Olga Lucía Cabrera

Five new species of Culicoides Latreille described from Colombia, yielding a new species list and country records (Diptera: Ceratopogonidae)

The following five new species of Culicoides from Colombia are described, illustrated and placed to subgenus or species group: Culicoides antioquiensis, Culicoides gabrieli, Culicoides inermis, Culicoides micayensis and Culicoides nigrifemur. C. gabrieli is also known from Peru. When possible, their position in previously published keys is indicated and their features discussed in light of the most recent revisions. A list of 180 Culicoides species known (114) or suspected of being in Colombia (66) is given in a Table. Of these, 12 including the new species are recorded from Colombia for the first time.

Establishment and characterisation of a new cell line derived from Culex quinquefasciatus (Diptera: Culicidae).

Insect cell cultures are an important biotechnological tool for basic and applied studies. The objective of this work was to establish and characterise a new cell line from Culex quinquefasciatus embryonic tissues. Embryonated eggs were taken as a source of tissue to make explants that were seeded in L-15, Graces, Graces/L-15, MM/VP12, Schneiders and DMEM culture media with a pH range from 6.7-6.9 and incubated at 28ºC. The morphological, cytogenetic, biochemical and molecular characteristics of the cell cultures were examined by observing the cell shapes, obtaining the karyotypes, using a cellulose-acetate electrophoretic system and performing random amplified polymorphic DNA-polymerase chain reaction analysis, respectively. The Graces/L-15 medium provided the optimal nutritional conditions for cell adhesion and proliferation. Approximately 40-60 days following the explant procedure, a confluent monolayer was formed. Cellular morphology in the primary cultures and the subcultures was heterogeneous, but in the monolayer the epithelioid morphology type predominated. A karyotype with a diploid number of six chromosomes (2n = 6) was observed. Isoenzymatic and molecular patterns of the mosquito cell cultures matched those obtained from the immature and adult forms of the same species. Eighteen subcultures were generated. These cell cultures potentially constitute a useful tool for use in biomedical applications.

Breeding sites of Culicoides pachymerus Lutz in the Magdalena River basin, Colombia

The breeding sites of Culicoides pachymerus are described for the first time in western Boyacá Province, Colombia, where this species is a public health problem. In addition to being a nuisance due to its enormous density and its high biting rates, C. pachymerus cause dermatological problems in the human population. Analysis of microhabitats by the sugar flotation technique and the use of emergence traps allowed us to recover 155 larvae of Culicoides spp and 65 adults of C. pachymerus from peridomiciliary muddy substrates formed by springs of water and constant rainwater accumulation. These important findings could aid in the design of integrated control measures against this pest.

Entering and exiting behaviour of the phlebotomine sand fly Lutzomyia longiflocosa (Diptera: Psychodidae) in rural houses of the sub-Andean region of Colombia.

The present study identified the entering and exiting sites for Lutzomyia longiflocosa in rural houses of the sub-Andean region in Colombia. Entering sites were identified with sticky traps set up outside the bedrooms, around the eave openings, and with cage traps enclosing the slits in the doors and windows inside the bedrooms. Exiting sites were identified by releasing groups of females indoors. These females were blood fed and marked with fluorescent powders. Females were recaptured with the trap placement described above but set up on the opposite sides of the openings. In the entering experiment, a significantly higher number of females were captured in the sticky traps at the zone nearest the eave openings (n = 142) than those captured in the other zones of the trap (n = 52); similarly, a higher number of females were captured on the front side of the house (n = 105) than at the rear side (n = 37). Only two females were collected in the cage trap. In the exiting experiment, at the ceiling, the highest percentage (86.2%) of females was recaptured with sticky traps nearest the eave openings and on the front side of the house (70.0%). Seven females were collected in the cage trap. Lu. longiflocosa entered and exited houses primarily through the eave openings in a non-random pattern in relation to the sides of the house.

Experimental hut to study the indoor behaviour and effects of insecticide-treated bednets on phlebotomine sand flies (Diptera: Psychodidae)

BACKGROUND Behavioural effects of insecticides on endophagic phlebotomine sand fly vectors of Leishmania are poorly understood mainly because of the lack of an experimental hut (EH) in which to study them. OBJECTIVE To build an EH to evaluate the effects of long-lasting insecticide-treated nets (LLINs) on Lutzomyia longiflocosa. METHODS The study had two phases: (1) Laboratory experiments using tunnel tests to select the traps for the EH; and (2) EH construction and evaluation of the effects of deltamethrin and lambda-cyhalothrin LLINs on L. longiflocosa females inside the EH. FINDINGS Phase 1: The horizontal-slit trap was the best trap. This trap collected the highest percentage of sand flies, and prevented them from escaping. Therefore, this trap was used in the EH. Phase 2: The main effects of LLINs on L. longiflocosa in the EH were: landing inhibition, inhibition from entering the bednet, induced exophily, and high mortality (total and inside exit traps). CONCLUSIONS The EH was effective for evaluating the effects of LLINs on endophagic sand flies. Although both types of LLINs showed high efficacy, the lambda-cyhalothrin-treated LLIN performed better. This is the first report of induced exophily in sand flies.

Insectos vectores de agentes infecciosos

El objetivo de este artículo es ilustrar con fotografías in vivo material de laboratorio útil para el estudio de la biología, la ecología y el comportamiento de diferentes grupos de insectos hematófagos. Se llama la atención sobre las características morfológicas de larvas, pupas y adultos utilizadas en la taxonomía de los ejemplares, los mecanismos de alimentación de las larvas y las técnicas de marcación de adultos, temas de interés para su estudio y control.