How to increase the population of a Phlebotomus perniciosus (Diptera: Psychodidae) colony: a new method

The sandfly Phlebotomus perniciosus is the most widespread vector of Leishmania infantum in Spain. Laboratory colonisation represents the most feasible source of information on the biology of these insects, but in conducting any study, the density of individuals in the colony may drop to such an extent that it is sometimes difficult to recover the initial population levels. A new technique was tested for the recovery of sandfly eggs in three different colonies; the recovery rate was studied by comparing the standard method of mass rearing with this new method of colony management. The results demonstrate a mean increase of 18.4 percent in adult production, a growth in colony productivity that justifies the inclusion of this process in the routine maintenance of any colony of sandflies.

Vector density and the control of kala-azar in Bihar, India

Bihar, India has been in the grip of kala-azar for many years. Its rampant and severe spread has made life miserable in most parts of the state. Such conditions require a comprehensive understanding of this affliction. The numbers coming out of the districts prone to the disease in the north and south Ganges have provided us with several startling revelations, as there are striking uniformities on both sides, including similar vegetation, water storage facilities, house construction and little change in risk factors. The northern areas have been regularly sprayed with DDT since 1977, but eradication of the disease appears to be a distant dream. In 2007 alone, there were as many as 37,738 cases in that region. In contrast, the southern districts of Patna and Nalanda have never had the disease in its epidemic form and endemic disease has been present in only some pockets of the two districts. In those cases, two rounds of spraying with DDT had very positive results, with successful control and no new established foci. In addition, an eleven-year longitudinal study of the man hour density and house index for the vector Phlebotomus argentipes demonstrated that they were quite high in Patna and Nalanda and quite low in north Bihar. Given these facts, an attempt has been made to unravel the role of P. argentipes saliva (salivary gland) in the epidemiology of kala-azar. It was determined that patchy DDT spraying should be avoided for effective control of kala-azar.

Effects of temperature and diet on the growth and longevity of phlebotomine sand flies (Diptera: Psychodidae)

Se realizó una serie de experimentos para estudiar los efectos de diferentes temperaturas ambientales (28 a 10ºC) y tipos de dieta sobre la tasa de crecimiento, el tamaño y la longevidad de los flebotomíneos: Se utilizaron cuatro colonias de laboratorio diferentes: Phlebotomus papatasi, P. perniciosus, Lutzomyia longipalpis (Brasil) y L. longipalpis (Colombia). Los períodos de desarrollo y supervivencia de los insectos fueron muy variables según la temperatura y la especie. Por debajo de 18ºC, la mayoría de las larvas y pupas de L. longipalpis murieron. A 15ºC, el tiempo de desarrollo de P. papatasi y P. perniciosus se prologó considerablemente (150 a 412 días) y muchas de las formas inmaduras murieron. En el rango de 28 a 15ºC, la longevidad de los adultos de P. papatasi y L. longipalpis aumentó a medida que la temperatura ambiente disminuía; a 15ºC los tiempos promedio de supervivencia de las hembras de P. papatasi y L. longipalpis fueron 63,2 y 37,1 días, respectivamente. El efecto de dos tipos de dieta diferentes (heces de animal/polvo de hígado y hojas en descomposición) sobre la tasa de crecimiento y el tamaño (peso de pupa) de L longipalpis también se determinó, estableciéndose que los insectos alimentados con heces de animal/polvo de hígado se desarrollaron más rápido y fueron más sincronizados y más grandes que aquellos alimentados con hojas de descomposición. Los resultados de este estudio entregan nueva información sobre los efectos de factores medioambientales en el crecimiento y la longevidad de flebotomíneos bajo condiciones de laboratorio

An improvised method of laboratory colonization of Phlebotomus papatasi, the vector of cutaneous leishmaniasis.

A cyclic colony of P. papatasi was successfully established, using wild caught females. The major obstacle in the colonization was infestation of fungus, which was solved when bentonite, a dehydrant was mixed in the larval diet i.e., powdered and sterilized faecal pellets of rabbit. The average duration of development from egg to adult was 46.41 +/- 3.26 days. Females readily engorged on mouse, which was kept immobilized inside restrainer cages Majority of the fed females laid viable eggs, when confined in improvised styro-foam humidity chambers and survived after oviposition. In this process a stable, cyclic colony was established and it is now in F39 generation.

Kala-azar in Varanasi (UP)--preliminary observations.

An epidemiological and entomological survey was conducted in Badohi town of Varanasi district of Uttar Pradesh (India) from where an outbreak of kala-azar was reported. Serological and clinical results showed 83 cases who responded to sodium antimony gluconate. Phlebotomus argentipes and P. papatasi could be detected in area of outbreak. An active transmission of kala-azar is strongly indicated.