Diotaiuti L, Azeredo B V, Busek S C, Fernandes A J
Fundação Oswaldo Cruz (FIOCRUZ), Centro de Pesquisas René Rachou, Belo Horizonte, Minas Gerais, Brasil.
Rev Panam Salud Publica. 1998 Jan;3(1):21-5. doi: 10.1590/s1020-49891998000100004.
Triatoma sordida, a predominantly peridomestic species, is currently the triatomine species most frequently collected in Brazil. To evaluate the effectiveness of control activities against this species, a survey to determine infestation rates was carried out in October 1993 in 12 rural localities in the municipality of Porteirinha, State of Minas Gerais, Brazil. In the survey, 772 T. sordida were captured, of which 3.6% were infected with Trypanosoma cruzi. Of the 406 dwellings investigated, 34.9% were infested, and 27.6% of 695 peridomiciliar ecotopes contained T. sordida. The area around the dwellings was relatively uniform, with few positive ecotopes per household and low triatomine densities (a maximum of five insects per colony). The study found an association between the presence of insects and wood: 72.8% of the insects were captured in this type of ecotope. The majority of the positive households (62.9%) were close to forests (12 to 299 m); 92.3% of the infested ecotopes were less than 20 m from the house. A census of peridomestic animals revealed that chickens were the most abundant (82.7%). All positive households found in the survey were sprayed immediately with deltamethrin (25 mg a.i./m2). New surveys were carried out 7 months (survey 2) and 12 months (survey 3) after spraying. In survey 2, the number of insects collected corresponded to 52.5% of the original total, and in survey 3, 79.1%. The decrease in population observed in survey 2 was mainly due to a reduction in the population of nymphs. The large proportion of adults captured in that survey supports the idea that T. sordida produces only a single generation per year in this region. In survey 3 the increase in the number of nymphs, attributable to the great availability of chickens as a source of food, resulted in population growth. Despite the difficulties of spraying and the short persistence of the insecticide, the slow population response of T. sordida suggests that one annual spraying is sufficient for effective control of this species. Higher effectiveness could be obtained by eliminating peridomestic hiding places, for example, by replacing wooden annexes with structures made from other materials.
污辱锥蝽是一种主要栖息于住宅周边的物种，目前是巴西最常采集到的锥蝽物种。为评估针对该物种的防控活动效果，1993年10月在巴西米纳斯吉拉斯州波特里尼亚市的12个乡村地区开展了一项确定感染率的调查。在此次调查中，捕获了772只污辱锥蝽，其中3.6%感染了克氏锥虫。在调查的406所住宅中，34.9%受到侵扰，在695个住宅周边生态位中，27.6%有污辱锥蝽。住宅周边区域相对统一，每户的阳性生态位较少，锥蝽密度较低（每个群落最多五只昆虫）。研究发现昆虫的存在与木材之间存在关联：72.8%的昆虫是在这类生态位中捕获的。大多数阳性家庭（62.9%）靠近森林（12至299米）；92.3%的受侵扰生态位距离房屋不到20米。对住宅周边动物的普查显示，鸡的数量最多（82.7%）。调查中发现的所有阳性家庭均立即用溴氰菊酯（25毫克有效成分/平方米）进行了喷洒。在喷洒后7个月（调查2）和12个月（调查3）进行了新的调查。在调查2中，采集到的昆虫数量相当于原始总数的52.5%，在调查3中为79.1%。调查2中观察到的种群数量下降主要是由于若虫数量减少。该次调查中捕获的成虫比例较高，支持了污辱锥蝽在该地区每年仅繁殖一代的观点。在调查3中，由于鸡作为食物来源丰富，若虫数量增加，导致种群增长。尽管喷洒存在困难且杀虫剂持效期短，但污辱锥蝽种群反应缓慢表明，每年喷洒一次足以有效控制该物种。通过消除住宅周边的藏身之处，例如用其他材料制成的结构取代木制附属建筑，可获得更高的防控效果。
