Antonino Sánchez-Ortega

Imaginal Feeding of Twelve Nemouroidean Stonefly Species (Insecta, Plecoptera)

Abstract We studied the gut contents of adults of 12 stonefly species of the superfamily Nemouroidea, belonging to 3 different families: Nemouridae (4 species), Capniidae (2 species), and Leuctridae (6 species) from the Sierra Nevada Mountains in Spain (southern Iberian Peninsula). For each species, we describe the male and female diet. After determining and quantifying the different components, we deduced that feeding is important among adults in this superfamily, and that the diet is varied, with cyanolichens and cyanophyceae being prominent, and hyphae and spores of Ascomycetes sometimes eaten, whereas pollen is amply consumed by some spring or spring–summer species.

Physico‐chemical factors that determine the distribution of mayflies and stoneflies in a high‐mountain stream in Southern Europe (Sierra Nevada, Southern Spain)

The Rfo Monachil, a high‐mountain stream in Sierra Nevada (South of Spain), was investigated. As a consequence of sewage discharges from a ski resort situated at the head of the stream and from populations along its banks, the river is affected by organic pollution. With the objective of finding what physico‐chemical factors determined the distribution of the Ephemeroptera and Plecoptera along the course of the stream, and in what manner they were affected, a stepwise multiple‐regression analysis was applied. Through this analysis it was possible to prove that, in general, the distribution and abundance of these two orders of insects in the Rfo Monachil are influenced by organic pollution. Nevertheless, at the species level other factors assume prime importance, such as temperature, oxygenation and mineralization of the waters, parameters which may or may not be related to pollution.

Implications of imaginal-size variation over the flight period in stoneflies (Plecoptera)

Abstract In the present study, the decrease in the mean size of specimens over the species flight period in Plecoptera (12 species, 5 families) was analysed, revealing a significant decrease in the adult mean size, for both males and female, in almost all the species without an extended flight-period pattern. Some of the data show that, in addition to temperature, other regulatory factors must govern these variations. Data support the explanation previously proposed for other insect groups that the individuals with appropriate development emerge at the beginning of the flight period or slightly afterwards, when environmental conditions are suitable, whereas individuals with suboptimal size emerge later trying to increase in size but under pressure to emerge during a specific period of the year. Nevertheless, our data suggest that maximum size does not necessarily coincide with the peak flight period (maximum reproductive possibility).

Protandry and Its Relationship with Adult Size in Some Spanish Stoneflies Species (Plecoptera)

Abstract Protandry in 11 stonefly (Plecoptera) species (representing five families) from Sierra Nevada (Spain) has been studied (recorded and quantified) over their flight period. All species exhibited a positive protandry coefficient (range, 0.07–0.33), indicating that no species shows proteroginy. Protandry was less pronounced in species having extended flight periods, brief flight periods, or highly concentrated flight maximums. The degree of protandry did not correlated with the degree of sexual dimorphism in size, contradicting the theoretical prediction of increased dimorphism with increased protandry.

Leuctra ketamensis a new species of Leuctridae from Northern Africa (Insecta, Plecoptera)

Leuctra ketamensis sp. n. is described from Northern Africa. This species belongs to the Leuctra nigra group. The male is easily distinguished by a pair of characteristic sclerotized processes on abdominal tergite VI, the absence of sclerotized processes on other tergites, the absence of the specillum and the presence of a complex paraproctal system; the female is distinguished by a subgenital plate split into two parts separated by a membranous area.