Maintenance and Productivity of a Lutzomyia longipalpis (Diptera: Psychodidae) Colony from an Area Endemic for Visceral and Cutaneous Leishmaniasis in Northeastern Brazil

Abstract

Studies on experimental sand fly infection require the availability of colonies and laboratory conditions. In Brazil, Lutzomyia longipalpis (Diptera: Psychodidae) (Lutz and Neiva 1912) is responsible for the highest infection rates by Leishmania spp. and this species is one of the most suitable species for laboratory colonization. In this study, we describe a method for growing Lu. longipalpis in laboratory conditions (10 generations) from natural populations sampled from a region of high endemicity for visceral leishmaniasis in the state of Maranhão, Northeastern Brazil. Using two methods (individualized or grouped females), the colony’s highest productivity occurred in the first four generations, where all stages presented with high frequency. Nonviable eggs represented more than 50% of the total eggs produced by engorged females, while pupae were more resistant to fungal contamination, with a mortality rate of only 2%. In both methods, there was a predominance of female emergence; however, the ratio between males and females did not show significant differences, IF (P = 0.8023) and GF (P = 0.1831). Using the method of individualized females, the F4 generation took the longest to appear (234 d; 64 ± 57 d); by grouped females, F3 took the longest to appear (102 d; 47 ± 20 d). This method provides sufficient numbers of insects to perform vector competence tests for Leishmania spp. that cause the cutaneous form of leishmaniasis, usually found in Lu. longipalpis sampled from the study location.

Study of the seasonal life cycle ofLutzomyia longiflocosa(Diptera: Psychodidae) under semi-controlled conditions in the department of Huila, Colombia

“…These results are much lower than other studies that analyzed this parameter. In 2021, Ribeiro da Silva et al [37] found an average fecundity of 33 in L. longipalpis;…”

“…In this sense, larval mortality is considered one of the main problems for the colonization of sandflies in the laboratory and, in particular, in the first stage, in which, due to their small size and low strength, individuals can be trapped in mycelia or in moisture condensation [33]. In contrast, Ribeiro Da Silva et al [37], obtained a low mortality in pupae of L. longipalpis, arguing that the reason may be due to the fact that, at this stage, they do not feed and prefer dry environments in which invasion by fungi and other microorganisms is difficult.…”

Seasonal life cycle of Pintomyia longiflocosa (Diptera: Psychodidae) under semi-controlled conditions in the Huila state, Colombia

“…In 2021, Ribeiro Da Silva et al . [ 39 ] also reported that average egg production of individualized females was lower in the established colony of Lu . longipalpis than that of females who remained in groups (31.4 and 35.7, respectively).…”

“…In 2021, Ribeiro da Silva et al . [ 39 ] found an average fecundity of 33 in Lu . longipalpis ; Escovar et al .…”

Experimental transmission of Leishmania (Leishmania) amazonensis to immunosuppressed mice through the bite of Lutzomyia longipalpis (Diptera: Psychodidae) results in cutaneous leishmaniasis

“…Specimens of Lu. longipalpis were reared in the laboratory, free from Leishmania infection, as previously described 21 . Twelve hours before the experiments, the feeding of female sand flies was suspended to increase the probability of the insects feeding on the mice infected by L. (L.) amazonensis (IFLA/BR/1968/PH8 strain).…”