Rosana Matos de Morais

Age and multiple mating effects on reproductive success of Grapholita molesta (Busck) (Lepidoptera, Tortricidae)

Age and multiple mating effects on reproductive success of Grapholita molesta (Busck) (Lepidoptera, Tortricidae). The reproductive success of the oriental peach moth was evaluated in four experiments: 1) assessment of the mating duration, fecundity, fertility and longevity of females paired with virgin and immediately mated males; 2) mating duration, spermatophore size, fecundity, fertility and longevity in females paired with virgin and up to four times mated males; 3) receptivity of females to additional copulations after mating with virgin or mated males, and the effects of this behavior in female fecundity, fertility and longevity; 4) influence of insects age in the reproductive output. Males (33%) could copulate immediately after a previous copula. They were fertile until the fourth mating, but only in the first copula they transferred the longest (1.43 ± 0.10 mm) and widest (0.83 ± 0.11 mm) spermatophore, presenting the fastest mating duration (34.8 ± 2.62 min). A high proportion of females copulated by non-virgin males (84%) was receptive to other copulas, in comparison to those copulated by virgin males (32.4%). However, the fecundity, fertility, and longevity were similar among females that copulate once or more. The age was the most important factor affecting reproductive variables, where one and three day old insects had a significant higher fecundity, fertility and presented a shorter mating duration in comparison with older individuals. Results pointed out that the reproductive capacity of Grapholita molesta changes a little with respect to the analyzed factors, highlighting the elevated biotic potential of the species.

Insetos predadores em copas de Citrus deliciosa (Rutaceae) sob manejo orgânico no sul do Brasil

Predatory insects in canopies of Citrus deliciosa (Rutaceae) under organic management in southern Brazil. The composition, abundance and diversity of predatory insects occurring on canopies of Citrus sinensis Tenore var. Montenegrina, in Montenegro, State of Rio Grande do Sul, Brazil, were studied from March 2004 to March 2005. A total of 658 predaceous insects were collected, representing 51 species from ten families and five orders, Coleoptera, Hymenoptera, Neuroptera, Thysanoptera and Hemiptera. The most abundant species were Camponotus sp. 1 (Hymenoptera, Formicidae) (16.87%) and Coccidophilus sp. (Coleoptera, Coccinellidae) (11.85%). The highest abundance, richness and evenness of predatory insects were recorded in spring, although no significant difference among seasons has been found.

Aranhas e ácaros predadores em copas de tangerineiras Montenegrina, mantidas sob manejo orgânico, em Montenegro, RS

A survey was conducted to study the spider and predatory mite fauna occurring in the canopies of tangerine trees (Citrus deliciosa Tenore, cultivar Montenegrina) of an organically managed orchard, at Montenegro County, RS. During a year, fortnightly, 24 randomly trees were selected and sampled in two canopies areas, by using a sheet of white cloth (1 m 2 ). A total of 3,129 arachnids were collected, being 2,559 spiders and 570 mites. Based on the adults, 53 species of Araneae were recognized, belonging to eight families. Among those, the most abundant were Sphecozone sp. (Linyphiidae) (21.8%) and Chrysso pulcherrima (Mello-Leitao) (Theridiidae) (9.9%). Autumn exhibited the greatest abundance of young and adults of Araneae (29.2%) and spring was the season richest in species (40). Margalef and Shannon-Wiener diversity indexes also showed the highest values in spring. The latter index did not show differences among seasons. Simpson complementary index was equal among seasons, refl ecting the same degree of species dominance. In Acari, eight species were identifi ed in three families. The most abundant species were the mites Leptus sp.1 (Erythraeidae) (59.4%) and Amblyseius saopaulus Denmark & Muma (Phytoseiidae) (30%). Autumn was the season richest in mite species (eight). The highest abundance (47%) was observed on winter and the lowest (0.88%) on summer. Among mites, Phytoseiidae showed the highest richness. Among the spiders, Anyphaenidae was the most abundant and Theridiidae had the highest species richness, following the patterns observed for the group.