Biology and predatory potential of chrysopids on invasive coconut rugose spiralling whitefly Aleurodicus rugioperculatus Martin

814-818The relatively new invasive rugose spiralling whitefly (RSW) Aleurodicus rugioperculatus (Hemiptera: Aleyrodidae) has become a serious threat to oil palm, particularly coconut plantation, in southern India. Here, we report biology and foraging potential of predatory neuropteran Green lace wings Chrysoperla zastrowi sillemi (Esben-Petersen) and Mallada boninensis (Okamoto) (Chrysopidae) on against RSW. Results revealed that A. rugioperculatus served as a suitable host for the both chrysopid predators. C. z. sillemi completed its life cycle in 19.91±1.90 days with a larval (grub) period of 9.44±3.91 days and adult longevity was 24.10±1.87 days. The developmental period of M. boninensis was 22.3±2.93 days, with a larval period of 11.85±1.71 days, while the adult longevity was 19.25±1.52 day. In the laboratory experiment, all the larval stages of the predators were observed to feed on A. rugioperculatus. It was observed that the 3rd instar grub of C. zastrowi sillemi with the developmental period of 3.24±1.73 days consumed a maximum of 313.2 whiteflies (all the life stages) followed by second and 1st instar grub stages of the predator, which consumed mean number of 200.2 and 140.2 eggs and nymphs of A. rugioperculatus, respectively during their developmental period of 3.58±1.84 and 2.62±1.34 days, respectively. In the case of M. boninensis, a single grub could consume a total of 929.8 whiteflies (both eggs and nymphal stages) during its total larval period of 9.44±3.91 days

Evaluation of Suitable Polymers for the Development of High-Concentrated Liquid Biofertilizers

An improvement in the present liquid formulation of biofertilizer is essential to expand its shelf life and enhance the bioefficacy potential of the inoculated crops. Here, we screened ten different water-soluble polymers for their feasibility as cell protectants in liquid biofertilizers for the duration of three months. The physio-chemical properties and Escherichia coli survival assay experiments identified five potential polymers: hydroxypropyl methylcellulose, polyvinyl alcohol, and natural polymers extracted from seaweed, red algae, and brown algae. These five polymers' aqueous solutions comply with the standard parameters of liquid biofertilizers. Further, these polymers were compared with standard liquid biofertilizer diluting medium (phosphate buffer with glycerol) for the shelf life of two biofertilizer strains, viz., Azospirillum lipoferum (Az204) and Bacillus megaterium var. phosphaticum (Pb1). All the polymers had high cell viability up to 60 days after incubation. In conclusion, the results suggest that these polymers could be effective encapsulating agents to improve the quality of liquid biofertilizers

Selective Isolation and Characterization of Phytophthora infestans from Potatoes Using Rye Agar Media in India

Phytophthora infestans is a pathogen that causes late blight, a major disease of potatoes. The isolation of P. infestans from infected potato plants using agar media has been challenging. This study investigated the use of Rye A and Rye B agar media for the isolation of P. infestans from infected potato tubers collected from the Nilgiris district of Tamil Nadu during 2022. The media were evaluated for hyphal growth, sporangial production, oospore formation, and long-term storage of P. infestans. Phenotypic diagnosis based on cultural and morphological characteristics confirmed the identity of P. infestans. The results were confirmed by a molecular identification test using primers specific to P. infestans. Pathogenicity tests were carried out to assess the virulence of the isolates. This study provides a useful protocol for the selective isolation and characterization of P. infestans, the potato late blight pathogen