Search

Research on economic, ecological and relative benefits from organic and conventional farming systems has gained significant importance. Organic farming increases species diversity, enhances biological control services, and thus complements sustainable pest management. However, published literature is scarce on cotton crops grown organically with respect to the abundance and diversity of biological control agents and their effects on herbivore populations, typically from developing nations. To address the question, the non‐transgenic cotton variety CIM‐573 was cultivated under two fertility management systems, that is, organic and conventional in 2019 and 2021, and subsequently, differences in the abundance and diversity of arthropod communities were carried out. We applied cattle manure in organic fields 1 month before planting; however, synthetic fertilizers were used in conventional fields. We sampled arthropods weekly after 7 weeks of sowing from the middle rows of treatments for both types of fields. We recorded 10 herbivores as well as eight natural enemy species. Herbivores were more abundant in conventional cotton. However, natural enemies were higher in organic cotton fields. Principal component analysis of herbivores assemblages depicted that Shannon diversity and abundance were positively correlated in the conventional cotton while Menhinick richness and Simpson dominance index were higher in organic cotton. Likewise, natural enemies' abundance, Shannon diversity, Menhinick richness and Simpson dominance were typically more concentrated in organic cultivated cotton. Regression analysis confirmed that the abundance and diversity of natural enemies played a significant role in lowering herbivores populations. Seed cotton yield was significantly higher in conventional cotton and the yield difference between organic and conventional cotton was 27.98%. Our study clearly demonstrates that organic cotton provides more functional and complementary niches to natural enemies and plays a crucial role in pest suppression. Implications of our results for future pest management with respect to ecosystem services in organically grown cotton crops are also discussed. [ABSTRACT FROM AUTHOR]

Fruit flies (Diptera: Tephritidae) species pose a significant threat to mango and citrus production worldwide including Pakistan. In the present study we identified and monitored the population dynamics of fruit flies species using male attractants Attrex® (methyl eugenol 98%, evyol group) and static Spinosad® (spinosad 2% and methyl eugenol 51%, target group) in mango and citrus orchards at different locations in Multan, Southern Punjab, Pakistan. Bactrocera zonata (Saunders) was the most abundant fruit fly species in this study. Our results indicated a positive and significant correlation between the species of fruit flies and mean temperature in mango and citrus orchards at all locations. In mango orchards, peak population of fruit fly complex was recorded from June to July, a period when the mangoes ripe and mean temperature is high. In citrus orchards, minimum population was observed from January to February, a period when the citrus fruit is available in the orchard but the temperature is too low for larval development. Several factors such as temperature, availability of preferred host and alternate host could contribute towards the population buildup of fruit flies in this region. [ABSTRACT FROM AUTHOR]

Curcuma longa L. (Zingiberales: Zingiberaceae) leaf and rhizome essential oils were evaluated for their toxicity and repellency against invasive fire ants: red imported fire ants (RIFA), Solenopsis invicta Buren, black imported fire ants (BIFA), Solenopsis richteri Forel, and a reproductively functional hybrid (HIFA). Ar-turmerone was the major constituent of leaf (42.4%) and rhizome (40.4%) essential oils. A range of concentrations starting from 156 µg/g until the failure of treatment were used. Removal of treated sand in digging bioassay was used as a criterion for repellency. Leaf essential oil showed significantly higher repellency at concentrations of 19.5, 9.8, and 4.9 µg/g against RIFA, BIFA, and HIFA workers, respectively, as compared with control whereas rhizome essential oil was active at 39, 19.5, and 4.9 µg/g against BIFA, RIFA, and HIFA, respectively. Ar-turmerone exhibited repellency at 19.5 µg/g against HIFA workers whereas DEET (N,N-diethyl-meta-toluamide) failed at 39 µg/g. Leaf essential oil showed LC50 values of 85.8, 97.7, and 182.7µg/g against RIFA, BIFA and HIFA workers, whereas the rhizome essential oil had LC50 values of 127, 109.9, and 151.2 µg/g against these species, respectively. Ar-turmerone, tested only against HIFA, with LC50 value of 57.2 was the most active compound. Bifenthrin, a commonly used pyrethroid, with LC50 of 0.03, 0.32, and 0.018 µg/g was toxic against RIFA, BIFA, and HIFA workers, respectively. Both the essential oils and ar-turmerone showed toxicity and repellency against imported fire ants. Different formulations of these natural products will be tested to explore the use potential of these natural products under field conditions., (© The Author(s) 2023. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)