Anderson Michel Soares Bolzan

Comportamento ingestivo e consumo de forragem por cordeiras em pastagem de milheto recebendo ou não suplemento

Avaliaram-se o comportamento ingestivo e o consumo de materia seca de cordeiras recebendo diferentes tipos de suplemento em pastagem de milheto (Pennisetum americanum (L.) Leeke). Foram utilizadas 24 cordeiras com peso inicial de 30,2 ± 2,6 kg, distribuidas em tres estrategias alimentares: pastagem de milheto exclusivamente; pastagem de milheto e suplementacao com farinha de mandioca; e pastagem de milheto e suplementacao com gluten de milho. Os suplementos foram fornecidos na quantidade de 1% do PV. Foram avaliados, em tres datas, os tempos diarios (min/dia) de pastejo, ruminacao e ocio e a taxa de bocados (boc/min) das cordeiras. O consumo de materia seca (CMS) foi estimado pela relacao entre a producao fecal e a indigestibilidade da materia seca e a digestibilidade da MS, pelo metodo in vitro. A estimativa da excrecao fecal foi realizada utilizando-se oxido de cromo como marcador externo. O delineamento experimental foi o inteiramente casualizado, com tres estrategias alimentares, duas repeticoes de area e quatro animais-teste por repeticao. O fornecimento de suplementos diminuiu o tempo de pastejo diario, a taxa de bocados e a massa de bocado. A ingestao de pasto foi menor entre as cordeiras que receberam gluten de milho que entre aquelas mantidas exclusivamente a pasto, todavia, a ingestao total de MS foi maior quando fornecidos os suplementos (947 g para suplementacao com gluten de milho; 907 g para suplementacao com farinha de mandioca; e 652 g para pastagem exclusiva). Cordeiras em pastagem de milheto sem suplementacao permanecem mais tempo em pastejo.

Carcass traits of feedlot crossbred lambs slaughtered at different live weights

Carcass traits of twenty Texel x Ile de France crossbred lambs slaughtered after weaning (52 days of age), or at 25, 30 and 35kg live weight were evaluated. Lambs were placed in individual stalls (1.5m2) and fed ad libitum with a diet composed of sorghum silage (Sorghum bicolor (L.) Moench) and a concentrate mix (ground corn, soybean meal, calcium carbonate and salt). Commercial dressing percentage was related quadratically with slaughter weight, being highest in lambs slaughtered after weaning. Real dressing percentage increased linearly. Shoulder proportion decreased with slaughter weight, whereas leg, rib and neck proportions remained constant. Carcass fat was positively correlated to the slaughter weight. Slaughter of feedlot Texel x Ile de France crossbred lambs can be recommended at 28kg live weight.

Tamanho de amostra para a estimação da média de duração dos períodos larval, pupal e larval mais pupal de "Microtheca" spp. por bootstrap

The objective of this research was to determine the sample size (number of insects) to estimate the average duration for larval, pupal and larval + pupal periods for M. ochroloma and M. semilaevis. Adults of both species were collected at a 0.25ha experimental area of forage turnip (Raphanus sativus L.) and for laboratory rearing (temperature 25±2°C, relative humidity 60±10% and photoperiod 12 hours). Afterwards larval, pupal and larval + pupal periods were measured, in days, of 119 and 81 insects, respectively, M. ochroloma and M. semilaevis. It was calculated measures of central tendency and variability and determined the sample size using bootstrap with replacement of 10000 samples. For estimating the average larval, pupal and larval + pupal periods, with amplitude of bootstrap confidence interval of 95%, equal a day, 42 and 35 insects are sufficient, respectively for both M. ochroloma and M. semilaevis.

First record of larvae of Allograpta exotica Wiedemann (Diptera, Syrphidae) preying on Aphis gossypii Glover (Hemiptera, Aphididae) in watermelon in Brazil

First record of larvae of Allograpta exotica Wiedemann (Diptera, Syrphidae) preying on Aphis gossypii Glover (Hemiptera, Aphididae) in watermelon in Brazil. Brazil is one of the largest world producers of watermelon (Citrullus lanatus Thumb. Mansf.) and Aphis gossypii Glover, 1877 (Hemiptera, Aphididae) is among the most important pest on this crop. Larvae of Allograpta exotica Wiedemann, 1830 (Diptera, Syrphidae) were found preying on A. gossypii in watermelon crop, in Santa Maria, Rio Grande do Sul State, what represents the first report of this tritrophic association in Brazil.

Características de carcaça de ovelhas de descarte das raças Ideal e Texel terminadas em dois sistemas de alimentação

Carcass traits of culling ewes from Texel and Polwarth breeds submitted to two feeding systems were evaluated. Twenty ewes (10 from Polwarth breed and 10 from Texel breed) were randomly distributed according to its genetic group, in two feeding systems (feedlot and cultivated pasture). The slaughter was carried out when the animals reached body condition score of 3.5 points. Hot carcass (HCW) and cold carcass (CCW) weights and hot carcass (HCD) and cold carcass (CCD) dressing of Texel ewes were higher than those of Polwarth ewes: 27.85 and 19.04 kg, 27.08 and 18.43 kg, 47.25 and 45.20 and 45.95 and 43.72%, respectively. The absolute weights of cuts for leg, shoulder, neck and rib, and absolute weights for muscles, bones and leg fat of ewes from Texel breed were higher than those obtained by Polwarth breed. When evaluated as relative weights, however, these characteristics did not differ between the two breeds. The feeding system did not constitute a change factor for carcass traits of culling ewes. Texel ewes breed showed cuts with higher weights than those obtained by Polwarth ewes breed.

Effect of temperature on immatures of Stiretrus decastigmus (Hemiptera: Pentatomidae)

Stiretrus decastigmus (Herrich-Schaeffer) (Hemiptera: Pentatomidae) is an important predator of the insect pest Microtheca ochroloma Stal (Coleoptera: Chrysomelidae). The present study investigated the pre-imaginal development of S. decastigmus at different temperatures. The temperatures were: 20, 25, and 30 °C, with a relative humidity of 70 ± 10% and a photofase of 12 h, and the nymphs were fed larvae of M. ochroloma. We evaluated the duration and viability of the egg and nymphal stages, the duration of each instar, and the predation potential. The incubation time decreased with increasing temperature, and the viability was highest at 25 °C. The duration of the nymphal stage was inversely proportional to the temperature, ranging from 18 days at 30 °C to 40.6 days at 20 °C. The highest S. decastigmus predation rates were found at 20 °C (90.4 larvae) and 30 °C (72.5 larvae). S. decastigmus showed the highest viability and lowest consumption of larvae of M. ochroloma at 25 °C.

Características da carcaça e dos componentes não carcaça de cordeiros oriundos de parto simples ou duplo

An experiment was conducted to evaluate the carcass and non-carcass traits of single and twin lambs. Sixteen Texel × Ile de France crossbred, non-castrated male lambs were weaned at 56 days of age and slaughtered at 28kg of body weight. Immediately after the slaughter each body component was individually weighed, while carcasses were evaluated after a 24h period of refrigeration at 2°C. Single lambs presented higher values of carcass weight and carcass dressing percentage. Moreover, the Longissimus muscle area was also greater for single lambs. On the other hand, as a proportion of empty body weight, rumen was greater for twin lambs, increasing their gastrointestinal content at slaughter. The results of this study indicated that at a same slaughter weight single lambs have better quality carcasses in comparison with those from twin lambs.

Euplectrus furnius parasitizing Spodoptera frugiperda in maize in Brazil

Brazil is among the worlds biggest maize producers and fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), is the main insect pest on this crop in the country. Despite the importance of its natural enemies, there still is a lack of information about parasitoids species that attack this insect-pest, such as larval parasitoids. This research reports Euplectrus furnius Walker (Hymenoptera: Eulophidae) parasitizing S. fugiperda larvae on maize crop in Brazil.

Occurence of Phidotricha erigens Raganot, 1889 (Lepidoptera: Pyralidae) in corn in Brazil

Among the factors that affect corn yields in Brazil is the occurrence of insect pests during the crop growth, especially during the reproductive phase, such as those that occur on ears. In other Latin America countries, among secondary insects is Phidotricha erigens Raganot, 1889 (Lepidoptera: Pyralidae), described to be attacking ears of corn in Peru and Colombia (Wille, 1943 apud Costa Lima, 1950, p. 83; Cajiao et al., 1984). In Brazil, it was misidentified as Pococera atramentalis Lederer, 1863 (Lepidoptera: Pyralidae) by Costa Lima (1950) (Vitor Osmar Becker, personal information) and it is reported in other cultivated species (Costa Lima, 1950; Nava et al., 2006), but there is no mention of any occurrence in corn. This work reports the first occurrence of P. erigens feeding on corn in Santa Maria, Rio Grande do Sul, Brazil. An experiment of 680 m2 (34 m × 20 m) at an experimental area of “Universidade Federal de Santa Maria” (UFSM), in Santa Maria (29° 43’ S and 53° 43’ W, 95 m asl) was carried out from January to May, 2011. The central crop area was divided into 20 plots of 24 square meters each (6 m × 4 m), and the remaining area was used as side boundaries. Sampling was performed by taking two ears randomly per plot (40 ears/sample), on a daily basis, during almost all the reproductive subperiod, from the seventh day after silking (DAS) until the 26th DAS, with a total of 20 samples and 800 evaluated ears. Collected material was identified and sent to a laboratory, where an occurrence of larvae was observed on each ear. Afterwards, insects were counted, separated and kept individually in 100 mL plastic cups having an artificial diet until adult emergence for proper identification. A total of 30 P. erigens larvae were found, distributed in three different body size ranges: <0.5cm (22 larvae), 0.6 – 1cm (3 larvae) and >1 cm (5 larvae) and represented the second lowest rate among lepidopteran insects. Earworm, Helicoverpa zea Boddie, 1850; Fall armyworm Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae), and Dichomeris famulata Meyrick, 1914 (Lepidoptera: Gelechiidae) were also found, with a total of 308, 90 and 26 insects, respectively. P. erigens larvae occurred from the 13th to 26th DAS, which corresponded to 27.03.2011 to 09.04.2011dates (last sample), during the R3 and R4 corn reproductive stages. The highest infestation was on the 18th and 23rd DAS, with six larvae (Figure 1), totaling 15% and 12.5% of evaluated corn ears infested, respectively. Likewise on the 23rd DAS, it was the only sample in which more than one larva per ear was found (two larvae). The record of P. erigens feeding on corn in Brazil demonstrates the adaptability of this insect to Brazilian subtropical conditions. This characteristic added to the diversity of host crops leads to a concern for monitoring this species even as a secondary insect pest.

Primeiro registro de Aphis craccivora Koch 1854 (Hemiptera: Aphididae) sobre plantas daninhas em Santa Maria, RS

Aphis craccivora Koch (Hemiptera: Aphididae) is an aphid pest which occurs in different crops and causes damages related to habit of sucking sap. In Brazil information about host weed species are rare, particulary in Rio Grande do Sul (RS) State. Weeds infested by aphids were found at an experimental area located at the Universidade Federal de Santa Maria, Santa Maria, RS, in two different dates, February 22nd and March 25th 2010. In the second record (March 25th), each weed plant was measured and evaluated on the number of aphids. The aphid species was identified as Aphis craccivora and the host weed as Amaranthus hybridus Linnaeus, 1753 (Amaranthaceae), and Solanum americanum Mill, 1768 (Solanaceae). This is the first report of both A. hybridus and S. americanum hosting A. craccivora in Santa Maria, Rio Grande do Sul State.