高原鼠兔不育控制对鸟类多样性影响（英文）

高原鼠兔种群数量过多被认为是青藏高原草地退化的主要原因之一。2007年4月,在青海省果洛州大武镇开展了高原鼠兔不育控制实验。为了解3种不育剂(炔雌醚、左炔诺孕酮和EP-1)对高原鼠兔和土著鸟类的影响,分别在2007年和2008年8-9月调查了高原鼠兔种群数量与鸟类多样性。结果表明,投药次年,炔雌醚能显著降低高原鼠兔各群数量,而对鸟类多样性和物种数均无显著影响;炔雌醚组白斑翅雪雀的数量显著低于对照组,棕颈雪雀的数量显著高于EP-1组。因此,炔雌醚能有效降低高原鼠兔种群数量,对土著鸟类多样性影响较小。使用炔雌醚开展不育控制是高原鼠兔种群管理的一种新途径。     

左炔诺孕酮和炔雌醚复合不育剂（EP-1）对雌性东方田鼠生殖的影响

  本文在实验室条件下通过一次性灌胃的方式研究了左炔诺孕酮-炔雌醚复合不育剂（EP-1）对雌性东方田鼠激素、生殖系统、胎仔数、受孕率的影响及药效持续时间,旨在检验其应用于野外东方田鼠不育控制的价值。结果表明,各浓度EP-1灌胃均能显著提高雌性东方田鼠的子宫系数,使子宫形态发生变化,对卵巢组织造成损伤,影响卵泡和黄体的发育,但是对雌二醇含量和子宫长度没有明显影响;60mg/kg EP-1灌胃能显著提高促卵泡刺激素含量和卵巢系数,而10mg/kg、30mg/kg EP-1灌胃对二者没有明显影响。室内繁殖实验表明,各浓度EP-1灌胃均能不同程度延迟初次怀孕时间,并降低试鼠的怀孕率和胎仔数,但抗生育作用具有可逆性且与药物浓度相关,10mg/kg、30mg/kg和60mg/kg剂量组生殖系统恢复时间分别为16 d、38 d和52 d。     

复合不育剂EP-1对小鼠空间记忆与焦虑行为的影响

EP-1是由炔雌醚和左炔诺孕酮按照1∶2的比例配制而成的一种用于鼠类不育控制的激素类复合不育剂,对鼠类的繁殖及繁殖行为等有一定影响,但对鼠类空间学习与记忆、焦虑行为等非繁殖行为的影响还没有报道。为此,用0(对照)、1.0、2.0、3.0 mg/kg剂量的EP-1对昆明小鼠(Mus musculus)进行灌胃处理,然后用Morris水迷宫和高架十字迷宫分别测定其空间记忆、焦虑行为。结果发现灌胃后15 d,剂量为2.0 mg/kg的EP-1使小鼠空间记忆能力显著下降,但30 d后其空间记忆能力有所恢复,表明2.0 mg/kg剂量的EP-1可以在一定时间范围内降低小鼠的空间记忆能力。但不同剂量的EP-1对小鼠焦虑行为无显著影响。该结果可以为从对非繁殖行为的影响的角度研究EP-1对鼠类的作用提供一定启示。     

EP-1对雄性中华姬鼠和黑线姬鼠繁殖力的影响

为了检测左炔诺孕酮-炔雌醚（EP-1）对雄性中华姬鼠和黑线姬鼠的不育效果, 将32只雄性中华姬鼠和30只雄性黑线姬鼠分为 30mg/kg 单剂量组、30mg/kg多剂量组和对照组, 15d 和 45d 后剖检, 比较睾丸、附睾、储精囊、精子密度、睾酮含量及睾丸组织形态的变化。结果发现：给药后第 15 天,两种试鼠的睾丸、附睾、储精囊的重量较对照组明显降低; 精子密度、睾酮含量显著下降; 曲细精管结构破坏明显。给药后第45天,处理组各生理指标继续下降,但与第15天相比差别不显著;单剂量组和多剂量组在两个时间点的差别并不显著。结果表明,EP-1对雄性中华姬鼠和黑线姬鼠的繁殖器官有显著抑制效果,单次给药与多次给药的不育效果差别不大。     

EP-1包合物制备及其对布氏田鼠繁殖器官的影响

EP系列鼠类不育剂的主要成分--左炔诺孕酮和炔雌醚在常温下难溶于水,给研究和应用造成很大不便.本研究利用2-羟丙基-β-环糊精(HPCD)提高了EP不育剂的水溶性,制备包合物;设置4个浓度梯度的EP-1包合物水溶液,分别对雌雄布氏田鼠进行灌胃,并在第2周和第4周测量繁殖器官指标,评价不育效果.结果表明,在20%的HPC...     

左炔诺孕酮和炔雌醚复合物(EP-1)及组分对鼠类不育效果的研究进展

由于当前传统灭杀带来的一系列问题,鼠害不育控制逐渐受到重视。自张知彬等2004年率先报道左炔诺孕酮和炔雌醚复合物(EP-1)对野生鼠类不育效果的研究以来,国内多个研究团队对EP-1及其组分的不育效果、剂量、饵料制作、环境安全性、行为与分子机理等方面开展了大量的验证和完善研究,取得了许多重要的进展。这些结果进一步说明EP-1及组分对鼠类具有很好的不育效果,并具有两性不育、高效低量、可持续、相对环保与安全、野外投放方便、经济可行等特点。EP-1或炔雌醚毒饵的不育剂量约为10-50μg/m L(0.001%-0.005%),甚至更低;其组分在土壤和水体的半衰期约为5-16 d和小于3 d。在鼠类繁殖的早期,采取野外一次饱和投放即可有效降低全年鼠类的繁殖,效果可延续至第二年。可见,EP-1及其组分有望成为鼠害控制的一个新手段。建议今后进一步加强野外不育与跨年持续效应的验证、环境安全性评价和行为生态学机制等研究工作。     

EP-1不育剂对黑线毛足鼠种群繁殖的影响

为检验EP-1 不育剂对野外鼠类的施用效果,2004 年在内蒙古锡林郭勒盟阿巴嘎旗白音图嘎800 hm² 草场进行了大田实验,并随后进行了逐月的夹线跟踪调查,分析了不育剂(EP-1) 对黑线毛足鼠种群繁殖的效应。结果表明,EP-1 不育剂对黑线毛足鼠种群繁殖的抑制效果良好,投药区与对照区相比,投药区黑线毛足鼠的子宫损伤率达到80% ,平均胎仔数下降到对照区的2 /3 水平,妊娠率也下降到对照区的20% 。但EP-1 不育剂对雄鼠睾丸下降率的作用不明显。一次性投放EP-1 不育剂,对黑线毛足鼠种群的繁殖作用时间可维持4 个月以上,基本可实现对整个繁殖期的控制成效,这可能与黑线毛足鼠具有储藏种子的习性,储藏药饵多次进食有关。     

高原鼢鼠、鼠兔及大鼠心肌和骨骼肌乳酸脱氢酶活力及同工酶谱

为了探讨高原鼢鼠和鼠兔的低氧适应机理,用紫外分光光度法测定了高原鼢鼠、鼠兔及大鼠心肌和骨骼肌乳酸脱氢酶(Lactate Dehydrogenase,LDH)的活力,通过聚丙烯酰胺凝胶电泳分离了LDH同工酶.结果显示:鼢鼠、鼠兔、大鼠心肌LDH活力分别为16.90±2.00 U/mg pro,20.55±2.46 U/mg pro,38.26±6.78 U/mg pm,鼢鼠和鼠兔差异不显著(P>0.05),大鼠与鼠兔差异显著(P<0.05),大鼠与鼢鼠差异极显著(P<0.01);骨骼肌LDH活力,鼢鼠、鼠兔、大鼠分别为39.34±3.74 U/mg pro,78.33±9.54 U/mg pro,67.80±10.89 u/mg pr0,大鼠和鼠兔差异不显著(P>0.05),二者均极显著高于鼢鼠(P<0.01).高原鼠兔与鼢鼠LDH同工酶M亚基的迁移率较为相近,而H亚基差别较大;鼢鼠和大鼠H亚基的迁移率较为相近,而M亚基差别较大.鼢鼠和鼠兔心肌LDH同工酶亚基组成以H亚基为主,M亚基含量较低,而骨骼肌LDH同工酶亚基组成以M业基为主,H业基含量较低.大鼠心肌和骨骼肌LDH同工酶H亚基和M亚基含量均很丰富.说明高原鼢鼠和鼠兔虽然生活在极其缺氧的环境中,但它们的组织并不缺氧;高原鼢鼠和鼠兔以不同的策略适应高原缺氧.     

不同剂量炔雌醚对小鼠器官鲜重、繁殖生理和肝肠CYP3A4酶含量的影响

为探究不同剂量炔雌醚对小鼠器官、激素和肝肠药解酶的影响,分别以0.008 mg/kg、0.04 mg/kg、0.2 mg/kg、1.0 mg/kg和5.0 mg/kg的炔雌醚油溶液连续3 d灌胃小鼠,首次给药7 d后解剖取材,检测其器官鲜重、雄鼠精子数量、血清中激素浓度、小肠和肝脏中CYP3A4酶含量的变化。结果发现：雌鼠肝脏鲜重随剂量增加而增大,5.0 mg/kg组比对照组增大89.7%;雌鼠小肠、肾脏和脾脏出现不同程度变化,但无明显剂量效应;0.2 mg/kg以上剂量炔雌醚导致雌鼠子宫不同程度的水肿;炔雌醚对雌鼠血清中雌二醇和促黄体素浓度无显著影响,仅1.0 mg/kg组雌鼠血清中卵泡生成素浓度较对照组显著升高;1.0 mg/kg和5.0 mg/kg组雌鼠肝脏中CYP3A4酶总含量较对照组分别显著增加59.1%和102.9%。不同剂量炔雌醚对雄鼠肝脏和脾脏鲜重影响显著,5.0 mg/kg剂量组肝脏和脾脏鲜重较对照组分别增大23.3%和130%,但小肠和肾脏无明显剂量效应;不同剂量炔雌醚对雄鼠睾丸鲜重无显著影响,附睾仅有5.0 mg/kg组较对照组显著减小;1.0 mg/kg和5.0 mg/kg组的精子密度和精子总数分别较对照组降低43.9%和70.5%;高剂量炔雌醚使血清中促黄体素和睾酮浓度均显著降低;5.0 mg/kg组雄鼠肝脏CYP3A4酶单位组织含量和总含量较对照组分别升高7.1%和30%。总之,炔雌醚对雌雄小鼠的繁殖均有抑制作用,但最低有效剂量不同,雌性有效剂量更低,而雌性肝脏及CYP3A4酶对炔雌醚的反应显著强于雄性,提示雌鼠肝脏对炔雌醚的代谢更快。     

植物次生代谢物含量的季节性变化及其对高原鼠兔食物选择的影响

2008 年6 ～9 月在中国科学院海北高寒草甸生态系统定位站通过自助餐式食物选择实验测定了高原鼠兔对20 种植物的取食量,采用紫外可见分光光度计法测定了不同季节20 种植物中黄酮、缩合单宁、简单酚和总酚4种植物次生代谢物的含量,分析了植物次生代谢物含量与高原鼠兔食物选择之间的相互关系。结果表明,在选定的20 种植物中高原鼠兔喜食的植物有7 种,可食的植物有7 种,厌食的植物有6 种。植物次生代谢物的含量在不同的植物间表现出一定的差异,且有生长季节早期含量低,随后逐渐增高的季节性变化趋势。高原鼠兔对植物的选择性与植物中黄酮含量有显著的负相关性,喜食植物的黄酮含量显著低于厌食植物,喜食植物的单宁含量显著小于可食植物,可食植物的单宁含量显著大于厌食植物。在喜食植物中,高原鼠兔取食量与简单酚和总酚含量呈显著负相关性。以上结果部分验证了植物次生代谢物作为植物的防御对策明显影响高原鼠兔对食物选择的假说。黄酮类次生代谢物明显抑制高原鼠兔的取食,缩合单宁对高原鼠兔食物选择也有一定的抑制作用,高原鼠兔有少量取食但避免大量取食简单酚和总酚含量高的植物的选择策略。     

Palatability and efficacy to possums and rats of pest control baits containing bird repellents

Repellents used to reduce by-kill of birds during pest control must not compromise acceptance by target species. Two repellents combined, anthraquinone (AQ; 0.4 g kg^?1) and d-pulegone (DP; 1.0) did not reduce the palatability of blue-coloured carrot baits to laboratory rats (Rattus norvegicus); nor did DP (2.0). Green-coloured carrot baits coated with AQ, DP or AQ + DP were taken from bait stations by wild possums (Trichosurus vulpecula) and rats. Toxic (1080) bait coated with AQ (0.4) and peanut oil (0.1) had reduced palatability but was accepted by laboratory rats. However, laboratory rats did not consume enough baits coated with AQ and bacon, peanut butter, cinnamon or DP to be killed. Anthraquinone (0.4 or 0.8) plus cinnamon and DP (0.5) did not affect palatability or lethality to captive ship rats (R. rattus) or possums. Anthraquinone and DP as surface coatings on baits are therefore acceptable to possums and possibly rats, at concentrations that deter some bird species.     

The palatability of undyed carrot surface-coated with repellents,or dyed blue or green to a terrestrial macroinvertebrate

ABSTRACT

Birds are at risk of being poisoned during pest control operations not only through eating toxic baits, but potentially by preying on invertebrates that have, themselves, consumed the toxic baits. Blue baits coated with anthraquinone and/or mint-scented repellents are avoided by some bird species compared with green baits coated with cinnamon oil; however, data on invertebrate avoidance patterns have not been explored. In our first experiment, we measured consumption rates in a large invertebrate, the Auckland tree wētā (Hemideina thoracica) for carrot that had been surface-coated with three repellent formulations: anthraquinone (0.8?g?kg^?1) (a secondary repellent); anthraquinone (0.8?g?kg^?1) and pennyroyal oil (a mint-scented product which acts as a primary repellent) (0.5?g?kg^?1); and cinnamon oil (0.15?g?kg^?1) (a primary repellent), over 4 days. In a second experiment, we tested whether tree wētā preferred carrot dyed either blue or green over 2 days. Tree wētā ate similar quantities of carrot from all three of the repellent formulations tested, but consumption of all three formulations was significantly lower than the control from the third day of the experiment. Tree wētā ate less blue-dyed carrot than green-dyed carrot on both days of the second experiment, but differences were not significant (day 1, P=?0.057; day 2, P?=?0.145). Our findings complement the results of previous studies on some bird species. Together they show the potential of surface-coating baits with anthraquinone and/or mint oil and dyeing them blue in pest control operations to reduce non-target avian by-kill, while not increasing the risk of secondary poisoning of insectivorous species. Our results also indicate that cinnamon oil can be used not only as a toxin mask but also as a repellent to wētā.     

Invertebrates feeding on baits used for vertebrate pest control in New Zealand

This study was initiated in response to concerns that vertebrate pest control operations in New Zealand may be having deleterious impacts on invertebrate populations and, secondarily, on insectivorous non-target vertebrate populations. Invertebrates feeding on non-toxic baits of the types used for vertebrate pest control were collected and identified. The bait types were diced carrots and three types of cereal-based baits (No.7, RS5, and AgTech). The study was conducted in two rata/kamahi dominated forests (Bell Hill Scenic Reserve and Kopara Forest, West Coast), in July and September 1996. The most common species found on baits was the ant Huberia brouni (Hymenoptera: Formicidae). Other common taxa were Orthoptera (at least eight species of weta including Zealandosandrus aff. gracilis, Gymnoplectron sp., and Pleioplectron sp.). Coleoptera (at least nine species of beetles including Saphobius nitidulus, Nestrius sp., and Phrynixus sp.), Dermaptera (at least one species of the earwig Parisolabis sp.), Opiliones (at least three species of harvestmen), and Acarina (at least three species of mites). The ants and weta were found predominately on cereal-based baits, and the beetles, earwigs, harvestmen, and mites predominantly on carrot baits. More invertebrates were found on carrot and RS5 cereal-based baits than on the other two bait types, and more on baits at night than during the day. Fewer invertebrates were found on cinnamon-flavoured baits (used for 1080-poisoning of possums) than on plain baits (used for brodifacoum-poisoning of rodents). The number of species and number of individual invertebrates found on baits were a small proportion of the number likely to be present in the forest litter. We predict that vertebrate pest control operations are unlikely to have any long term deleterious impacts on invertebrate populations. This prediction should be tested by monitoring populations of invertebrate species, found to ear baits, during vertebrate pest control operations.     

Efficacy of commercial baits and new active ingredients against firebrats and silverfish (Zygentoma: Lepismatidae)

Commercial baits containing boric acid, hydramethynon, and indoxacarb were tested against the firebrat, Thermobia domestica (Packard), and silverfish, Lepisma saccharina L. (both Zygentoma: Lepismatidae), under laboratory conditions. Three boric acid baits were consumed in significantly smaller amounts than untreated control food and did not effectively control either species. Baits containing hydramethylnon and indoxacarb were consumed in greater amounts than boric acid baits, but were relatively ineffective, with LT50 values >9 d. Presence or absence of competitive untreated food did not consistently affect bait efficacy. A ground oat matrix was used to evaluate the potential effectiveness of abamectin, chlorfenapyr, dinotefuran, fipronil, hydramethylnon, metaflumizone, and novaluron baits. The most effective compound was chlorfenapyr. At 0.05 and 0.20% (wt:wt) rates, chlorfenapyr baits produced LT50 values, for both species, ranging from 2 to 4 d. All other compounds had LT50 values >7 d.     

Testing a molasses-based bait for oral vaccination of white-tailed deer (Odocoileus virginianus) against Mycobacterium bovis

White-tailed deer (Odocoileus virginianus) in Michigan, USA, are wildlife reservoirs of bovine tuberculosis (bTB) with documented spread to cattle. In vaccine efficacy trials, Mycobacterium bovis bacillus Calmette–Guerin (BCG) administered orally reduces colonization and bTB-associated lesions in white-tailed deer after experimental challenge with virulent M. bovis. The objective of this study was to develop and evaluate the palatability of a molasses-based bait for oral delivery of BCG to white-tailed deer. Relevant practical properties of the bait such as physical stability under various environmental conditions were evaluated, as well as palatability. Captive deer consumed baits within 3 h of introduction during 48 of 50 trials. Digital game cameras revealed consumption of all placed baits by one deer over 62 % of the time. Addition of BCG vaccine did not negatively impact palatability. Physical stability analysis demonstrated that ice and water significantly reduced bait stability as measured with a compression assay. Storage of BCG-containing baits at 4 °C showed a slight decrease in colony-forming units (CFUs) by day 31. In contrast, storage at ?20 or ?80 °C over the same 31-day period showed no significant decrease in BCG viability. The results of this study suggest that molasses-based baits, as prepared here, represent a plausible means of oral delivery of BCG to white-tailed deer under most environmental conditions.     

Processing cereal straws by steam explosion in a pilot plant to enhance digestibility in ruminants

Wheat, barley and oat straws were treated by steam explosion (SE) and then washed with 50g/l NaOH solution. The SE treatment was optimized at batch scale on the basis of carbohydrate recovery. Stocks of fodder (300kg) were produced at 198 degrees C for 2.5min by a continuous reactor and used for in vivo digestibility tests carried out on sheep. The flow-sheet and the mass balances were obtained for the entire process. For the three straws, the water consumption has been 7.3kg/kg of straw. To delignify and improve the digestibility of the straws, 20g of NaOH/kg straw was used. The yield of fodder, lignin and hemicellulose is dependant on the nature of the starting straw. Delignified fodder (insoluble fraction) can be produced with a yield of 0.64, 0.59, 0.55, respectively, from wheat, barley and oat straw. SE improved the digestibility of the straw by 25%; alkaline washing further increased it by 9%. Balanced rations containing, on a DM basis, 1/4 of treated straw, had digestibility coefficients similar to those of commercial rations based on alfalfa.     

Mortality of North Island tomtits (

Aerial poisoning operations with carrot or cereal baits are used to control brushtail possum (Trichosurus vulpecula) populations in New Zealand forests for ecosystem conservation and to stop the spread of bovine tuberculosis to cattle and deer herds on adjacent farmland. Although various measures have been implemented to reduce the incidence of bird kills, dead birds continue to be found after poison operations. Colour- banded North Island tomtits (Petroica macrocephala toitoi) were monitored in treatment and non-treatment areas in Pureora Forest Park to determine the costs and benefits of aerial 1080 possum poisoning operations to tomtit populations. The August 1997 operation (carrot baits with very little chaff, 0.08 % w/w 1080, 10 kg ha(-1)), resulted in 11 (79%) of 14 tomtits disappearing, but none of nine from the non-treatment area. Whether the birds died of primary or secondary poisoning is unknown. No tomtits in either treatment or non-treatment areas disappeared following the August 1998 operation (cereal baits, 0.08% w/w 1080, 5 kg ha(-1)). The carrot bait operation resulted in almost all possums and rodents being killed, but a few possums and rodents survived the cereal bait operation, apparently because of a gap in bait distribution. During the 1997/98 nesting season, tomtit pairs in the 1997 treatment area had high nesting success (80% of nests fledged chicks, mean of four fledglings per nest). Even so, by the following spring it seemed that the population had not recovered to its pre-poison level. Further research on this topic is warranted, the priority being to monitor tomtit mortality during more aerial 1080-cereal bait operations in order to assess the likely risks of using those baits.     

Effects of Cropping Sequences on Population Densities of Meloidogyne hapla and Carrot Yield in Organic Soil

The influence of various cropping sequences on population densities of Meloidogyne hapla and carrot yield was studied in organic soil under microplot-and field conditions. Spinach, radish, barley, oat, and wheat were poor or nonhosts for M. hapla. Population densities of M. hapla were maintained or increased on cabbage, celery, lettuce, leek, marigold, and potato. Marketable percent-age and root weight of carrots were greater following spinach, oat, radish, and fallow-onion than those following two crops of onion or carrot in microplots. Under field conditions, the carrot-onion-oat-carrot cropping sequence decreased M. hapla population densities and provided a 282% increase in marketable yield of carrot compared to a carrot monoculture. Two consecutive years of onion increased M. hapla population densities causing severe root galling and a 50% yield loss in the following crop of carrot. Based on root-gall indices, carrots could be grown economically for 2 years following radish, spinach, and oat, but not following onion and carrot without the use of nematicides.     

Feeding by Captive Rare Birds on Baits Used in Poisoning Operations for Control of Brushtail Possums

Non-toxic plain and cinnamon-flavoured carrots and cereal-based baits used in poisoning operations for control of the brushtail possum (Trichosurus vulpecula) were offered to seven species of captive rare birds at Mt Bruce National Wildlife Centre. Some individuals of all species ate plain baits. Antipodes Island parakeets (Cyanoramphus unicolor) preferred carrot to cereal- based baits, North Island kokako (Callaeas cinerea wilsoni) and North Island saddlebacks (Philesturnus carunculatus rufusater) preferred cereal-based baits to car-rots, but the other species showed no bait preference. Most baits eaten were greater than 2 g. Some individuals of all species also ate cinnamon-flavoured baits. However, cinnamon deterred North Island kaka (Nestor meriodionalis septentrionalis), Antipodes Island parakeets, and kokako from feeding on baits the first day offered, though not subsequently. Insufficient baits were eaten by North Island weka (Gallirallus australis greyi), red-crowned parakeets (Cyanoramphus novaezelandiae novaezelandiae), and Reischek's parakeets (Cyanoramphus n. hochstetteri) to determine whether they were also deterred by cinnamon. Only saddlebacks were definitely not deterred. All species except red-crowned and Reischek's parakeets probably ate sufficient to receive a lethal dose if the baits had been toxic. Baits may be made less acceptable to birds by increasing the strength or slowing the release of cinnamon, or by using a more repellent flavour. Because baits may always be acceptable to some birds, wildlife managers need to know the chances of wild rare birds feeding on baits before approving poisoning operations in areas where they occur.     

Development of a toxic bait for control of eastern lubber grasshopper (Orthoptera: Acrididae)

This study assessed baits for eastern lubber grasshopper, Romalea guttata (Houttuyn). When offered a choice among several grain-based baits (rolled oats, wheat bran, oat bran, yeast, corn meal, cornflakes) and vegetable oils (canola, corn, peanut, soybean), eastern lubber grasshopper adults preferred bait consisting of wheat bran carrier with corn oil as an added phagostimulant. Other carriers were accepted but consumed less frequently. Discrimination by eastern lubber grasshoppers among oils was poor. Similarly, addition of flavorings (peppermint, anise, lemon, banana) resulted in few significant effects. The carbaryl, wheat bran, and oil bait developed in this study was effective at causing eastern lubber grasshopper mortality in field-cage studies. Significant mortality occurred even though grasshoppers had to locate dishes of bait in a large cage, and could feed on daylilies, or grass growing through the bottom of the cage, rather than on the bran flakes. Consumption of as little as a single carbaryl-treated bran flake could induce mortality, although individuals varied greatly in their susceptibility. The bait matrix developed in this study was readily consumed when in the presence of some plant species. We expect that wheat bran and corn oil bait would be most effective as protection for less preferred plants (tomato, pepper, eggplant, leek, parsley, fennel, daylily, lily of the Nile, and canna lily) because baits were readily consumed in the presence of these plants. Plants that are readily consumed in the presence of bait (preferred plants) included butter crunch lettuce, carrot, yellow squash, cauliflower, collards, green onion, chive, cucumber, cabbage, cantalope, endive, red leaf lettuce, society garlic, caladium, and amaryllis. Baits are likely to be less effective in the presence of such plants. On average, vegetables in Solanaceae (i.e., tomato, pepper, and eggplant) and Apiaceae (i.e., fennel and parsley) elicited high levels of bait-feeding activity, indicating that these vegetables were not highly preferred. The plants tested from Liliaceae, Cucurbitaceae, Asteraceae, and Brassicaceae elicited an intermediate-to-low level of bait feeding.