The use of selective insecticides is essential to harmonize chemical and biological control in coffee crops. This study evaluated the selectivity of chlorpyrifos, cartap hydrochloride, pyriproxyfen, profenofos/lufenuron, fenpropathrin, and zeta-cypermethrin toward pupae and adults of Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae), a key predator of mealybugs in coffee crops. Topical bioassays were conducted on pupae and adults (24-h-old) under laboratory conditions, and reproductive parameters of the offspring originating from treated individuals were also assessed. Fenpropathrin and zeta-cypermethrin reduced pupal survival without affecting pupal duration. All insecticides reduced adult survival, with fenpropathrin, zeta-cypermethrin, and cartap causing the lowest survival rates. Offspring fecundity was reduced by fenpropathrin and zeta-cypermethrin when pupae were treated, and by fenpropathrin, zeta-cypermethrin, and cartap hydrochloride when adults were exposed. Egg viability was affected differently: offspring from treated pupae showed reduced hatching rates only with fenpropathrin and zeta-cypermethrin, whereas offspring from treated adults had lower egg viability after exposure to chlorpyrifos, cartap, profenofos/lufenuron, and fenpropathrin. Chlorpyrifos, pyriproxyfen, and profenofos/lufenuron were harmless to the pupae. Pyriproxyfen was the only compound classified by the IOBC as harmless (Class 1) to both life stages, while fenpropathrin was considered harmful (Class 4) to adults, and the other insecticides were classified as slightly harmful (Class 2). These results indicate that insecticides classified as Class 1 or 2 are compatible with C. montrouzieri, which supports their potential integration into integrated pest management programs in coffee agroecosystems.
The cotton leafhopper, Amrasca biguttula biguttula (Ishida), is one of the most destructive sucking pests of upland cotton (Gossypium hirsutum L.), causing yield losses of up to 40
Tetranychus urticae Koch is a destructive herbivorous mite, yet its physiological and metabolic associations with medicinal plants remain poorly characterized. This study examined the progressive infestation of Acorus calamus by T. urticae under glasshouse conditions. Because infestation developed naturally, stages were not predetermined; early–progressive (20–30 days), progressive (50–60 days), and advanced (80–90 days after initial detection) phases were assigned from the observed progression of mite density, infestation severity, webbing intensity, and leaf damage. Quantitative assessment supported increasing infestation pressure: egg density rose from 24.54 ± 5.45 to 187.34 ± 21.56 eggs leaf⁻1, while leaf damage index increased from 8.57 ± 1.44
The nesting whitefly (NW), Paraleyrodes pseudonaranjae Martin (Hemiptera: Aleyrodidae), is an invasive and highly polyphagous species originating from the Neotropics that has recently expanded into Asia. Here, we report the first confirmed occurrence of P. pseudonaranjae in Bangladesh, detected on coconut palm (Cocos nucifera L.) in Mymensingh, a north-central district of the country. Species identity was confirmed based on morphological characteristics and DNA barcoding of the mitochondrial cytochrome c oxidase subunit I (mtCOI) gene. Morphological examination confirmed key diagnostic features of P. pseudonaranjae, including “modified X-shaped” grey bands on the forewings and distinct male genitalia, clearly distinguishing it from the morphologically similar species, Paraleyrodes bondari. Molecular analysis of the mtCOI gene revealed 99–100
Fall armyworm (Spodoptera frugiperda) poses a major threat to maize production in sub-Saharan Africa, underscoring the importance of identifying durable sources and biochemical markers of host-plant resistance. This study investigated the constitutive metabolic basis of partial FAW resistance in tropical maize by integrating insect bioassays with complementary GC–MS and LC–Q-TOF–MS profiling. Whole-leaf tissues collected before infestation from three resistant (Mp716, CML71, and CKSBL10008) and three susceptible (CML370, CKSBL10025, and CML444) inbred lines were analyzed, and the same tissues were incorporated into artificial diets to evaluate larval growth and feeding preference. Diets derived from resistant genotypes consistently reduced larval relative growth rates and were less preferred by neonates than diets derived from susceptible lines, providing evidence that pre-existing leaf chemistry contributes to both antibiosis- and antixenosis-associated resistance. GC–MS detected approximately 800 analytical features and highlighted resistance-associated trends in amino-acid, nitrogen, and central-carbon metabolism. LC–Q-TOF–MS detected approximately 1,700 features, with 384 differing significantly between resistance classes after false-discovery-rate correction, revealing extensive remodeling of specialized metabolism. Resistant lines were characterized by higher relative abundances of several putative amino acids, purine-related metabolites, phytosterols, and putative defense-associated compounds, including a DIMBOA-hexoside-related feature. In contrast, susceptible lines generally contained higher levels of putative soluble sugars, central-carbon metabolites, and several flavonoid- and phenylpropanoid-related features. Pathway analysis identified 28 differentially abundant consolidated metabolites and significant enrichment of phenylpropanoid biosynthesis, indicating selective metabolic reconfiguration rather than generalized accumulation of secondary metabolites. Together, these findings demonstrate that partial FAW resistance is associated with a coordinated constitutive metabolic signature integrating nutritional composition and specialized defense chemistry. Although targeted and spatially resolved validation is required to establish the functions of individual metabolites, the identified signatures provide promising biochemical candidates for resistance screening and metabolomics-assisted breeding of FAW-resistant maize.
