Behavior of triatomines (Hemiptera, Reduviidae) vectors of Chagas' disease. II. Influence of feeding, lighting and time of day on the number of mating, mating speed and duration of copulation of Panstrongylus megistus (Burm, 1835) under laboratory conditions

Abstract

To determine the influence of feeding, lighting and time of day on the copulating behavior of Panstrongylus megistus, 480 insect pairs were divided into four groups of 120 each and tested in the following respective situations: without food deprivation (F.D.), with five days of F.D., with ten days of F.D., and with 20 days of F.D. The tests were performed between 9:00 a.m. to 12:00 a.m. and 7:00 p.m. to 10:00 p.m., with light (700-1400 lux) and in the dark (1.4-2.8 lux) and behavior was recorded by the time sampling technique. Mating speed (MS) and duration of copulation (DC) were also calculated for each situation. The maximum frequency of copulation was observed after five days of F.D., at night, in the dark (n = 16), and the minimum was observed for recently-fed pairs, at night, with light (n = 4). Males approached females more often than females approached males. MS was lowest in pairs with twenty days of F.D., at night, with light (mean = 23.0 +/- 16.0 minutes), and highest in recently-fed pairs, during the day, with light (mean = 2.9 +/- 2.5 minutes). DC was shortest in recently-fed insects, during the day, in the dark (mean = 23.5 +/- 6.7 minutes), and longest in recently-fed animals, at night, in the dark (mean = 38.3 +/- 6.9 minutes).

The sexual behaviour of Panstrongylus megistus (Hemiptera: Reduviidae): an experimental study

“…Manrique and Lazzari (1994) working with T. infestans described that 16 days after feeding approximately 100% of the pairs expressed their motivation to copulate daily. Differently, our results with P. megistus reached a maximum daily level of 40% copulating pairs only after 12 days post-feeding, percentage which resembles results obtained by Lima et al (1986b). This lower daily motivation to copulate does not necessarily reflect that the insects are immature, as approximately 75% of the pairs expressed their motivation to copulate at least once at the end of this experiment.…”

“…The sequence of behavioural steps that lead to mating in P. megistus follows the general model described by Lima et al (1986b) in this species. Males of P. megistus are the sex that actively performs the approximation of the couple, as in all triatomines studied to date.…”

Effects of blood meal source on food resource use and reproduction inTriatoma patagonicaDel Ponte (Hemiptera, Reduviidae)

“…This fact is important from an epidemiological point of view, because those females that have mated once may lay fertile eggs, thereby increasing the chances of forming new colonies. For other triatomine species, it has been stated that only one mating is enough for a female to maintain fertile eggs for her entire life span (Lima et al 1987, Pires et al 2004). In T. brasiliensis , T. infestans , and Rhodnius prolixus females need more than one copulation to ensure fertile ovipositions (Stoka et al 1987, Daflon‐Texeira et al 2009, Pontes and Lorenzo 2011) Moreover, in T. infestans and Rhodnius prolixus , males aggregated around a mating couple and several copulations occurred (Pontes and Lorenzo 2011).…”

“…Accordingly, blood consumption constitutes an important indicator of the amount of ingested blood that is converted into body substance. The importance of and the relationship between feeding and reproductive factors are well known for several triatomine species (Brasileiro 1982, Catalá de Montenegro 1983, Cabello et al 1987, Lima et al 1987, Guarneri et al 2000, Pires et al 2004). For T. patagonica , there is information on feeding and defecation patterns in nymphs and adults (Nattero et al 2002, Rodriguez et al 2009), however, feeding patterns and the use of blood ingested have still not been explored in terms of reproductive parameters.…”

Female metasternal gland odours mediate male aggregation in Rhodnius prolixus, a triatomid bug

“…To date, reports indicate that the sexual behaviour of triatomines can be ascribed to two categories. On one side, Panstrongylus megistus (Heteroptera: Reduviidae) (Burmeister) females are receptive to copulation only once or very few times during their adult lifespan (Lima et al, 1986;Pires et al, 2004), whereas P. megistus males do not aggregate in response to mating pairs (Pires et al, 2004). By contrast, copulating pairs of R. prolixus and T. infestans promote male aggregations and as a result, a polyandric reproductive strategy is assured (Baldwin et al, 1971;Manrique & Lazzari, 1995;this report).…”