Solanum viarum Dunal (Solanaceae), Primer Reporte para Honduras

La maleza invasora Solanum viarum Dunal (Solanaceae) es reportada por primera vez para Honduras. La planta, nativa de Sudamérica, fue localizada en un estacionamiento de la Escuela Agrícola Panamericana, El Zamorano, Honduras, el 26 de noviembre de 2007.  Esta maleza es altamente invasora en pasturas debido a que el ganado puede transportar semillas en su tracto digestivo.DOI: http://dx.doi.org/10.5377/ceiba.v49i1.30

Temperature-dependent development, cold tolerance, and potential distribution of cricotopus lebetis (Diptera: Chironomidae), a tip miner of hydrilla verticillata (Hydrocharitaceae)

© The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America. A chironomid midge, Cricotopus lebetis (Sublette) (Diptera: Chironomidae), was discovered attacking the apical meristems of Hydrilla verticillata (L.f. Royle) in Crystal River, Citrus Co., Florida in 1992. The larvae mine the stems of H. verticillata and cause basal branching and stunting of the plant. Temperature-dependent development, cold tolerance, and the potential distribution of the midge were investigated. The results of the temperature-dependent development study showed that optimal temperatures for larval development were between 20 and 30°C, and these data were used to construct a map of the potential number of generations per year of C. lebetis in Florida. Data from the cold tolerance study, in conjunction with historical weather data, were used to generate a predicted distribution of C. lebetis in the United States. A distribution was also predicted using an ecological niche modeling approach by characterizing the climate at locations where C. lebetis is known to occur and then finding other locations with similar climate. The distributions predicted using the two modeling approaches were not significantly different and suggested that much of the southeastern United States was climatically suitable for C. lebetis

Will Cotesia flavipes drive its African homologue, Cotesia sesamiae, to extinction?

This paper addresses the competitive interaction between Cotesia sesamiae, a gregarious larval endoparasitoid that is native to Africa, and Cotesia flavipes, an introduced parasitoid from southern Pakistan which has recently been established in East Africa for biological control of the exotic stemborer, Chilo partellus. The two parasitoids are morphologically similar, and they both attack medium-sized to large larval stages of gramineous lepidopteran stemborers. Based on previous work which suggested that Cotesia flavipes was competitively superior to Co. sesamiae, we speculated that Co. sesamiae may be locally extirpated in some areas of Africa. However, evidence from the field does not support this prediction. Recent field surveys in areas where both parasitoids occur, revealed that Co. sesamiae was still present, and densities were not declining. The interaction of the two parasitoids, as well as the influence of this interaction on host regulation, are discussed. RÉSUMÉ Cet article discute de la compétition entre Cotesia sesamiae et Cotesia flavipes deux parasitoïdes internes et grégaires, morphologiquement semblables. Ils attaquent les larves de foreurs de tige de graminés. Le premier est endémique á l'Afrique et le second a été importé du sud Pakistan dans la cadre de la lutte biologique classique en Afrique de l'est contre, Chilo partellus, un foreur de tige de céréales originaire d'Asie. Sur la base des travaux antérieurs qui ont montré que Co. flavipes était competitivement supérieur á Co. sesamiae, nous avions spéculé que Cotesia sesamiae pourrait eventuellement être éliminé dans certaines régions d'Afrique. Toutefois, des données récentes de terrain ne sont pas en accord avec cette hypothèse. Des enquêtes récentes dans les régions où les deux parasitoïdes existent ont montré que Co. sesamiae est toujours présent et que ses densités ne décroissent pas. Les interactions entre les deux parasitoïdes et l'effet de cette interaction sur la régulation de l'hôte sont discutés

Temperature-dependent development, diapause and cold tolerance of Gratiana graminea, a potential biological control agent of Solanum viarum in Florida, USA

The objectives of this study were to examine temperature-dependent development, diapause and cold tolerance of Gratiana graminea Klug (Chrysomelidae), a candidate biological control agent of tropical soda apple, Solanum viarum Dunal (Solanaceae). Immature development was examined at six constant temperatures ranging from 15°C to 30°C. Diapause induction was determined by exposing adults to either long or short photoperiods at 20°C and cold tolerance was assessed by exposing adults to 0°C. G. graminea completed development at temperatures ranging from 20°C to 30°C. Linear regression estimated a lower temperature threshold of 11.7°C and 312 degree-days were required to complete development. Diapause was induced when adults were exposed to short photoperiods (10:14 L:D h) at 20°C. The lethal times for diapausing adults of G. graminea at 0°C (LT 50 = 19 days, LT 90 = 41 days) were two times higher compared to Gratiana boliviana Spaeth, a biological control agent already established in south and central Florida, USA. The presence of diapause and the greater cold tolerance suggest that G. graminea may establish and perform better than G. boliviana in northern Florida. © 2012 International Organization for Biological Control (IOBC)

CHANGES IN THE DISTRIBUTION OF LEPIDOPTERAN MAIZE STEMBORERS IN KENYA FROM THE 1950S TO 1990S

Three hundred and ninety-two maize fields in the southern arable zone of Kenya were sampled for lepidopteran cereal stemborers from 1996-2000. Chilo partellus (Swinhoe) was the most abundant stemborer, and was found at all locations with elevations below 1500 m, and at some locations between 1500 and 2300 m. The highest density of C. partellus was in the semi-arid ecological zone of eastern Kenya. Chilo orichalcociliellus (Strand) was found in the lowland southern coastal area, and a few inland sites on the border of Tanzania in southeastern Kenya. Busseola fusca Fuller was dominant in highland areas. In the Lake Victoria Basin, which has an elevation of about 1100 m, B. fusca was dominant at some sites, but overall, C. partellus was more abundant. Sesamia calamistis Hampson was present at all elevations and all locations, but typically at low densities. Eldana saccharina (Walker) was found in two-thirds of the fields sampled in the Lake Victoria Basin. These results are compared with the distributions of the various stemborers in the 1950s to 1960s, as reported in the literature. RÉSUMÉ Trois cent quatre vingt douze champs de maïs ont été échantillonnés dans la zone arable du sud Kenya pour les lépidoptères foreurs de tiges entre 1996 et 2000. Chilo partellus (Swinhoe) est le foreur le plus abondant, il a été trouvé dans toutes les localités situées à une altitude inférieure à 1500 m, et dans certaines localités entre 1500 et 2300 m. La plus forte densité de C. partellus a été trouvée dans les zones écologiques semi-arides de l'Est du Kenya. On trouve Chilo orichalcociliellus dans les basses terres de la zone côtière sud et dans plusieurs localités de l'intérieur des terres près de la frontière tanzanienne au sud-est du Kenya. Busseola fusca Fuller est dominant dans les hautes terres. Près du bassin du lac Victoria, qui a une altitude d'environ 1100 m, B. fusca est dominant dans certaines localités, mais d'une manière générale, C. partellus est l'espèce la plus abondante. Sesamia calamistis Hampson est présent à toutes les altitudes et toutes les localités, mais à faibles densités. On trouve Eldana saccharina (Walker) dans deux tiers des champs échantillonnés sur le bassin du lac Victoria. Ces résultats sont comparés avec la distribution des foreurs de tiges des années 1950 et 1960, rapportée dans la litérature

Systematics and biology of cremastobombycia chromolaenae, new species (Gracillariidae), a natural enemy of chromolaena odorata (L.) king and H. Robinson (Asteraceae)

A new species, Cremastobombycia chromolaenae, is described from Florida and Texas, USA. The larva is a leaf miner on Chromolaena odorata (L.) King and H. Robinson, a 2-3 m tall perennial shrub of the family Asteraceae, whose native range extends from southern Florida south to northern Argentina (Fig. 1). The plant is also known to occur in Africa, Asia, and Australia where it is considered exotic and in some countries has become a major weed. The larvae of C. chromolaenae are hypometamorphic and possess two distinct larval body forms and feeding behaviors-an early stage sap-feeding form with a flattened body and prognathous mouthparts and a later stage tissue-feeding form with a more cylindrical body and possessing hypognathous mouthparts. Based on head capsule counts and measurements, the larvae undergo five instars, with the first three instars being of the sap-feeding form and the last two tissue-feeding instars. The larval mine begins as a short, serpentine track which enlarges to a rounded, whitish, and eventually tentiform blotch. Cremastobombycia chromolaenae may have value as a biocontrol agent in those areas where the host plant has become a major problem