Feeding responses of carabid beetles to dimethoate-contaminated prey

1 The feeding responses of Pterostichus madidus Fab., P. melanarius Illiger and Nebria brevicollis Fab. (Coleoptera: Carabidae) to dimethoate-contaminated prey were investigated in 'no-choice' and 'choice' feeding tests. 2 In the no-choice tests, starved beetles were presented with aphid prey treated with four concentrations of dimethoate. In the choice tests, treated and untreated prey were presented together and the feeding preferences of the starved beetles observed. 3 No avoidance or rejection behaviour was seen in any of the carabids in either of the tests, i.e. no discrimination of the treated and untreated prey was observed. 4 Sufficient dimethoate was consumed with the aphid prey to cause significant mortality levels in the carabids. 5 The concentrations of dimethoate used in these experiments are comparable to field exposure, so carabids feeding in treated fields and field margins could potentially suffer lethal effects via the indirect exposure route of consuming contaminated prey.

Effect of free-choice feeding on the performance and ileal digestibility of nutrients in broilers

An experiment was conducted to study ileal digestibility of nutrients and to verify the ability of broilers to select feed in order to meet their requirements for protein and energy. The treatments consisted of six diets: R+S: free-choice feeding with rice bran (energy) and soybean meal (protein); C+G: free-choice feeding with corn (energy) and corn gluten meal (protein); R+G: free-choice feeding with rice bran (energy) and corn gluten meal (protein); C+S: free-choice feeding with corn (energy) and soybean meal (protein); R+C+G+S: free-choice feeding with rice bran and corn (energy) and corn gluten meal and soybean meal (protein); and BD: basal diet represented by a complete diet composed of 63% corn and 33% soybean meal. The results indicated that the adjustment to nutritional requirements does not depend only on the ability of birds to select feed. It might also depend on intake and ingredient quality, since some ingredients did not provide a balanced amount of nutrients. The birds were able to fulfill their requirements for maintenance, that is, they consumed the minimum amount of amino acids (g per day) for maximum growth. The free-choice group with corn gluten meal as the protein source had the worst performance, which indicated that this feed is not recommended as a primary source of amino acids for broilers. The C+G diet presented the highest digestibility coefficient of dry matter and crude protein, whereas the C+S diet resulted in the highest digestibility coefficient of ether extract and nitrogen-free extract, indicating that diet digestibility was affected by the type of feed used as energy and protein sources. In general, the high digestibility values indicate that broilers are able to efficiently digest and absorb the supplied feed.

Effects of nutrients on feeding activities of the pest termite Heterotermes tenuis (Isoptera : Rhinotermitidae)

Heterotermes tenuis is a native termite of large negative impact on the Brazilian economy. Many studies have focused on optimizing the baiting method for termite control by improving its use and its efficacy. In order to maximize termite bait consumption, this study aimed to select nutrient solutions which are able to enhance termite feeding. The effects of some sugars and urea on feeding preference of the subterranean termite H. tenuis were determined by double choice feeding tests, and the consumption was evaluated by variation in dry mass of filter paper after 28 days of termite feeding. Most of the solutions tested did not significantly influence feeding of H. tenuis. Termites fed preferentially on filter paper treated with 0.03 g/ml trehalose and 0.015 g/ml urea solutions. The data indicate that trehalose and urea solutions are phagostimulants to H. tenuis, and their future use in bait matrices may increase consumption of baits and improve this control technique.

Protein Hydrolysates Are Avoided by Herbivores but Not by Omnivores in Two-Choice Preference Tests

Background: The negative sensory properties of casein hydrolysates (HC) often limit their usage in products intended for human consumption, despite HC being nutritious and having many functional benefits. Recent, but taxonomically limited, evidence suggests that other animals also avoid consuming HC when alternatives exist. Methodology/Principal Findings: We evaluated ingestive responses of five herbivorous species (guinea pig, mountain beaver, gopher, vole, and rabbit) and five omnivorous species (rat, coyote, house mouse, white-footed mouse, and deer mouse; N = 16–18/species) using solid foods containing 20% HC in a series of two-choice preference tests that used a nonprotein, cellulose-based alternative. Individuals were also tested with collagen hydrolysate (gelatin; GE) to determine whether it would induce similar ingestive responses to those induced by HC. Despite HC and GE having very different nutritional and sensory qualities, both hydrolysates produced similar preference score patterns. We found that the herbivores generally avoided the hydrolysates while the omnivores consumed them at similar levels to the cellulose diet or, more rarely, preferred them (HC by the white-footed mouse; GE by the rat). Follow-up preference tests pairing HC and the nutritionally equivalent intact casein (C) were performed on the three mouse species and the guinea pigs. For the mice, mean HC preference scores were lower in the HC v C compared to the HC v Cel tests, indicating that HC’s sensory qualities negatively affected its consumption. However, responses were species-specific. For the guinea pigs, repeated exposure to HC or C (4.7-h sessions; N = 10) were found to increase subsequent HC preference scores in an HC v C preference test, which was interpreted in the light of conservative foraging strategies thought to typify herbivores. Conclusions/Significance: This is the first empirical study of dietary niche-related taxonomic differences in ingestive responses to protein hydrolysates using multiple species under comparable conditions. Our results provide a basis for future work in sensory, physiological, and behavioral mechanisms of hydrolysate avoidance and on the potential use of hydrolysates for pest management.

Feeding tests and auxiliary studies on sorbitol, mannitol and four types of nonionic emulsifiers derived from long chain fat-forming fatty acids.

Cover title.

Chemosterilants screened against the boll weevil in dipping and feeding tests /

"In cooperation with Mississippi Agricultural Experiment Station."

Preferência alimentar de Diabrotica speciosa (Germ.) e Cerotoma sp. por genótipos de soja

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Resistência de genótipos de amendoim (Arachis hypogaea L.) de hábitos de crescimento ereto e rasteiro a Anticarsia gemmatalis Hübner, 1818 (Lepidoptera: Noctuidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Não preferência para alimentação e antibiose em cultivares de amendoim a Stegasta bosquella (Chambers) (Lepidoptera: Gelechiidae)

This work aimed to evaluate the attractiveness, non-preference for feeding and antibiosis in straight and runner growth habit peanut cultivars to Stegasta bosquella (Chambers). Eight cultivars were evaluated, four of straight growth habit (IAC Tatu, IAC 22, IAC 8112 and IAC 5) and four of runner growth habit (IAC Runner 886, IAC 147, IAC 125 and IAC 503). Free-choice and no-choice feeding tests were performed, using pairs of overlapped leaf discs with 1.0 cm diameter, which were placed in Petri dishes where third instar larvae of S. bosquella were released. The attractiveness to the larvae was assessed in predetermined times, in addition to the dry mass consumed. In the antibiosis assay, the biological parameters were evaluated: period and viability of larvae, pre-pupae, pupae, and total, weight of larvae and pupae, sex ratio and longevity. None of the runner growth habit cultivars exhibited non-preference for feeding-type resistance. Among the straight growth habit cultivars, IAC 5 and IAC 22 were the least attractive and consumed in the free-choice feeding test, and IAC 5 and IAC 8112 were the least attractive in the no-choice test. The runner growth habit cultivars IAC 147 and IAC Runner 886 affected the larval survival of S. bosquella, exhibiting antibiosis-type resistance. For the straight growth habit cultivars, IAC 22 and IAC 8112 affected the larval viability, presenting antibiosis-type resistance. The straight and runner growth habit cultivars did not influence the biological parameters of weight of pupae, sex ratio and longevity of S. bosquella.

Spider fauna of soybean crops in south-east Queensland and their potential as predators of Helicoverpa spp. (Lepidoptera: Noctuidae)

Spiders are among the most abundant predators recorded in grain crops in Australia. They are voracious predators, and combined with their high abundance, may play an important role in the reduction of pest populations. The significance of spider assemblages as biological control agents of key pests such as Helicoverpa spp. in Australian agroecosystems is largely unknown. A thorough inventory was made of the spider fauna inhabiting unsprayed soybean fields at Gatton, south-east Queensland. One-hundred-and-two morphospecies from 28 families were collected using vacuum sampling and pitfall traps across two summer seasons (2000-01, 2001-02). No-choice feeding tests in the laboratory, using eggs and larvae of Helicoverpa armigera (Hubner) as prey, were used to ascertain the predatory potential of each spider group. The field-collected spider assemblage ate on average 2.4 (+/-0.7 standard error) to 5.0 (+/-0.8) eggs per 24 h per spider (10-25% of those available), depending on level of starvation. Clubionidae were the only spiders to readily consume eggs in the laboratory (mean of 18.4 +/- 1.5 eggs per starved spider and 8.2 +/- 3.9 per non-starved spider after 24 h). Starved spiders consumed 9.4 (+/- 0.1) first-instar larvae per 24 h per spider (90% of those available). This information was combined with field observations and literature from Australian and overseas studies to assess the potential of spider groups as predators of Helicoverpa spp. Lycosidae, Clubionidae, Oxyopidae, Salticidae and Thomisidae have the capacity to contribute to control of Helicoverpa spp.

Preferência alimentar de adultos de Diabrotica speciosa (Germar) (Coleoptera: Chrysomelidae) por genótipos de batata (Solanum spp.)

Avaliou-se a preferência alimentar de adultos de Diabrotica speciosa (Germar), pelos genótipos de batata Achat, Baronesa, Monalisa, N 140-201 e NYL 235-4. Foram realizados ensaios com e sem chance de escolha, em laboratórios e em casa de vegetação, na FCAV/UNESP, Jaboticabal, SP. em dois testes utilizaram-se discos de folíolos provenientes de plantios em vaso (plantas com 40 dias); em outros seis semelhantes (exceção ao genótipo N 140-201) foram utilizados discos de folíolos provenientes de plantio de campo (plantas com 30, 50 e 70 dias). Nas placas de Petri (repetições) foram liberados dois adultos/disco. Dois outros ensaios foram efetuados em gaiolas (sem chance de escolha), no interior de casa de vegetação, com plantas com 15 e 45 dias de idade, liberando-se três e 10 adultos/planta respectivamente, avaliando-se o consumo de área foliar quatro e cinco dias após. Nos testes em laboratório com material de vaso, o genótipo NYL 235-4 (com e sem chance) foi o menos consumido (1,08 a 1,12 mg de peso seco). Com material de campo (com e sem chance), o peso de matéria fresca consumida pela praga foi menor em NYL 235-4 (médias de 26,2 e 66,1 mg) e Baronesa (30,2 e 57,9 mg). Nos ensaios em gaiolas (sem chance) também verificou-se menor consumo em NYL 235-4 (3,35 cm² e 16,70 cm²/planta). Esses resultados revelam que o genótipo NYL 235-4 apresenta resistência do tipo não-preferência para alimentação em relação a D. speciosa.

Preferência alimentar de adultos de Diabrotica speciosa (Ger.) (Coleoptera: Chrysomelidae) por genótipos de feijoeiro

Tests were carried out to evaluate resistance of common bean (Phaseolus vulgaris L.) to Diabrotica speciosa (Ger.) with the genotypes Goiano Precoce, Jalo Precoce, PR 95105146, PR 95105142 (Andean domestication center, AN), Emgopa 201 Ouro and IAPAR 57 (Middle American domestication center, MA). The experiments were conducted in 1998 and 1999, at the farm of UNESP-FCAV, Jaboticabal, SP, Brazil. The genotypes were planted in pots and 20 day-old leaflets were collected and foliar disks were cut of for the test. Two trials, a no-choice test and a free-choice test, were set up in BOD. In free-choice test, two disks of each genotype were kept in a 140-mm-diameter petri dish (total of 12 disks), where 12 adults were confined. In no-choice test, two disks of one genotype and two insects were placed in a 60-mm-diameter petri dish. A field experiment was conducted when 400 adults of D. speciosa were released. Fifteen leaflets per plot were collected 30 days after planting and the leaf area consumption was evaluated. A no-choice experiment was carried out with 20 day-old genotypes protected in individual cages and infested by 10 adults, for 72h. The MA genotypes were the most preferred on feeding tests conducted at BOD, field and individual cages, while the AN genotypes were less eaten.

Tipos e graus de resistência de genótipos de soja a Spodoptera eridania (Cramer, 1782) (Lepidoptera: Noctuidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)