The main open-field producer regions of cucurbits (watermelon, squash, melon and cucumber) in Panama (Los Santos, Herrera and Coclé provinces) were surveyed for molecular identification, occurrence and distribution of Thrips palmi (the most important pest thrip species on cucurbits in Panama), Frankliniella intonsa and Frankliniella cephalica during the growing seasons of 2009 to 2013 and 2017 to 2018. Forty plots were surveyed and DNA extracts of 186 thrips (larvae and adults) were analyzed by multiplex PCR, using a set of T. palmi-specific primers in combination with a set of insect-universal primers. DNA extracts corresponding to 174 individual thrips (93.5%) rendered both PCR products of expected size with T. palmi-specific and insect-universal primers, whereas the remaining DNA extracts corresponding to 12 individual thrips (6.5%) only rendered the product of the expected size with insect-universal primers. Sequencing of those PCR products and BLAST analysis allowed for the identification of F. intonsa and F. cephalica. Thrips palmi was detected in all three provinces, while F. intonsa and F. cephalica were detected in Herrera and Los Santos provinces. To our knowledge, this is not only the first detection of F. intonsa in Panama, but also the first detection of F. cephalica in Panamanian cucurbit crops.

The aim of the study was to recognise the accumulation of organic carbon (SOC) in the soils of Polish grasslands (GL) and to consider the possibility of increasing its sequestration in these soils. The Tiurin method (mineral soils) and the mass loss method (soil of organic origin) were used. It was found that: (i) the average SOC content of mineral soils is 2.44% and of organic soils – 10.42%; (ii) according to the Polish criteria, approximately 84% of GL mineral soils are classified as classes with high and very high SOC content, and over 15% and 1% – in classes with medium and low SOC content, respectively; more than 99% of organic soils belong to two classes with the highest SOC content and less than 1% to the class with an average content; (iii) according to the European Soil Bureau, the share of GL mineral soils with a high SOC content is slightly over 4%, medium – slightly over 47%, and low and very low – around 50%; for organic soils they are 67, 29, and 4%, respectively; (iv) the reserves of organic carbon in the 0–30 cm layer on the entire surface of GL soils amount to 412.7 Tg of SOC. There is considerable scope for increasing the SOC stock in meadow-pasture soils.