Joumal of the American Mosquito Control Association, 17(3):209-210,2OOl Copyright O 2001 by the American Mosquito Control Association, Inc.

SCIENTIFIC NOTE UPDATE ON THE BIOLOGY OF DIMIDIATA LATREILLE (: ) UNDER LABORATORY CONDITIONS

JOSE A. MARTiNEZ-IBARRA,I ALEJANDRO MIGUEL-ALVAREZ,, JUAN I, ARREDONDo-JIMENEZ, AND MARIO H. RODRiCUEZ.LOPEZ'

ABSTRACT, Feeding time, postfeeding defecation delay, and lif'e cycle for each stage of a cohort of recently colonized Mexican Triatoma dimidiata were evaluated, eLndresults were compared to existing published infor- mation on this species. Seventy-five nymphs (4l.l7o) completed a cycle with an average time from N-I to adult of 142 + 64 days. The average span in days for each stage was 2O.2 for N-I, 17.9 for N-II, 10.1 fbr N-III, 43.6 for N-IV, and 55.1 for N-V- First-stage nymphs had the highest mean feeding time (25 min) and the longest postfeeding defecation delay (45 min). Differences among biological data from previous studies and the present study confirm the importance of conducting research on the behavior of the indigenous triatomine species from various countries.

KEY WORDS Triatoma dimidiata. Reduviidae. Chaeas disease

Six species of Triatoma are considered important through I h after feeding. Feeding time and time as vectors of Chagas disease in Mexico. Of these, between blood meal and defecation were recorded. Triatoma dimidiata Latreille is the most common, Seventy-five nymphs completed development to occurring in homes and chicken roosts in the vil- the adult stage (34 males and 4l females). The av- lages of 16 states (SOVo)of central, western, south- erage egg-to-adult development time was 161.7 ern, and southeastern Mexico (Zdrate and Zdrate days (range 88-325 days; Table 1). Mean blood- 1985, Guzm6n-Marin et al. 1991, Vidal-Acosta et feeding time did not differ significantly (P > 0.05) al. 2000). The biology and behavior of T. dimidiata among nymphal stages (Table 2). Likewise, the have been studied previously with specimens from mean time between bloodfeeding and defecation Costa Rica (Zeled6n et al. 19'70, 1977). However, did not differ significantly (P < 0.05) among the because of the high variability in behavior observed 2nd through 5th nymphal stages. However, this in this species among different habitats in Mexico, time for l st-stage nymphs was significantly differ- a comparison of published biological data from ent from all other stages (Thble 2). Costa Rican specimens was made with data from The developmental cycle of triatomines varies recently colonized Mexican T. dimidiata speci- according to species, environmental conditions, and mens. especially the availability of blood sources (Scho- A laboratory colony established in 1998 from field 1985). The average development time of Z. bugs captured in Nueva America, Huixtla, Chiapas, dimidiata in this study (161.1 + 7.4 days) f'ed + was used. The colony was maintained at 27.3 weekly on rabbits and maintained aI 27 -f 3'C, 65 + 3"C and 65 lOVo relative humidity (RH) and was + 5Vo RH was shorter than those for T. dimidiata fed every 7 days on immobilized rabbits. Eggs were in a previous study in Costa Rica (332 days, range grouped by date of oviposition to initiate a cohort 257-411 days, maintained at 24.4-21.8"C, 757o of 180 eggs. Three days after eclosion, the nymphs RH; 252.9 days, range 180-285 days, maintained were individually offered a meal on an immobilized at 26.5"C, 45-55Vo RH) fed weekly or every 3 wk New Zealand rabbit for a l-h period, followed by on rabbits. However, the Costa Rican triatomines a feeding every 7th day. The bugs were maintained were from a colony established from cap- in + + a dark incubator at 27 3"C and 65 5Vo RH, tured under very different environmental conditions and were checked daily for ecdysis or death. (Zd.ed6n et al. 1970). Developmental times in our Nymphs were observed from blood-meal exposure studies were similar to those for Triatoma pallidi- pennis (Stal) (168.7 't ll.7l days) fed every 3 days IArea de Entomologia M6dica, Laboratorio de Salud on hens and maintained at 25 + 4oC and 6O + TOVo Priblica, Centro Universitario del Sur, Col6n S/N, 49000, RH (Martfnez-Ibarra and Katthain-Duchateau Ciudad Guzmdn. Jalisco. M6xico. 1999). Developmental time was less for Triatoma 'Cenffo de Investigacidn de Paludismo, Instituto Na- infestans (Klug) (141 days) fed weekly on hens and cional de Salud hiblica, Cuarta Norte y l9 Calle Poniente, maintained at 26 + + 30700, Tapachula, Chiapas, M6xico. l"C and 6O lOVo RH (Rabi- r Centro de Investigaciones Sobre Enfermedades Infec- novich 1972), and for T. barberi Usinger (143.7 ciosas, Instituto Nacional de Salud Priblica, Avenida days for females and 205.3 days for males) fed ev- Universidad 655, Colonia Santa Marfa Ahuacatitkin. ery 4.2 days on rabbits and maintained at 27"C and 62508, Cuernavaca, Morelos, M6xico. 6O + lOVo RH (Zrirate et al. 1984). The mean f'eed-

209 .17, 210 JouRN,cr-ol. tue Avgnlc,q,NMoseulro CoNrnor AssocrATloN VoL. No. 3

Table 1. Egg-to-adult developmental cycle of Triatoma REFERENCES CITED dimidiata, f'ed every 7 days on rabbits. GonEalves TCM, Cunha V, de Oliveira E, Jurberg J. 1997 . Algunos aspectos da biologia de Triatoma pseudoma- Duration in days culata Con€a & Espinola, 1964, em condig6es de la- Num- Mini- Maxi- boratorio (Hemiptera: Reduviidae: ). M em Stage ber murn mum Mean + SD Inst Oswaldo Cruz 92:275-28O. GonEalves TCM, Cunha Jurberg J, Victorio + Y Egg to N-I 120 t4 23 19.1 3.1 VMN. 1988. Biologia d

Table 2. Mean feeding times and postfeeding defecation delay in Triatoma dimidiata under laboratory conditions

Mean feeding time (min) Defecation delay (min)

Stage Minimum Maximum '+SD Minimum Maximum '+SD First 120 22 29 25+2 39 51 45+6 Second 106 r'l 26 2l+4 ll -)z 21+lO Third 96 t4 25 19+6 t5 30 22+6 Fourth 88 13 20 15+3 t3 -)l 2l+8 Fifrh 81 12 26 19+8 tl 29 22+ 6 Female 4l 10 21 15+5 t5 25 20+6 Male 34 o 20 14+5 t4 2'7 2l+7