Natural parasitism of the coffee leaf miner: climate factors, insecticide, and landscape affecting parasitoid diversity and their ecosystem services in coffee agroecosystems.

Climate factors, pesticides, and landscape in coffee agroecosystems directly affect the populations of the coffee leaf miner and its parasitoids. This study aimed to investigate the effects of climate factors, insecticide use, and landscape on natural parasitism, parasitoid diversity, and infestation of L. coffeella in coffee plantations in the Planalto region, Bahia, Brazil. Mined leaves were collected monthly in six coffee plantations with varying edge density, vegetation cover, landscape diversity in scales of 500 to 3000 m of radius, insecticide use, and climate factors. Closterocerus coffeellae, and Proacrias coffeae (Eulophidae) predominated in the pest's natural parasitism. Our record is the first for the occurrence of Stiropius reticulatus, Neochrysocharis sp. 1, Neochrysocharis sp. 2, and Zagrammosoma sp. in Bahia. Higher temperature and larger forest cover increased the coffee leaf miner infestation. Higher rainfall values, insecticide use, and landscape diversity decreased the pest infestations. Natural parasitism and species diversity are favoured by increase in temperature, forest cover, and edge density, while increase in rainfall, insecticide use, and landscape diversity lead them to decrease.The natural parasitism and diversity of parasitoid species of the coffee leaf miner have been enhancing in the areas with greater forest cover and edge density associated with low use of insecticides. The areas composed of different lands with annual croplands surrounding the coffee plantations showed less natural parasitism and parasitoid species diversity. The ecosystem services provided by C. coffeellae and P. coffeae in coffee crops areas require conservation and these species are potential bioproducts for applied biological control programmes.

The effects of thiamethoxam on coffee seedling morphophysiology and Neotropical leaf miner (Leucoptera coffeella) infestations.

BACKGROUND: Coffee (Coffea arabica L.) is one of the main commodities produced in Brazil. Insecticides like the (systemic) neonicotinoid thiamethoxam are widely used to suppress pest populations during coffee production, in particular the Neotropical leaf miner (Leucoptera coffeella Guérin-Mèneville & Perrottet, 1842) (Lepidoptera: Lyonetiidae). In addition to its efficacy against this pest species, thiamethoxam is also thought to be a bioactivator of plant metabolism, but has not yet been tested for such activity. Thus, the objectives of the present study were (1) to assess the concentration-response effects of thiamethoxam on the vegetative vigor of coffee seedlings (C. arabica 'Catuaí 144' cultivar) at different concentrations [2, 20, 40, 80 and 200 mg active ingredient (a.i.) kg-1 ] applied via soil drenching and (2) to evaluate if the plant response interferes with the effectiveness of thiamethoxam in controlling leaf miner populations. The morphophysiological traits of the coffee seedlings were evaluated 20, 40, 60 and 80 days after application, and leaf miner infestations were recorded starting 20 days after the insecticide application with the releasing of adults, and every 20 days afterwards. RESULTS: The results indicated that thiamethoxam has a deleterious effect on the morphophysiological traits of the plants compromising their development with increase in concentrations. However, leaf area exhibited a different pattern with a peak at 50 mg a.i. kg-1 consistent with thiamethoxam-induced hormesis (i.e. biphasic response with stimulatory effect at sublethal range of a toxic substance at the higher concentration). Nonetheless, such bioactivator effect did not affect thiamethoxan effectiveness against the leaf miner even at the lowest concentration tested. CONCLUSION: Thiamethoxan exhibited bioactivation effect on leaf at low concentration, but without compromising efficacy against leaf miner populations. Therefore, its proposed metabolism-boosting properties may encourage the unnecessary use of this insecticide, potentially leading to higher selection for insecticide resistance and an eventual decline in its effectiveness against the Neotropical leaf miner. © 2022 Society of Chemical Industry.

Six-Year Follow-Up of Immature Tooth Revascularization With Enamel Matrix Proteins.

Novel endodontic revascularization techniques have been considered as alternative options for treatment of immature teeth affected by apical periodontitis. The continuous development of the root canal has been recognized as a major advantage of these techniques over traditional apexification approaches. This article reports a case in which endodontic revascularization using extracellular matrix proteins (EMPs) as a scaffold was utilized to treat an immature maxillary lateral incisor with history of trauma and chronic apical periodontitis. The root canal was accessed and sequentially irrigated with sodium hypochlorite (NaOCl) (2 mL, 5.25%), saline solution (10 mL), and gluconate chlorhexidine (10 mL, 0.12%). The root canal was then dried, filled with an antibiotic paste (ciprofloxacin, metronidazole, and minocycline), and sealed for 3 weeks. The antibiotic paste was then removed by irrigating the canal with NaOCl (10 mL, 5.25%). The intracanal scaffold was obtained by injecting a commercially available enamel EMP into the newly formed intracanal blood clot. Mineral trioxide aggregate was used to seal the scaffold in place, and a composite resin restoration was then placed using a universal restorative. At 3 and 72 months, clinical and radiographic analyses demonstrated short- and long-term success of the technique presented. The authors' findings indicate revascularization techniques are promising in the treatment of immature teeth with apical periodontitis. Longitudinal clinical trials are necessary to confirm the findings reported herein.