Dolores del Carmen Castro

Predation by Misumenops pallidus (Araneae: Thomisidae) on insect pests of soybean cultures in Buenos Aires Province, Argentina.

Abstract This study analyzes predation by adult females of Misumenops pallidus (Keyserling 1880) on pairs of prey items representing non-pest insects and potential pests. The phenology of the potential pests was such that each insect guild peaked sequentially, while non-pest herbivorous and insectivorous insects were present during the entire period. Field experiments were made in a commercial 50-ha soybean plot during two successive years. Ten cages 1 × 1 × 0.5 m were placed in peripheral furrows of a soybean commercial plot. The pest species were preyed on differentially, with the order from the most favored species to the least with respect to non-pest herbivorous and insectivorous insects was as follows: defoliating lepidopterous larvae, seed feeding pentatomids in their early nymphal instars, stem boring lepidopterous larvae, and seed feeding pentatomids in older nymphal and adult instars. Adult females of M. pallidus fed on all the insect species offered, but in the presence of defoliator larvae, they hardly accepted alternative prey, whereas in the presence of other prey, they maintained a more generalized diet.

CONTRIBUCION AL CONOCIMIENTO DE LOS PHTHIRAPTERA (ANOPLURA, Hoplopleura) PARASITOS DE ROEDORES EN CHILE

Se cita por primera vez a Hoplopleura travassosi Werneck 1932 como asimismo su hospedero, Oligoryzomys longicaudatus (Bennett 1832) para Chile. Ademas, se amplia la distribucion de Hoplopleura andina Castro 1981 sobre Akodon olivaceus Waterhouse, 1835, desde la VIII hasta la V Region de Chile. El estatus de las especies neotropicales del genero Hoplopleura y su distribucion geografica actual es discutido

Development and Recruitment of Misumenops pallidus (Keyserling) (Araneae: Thomisidae), and Its Synchronicity with Three Potential Prey Species in Soybean Cultures from Argentina

ABSTRACT: Misumenops pallidus life cycle and recruitment were studied under both laboratory and field conditions during two consecutive years. The life cycle included the egg stage, seven or eight juvenile instars and the adult stage. The first three instars developed within the egg sac, while the others developed as free-living individuals. Total body length increased from 3.2mm in the 3rd instar up to 14mm in adult females in average, and from 3.2mm up to 9mm in males. Predatory rate increased according to growth and maturity in females (females would consume 81% of all prey in the adult stage). Longevity of males and females as adults averaged 69.2 (± 30.76) and 161.3 (± 45.4) days, respectively. The developmental time from IV instar (the first free living instar) to the adult stage (114.2 ± 22.83 days) was very variable and long, suggesting that all IV instars of M. pallidus found in 94% of all sampling dates would represent different cohorts of the same parental generation. Three of potential prey: Rachiplusia nu defoliating larvae and young nymphs of Nezara viridula and Piezodorus guildinii exhibited complete synchrony with the local spider population in the studied commercial soybean plot.

Las especies del género Gyropus Nitzsch, 1818 (Phthiraptera: Gyropidae) parásitas de Octodontidae (Mammalia: Rodentia)

Este trabajo tiene por finalidad otorgar status especifico pleno a la subespecie Gyropus parvus elongatus Castro, Cicchino & Torres-Mura, 1987, describir la nueva especie Gyropus distinctus a partir de materiales recolectados sobre Octodon degus (Molina, 1782) y Octodon lunatus Osgood, 1943 procedentes del centro de Chile y, finalmente, ofrecer un analisis de las posibles razones de la distribucion geografica y del rango de hospedadores conocidos para estas tres especies

Two remarkable species of Phtheiropoios (Phthiraptera: Gyropidae) from Tucumán Province, Argentina

This study deals with two species of the genus Phtheiropoios, redescribing P. tucumanus Cicchino, 1990, previously known from five specimens collected on Ctenomys tucumanus Thomas, 1900, and describing P. inaequalis sp. nov. from C. tuconax Thomas, 1925, both from different localities in Tucumán Province, Argentina. Diagnostic features for the new species include proportion of the male forficula, male external genitalia, and counts of setae and body measurements in both sexes. Brief comments on the morphological affinities of these species with other species of Phtheiropoios, and a key to males of all species of the genus Phtheiropoios known to parasitize rodents of the genus Ctenomys, are included.

Nuevos registros de Phthiraptera (Artropoda: Insecta) en Lama pacos Linnaeus 1758, en Chile

SUMMARY For the first time in Chile, the presence of Microthoracius mazzai (Werneck 1932) and Bovicola breviceps (Rudow 1866), are reported, and the presence of M. praelongiceps (Neuman 1909) parasiting alpacas in the General Lagos area (I Region) is also confirmed. The importance of this situation is discussed in the present report.

Una nueva especie de Hoplopleura (Phthiraptera, Anoplura) parásita de tres especies de Bibimys (Muridae, Sigmodontinae, Rodentia)

A new species Hoplopleura massoiai is described, based on specimens collected on three species of Bibimys Massoia, 1979: B. torresi Massoia, 1979, B. chacoensis (Shamel, 1931) and B. labiosus (Winge, 1887), from Chaco, Misiones and Buenos Aires provinces, Argentina. Male, female, first nymphal instar, external architecture of eggs and sites of oviposition are described, providing differences with its close relative Hoplopleura scapteromydis Ronderos, 1965; comments on distribution of the new species on its hosts are done.

Nymphal Stages of Abrocomophaga hellenthali (Phthiraptera, Gyropidae), a parasite of Octodon degus (Rodentia, Octodontidae)

The three nymphal instars of Abrocomophaga hellenthali Price & Timm, 2000 are described and compared with both sexes of the adult stage. The most remarkable quali and quantitative body features of all instars are cathegorized and its progression along the development stated.

Una nueva especie de Hoplopleura (Hoplopleuridae: Anoplura) parásita de roedores cricetidos

The authors described a new species, Hoplopleura misionensis sp. n., based on specimens collected on Oxymycterus hispidus misionalis Sanborn. Descriptions are given for holotype male, alotype female and the three nymphal instars. External architecture of eggs and sites of oviposition are also presented, providing differences with other lice from Oxymycterus, Hoplopleura oxymycteri Ferris and Hoplopleura fonsecai Werneck. Comments on distribution of these species on their hosts are presented.

A NEW SPECIES OF PHTHEIROPOIOS EICHLER, 1940 (PHTHIRAPTERA: AMBLYCERA: GYROPIDAE) FROM ARGENTINA, WITH A KEY TO THE MALES COLLECTED FROM CTENOMYS (MAMMALIA: RODENTIA) FROM SOUTH AMERICA

ABSTRACT The species Phtheiropoios susquensis sp. nov. is described and illustrated from specimens of Ctenomys sp. collected from Laguna Múcar, Susques District, Jujuy Province, Argentina. Diagnostic features for the new species include a proportion of male forficula, male external genitalia, and counts of setae, body measurements in both sexes and external architecture of the egg. Its morphological affinities with allied species are briefly commented. A key to males of all species of the genus Phtheiropoios known to parasitize rodents of the genus Ctenomys, is included.