Use of Fruit Beetles, Waxworms Larvae and Tiger Worms in Waste Conditioning for Composting

In many countries, cow dung is used as farm manure and for biogas production. Several bacterial strains associated with cow dung such as Campylobacter, Salmonella sp. and Escherichia coli cause serious human diseases. The objective of the present study was to investigate the use of insect larvae including fruit beetle, waxworms and tiger worms to improve the breakdown of agricultural wastes and reduce their pathogen loads. Fresh cow faeces were collected from a cattle farm and distributed into plastic boxes (100 g/box). Each box was provided with 10 larvae of fruit beetle, Waxworms and Tiger worms, respectively. There were 3 replicates in each treatment including the control. Bacteria were isolated weekly from both control and cow faeces to which larvae were added to determine the bacterial populations. Results revealed that the bacterial load was higher in the cow faeces treated with fruit beetles than in the control, while the bacterial load was lower in the cow faeces treated with waxworms and tiger worms than in the control. The activities of the fruit beetle larvae led to the cow faeces being liquefied which provided a more conducive growing media for bacteria. Therefore, higher bacterial load in the cow faeces treated with fruit beetle might be attributed to the liquefaction of cow faeces

Impact of vitellogenin based dsRNA feeding on reproductive biology of red palm weevil, Rhynchophorus ferrugineus (Olivier), (Coleoptera: Dryophthoridae) under laboratory conditions

Objective: Red palm weevil, Rhynchophorus ferrugineus is a crucial pest of date palm, in the Kingdom of Saudi Arabia including several other palm producing countries of the World. The vitellogenin gene play very important role for oocytes development in all oviparous animals. Recently, we have silenced the vitellogenin gene by injecting the RfVg-based dsRNA and proved that RNAi technology can be used to manage red palm weevil. The main challenge in RNAi-based plant protection methods is selecting a suitable tactic for successfully delivering the dsRNA. Methods: In the present study, 9-10th instar red palm weevil larvae were provided with Vg-based dsRNA in diet and as drops to determine its effects on red palm weevil reproductive traits, such as pre-oviposition period, fecundity, oviposition period, post oviposition period, eggs size, and female and male life span. Results: Results demonstrated that the RfVg gene function was successfully suppressed using Vg-based RNAi. When applied via drops, resulting in a significant decline in red palm weevil eggs hatchability and Vg expression measured by quantitative real time Polymerase chain reaction. However, when applied via diet, Vg-based dsRNA did not show any significant effect on fecundity, oviposition period, post oviposition period, eggs size, and female and male life span. Conclusions: Based on present overall results and our previous findings, along with the documented information, we can conclude that Vg-based RNAi has a high potential for use as a target specific and eco-friendly technique for the sustainable control of this crucial pest