Manisha Mishra

The use of Steinernema carpocapsae infective juveniles as biological control agents is a long-standing practice, yet the oral impact of their secreted venom proteins on crop pests remains largely unknown. We evaluated the oral toxicity of S. carpocapsae venom proteins against Spodoptera frugiperda using artificial diet assays. Ingestion caused significant dose-dependent toxicity in early-instar larvae, resulting in mortality and a prolonged developmental duration. Carry-over effects were profound; treated pupae were smaller and malformed, with only 19% of larvae fed on 1000 ng g⁻¹ venom protein-supplemented diet reaching adulthood compared to 92% in controls. Surviving adults lived 30% fewer days and laid over 90% fewer morphologically normal eggs. These physiological disruptions coincided with elevated oxidative stress and detoxification enzyme activity, suggesting the venom induces oxidative and detoxification responses, which may be associated with the observed phenotypic alterations. This study provides the first demonstration of the oral toxicity of entomopathogenic nematode venom proteins, positioning them as a promising resource for the discovery of novel insecticidal proteins for sustainable pest management.

Spodoptera litura (Lepidoptera: Noctuidae) is globally considered one of the most important agricultural pests.

Whiteflies are a group of universally occurring insects that are considered to be a serious pest in their own way for causing both direct and indirect damages to crops. A few of them serve as vectors of plant viruses that are detrimental to the crop in question and cause an actual loss in productivity. A lot of attention is focused on pest control measures under the umbrella of IPM. In this review, we attempt to summarize the existing literature on how and why whiteflies are a serious concern for agriculture and society. We reviewed why there could be a need for fresh insight into the ways and means with which the pest can be combated. Here, we have emphasized next-generation strategies based on macromolecules, i.e., RNA interference and genetic engineering (for the expression of anti-whitefly proteins), as these strategies possess the greatest scope for research and improvement in the future. Recent scientific efforts based on nanotechnology and genome editing, which seem to offer great potential for whitefly/crop pest control, have been discussed. Comprehensive apprehensions related to obstacles in the path of taking lab-ready technologies into the farmers’ field have also been highlighted. Although the use of RNAi, GM crops, nanotechnologies, for the control of whiteflies needs to be evaluated in the field, there is an emerging range of possible applications with promising prospects for the control of these tiny flies that are mighty pests.

A thermotolerant protein with trypsin inhibitory activity designated as CaTI was purified to homogeneity from seeds of Cassia absus. Gel filtration chromatography and SDS-PAGE analysis showed the apparent molecular mass of ~20 kDa. Partial internal sequences indicate that CaTI belongs to Kunitz-inhibitor family. CaTI inhibits the bovine trypsin in 1:1 molar ratio and exhibited a competitive-type inhibitory activity with K_i = 5.6 10^-9 M. The inhibitory activity was retained over a broad pH range (2-12). Thermal stability study showed that it is stable up to 80 °C and inhibition activity reduced at and above 90 °C which might be due to the presence of predominantly β-sheets revealed by the CD study. The proteolysis studies of CaTI exhibited strong resistance to proteolysis by different proteases tested. The studies show that CaTI can be used as potential candidates for the development of the transgenic plant against the microbes and insect pests.