Green Synthesis of Bimetallic Nanoparticles From Prosopis juliflora(Sw)DC.,and Its Effect Against Cotton Mealybug,Phenacoccus solenopsis(Hemiptera:Pseudococcidae)

Phenacoccus solenopsis has been recognized as an aggressively invasive species on cotton plants in different countries.This study was conducted to investigate the effect of green synthesized Cu/Zn-nanoparticles using aqueous leaf extract of Prosopis juliflora(mezquite)against P.solenopsis.The scanning electron microscope(SEM)showed bimetallic nanoparticles of Cu/Zn-NPs with spherical shape with varying size of 74.33 nm to 59.46 nm.More than 30%mortality of P.solenopsis was observed with Cu/Zn-nanoparticles(100 ppm)at 96 hours after treatment.Negligible mortality of P.solenopsis was recorded with Cu/Zn solution(100 ppm)and aqueous P.juliflora extracts.The results of the viability test for Cu/Zn-nanoparticles of P.juliflora showed a significant reduction of the cell viability by 50%in insect exposed to Cu/Zn-nanoparticles-P.juliflora.Therefore studies about nanotoxicity of Cu/Zn-NPs of P.juliflora are needed to reveal the mechanism of toxicity this phytonanoparticles in P.solenopsis.

Parasitic Effects of Solitary Endoparasitoid, Aenasius bambawalei Hayat (Hymenoptera: Encyrtidae) on Cotton Mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae)

Parasitization has an enormous impact on host physiology, development and reproduction. The effect of parasitism by endoparasitoid, Aenasius bambawalei Hayat (Hymenoptera: Encyrtidae) on survival and reproduction of mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) on different host stages was studied. Our data reveals that host mealybugs parasitized by the wasp at the 2nd instar stage were died during the 3rd instar stage of their life. However, those parasitized at the 3rd instar stage could reach the adult stage and were able to produce their progeny. After 6 days of parasitization, all parasitized hosts of the 2nd, 3rd and adult stages were died except the 1st instar. Results showed that parasitized host mealybugs had significantly lower reproductive potential than the unparasitized ones. Maximum parasitoid emergence was recorded in the 3rd instar host stage. This basic research regarding survival and reproduction of the parasitized host mealybugs would be very helpful in devising sustainable biological control strategies for cotton mealybug.

Invasion biology of the cotton mealybug, Phenacoccus solenopsis Tinsley: Current knowledge and future directions

The cotton mealybug Phenacoccus solenopsis Tinsley(Hemiptera: Pseudococcidae), which is native to North America, emerged as a major invasive insect pest of multiple crops in Asia at the beginning of the 21 st century. Considering the economic significance of this insect and its rapid worldwide spread, we examined the possible factors driving its invasions. In this paper, we summarize the life history traits of P. solenopsis conceivably related to population development in invaded regions; these traits include its use of diverse host plants, reproductive capacity and mode, adaptation to temperature, response to food shortage, and insecticidal resistance. Then, focusing on the multiple trophic interactions that may promote or hinder invasion, we review the mutualistic relationship of this mealybug with ants and predation and parasitism by natural enemies. Finally, we suggest topics for future research and provide our perspective on the biological invasions of this mealybug. We speculate that specific biological factors associated with this mealybug, particularly its wide host range, high reproductive potential, evolved changes in life history traits, and mutualism with ants have played important roles in its invasions, allowing this pest to become established and rapidly increase its population upon its introduction into new regions.