A new species of Pamphobeteus Pocock, 1901, is described from the Colombian Andes, Medellín, Antioquia. The biochemistry and molecular characteristics of the venom of this new species (previously identified as Pamphobeteus aff. nigricolor ) has been already described. A detailed taxonomic study, comparing this species with holotypes and additional material of Pamphobeteus species, allowed us to recognize it as new, and to describe it here as Pamphobeteus verdolaga sp. nov. The male of P. verdolaga sp. nov. is distinguished by the palpal bulb with broad embolus, poorly developed apical keel (A), prolateral inferior keel (PI) and prolateral accessory keel (PAc) present but poorly developed, and retrolateral keel (R) of similar length as A. Females are distinguished by the morphology of spermatheca with a wide base and very short oval seminal receptacles, which are curved toward the center. This is the thirteenth species described in Pamphobeteus and the sixth species reported from Colombia. The species description is complemented by a molecular characterization of a partial CO1 sequence.

The antimicrobial and antiparasite activity of phospholipase A₂ (PLA₂) from snakes and bees has been extensively explored. We studied the antiplasmodial effect of the whole venom of the snake Bothrops asper and of two fractions purified by ion-exchange chromatography: one containing catalytically-active phospholipases A₂ (PLA₂) (fraction V) and another containing a PLA₂ homologue devoid of enzymatic activity (fraction VI). The antiplasmodial effect was assessed on in vitro cultures of Plasmodium falciparum. The whole venom of B. asper, as well as its fractions V and VI, were active against the parasite at 0.13 ± 0.01 µg/mL, 1.42 ± 0.56 µg/mL and 22.89 ± 1.22 µg/mL, respectively. Differences in the cytotoxic activity on peripheral blood mononuclear cells between the whole venom and fractions V and VI were observed, fraction V showing higher toxicity than total venom and fraction VI. Regarding toxicity in mice, the whole venom showed the highest lethal effect in comparison to fractions V and VI. These results suggest that B. asper PLA₂ and its homologue have antiplasmodial potential.

Scorpions use their venom in defensive situations as well as for subduing prey. Since some species of scorpion use their venom more in defensive situations than others, this may have led to selection for differences in effectiveness in defensive situations. Here, we compared the LD₅₀ of the venom of 10 species of scorpions on five different species of target organisms; two insects and three vertebrates. We found little correlation between the target species in the efficacy of the different scorpion venoms. Only the two insects showed a positive correlation, indicating that they responded similarly to the panel of scorpion venoms. We discuss the lack of positive correlation between the vertebrate target species in the light of their evolution and development. When comparing the responses of the target systems to individual scorpion venoms pairwise, we found that closely related scorpion species tend to elicit a similar response pattern across the target species. This was further reflected in a significant phylogenetic signal across the scorpion phylogeny for the LD₅₀ in mice and in zebrafish. We also provide the first mouse LD₅₀ value for Grosphus grandidieri.