Demographic analysis and biotic potential of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) on pea.

The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is a highly destructive polyphagous pest that primarily damages maize. Maize is considered a most versatile crop for growing intercrops due to the wide row it needs. Maize-pea intercropping is preferred by small and marginal farmers worldwide due to various advantages including higher yield and improved economic benefits. However, the success of this intercropping system may be hampered if pea could sustain the FAW population. Thus, to clarify the fitness and potential effect of S. frugiperda on pea, we analysed the survival and development of S. frugiperda fed on pea leaves in the laboratory and constructed age-stage and two-sex life tables. Results showed that FAW successfully completed its life cycle when fed on pea and produced fertile offspring. The pre-adult duration was significantly higher on pea than maize. The net reproductive rate, intrinsic and finite rate of population increase on pea (135.06 offspring per individual, 0.12 offspring per individual per day and 1.13 times per day) were all significantly different from those on maize (417.64 offspring per individual, 0.19 offspring per individual per day and 1.21 times per day). The probability of survival of S. frugiperda at each stage was lower when fed on pea leaves than that of maize-fed larvae. Due to the overlapping growth periods of the maize and pea, S. frugiperda can easily proliferate throughout the year by shifting between adjacent crops. Thus, this study revealed the adaptability of S. frugiperda for pea and provides the foundation for further assessment of FAW risk to other inter-crops.

Unraveling the enigma of root-knot nematodes: from origins to advanced management strategies in agriculture.

MAIN CONCLUSION: Integrated management strategies, including novel nematicides and resilient cultivars, offer sustainable solutions to combat root-knot nematodes, crucial for safeguarding global agriculture against persistent threats. Root-knot nematodes (RKN) pose a significant threat to a diverse range of host plants, with their obligatory endoparasitic nature leading to substantial agricultural losses. RKN spend much of their lives inside or in contact by secreting plant cell wall-modifying enzymes resulting in the giant cell development for establishing host-parasite relationships. Additionally, inflicting physical harm to host plants, RKN also contributes to disease complexes creation with fungi and bacteria. This review comprehensively explores the origin, history, distribution, and physiological races of RKN, emphasizing their economic impact on plants through gall formation. Management strategies, ranging from cultural and physical to biological and chemical controls, along with resistance mechanisms and marker-assisted selection, are explored. While recognizing the limitations of traditional nematicides, recent breakthroughs in non-fumigant alternatives like fluensulfone, spirotetramat, and fluopyram offer promising avenues for sustainable RKN management. Despite the success of resistance mechanisms like the Mi gene, challenges persist, prompting the need for integrative approaches to tackle Mi-virulent isolates. In conclusion, the review stresses the importance of innovative and resilient control measures for sustainable agriculture, emphasizing ongoing research to address evolving challenges posed by RKN. The integration of botanicals, resistant cultivars, and biological controls, alongside advancements in non-fumigant nematicides, contributes novel insights to the field, laying the ground work for future research directions to ensure the long-term sustainability of agriculture in the face of persistent RKN threats.

"Effect of total phenol on the control of leafminer (Phytomyza horticola) infestation in Pea plants".

To determine how vulnerable various pea genotypes are to leafminer infestation, a field experiment was conducted. On the basis of the presence of mines on five randomly selected leaflets from the upper, middle and lower parts of the plant, observations of larvae were made throughout the growing season. The total phenols were determined using the method described by Bray and Thorpe (1954, Analysis of phenolic compounds of interest in metabolism. Methods Biochem Anal. 52:1-27) and absorbance at 650 nm was measured using a spectrophotometer. There was a negative correlation between leafminer infestation and total phenol content. The UHF Pea-12 genotype, characterised by the lowest total phenol concentration (20.87 mg/100 g), exhibited the highest level of leaflet infestation (17.33%). Although UHF Pea-1 genotype had the lowest mean leaflet infestation (6.58%), it also had the highest phenol concentration (41.91 mg per 100 g). In context with this, the present study highlights the significance of host-plant resistance (HPR) in pest management.

Effect of prey density on the performance of Eupeodes corollae and its predation rate against the cabbage aphid, Brevicorynae brassicae (L.).

Eupeodes corollae (F.) (Diptera: Syrphidae) is the most abundant syrphid fly which is distributed worldwide and is the sole predator of aphids. Therefore, the present study was conducted to evaluate the predation rate and functional response of E. corollae against the cabbage aphid, Brevicoryne brassicae (L.). The experiment was carried out under laboratory conditions at 25 ± 2°C with 60-70% relative humidity. The results revealed that age-specific net predation rate (qx) increased after the 4th day and a peak was recorded on the 10th day of pivotal age in the third larval instar. The stable host kill rate and finite host kill rate of E. corollae were 18.63 and 21.07, respectively, against the B. brassicae and predicted that a mean of 20.78 aphids was needed for E. corollae to produce one offspring. A negative linear coefficient (P < 0) indicated the type II functional response for all larval instars of E. corollae against the B. brassicae. At higher prey density, the prey consumption was significantly at par with second and third instar larvae of E. corollae as the prey consumption was increased with increasing the prey density, which then decreased after attaining the upper asymptote (76.40 and 81.40% consumption, respectively). The Roger's predator random equation for type II functional response was fitted to estimate attack rate (a) and handling time (Th). The maximum prey consumption was recorded for third instar of E. corollae with a higher attack rate (0.336 h-1) and lower handling time (0.514 h) against B. brassicae, followed by the second and first instar. Thus, it is concluded that the third larval instar of E. corollae was the voracious feeder and used as an efficient biocontrol agent in the IPM programme.