1T. eugenii en México Folia Entorno/. Mex., 42(2): 161-168 (2003) · ows. Media Cybemetics, Silver Spring, . A WHARTON. 2000. Toxoneuron (Hy­ mdae): designation of a neotype for its ON THE REPRODUCTIVE BEHAVIOR AND POPULATION ECOLOGY and discovery of a possible senior syno­ ow species, T. nigriceps. Annals of the OFLETHOCERUSCOLOSSJCUSSTÁL tety ofAmerica, 93(2): 208-219 . (HETEROPTERA: BELOSTOMATIDAE) .enópteros parasitoides de Apion spp. honmdea: Apionidae) en Tepoztlán Mo- ológica Mexicana, 63: 39-46. ' R. A WHARTON 1997. Morphology and RüGELIO MACÍAS-ORDÓÑEZ 9-37. In: Wharton, R. A, P M. Marsh eds.). Manual ofthe New World Genera nidae (Hymenoptera). lntemational So­ Departamento de Ecología de Comportamiento Animal, Instituto de Ecología, A.C., Apartado Postal 63, Xalapa, Veracruz ists. Special publication l. 91000, México. Correo electrónico: <[email protected]> UDDLESTON. 1991. Classification and wasps. Handbooksfor the Identification (11): 1-126. Macías-Ordóñez, R. 2003. On the reproductive behavior and population ecology of Lethocerus colossicus Sta! (Heteroptera: nidae. Chapter 12.2, pp. 431-463,/n: Belostomatidae). Folia Enlomo/. Mex., 42(2): 161-168. ~u!~ [eds.]. The Hymenoptera ofCos­ vemty Press, Oxford. ABSTRACT. The reproductive behavior and dispersa! patterns of Lelhocerus colossicus (Heteroptera: Belostomatidae) were 0: Braconidae 2: Helconinae [sic], Ca­ studied in the field and in the laboratory, in Puerto Morelos, S tate ofQuintana Roo, in the Yucatán Península. A female skewed mae, Triaspinae./n: Ferriere, Ch. and sex ratio and sexual dimorphism were found in field populations Adults migrate short after the final molt, and apparently remain .) Hymenopterorum Catalogus (nov. in the same pond throughout their lives once they ha ve started to breed. A field population consisting of around 17 adults bred continuously between April and September. Courtship, mating and exclusive male parental careare described. The male guards . MARSH AND M.J. SHARKEY (eds.). the clutch during the complete incubation period, moistening the eggs once or twice a day, and aggressively defending them New WorldGeneraojthe Family Era­ against "potential predators" (i.e. the observer). After hatching, larvae disperse and reach adulthood after 3 months. The sexual ra). lntemational Society ofHymenop­ tion l. behavior of L. colossicus is discussed in the context ofthe evolution ofreproductive strategies in belostomatids. KEYWORDS: Belostomatidae, dispersa!, Lethocerus colossicus, parental care, reproductive behavior, sex ratio, sexual dimorphism. V. LoPEZ-MARTINEZ. 2000. A new id~y (Hymenoptera: Braconidae) pa­ Macías-Ordóñez, R. 2003. Sobre el comportamiento reproductivo y ecología poblacional de Lelhocerus colossicus Sta! VII, Anthonomus eugenii Cano (Co­ (Heteroptera: Belostomatidae). Folia Enlomo/. Mex., 42(2): 161-168. ). Proceedings ofthe Entomological 02(4): 794-801. RESUMEN. Se estudiaron la conducta reproductiva y los patrones de dispersión de Lethocerus colossicus (Heteroptera: Belostomatidae) en campo y en laboratorio, en Puerto Morelos, Quintana Roo, en la península de Yucatán. En poblaciones de campo se encontró una proporción sexual sesgada a hembras así como dimorfismo sexual. Los adultos se dispersan poco después de su muda final, y aparentemente permanecen el rysto de su vida en el mismo cuerpo de agua una vez que empiezan a reproducirse. Una de las poblaciones estudiadas que consistía de 17 adultos se reprodujo continuamente desde abril a septiembre. Se describe el cortejo, la cópula y el cuidado parental exclusivo por parte del macho. El macho resguarda la puesta durante todo del2001. el periodo de incubación, humedeciendo los huevos una o dos veces al día, ydefendiéndolos agresivamente contra "depredadores 2003. potenciales" (i.e. el observador). Después de la eclosión las larvas se dispersan y alcanzan el estado adulto al cabo de tres meses. Se discute la conducta sexual de L. colossicus en el marco de la evolución de estrategias reproductivas en belostomátidos. PALABRAS CLAVE: Belostomatidae, dispersión, Lelhocerus colossicus, cuidado parental, comportamiento reproductivo, proporción sexual, dimorfismo sexual. Giant water bugs (Heteroptera: Belostomatidae) family Belostomatinae have long been known to are large carnivorous aquatic insects, and repre­ exhibit exclusive mal e parental care in which the sent the great majority of arthropod species exhi­ female lays the eggs on the male's back; males biting exclusive maJe parental care described so then perform specific behavioral pattems in order far (Smith, 1997). All extant genera from the sub- to provide optimal conditions for embryologic Macías-Ordóñez: Reproduction and population ecology ofLethocerus colossicus development (Smith, 1976). to Morelos" Research Station (ICMyLIUNAM). ter, surrounded by dense vege1 The monotypic subfamily Lethocerinae has The station is located on the East shoreline ofthe perature at the surface was 28' been proposed as the most primitive ofthe family Yucatán Península on the Mexican Caribbean the study, with variations ofle! (China, 1955; Lauck and Menke, 1961; Mahner, (20°52' N, 86°52' W). was 40+ meters (maximum de 1993 ). It in eludes only one extant genus, Letho­ After assessing body wear ( see below) and due SCUBA, the bottom could no1 cerus, distributed worldwide. A form ofparental to laboratory space limitations, only the first 100 signs of macrobiota were obs~ care, different from that of Belostomatinae, has picked were kept in individual one-liter contai­ meters. Adult L. colossicus ob! been described more recently in two species of ners, the remaining males were released ( n= 15 ) were captured using a hand net lethocerines: L. deyrollei (lchikawa, 1988) and L. and the remaining females were eutanized and and uniquely tagged with nail medius (Smith and Larsen, 1993 ). In these spe­ later dissected to count mature eggs in ovaría (n pulation size was estimated u cies, females !ay eggs on emergent substrate bet­ = 26). The sex of adults was determined by sex average method (Begon, 197S ween repeated mal e genitalic intromissions. Only specific differences at the tip ofthe genital oper­ removed from this pond. Re1 the male stays to brood the eggs, spending varia­ culum (males have a rounded tip while females larval instars were also made ble periods oftime underwater, but with variable present a small indentation). Sex and body assessed by size, based on av< frequency climbs out ofthe water to moisten the length (excluding siphons) of kept adults were boratory reared hatchlings (see clutch with water dripping from his proboscis recorded the next moming (out of the 100, six number of clutches produced (lchikawa, 1995). Brooding males also exhibit escaped ovemight before their sex and period was estimated as the behavioral pattems that suggest defense against measurements could be obtained), as well as number of days of continuo1 predators. Brooding behavior continues for the weight of a random sample of 60 adults. instars 1 in the cenote divided entire embryologic development and ends soon Adults collected were fed live Gambusia sp. time in the lab culture. after hatching. In a recent review ofbelostomatid fish every other day under a·l2L:l2D light pe­ As an indicator of age, body reproductive behavior, Smith (1997) stated that riod. Thirty-eight male-female pairs were placed by recording loss ofleg sectim "the complexity and variety in brooding pattems each in 160 l aquaria in 15 cm of water depth, flying and cenote individuals. shown among the few Lethocerus spp. studied with two wood perches (40 cm long and 2-3 cm tact adults in both samples we clearly suggests the need for more intensive work in diameter). Courtship, mating and brooding be­ a chi-square analysis on a 2x2 on previously studied species as well as a survey havior were recorded. Pairs were observed every (Siegel and Castellan, 1988). of brooding pattems in al! members of this three hours until sorne interaction ( courtship or Analyses ofsex ratio bias we genus". mating) was detected, in which case continuous the binomial test (Siegel anc The biology of L. colossicus, one ofthe largest focal observations were made throughout the in­ considering a 1: 1 sex ratio as t aquatic insects, has not been previously studied. teraction. Differences in sex ratio betw Mating and brooding on emergent substrate in L. In order to record size and length of instars, note samples were also com¡ colossicus are described in this paper, and dis­ eggs from one clutch laid on a brick (provided as square analysis on a 2x2 cont cussed in the context ofprevious research. l also grasping substrate) by one ofthe collected fema­ xual dimorphism was analyze compare flying L. colossicus (collected when les, were kept ¡poistened. Upon hatching, hatch­ t test on length and weight dat attracted to lights) to those found in permanent lings were individually reared and fed live Gam­ re two tailed except those on s water and discuss dispersion pattems, sex ratio, busia sp. fish. the altemate hypothesis was a population size and reproductive activity. Thirty four field censuses were conducted on a ratio, as found in other belos L. colossicus population, between 19:00 (dusk) ring, 1932; Kraus, 1989a). Me MATERIAL AND METHODS and 22:00 hrs, from April21 through September in parentheses. A sample of 141 "flying" adults ofL. colossicus 15, 1991. The site was a permanent cenote (Ma- was collected the night ofMarch 21, 1991. They yan word for natural ponds in the area, formed RESULTS were hand-picked