CAB International

Crop-feeding herbivores reduce the world's food output by approximately 20% and climate change (CC) is bound to deepen those losses. Endemic or introduced consumer organisms (i.e., biological control agents) naturally regulate herbivore populations and secure a quarter of crop yields, but are exceptionally susceptible to CC-related disturbances. Here, we use niche modeling for 14 globally-important herbivores (or pests) to forecast how richness of the associated biological control agents of each pest-as a proxy of service strength-may alter under a CC-driven range expansion. Results show that 57%-100% of pests are bound to lose parasitoid and predator associates. The cassava mealybug Phenacoccus manihoti may experience a 27% decline in parasitoid pressure, whereas cosmopolitan pests of cereal and horticultural crops benefit from 6% to 7% drops in predator pressure. Such 'enemy release' can possibly exacerbate pest-induced yield losses and threaten future harvests. Ant-pest associations change in both directions, implying that pests may either face strengthened or weakened biological control. For pests spreading towards or within food-deficit regions in the equatorial belt, parasitoid declines and increases in ant pressure are most pronounced. By exposing the fragility of biodiversity-based ecological safeguards in farmland, our work calls for urgent, integrative, and nature-friendly solutions to uphold food security under environmental change.

Abstract Stripe rust, caused by Puccinia striiformis f. sp. tritici , significantly reduces wheat ( Triticum aestivum L.) yields when uncontrolled. This study developed predictive models for stripe rust severity using weather variables. Field experiments were conducted from 2017 to 2019 at the Research Farm, Chatha, using susceptible wheat variety PBW 343 in a randomized block design with four replications. Disease severity was assessed weekly using the modified Cobb scale. Additional historical weather and disease data from 2005 to 2017 were incorporated to develop comprehensive forecasting models. Strong positive correlations were observed between disease severity and maximum temperature ( r = 0.89–0.91) and minimum temperature ( r = 0.75–0.91), while morning relative humidity showed negative correlation ( r = −0.80). Rainfall exhibited no significant correlation with disease progression. Two multiple linear regression models were developed: for 2005–2017, Y = −502.14 + 0.64 X 1 + 8.57 X 2 + 3.04 X 3 + 1.42 X 4 + 0.58 X 5 ; and for 2017–2019, Y = 322.57 + 9.41 X 1 − 4.14 X 2 − 2.56 X 3 − 0.71 X 4 + 0.26 X 5 , where Y represents disease severity and X 1 – X 5 represent weather parameters. Both models explained approximately 89%–91% of variation in disease severity. Spore concentration increased 84% from 51st to seventh standard meteorological week during 2017–2019. These models provide quantitative tools for predicting stripe rust severity using readily available weather data, enabling timely disease management decisions and supporting sustainable wheat production.

Spodoptera frugiperda (J.E. Smith) is a destructive pest threatening maize production and global food security. Diet quality plays a crucial role in its growth and survival, which is essential for laboratory rearing and pest management research. This study evaluated the effects of natural maize leaves and an artificial diet on the growth, development, and survival of S. frugiperda under controlled laboratory conditions. Second-instar larvae were reared in a completely randomized design with two diet treatments. Larvae fed the artificial diet developed significantly faster, attained greater biomass, and exhibited longer adult longevity compared with those fed maize leaves (P ≤ 0.05). Survival, pupation, and adult emergence were also significantly higher in the artificial diet treatment. These results demonstrate that diet quality strongly influences the biological performance of S. frugiperda. The artificial diet provided superior growth and survival and is therefore recommended for laboratory rearing and experimental studies.

Red spider mite Tetranychus macfarlanei Baker and Pritchard (Acari: Tetranychidae) poses a serious threat to successful crop production across Bangladesh. Farmers predominantly rely on chemical pesticides; however, the rapid development of resistance after repeated applications reduces their effectiveness. The aim of this laboratory study was to evaluate the efficacy of selected biopesticides as ecofriendly alternatives for managing T. macfarlanei. Four biopesticides- Celastrus angulatus 1% EW (Bio-Chamak), D-limonene 5% ML (Bio-Clean), Martin 0.5% AS (Biotrin), and Matrin (0.5%) + plant oil (K-mite) - were tested against eggs and adult females of T. macfarlanei. Female mortality was recorded at 12 hr intervals for 18 days, and egg hatchability was assessed 10 days post-treatment. The lethal concentration (LC50) values for adult females were calculated to determine relative toxicity. Results indicated that D-limonene 5% ML and C. angulatus 1% EW exhibited moderate ovicidal activity, while Martin 0.5% AS and Matrin (0.5%) + plant oil had minimal effects on egg hatchability. In contrast, Matrin (0.5%) + plant oil and Martin 0.5% AS showed strong adulticidal effects, with LC50 values of 0.16 ppm and 0.21 ppm, respectively, compared to 6.16 ppm for D-limonene 5% ML and 75.82 ppm for C. angulatus 1% EW. These findings suggest that Matrin (0.5%) + plant oil and Martin 0.5% AS are the most potent formulations against adult T. macfarlanei. In conclusion, these biopesticides, particularly Matrin (0.5%) + plant oil, could serve as promising alternatives to chemical acaricides for the sustainable management of T. macfarlanei and should be further validated in field conditions for integration into future Integrated Pest Management (IPM) programs.

Abstract A new distribution map is provided for Cytorhabdovirus colocasiae (Colocasia bobone disease virus). Monjiviricetes: Mononegavirales: Rhabdoviridae. Host: taro (Colocasia esculenta).

Abstract A new distribution map is provided for Diaporthe humulicola Allan-Perkins et al. Sordariomycetes: Diaporthales: Diaporthaceae. Host: hop (Humulus lupulus).

Abstract A new distribution map is provided for Badnavirus tessellotheobromae (Cacao mild mosaic virus). Revtraviricetes: Ortervirales: Caulimoviridae. Host: cocoa (Theobroma cacao).

Abstract A new distribution map is provided for Babuvirus musae (Banana bunchy top virus). Arfiviricetes: Mulpavirales: Nanoviridae. Main host: Musa spp.

Abstract A new distribution map is provided for Tobamovirus fructirugosum {Tomato brown rugose fruit virus). Alsuviricetes: Martellivirales: Virgaviridae. Hosts: tomato (Solanum lycopersicum), pepper (Capsicum annuum).