Choice Feeding Research Articles

Efficacy of acetamiprid and fipronil fly baits against the housefly (Musca domestica L.) under laboratory conditions.

Background:The housefly Musca domestica L. (Diptera: Muscidae) is permanent pests in livestock facilities. High fly density in livestock and poultry farms can increase the risks of economic loss and public health. Treatment with toxic baits is one of the methods for housefly control. However, development of resistance to insecticides makes it difficult to manage of flies. Anti-resistance strategies include the use of multiple pesticides with different modes of action.Aim:This study was conducted to estimate the efficacy of neonicotinoid acetamiprid and phenylpyrazole fipronil, applied alone or in the mixture, against adults of M. domestica and to evaluate the efficacy of fly bait formulations containing acetamiprid and fipronil under laboratory conditions.Materials and Methods:The adult flies, M. domestica of laboratory strain, were used in laboratory bioassays. The efficacy of acetamiprid and fipronil as technical substances, when applied alone and in the mixture, against adult flies was tested by no-choice feeding bioassays. The insecticidal efficacy of bait formulations (wet powder) with acetamiprid or fipronil or their mixture was tested against flies by choice feeding bioassays. The probit analysis was used to calculate lethal concentrations of insecticides, and the χ2 test was used to analyze the interaction between fipronil and acetamiprid in the mixture.Results:Fipronil was more toxic to adults of M. domestica than acetamiprid in laboratory tests. Lethal concentrations for 50% mortality (95% confidence interval) of flies were 0.0159% (0.0124-0.0205) of acetamiprid and 0.000119% (0.000039-0.0002640) of fipronil. The mixture containing fipronil at concentration 0.005% and acetamiprid at concentration 0.05% had the additive effect on fly mortality.Conclusion:The results of laboratory feeding bioassays indicate that the mixture of fipronil and acetamiprid might have a potential to use in toxic bait formulations against houseflies.

Impaired Taste Associative Memory and Memory Enhancement by Feeding Omija in Parkinson's Disease Fly Model.

Neurodegeneration can result in memory loss in the central nervous system (CNS) and impairment of taste and smell in the peripheral nervous system (PNS). The neurodegeneration seen in Parkinson’s disease (PD) is characterized by functional loss of dopaminergic neurons. Recent studies have also found a role for dopaminergic neurons in regulating taste memory rewards in insects. To investigate how taste memories and sugar sensitivity can be affected in PD, we utilized the DJ-1β mutant fruit fly, DJ-1βex54, as a PD model. We performed binary choice feeding assays, electrophysiology and taste-mediated memory tests to explore the function of the DJ-1β gene in terms of sugar sensitivity as well as associative taste memory. We found that PD flies exhibited an impaired ability to discriminate sucrose across a range of sugar concentrations, with normal responses at only very high concentrations of sugar. They also showed an impairment in associative taste memory. We highlight that the taste impairment and memory defect in DJ-1βex54 can be recovered by the expression of wild-type DJ-1β gene in the dopaminergic neurons. We also emphasized the role of dopaminergic neurons in restoring taste memory function. This impaired memory property of DJ-1βex54 flies also allows them to be used as a model system for finding supplementary dietary foods that can improve memory function. Here we provide evidence that the associative taste memory of both control and DJ-1βex54 flies can be enhanced with dietary supplementation of the medicinal plant, omija.

Dietary diversity affects feeding behaviour of suckling piglets

Stimulating solid feed intake in suckling piglets is important to facilitate the weaning transition, exemplified by the positive correlation between pre- and post-weaning feed intake. The present study compared the effect of dietary diversity (i.e. offering two feeds simultaneously) and flavour novelty (i.e. regularly changing the flavour of one feed) on the feeding behaviour and performance of suckling piglets until weaning at day 22. It was hypothesized that presentation of the feed in a more diverse form, by varying multiple sensory properties of the feed, stimulates pre-weaning feed intake. Piglets received ad libitum feed from 2 days of age in two feeders per pen (choice feeding set-up). One group of piglets (dietary diversity (DD), n = 10 litters) were given feed A and feed B which differed in production method, size, flavour, ingredient composition and nutrient profile, smell, texture and colour. The other group of piglets (flavour novelty (FN), n = 9 litters) received feed A plus feed A to which one of 4 flavours were added from day 6 in a daily sequential order. Feeding behaviour was studied by weighing feed remains (d6, 12, 16, 22) and by live observations (4-min scan sampling, 6 h/d; d9, 14, 21; n = 6 litters per treatment). Observations were also used to discriminate ‘eaters’ from ‘non-eaters’. All piglets were weighed at d2, 6 and 22. Piglets did not prefer feed A (d2–22: 1.4 ± 0.16 kg/litter) over B (1.6 ± 0.18) within DD nor had a preference for feed A with (d6–22: 1.1 ± 0.06 kg/litter) or without additional flavours (0.9 ± 0.07) within FN. Nevertheless, DD-litters (d2–22: 3.0 ± 0.32 kg) ate significantly more than FN-litters (2.0 ± 0.12 kg; P = 0.02) and explored the feed 2.6 times more at d14 (P = 0.001). Furthermore feed A, the common feed provided in DD and FN, was more consumed in DD (d2–22: 1.4 ± 0.16 kg) compared to FN (1.0 ± 0.07 kg; P = 0.04). The percentage of eaters within a litter did not differ over time between DD (d9: 26%, d14: 78%, d21: 94%) and FN (20%, 71% and 97%) and no effect was found on pre-weaning weight gain. In conclusion, this study showed that provision of dietary diversity to suckling piglets stimulated their feed exploration and intake more than dietary flavour novelty only, but did not enhance the percentage of piglets within a litter that consume the feed or their growth performance. These data suggest that dietary diversity could be an innovative feeding strategy to stimulate solid feed intake in suckling piglets.

Antixenosis resistance in okra accessions against shoot and fruit borer Earias vittella (Fab.)

The present study is to analyse the antixenosis mechanisms of resistance in ten okra accessions against Shoot and Fruit borer E. vittella. With regard to the free choice feeding preference, the accessions IC140880 and Trichi local were not preferred by any larvae even up to 8 h. The fruit damage of Coimbatore local by the larvae in 8 hours was recorded as lowest, in confined condition. The accession IC 282228 fruit was bored up to a length 9.1 cm by the larvae in 8 h. On studying the oviposition preference, the accessions IC140880 and Trichi local were least preferred by E. vittella adults. The length and breadth and number of trichomes of these accessions were recorded as maximum. It was observed that the fruit length of IC140880 were greater than other accessions whereas Trichi local recorded higher fruit width compared to other accessions. While assessing the Fruit angle to stem, Coimbatore local recorded a higher value followed by Trichi local, IC140880 and IC 218877. The incidence of shoot and fruit borer was high in IC282228. In overall observation, weight and yield of the fruit is high in IC140880 followed by Trichi local.

Impact of on-range choice feeding with black soldier fly larvae (Hermetia illucens) on flock performance, egg quality, and range use of free-range laying hens.

Semi-intensive free-range farm systems are common in Australia, and these systems frequently practise on-range feeding. The objective of this study was to investigate the benefit of on-range choice feeding on flock performance, egg quality, and range use of free-range laying hens using black soldier fly larvae (Hermetia illucens, BSF). A total of 160 mature ISA brown laying hens, previously determined to range daily, were allocated to a control group (control) or a treatment group (BSF) with various replicates depending on the parameter investigated. All hens were fed ad libitum indoors with a wheat-soy based diet formulated according to breed requirements. Black soldier fly hens were offered dried BSF larvae ad libitum on the range. Body weight, feed intake, BSF intake, egg production, feed conversion ratio, internal and external egg quality parameters, and individual range use using radio-frequency identification (RFID) technology was evaluated. Black soldier fly hens consumed on average 15 ± 1.7 g BSF larvae/hen per day. There were no differences between BSF and control hens for any of the performance parameters obtained (P > 0.05). Egg weight, shell weight, and shell thickness of eggs from BSF hens were significantly lower (P = 0.003, P = 0.001, and P = 0.004, respectively) than those of eggs from control hens. Egg yolk colour was significantly paler in eggs from BSF hens (P < 0.001). No significant ranging differences between the BSF and control hens were observed (P > 0.05) except for BSF hens showing longer total maximum time for a single visit to the range (P = 0.011). In conclusion, the average intake of BSF larvae indicated a good level of acceptance. Feed formulation should be adjusted for the intake of the choice fed source. The impact of choice-feeding on range use was minor.

Effect of Azolla feeding on the growth, feed conversion ratio, blood biochemical attributes and immune competence traits of growing turkeys.

Background and AimIn the recent past,few studies have been carried out in chicken to assess the effect of Azolla meal and raw Azolla feeding on the performance of chicken. If turkeys effectively use unconventional feedstuffs like Azolla without reducing the performance, it will increase the profitability of turkey business. Hence, a study was carried out to evaluate the effect of dried Azolla pinnata vis-a-vis raw Azolla as choice feeding on the growth, feed conversion ratio (FCR), blood biochemical attributes, and immune competence traits of growing turkeys under intensive system.Materials and MethodsA total of 72, 8-week-old grower turkey poults of black variety were randomly distributed into three dietary treatments having three replicates each with eight birds. The birds of the control group (T1) were fed a basal diet (CP - 19.71% and ME - 2789.79 Kcal/kg), while the other group (T2) and choice-feeding group (T3) were fed 5% of basal diet replaced by dry Azolla powder on DM basis and ad libitumAzolla along with basal diet, respectively.ResultsThere was no significant difference among the different groups in the average weekly weight gain during the entire experiment. FCR was significantly better (p<0.05) in the choice-feeding group compared to the other two experimental groups during 8-16 weeks of age. There was no significant difference among the treatment groups in any of the blood biochemical indices except plasma uric acid, which was significantly decreased (p<0.01) in T2 compared to T1 at 16 weeks of age. HA and IgM response to 1% sheep red blood cells (log2 titer) were numerically better in T2 and T3 compared to the T1.ConclusionThus, it may be inferred that choice feeding with Azolla, and basal diet may improve FCR without any adverse effect on blood biochemical attributes and immune competence traits.

Are invasive apple snails important neglected decomposers of rice straw in paddy fields?

Few studies have tested for the potential of invasive species, particularly pests, to contribute to ecosystem services. The apple snail Pomacea canaliculata is invasive in many countries around the globe. They are best known as pests of rice and great efforts are made by farmers to control the snails. However, apple snails might also act as decomposers of organic litter, and it was hypothesised that they might enhance the decomposition of rice straw. To test the ability of apple snails to feed on rice straw, choice and no choice feeding experiments were conducted offering rice straw to P. canaliculata for 2 weeks. As mature rice plants are not consumed by apple snails, the straw was incubated in water for 5 days and in water with a mixture of microorganisms for 25, 50 and 75 days prior to the feeding experiments. Rice straw of all treatments was consumed by snails without preference (11.6% more weight loss on average compared to controls in which snails had no access). In another experiment, snails were fed on rice straw for 6 weeks; body mass of snails was measured weekly. In treatments where access to straw was not restricted, all snails survived and body mass remained constant, whereas if access was restricted, snails lost body mass slightly. It was concluded that rice straw served as an alternative food for apple snails. Invasive apple snails spared in times when rice plants are not vulnerable could accelerate nutrient release from rice straw providing a benefit for farmers.

Evaluation of different woods against fungus-growing termite Odontotermes obesus (Rambur) (Blattodea: Termitidae: Macrotermitinae) for use in bait stations

Fungus-growing termites are important pests in buildings and agriculture in Pakistan and are difficult to control with existing bait systems. Development of bait systems requires the knowledge of foraging behavior of termite species. Behavior of foraging workers depends upon the quality and quantity of the food placed in the bait stations. In the current study, we tested 16 different woods (of varying density) for their susceptibility to an important fungus-growing termite, Odontotermes obesus (Rambur). The aim was to find a highly susceptible wood for use in bait stations. The woods were evaluated in no-choice and choice feeding experiments in the field by mass loss and visual ratings to the termites. Statistically significant differences were recorded (P < .001). Woods having low density were preferred to high density woods. Highest mass losses (%) were recorded from Ficus religiosa (86.49–87.8%), Bombax malabaricum (86.53–88.43%) and Populus euramericana (75.62–76.31%) in both no-choice and choice tests under “very heavy attack (almost collapsed) to completely consumed” visual rating category. The woods having least mass losses were Albizia lebbeck heartwood (7.03–9.91%), Syzygium cumini (14.25–19.89%) and Dalbergia sissoo heartwood (14.35–24.88%) and had “slightly to superficial attack” with minimum rating values. Ficus religiosa, B. malabaricum and P. euramericana appear suitable woods for use in bait stations for fungus-growing termites.

Measurement of termite resistance of particleboard panels made from Eastern redcedar using nano particle added modified starch as binder

The objective of this study was to evaluate the resistance of experimental particleboard panels exposed to subterranean termites, (Reticulitermes flavipes Kollar). Panels were manufactured from Eastern redcedar (Juniperus virginiana L.) using nano-SiO2 particles added modified starch as a binder. The termite resistance of samples was evaluated using choice and no-choice bioassay approach for 12 weeks. Radiata pine control samples had 87.65% weight loss as compared with 9.92–14.07% weight loss of panel samples. The damage rating index (DRI) of the choice feeding test had the highest value of 4.00 in the case of radiata pine samples and the lowest value of 2.25 resulted from A1 panels having 0.60 g/cm3 density level and 1% of nanoparticles. In no-choice feeding tests, panel samples had less feeding damage compared to that of radiata pine samples and termite worker survival rate was less than 2%, in contrast to 87% survival rate for radiata pine control specimens as a result of 12-week exposure time. The average lowest weight loss value of 9.25% was found for A3 panels, having 0.60 g/cm3 density level and 3% of nanoparticles, and the average highest value of 14.08% was determined for the control samples. Based on the findings in this work it appears that experimental panels manufactured in this study had a certain level of resistance against the damage by subterranean termites.

Examining olfactory and visual cues governing host-specificity of a weed biological control candidate species to refine pre-release risk assessment

In weed biological control programs, pre-release host-specificity testing relies traditionally on no-choice and choice feeding, oviposition, and development tests. Rarely have they included detailed examination of behavioral responses to olfactory and visual cues of biological control candidates, although a better understanding of the mechanisms underlying host recognition may explain potential discrepancies between choice and no-choice tests, and/or between tests conducted in the lab versus field conditions. We investigated how the seed-feeding weevil, Mogulones borraginis, distinguishes its host plant, Cynoglossum officinale, from three native confamilial non-target species in North America. In behavioral bioassays, M. borraginis responded to olfactory and visual cues individually and, to an even greater extent, to both plant cue modalities when offered simultaneously. In tests with the combined cues, M. borraginis was attracted to C. officinale but responded with indifference or was repelled by non-target plants. In electrophysiological experiments, we identified that M. borraginis responded to ten volatile compounds and four wavelengths of lights from inflorescences of C. officinale. We propose that studies of responses to multimodal plant cues can advance our understanding of how biocontrol candidate species discriminate among host plants and closely related non-target species, thereby increasing the accuracy of environmental safety assessments pre-release.

Laboratory assessment of feeding injury and preference of brown marmorated stink bug, Halyomorpha halys Stål (Hemiptera: Pentatomidae), for Actinidia chinensis var. deliciosa ‘Hayward’ (Zespri® Green) and Actinidia chinensis var. chinensis ‘Zesy002’ (Zespri® SunGold)

ABSTRACTThe brown marmorated stinkbug (BMSB), Halyomorpha halys Stål (Hemiptera: Pentatomidae), is native to Asia and is characterised by its polyphagous feeding habits and high hitchhiking potential. In invaded areas, such as the eastern USA, economic damage to agricultural crops by BMSB has been significant. In northern Italy, where BMSB is invasive, feeding damage has been recorded in commercial kiwifruit orchards. In New Zealand, a major kiwifruit producer, BMSB originating from the USA, Italy and China (the native range of kiwifruit) have been intercepted. These BMSB interceptions pose a high biosecurity risk to key agricultural industries in New Zealand, including kiwifruit. However, information on the ability of BMSB to feed on key commercial kiwifruit varieties, and the types of damage it may cause to this crop, is lacking. To address this issue, Actinidia chinensis var. ‘SunGold’ (G3) and Actinidia deliciosa var. ‘Green’ (Hayward), were exposed to adult BMSB under no-choice and choice feeding trials. Across kiwifruit cultivars (i.e. Green and SunGold) and experimental setups (i.e. choice and no-choice), mixed adult groups (i.e. males and females feeding together) caused significantly more damage than individual females and males. After accounting for adult density, there was no experimental evidence that BMSB exhibited a feeding preference for either SunGold or Green varieties. However, there were variety differences for the development of BMSB feeding injury, with lower incidence of damage recorded for SunGold.

Effect of oat hulls as a free choice feeding on broiler performance, short chain fatty acids and microflora under a mild necrotic enteritis challenge.

Structure of fibre has been reported to enhance performance, intestinal function and modify the composition and quantity of the microbial population in the chicken gastrointestinal tract. It is hypothesised that insoluble fibre in oat hulls may improve gut health and reduce intestinal Clostridium perfringens number. This research assessed the effect of free choice oat hulls (OH) on performance and gut microbiota in broilers during a mild (subclinical) necrotic enteritis (NE) challenge. A total of 240 day-old male Ross 308 broiler chickens were assigned to 24 cages in a 2 × 2 factorial arrangement of treatments. Factors were challenge − or +; and OH − or +. On d 16, challenged broilers had lower weight gain and feed intake (P < 0.05) compared with unchallenged broilers. On d 16, broilers given OH had lower feed intake (P < 0.05) and tended to have lower (P = 0.062) feed conversion ratio (FCR) compared with those without access to OH. Broiler performance, however, was not affected by OH nor by challenge on d 24 and 35. The broilers given OH had heavier gizzards (P < 0.05) compared with those without OH at d 35 but not at d 13 or 16. Increased numbers of C. perfringens (P < 0.001) and reduced numbers (P < 0.05) of Lactobacillus and Salmonellae were observed in the caecal contents of challenged broilers on d 16. Challenged broilers had a lower concentration of caecal acetic acid (P < 0.01) compared with unchallenged broilers at d 16. The broilers given OH had lower concentrations of caecal acetic acid (P < 0.05), propionic acid (P < 0.05), and valeric acid (P < 0.01) compared with those without access to OH. An OH by challenge interaction on succinic acid concentration was observed on d 16 (P < 0.05). Oat hulls elevated the caecal succinic acid concentration only in the unchallenged broilers. This study indicated a positive role of OH through improved gizzard function and increased succinic acid in the gut but its role in controlling NE was not conclusive.

Leaf Chemical Compositions of Different Eggplant Varieties Affect Performance of Bemisia tabaci (Hemiptera: Aleyrodidae) Nymphs and Adults.

The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) MEAM1 is a serious pest of many crops worldwide, and its control mostly depends on insecticides. One of the most preferred host plants of B. tabaci is eggplant, Solanum melongena, although preferences among different cultivars of the whiteflies vary. We hypothesized that certain nutritional and defensive chemicals of plant leaves, such as nitrogen, glucose, fructose, sucrose, amino acids, total phenolic components, and moisture content may affect whitefly's feeding and ovipositional preference, fecundity and longevity, nymph development, and survival among different eggplant varieties. To seek the most susceptible eggplant variety for use as an attractive trap crop for whitefly adults, we determined the variation of leaf chemical compositions among six eggplant varieties (H149, JSZ, JGL, TLB, DYZ, and QXN) and evaluated the effects of their leaf chemicals to the performance of nymphs and adults of B. tabaci. In choice feeding and oviposition tests, the varieties 'H149' and 'JSZ' had the most eggs. The whiteflies had significantly higher fecundity, longevity, lowest nymph development period, and higher survivals on JSZ than on other varieties. The least preferred TLB variety possessed the lowest adults and eggs, the lowest fecundity and longevity, and nymph development period. JGL, DYZ, and QXN were considered as a moderately preferred variety. Leaf chemistry revealed that highly susceptible variety possessed higher concentration of nitrogen, glucose, amino acids, and lower moisture content. The resistant variety possessed higher amount of total phenolic component. Both nutritional and defensive chemicals combined associated with nymph and adult performance of whitefly.

Stability of Cortisol and Cortisone in Human Breast Milk During Holder Pasteurization

Human donor milk is the feeding of choice for preterm infants, when own mother's milk is not available. Holder pasteurization is necessary to secure the safety of donor milk, although it can affect milk quality by reduction of nutritional and bioactive components. Recently, research has focused on the potential role of breast milk glucocorticoids for infant development. At this moment, it is unknown whether pasteurization affects milk glucocorticoid levels. Therefore, we assessed whether Holder pasteurization, the most frequently used method nowadays, reduces breast milk cortisol and cortisone levels, using breast milk samples from 30 women who delivered at term. We found tight correlations between pre- and postpasteurization levels of cortisol (R = 0.99) and cortisone (R = 0.98), and good agreement in Passing and Bablok regression analysis. In conclusion, cortisol and cortisone in human term breast milk are not significantly affected by Holder pasteurization.

Inclusion levels and modes of whole grain incorporation into wheat-based rations differentially influence the performance of broiler chickens

ABSTRACT1. The objective was to compare three whole grain (WG) inclusion levels (7.5, 15 and 30%) offered to broiler chickens by three modes of WG incorporation: (i) pre-pellet WG inclusion, (ii) post-pellet WG inclusion as a blend of WG and pelleted concentrate and (iii) post-pellet WG inclusion where WG and pelleted concentrate were provided in separate feed trays against a ground-grain, wheat-based control diet.2. Ten dietary treatments were offered to 6 replicate cages (6 birds per cage) of male Ross 308 chickens from 7 to 28 d post-hatch. The effects of treatment on relative gizzard weights, gizzard contents, pancreatic weights and pH of gizzard digesta were monitored. Parameters of growth performance, nutrient utilisation (apparent metabolisable energy [AME], metabolisable to gross energy [ME:GE] ratios, nitrogen [N] retention and N-corrected AME [AMEn]), apparent starch and protein (N) digestibility coefficients and disappearance rates in for small intestinal segments and concentrations of free amino acids in plasma taken from the anterior mesenteric vein were determined.3. Whole grain feeding (WGF) did not influence weight gain, but 30% post-pellet blended and 15 and 30% post-pellet separated treatments significantly depressed (P < 0.05) feed intakes while the 30% post-pellet separated treatment improved (P < 0.01) feed conversion ratios (FCR). WGF regimes significantly increased relative gizzard weights.4. Overall, WGF generated profound responses in AME, ME:GE ratios, N retention and AMEn that were highly correlated with relative gizzard weights. In general, WGF improved starch and protein (N) digestibilities and again there were some correlations with these outcomes and relative gizzard weights.5. Post-pellet WG inclusions where WG and pelleted concentrate were offered separately provided chickens with the opportunity to choice feed. Birds showed a preference for the relatively high-protein pelleted concentrate and at 30% WG, this resulted in an improvement in FCR of 7.69% (1.260 versus 1.365; P < 0.001) relative to the ground-grain control diet.

Suitability of multiple Mediterranean oak species as a food resource for Reticulitermes grassei Clément (Isoptera: Rhinotermitidae).

The subterranean termite Reticulitermes grassei Clément causes lesions in the trunk of Quercus suber L. by constructing feeding galleries, but no information is available regarding other Quercus species from the Mediterranean region. This work aimed to study the suitability of the other main oak species of Mediterranean forests as a food resource for R. grassei. Two experiments, choice and non-choice feeding, were conducted lasting for 15, 30, and 45 days each. In the non-choice experiment, termites were offered one of the following food types: Quercus suber, Quercus ilex L., Quercus faginea Lam, cork or Pinus pinea L., which was considered the control. The choice feeding experiment used all the same food types listed above, supplied simultaneously in the same container. Food selection was examined by analysing the relationships over time between surviving termites and food consumption. The results indicated that R. grassei could be considered a generalist species, as it consumed the cork and wood of all oak species, as well as displaying a clear preference for soft wood (pine). Correlation analysis indicated that consumption was not dependent on wood density. Survival of R. grassei was influenced by the time of exposure to different oak species, but a high survival rate was maintained over time in the pine treatment (upper 70% in the three experiments). Given these results, it can be concluded that all the oak species are a suitable food source for R. grassei.

The influence of the selection of macronutrients coupled with dietary energy density on the performance of broiler chickens.

A total of 360 male Ross 308 broiler chickens were used in a feeding study to assess the influence of macronutrients and energy density on feed intakes from 10 to 31 days post-hatch. The study comprised ten dietary treatments from five dietary combinations and two feeding approaches: sequential and choice feeding. The study included eight experimental diets and each dietary combination was made from three experimental diets. Choice fed birds selected between three diets in separate feed trays at the same time; whereas the three diets were offered to sequentially fed birds on an alternate basis during the experimental period. There were no differences between starch and protein intakes between choice and sequentially fed birds (P > 0.05) when broiler chickens selected between diets with different starch, protein and lipid concentrations. When broiler chickens selected between diets with different starch and protein but similar lipid concentrations, both sequentially and choice fed birds selected similar ratios of starch and protein intake (P > 0.05). However, when broiler chickens selected from diets with different protein and lipid but similar starch concentrations, choice fed birds had higher lipid intake (129 versus 118 g/bird, P = 0.027) and selected diets with lower protein concentrations (258 versus 281 g/kg, P = 0.042) than birds offered sequential diet options. Choice fed birds had greater intakes of the high energy diet (1471 g/bird, P < 0.0001) than low energy (197 g/bird) or medium energy diets (663 g/bird) whilst broiler chickens were offered diets with different energy densities but high crude protein (300 g/kg) or digestible lysine (17.5 g/kg) concentrations. Choice fed birds had lower FCR (1.217 versus 1.327 g/g, P < 0.0001) and higher carcass yield (88.1 versus 87.3%, P = 0.012) than sequentially fed birds. This suggests that the dietary balance between protein and energy is essential for optimal feed conversion efficiency. The intake path of macronutrients from 10–31 days in choice and sequential feeding groups were plotted and compared with the null path if broiler chickens selected equal amounts of the three diets in the combination. Regardless of feeding regimen, the intake paths of starch and protein are very close to the null path; however, lipid and protein intake paths in choice fed birds are father from the null path than sequentially fed birds.

Picky Pugettia: a tale of two kelps

Herbivores strongly influence macroalgal community structure. Crustacean herbivores may be important in some systems; the Northern Kelp crab (Pugettia producta) is a common sub-tidal species with reported feeding preferences for kelp. In the Salish Sea, standing beds of Macrocystis pyrifera, a highly preferred food of Pugettia in California, do not occur; instead, the dominant canopy-forming kelp is Nereocystis luetkeana. However, drift Macrocystis occasionally washes up following autumn storms. This study used laboratory feeding trials to address whether Pugettia that live where Macrocystis beds do not occur will consume it and how their consumption of this less-familiar kelp compares to their feeding on the locally abundant Nereocystis. We found that Pugettia consumed much greater quantities of drift Nereocystis than drift Macrocystis in both choice and no-choice feeding experiments. Chemical analyses suggest no difference in phlorotannin levels between Nereocystis and Macrocystis, although Nereocystis had a slightly more favorable C:N than Macrocystis. The observed preference for bull kelp exhibited by Pugettia in the Salish Sea may be explained by the fact that only bull kelp is familiar, locally abundant, nutritious, and provides suitable crab habitat.

Feeding preference of the drywood termite Cryptotermes cynocephalus (Kalotermitidae) against industrial tree plantation species in the Philippines

The feeding preference of the drywood termite Cryptotermes cynocephalus Light (Isoptera: Kalotermitidae) was investigated against five fast growing industrial tree plantation species in the Philippines, viz., Gmelina arborea Roxb, Acacia mangium Willd Paraserianthes falcataria (L.) Nielsen, Swietenia macrophylla King, and Eucalyptus deglupta Blume. No-choice and choice feeding tests were conducted to determine mass loss, wood consumption, level of resistance, and termite survival after 12weeks of exposure period. Results showed that the order of feeding preference of C. cynocephalus from most to least preferred was P. falcataria, A. mangium, G. arborea, S. macrophylla and E. deglupta in no-choice and choice feeding tests.

Quarantine host range of Bikasha collaris, a potential biological control agent of Chinese tallowtree (Triadica sebifera) in North America

AbstractChinese tallowtree, Triadica sebifera (L.) Small (Euphorbiaceae), is one of the worst invasive weeds of the southeastern USA impacting coastal wetlands, forests, and natural areas. Traditional mechanical and chemical controls have been unable to limit the spread, and this invasive species continues to expand its range. A proposed biological control candidate, the flea beetle Bikasha collaris (Baly) (Coleoptera: Chrysomelidae), shows high specificity for the target weed Chinese tallowtree. Results from a series of no‐choice and choice feeding tests of B. collaris adults and larvae indicated that this flea beetle was highly specific to Chinese tallowtree. The larvae of B. collaris feed by tunneling in the roots, whereas the adults feed on the leaves of Chinese tallowtree. A total of 77 plant taxa, primarily from members of the tallow plant family Euphorbiaceae, were tested in numerous test designs. Larval no‐choice tests indicated that larvae completed development only on two of the non‐target taxa. Of 80 B. collaris larvae fed roots of Hippomane mancinella L. and 50 larvae fed roots of Ricinus communis L., two and three larvae completed development, respectively. The emerging adults of these five larvae died within 3 days without reproducing. Larval choice tests also indicated little use of these non‐target taxa. Adult no‐choice tests indicated little leaf damage by B. collaris on the non‐targets except for Ditrysinia fruticosa (Bartram) Govaerts &amp; Frodin and Gymnanthes lucida Sw. When given a choice, however, B. collaris adults consumed much less of the non‐targets D. fruticosa (7.4%) and G. lucida (6.1%) compared with the control leaves. Finally, no‐choice oviposition tests indicated that no eggs were produced when adults were fed all non‐target taxa, except those fed G. lucida. These B. collaris adults fed G. lucida leaves produced an average of 4.6 eggs compared with 115.0 eggs per female when fed Chinese tallowtree. The eggs produced from adults fed G. lucida were either inviable or the emerging larvae died within 1 day. These results indicate that the flea beetle B. collaris was unable to complete its life cycle on any of the non‐target taxa tested. If approved for field release, B. collaris will be the first biological control agent deployed against Chinese tallowtree in the USA. This flea beetle may play an important role in suppressing Chinese tallowtree and contribute to the integrated control of this invasive weed.