Spilostethus

Abstract: Field surveys of Roselle plant fields were conducted during two successive seasons of 2006 and 2007. The total counted insects on Roselle, Hibiscus sabdariffa attained 16 species belong to seven insect Orders [(Hemiptera (3 species), Homoptera (1 species), Lepidoptera (3 species), Neuroptera (1 species), Coleoptera (3 species), Diptera (1 species), Hymenoptera (4 species)]. Variable numbers of insects were counted on different Roselle varieties and in the two seasons. The most prevailing insect species were the piercing sucking pests [Empoasca spp.; Spilostethus longulus Dallas; Nezara viridula L. and Oxycarenus hyalinipennis (Costa)] and the predators [Polistes sp., Coccinella undecimpunctata and Scymnus syriacus]. Honeybee (Apis mellifera L.) proved to be the most abundant pollinator, averaging 13, 17, 18 individuals/25double strikes in cultivations of Sudani, Masri and White varieties of Roselle plants during flowering of the first season respectively. Similar results were also obtained in the second s...

Abstract: Western European, and especially German-based multinational food processing companies tend to have “alimentary purpose” sunflower hybrlds and varieties grown in Hungary. This “commercial” product is highly preferred as Substitute of walnuts, or as filling in chocolate, bread, other bakery products, or baked into the top layer thereof. In early 1990s German companies rejected several truckloads of export goods due to “greening of the seed in the achene”. Almost 90% of the rejected consignments originated from the Sandy ridge of the region between the rivers Danube and Tisza, which is severely infected with Asclepias syriaca L weed. Field investigations revealed unambiguously that the greening of the seed in the achene had been caused by the Spilostethus [= Lygaeus] equestris L plant bug. This species is able to cause extensive damages and discontinuities in the so-called Shoulder part of the achene with its powerful stinging-suctorial mouth organ. In the damaged area of intensive Chlorophyll formation begins due to the solar effect, which is the unambiguous cause of the greening of the seed in the achene. In our investigations the industrial purpose sunflower plantations in two neighbouring areas (Bacsalmas and Katymar) were studied in respect of the damage caused by the Spilostethus [= Lygaeus] equestris L. While in Bacsalmas (that district was less infected with the Asclepias syriaca L) we found a damage of decreasing intensity (8.85 damaged achenes per sunflower disc) as advancing towards the centre of the plantation, while in the area of Katymar (this area was severely infected with Asclepias syriaca L), this value was almost three times as high, reaching 31.71 damaged achenes per disc. Though the numbers are not very high in themselves -assuming that a well-built disc contains 1100 to 1200 seeds -, but the damage may result in significant fall of quality, or even prevent exporting. Our extensive research into the causes of the greening of the sunflower seeds made it clear that the Spilostethus [- Lygaeus] equestris L has a significant influence on the contents of the seeds it has damaged: it increases the proportion of linoleic acid (C18:2) by about 2.5 %. That affects the lasting quality of the achene unfavourably (HORVATH & BUJAKI, 1991). For this reason, a comprehensive study of the biology of the Spilostethus /= Lygaeus] equestris L became necessary for the developing possible protection methods. Such studies also represented the beginning of the investigation of any external or endogenous factors, that might obstruct the successful use of alimentary purpose sunflower hybrids or varieties in the food industry. According to GUNTHER (1975), the S. equestris L is indigenous from southern England to Siberia, and from central Sweden to the Mediterranean areas. It is less common north of Central Europe; it prefers areas with warmer climate. It likes staying both on the ground or in the flowers of various plants. It especially likes the tarne poison or swallowwort (Vincetoxicum officinale MNCH., syn.: Cynanchum vincetoxicum (L) PERS.). Data on the way of life of the S. equestris L in Hungary is extremely scarce, despite the fact that the species is widespread in our country. Information on its nourishing plants and habits can only be found in the publications of HORVATH (1984; 1986; 1987b; 1989; 1999) and BUJAKI & HORVATH (1992). Horvath (1984) inferred the nourishing plant specialization of the species from the total nitrogen contents of various plant seeds, such as those of the Asclepias syriaca L, and the sunflower (Helianthus annuus L). Amino-acid composition in the seeds of the A. syriaca is the most similar to that of the sunflower, soy or peanut. It may be assumed that its similarity to the sunflower seed is the cause of the fact that the S. equestris willingly sucks the ripening achenes of the sunflower, too. (HORVATH, 1984).

Abstract: The Heteroptera fauna of cotton fields of Garmsar and vicinity (Semnan province) is studied in this paper; a total of 17 species were collected and determined. The studied families and genera are Alydidae (Camptopus Amyot & Serville), Anthocoridae (Anthocoris Fallen, Orius Wolff), Coreidae (Centrocoris Kolenati, Phyllomorpha Laporte), Rhopalidae (Maccevethus Dallas, Rhopalus Schilling), Geocoridae (Geocoris Fallen), Lygaeidae (Spilostethus Stal), Piesmatidae (Piesma Lepeletier & Serville), Reduviidae (Coranus Curtis, Nagusta Stal), and Pentatomidae (Andrallus ergroth, Nezara Amyot & Serville, Graphosoma Laporte).

Abstract: Molecular characterisation of two species of Spilostethus viz. S.hospes (Fab.) and S.pandurus (Scop.) based on the 16S rRNA sequence was carried out to differentiate the taxa which are otherwise morphologically identical at the nymphal stages. The 16S rRNA gene was amplified by polymerase chain reaction. The primers used for amplification were forward LR-J-13017: 5'-TTA CGC TGT TAT CCT AA-3' and reverse LR-N-13398: 5'-CAC CTG TTT AAC AAA AAC AT-3'. The sequencing was carried out in a ABI PRISM 3730XL Analyzer. The 16S rRNA sequence of S. hospes and S.pandurus differed in the total number of base pairs as well as in the percentage G+C and A+T content. However, a sequence similarity of 97.86 % was recorded. The nucleotide paired frequencies among the two species showed 274 identical pairs. The ratio of the transitional to transversional pairs was 1.5. The sequence similarity search among other lygaeid bugs was done using BlastN and nucleotide sequences were aligned using the ClustalW option of MEGA5 software. Analysis of the maximum likelihood of 24 different nucleotide substitution patterns, indicated that the GTR+G had the least BIC and AIC scores and therefore considered the best model for the present data set. The phylogenetic tree constructed indicated the two species of Spilostethus to share a most recent common ancestor and are clustered at 70%. This clade is a sister group to Lygaeus equestris and Oncopeltus fasciatus, both being members of subfamily Lygaeinae. Species of the subfamily Rhyparochrominae, Dieuches sp and Laryngodus sp, have been positioned distantly.