induced serious changes in newly hatching of affected S. gregaria eggs with lufenuron and rice bran extract treatments and these associated with their toxic effects which were reported by Mahdy et al (2019Mahdy et al ( & 2020, where they caused a disturbance in the protein and DNA of eggs resulting from treated females as fifth nymphal instars with LC50 of them leading to histopathological variations of embryonic structure and inhibition of embryonic development and hatching in some eggs, and this explains, why some affected eggs produce abnormal newly hatched nymphs.…”

“…S. gregaria fifth nymphal instar females were treated using the feeding technique with LC50 concentrations of lufenuron (10%) and rice bran extract which were calculated by Mahdy et al (2020) and were (95 & 14.3×10 3 ppm) respectively. Samples of newly hatched nymphs were collected from normal and affected eggs resulting from these treatments to study the latent effect of these compounds on different organs and jumping legs using the histological technique.…”

“…Botanical insecticides such as agricultural waste products and plant extracts degrade quickly in air and moisture by detoxification enzymes; this refers to less environmental persistence and lower dangers to organisms that aren't the target (Isman, 2008). Rice bran extract is one of the agricultural waste products that showed a serious effect on the desert locust S. gregaria life cycle (Mahdy et al, 2019(Mahdy et al, & 2020.…”