Test of the enemy release hypothesis: the native magpie moth prefers a native fireweed (Senecio pinnatifolius) to its introduced congener (S.Madagascariensis)

Abstract The enemy release hypothesis predicts that native herbivores will either prefer or cause more damage to native than introduced plant species. We tested this using preference and performance experiments in the laboratory and surveys of leaf damage caused by the magpie moth Nyctemera amica on a co-occuring native and introduced species of fireweed (Senecio) in eastern Australia. In the laboratory, ovipositing females and feeding larvae preferred the native S. pinnatifolius over the introduced S. madagascariensis. Larvae performed equally well on foliage of S. pinnatifolius and S. madagascariensis: pupal weights did not differ between insects reared on the two species, but growth rates were significantly faster on S. pinnatifolius. In the field, foliage damage was significantly greater on native S. pinnatifolius than introduced S. madagascariensis. These results support the enemy release hypothesis, and suggest that the failure of native consumers to switch to introduced species contributes to their invasive success. Both plant species experienced reduced, rather than increased, levels of herbivory when growing in mixed populations, as opposed to pure stands in the field; thus, there was no evidence that apparent competition occurred.

Gene transfer to plants by diverse species of bacteria

Agrobacterium is widely considered to be the only bacterial genus capable of transferring genes to plants. When suitably modified, Agrobacterium has become the most effective vector for gene transfer in plant biotechnology1. However, the complexity of the patent landscape2 has created both real and perceived obstacles to the effective use of this technology for agricultural improvements by many public and private organizations worldwide. Here we show that several species of bacteria outside the Agrobacterium genus can be modified to mediate gene transfer to a number of diverse plants. These plant-associated symbiotic bacteria were made competent for gene transfer by acquisition of both a disarmed Ti plasmid and a suitable binary vector. This alternative to Agrobacterium-mediated technology for crop improvement, in addition to affording a versatile ‘open source’ platform for plant biotechnology, may lead to new uses of natural bacteria– plant interactions to achieve plant transformation.

Is a mango just a mango? Testing within-fruit oviposition site choice and larval performance of a highly polyphagous fruit fly

For fruit flies, fully ripe fruit is preferred for adult oviposition and is superior for offspring performance over unripe or ripening fruit. Because not all parts of a single fruit ripen simultaneously, the opportunity exists for adult fruit flies to selectively choose riper parts of a fruit for oviposition and such selection, if it occurs, could positively influence offspring performance. Such fine scale host variation is rarely considered in fruit fly ecology, however, especially for polyphagous species which are, by definition, considered to be generalist host users. Here we study the adult oviposition preference/larval performance relationship of the Oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), a highly polyphagous pest species, at the “within-fruit” level to see if such a host use pattern occurs. We recorded the number of oviposition attempts that female flies made into three fruit portions (top, middle and bottom), and larval behavior and development within different fruit portions for ripening (color change) and fully-ripe mango, Mangifera indica L. (Anacardiaceae). Results indicate that female B. dorsalis do not oviposit uniformly across a mango fruit, but lay most often in the top (i.e., stalk end) of fruit and least in the bottom portion, regardless of ripening stage. There was no evidence of larval feeding site preference or performance (development time, pupal weight, percent pupation) being influenced by fruit portion, within or across the fruit ripening stages. There was, however, a very significant effect on adult emergence rate from pupae, with adult emergence rate from pupae from the bottom of ripening mango being approximately only 50% of the adult emergence rate from the top of ripening fruit, or from both the top and bottom of fully-ripe fruit. Differences in mechanical (firmness) and chemical (total soluble solids, titratable acidity, total non-structural carbohydrates) traits between different fruit portions were correlated with adult fruit utilisation. Our results support a positive adult preference/offspring performance relationship at within-fruit level for B. dorsalis. The fine level of host discrimination exhibited by B. dorsalis is at odds with the general perception that, as a polyphagous herbivore, the fly should show very little discrimination in its host use behavior.

Host Tree Influences on Longicorn Beetle (Coleoptera: Cerambycidae) Attack in Subtropical Corymbia (Myrtales: Myrtaceae)

Phoracantha longicorn beetles are endemic to Australia, and some species have become significant pests of eucalypts worldwide, yet little is known about their host plant interactions and factors influencing tree susceptibility in Australia. Here, we investigate the host relationships of Phoracantha solida (Blackburn, 1894) on four eucalypt taxa (one pure species and three hybrid families), examining feeding site physical characteristics including phloem thickness, density, and moisture content, and host tree factors such as diameter, height, growth, taper, and survival. We also determine the cardinal and vertical (within-tree) and horizontal (between-tree) spatial distribution of borers. Fewer than 10% of P. solida attacks were recorded from the pure species (Corymbia citriodora subsp. variegate (Hook)), and this taxon also showed the highest survival, phloem thickness, relative growth rate, and bark:wood area. For the two most susceptible taxa, borer severity was negatively correlated with moisture content, and positively related to phloem density. Borers were nonrandomly and nonuniformly distributed within trees, and were statistically aggregated in 32% of plots. More attacks were situated on the northern side of the tree than the other aspects, and most larvae fed within the lower 50 cm of the bole, with attack height positively correlated with severity. Trees with borers had more dead neighbors, and more bored neighbors, than trees without borers, while within plots, borer incidence and severity were positively correlated. Because the more susceptible taxa overlapped with less susceptible taxa for several physical tree factors, the role of primary and secondary chemistries in determining host suitability needs to be investigated. Nevertheless, taxon, moisture content, phloem density, tree size, and mortality of neighboring trees appeared the most important physical characteristics influencing host suitability for P. solida at this site.

Fungal community structure in disease suppressive soils assessed by 28S LSU gene sequencing

Natural biological suppression of soil-borne diseases is a function of the activity and composition of soil microbial communities. Soil microbe and phytopathogen interactions can occur prior to crop sowing and/or in the rhizosphere, subsequently influencing both plant growth and productivity. Research on suppressive microbial communities has concentrated on bacteria although fungi can also influence soil-borne disease. Fungi were analyzed in co-located soils 'suppressive' or 'non-suppressive' for disease caused by Rhizoctonia solani AG 8 at two sites in South Australia using 454 pyrosequencing targeting the fungal 28S LSU rRNA gene. DNA was extracted from a minimum of 125 g of soil per replicate to reduce the micro-scale community variability, and from soil samples taken at sowing and from the rhizosphere at 7 weeks to cover the peak Rhizoctonia infection period. A total of ∼994,000 reads were classified into 917 genera covering 54% of the RDP Fungal Classifier database, a high diversity for an alkaline, low organic matter soil. Statistical analyses and community ordinations revealed significant differences in fungal community composition between suppressive and non-suppressive soil and between soil type/location. The majority of differences associated with suppressive soils were attributed to less than 40 genera including a number of endophytic species with plant pathogen suppression potentials and mycoparasites such as Xylaria spp. Non-suppressive soils were dominated by Alternaria , Gibberella and Penicillum. Pyrosequencing generated a detailed description of fungal community structure and identified candidate taxa that may influence pathogen-plant interactions in stable disease suppression. © 2014 Penton et al.

Phylogenetics, taxon delimitation and phylogenetic diversity

Throughout the history of Linnean taxonomy, species have been described with varying degrees of justification. Many descriptions have been based on only a few ambiguous morphological characters. Moreover, species have been considered natural, well-defined units whereas higher taxa have been treated as disparate, non-existent creations. In the present thesis a few such cases were studied in detail. Often the species-level descriptions were based on only a few specimens and the variation previously thought to be interspecific was found to be intraspecific. In some cases morphological characters were sufficient to resolve the evolutionary relationships between the taxa, but generally more resolution was gained by the addition of molecular evidence. However, both morphological and molecular data were found to be deceptive in some cases. The DNA sequences of morphologically similar specimens were found to differ distinctly in some cases, whereas in other closely related species the morphology of specimens with identical DNA sequences differed substantially. This study counsels caution when evolutionary relationships are being studied utilizing only one source of evidence or a very limited number of characters (e.g. barcoding). Moreover, it emphasizes the importance of high quality data as well as the utilization of proper methods when making scientific inferences. Properly conducted analyses produce robust results that can be utilized in numerous interesting ways. The present thesis considered two such extensions of systematics. A novel hypothesis on the origin of bioluminescence in Elateriformia beetles is presented, tying it to the development of the clicking mechanism in the ancestors of these animals. An entirely different type of extension of systematics is the proposed high value of the white sand forests in maintaining the diversity of beetles in the Peruvian Amazon. White sand forests are under growing pressure from human activities that lead to deforestation. They were found to harbor an extremely diverse beetle fauna and many taxa were specialists living only in this unique habitat. In comparison to the predominant clay soil forests, considerably more elateroid beetles belonging to all studied taxonomic levels (species, genus, tribus, and subfamily) were collected in white sand forests. This evolutionary diversity is hypothesized to be due to a combination of factors: (1) the forest structure, which favors the fungus-plant interactions important for the elateroid beetles, (2) the old age of the forest type favoring survival of many evolutionary lineages and (3) the widespread distribution and fragmentation of the forests in the Miocene, favoring speciation.

Studies of fungi associated with Tomicus piniperda L. in Finland

The Scots pine bark beetle, Tomicus piniperda is a secondary colonizer of pine and other conifers. It is a native species from Europe and Asia that was recently introduced in North America. Although it is necessary to understand this insect's interactions with other organisms, few studies have focussed on its fungal associates. This study focused on the effect of latitude in the occurrence of fungi associated with T. piniperda. T. piniperda were collected from Pinus sylvestris in Northern (Rovaniemi) and Southern (Hyytiala) Finland. Both endo- and epi- mycota were isolated. The fungi were identified using a combination of morphological features and molecular data. The results revealed a great diversity of fungi species associated with T. piniperda, with a total of 3073 isolates representing 23 species. The most frequently isolated fungi in the bark beetles from Northern Finland were Beauvaria bassiana, Kuraishia sp. and Penicillium sp. whereas P. brevicompactum and Mortierella sp. were mostly observed in the South. Ophiostoma canum and O. minus were also observed. The number of isolates per insect in the north was 2.83 epi- and 2.38 for endo-mycota fungus. In the south, the number of isolates per insect was 4.1 for epi- and 3.5 for endo-mycota. Statistical analysis indicated that there was significant differences in fungal populations associated with the beetles in Southern and Northern Finland. There was however no significant difference between the epi- and endo-mycota fungal populations. The highest richness and diversity of the fungal species was observed in the South. However, the overall fungal diversity index analysis revealed that the mycobiota was undersampled.

Divvying up an incubator: How parasitic and mutualistic fig wasps use space within their nursery microcosm

Differential occupancy of space can lead to species coexistence. The fig-fig wasp pollination system hosts species-specific pollinating and parasitic wasps that develop within galls in a nursery comprising a closed inflorescence, the syconium. This microcosm affords excellent opportunities for investigating spatial partitioning since it harbours a closed community in which all wasp species are dependent on securing safe sites inside the syconium for their developing offspring while differing in life history, egg deposition strategies and oviposition times relative to nursery development. We determined ontogenetic changes in oviposition sites available to the seven-member fig wasp community of Ficus racemosa comprising pollinators, gallers and parasitoids. We used species distribution models (SDMs) for the first time at a microcosm scale to predict patterns of spatial occurrence of nursery occupants. SDMs gave high true-positive and low false-positive site occupancy rates for most occupants indicating species specificity in oviposition sites. The nursery microcosm itself changed with syconium development and sequential egg-laying by different wasp species. The number of sites occupied by offspring of the different wasp species was negatively related to the risk of syconium abortion by the plant host following oviposition. Since unpollinated syconia are usually aborted, parasitic wasps ovipositing into nurseries at the same time as the pollinator targeted many sites, suggesting response to lower risk of syconium abortion owing to reduced risk of pollination failure compared to those species ovipositing before pollination. Wasp life history and oviposition time relative to nursery development contributed to the co-existence of nursery occupants.

亚热带森林外生菌根真菌的生态学研究

菌根是一种植物营养根与土壤真菌形成的共生体，在自然界中分布广泛。外生菌根真菌是菌根真菌的重要类群，其宿主植物约占陆地植物总数的3%左右。由于外生菌根真菌的宿主植物常常是一些生态系统的优势种和建群种，并且这些真菌还参与了许多森林生态系统的有机和无机元素循环、物种的竞争和共存、生物多样性的维持、生态系统的演替等过程，因而对外生菌根真菌的研究有助于对这些生态系统维持和演替机制的深入理解。本文通过外生菌根真菌的种类鉴定和多样性，外生菌根真菌种群的遗传结构，外生菌根真菌群落的结构、空间格局及植物-菌根真菌空间关系，外生菌根真菌接种对植物生长和竞争的影响等四个方面的研究，使我们对这一地区的外生菌根真菌的种类组成、空间分布和传播规律、年度变化、以及对植物群落组成和多样性的影响等方面，有一个初步了解。 外生菌根真菌的鉴定和种类组成是进行菌根真菌研究的前提之一。在第一章中，主要通过子实体形态分类和分子方法，对大型真菌的种类进行了鉴定。在对东灵山和都江堰森林的调查中分别发现的大型真菌106种和98种，菌根真菌比例分别为44.3%和69.4%，木生真菌比例分别为16%和10.2%。按Fellner的评价标准，两个森林群落均属于健康的生态系统。我们应用ITS-RFLP和ITS序列比较的方法对地上子实体、地下菌根及分离培养的菌种进行了种类鉴定和分析。结果表明，ITS-RFLP可以用来进行外生菌根真菌的种类鉴定，而序列分析能够提供更为可靠的信息。二者的结合，可以使我们建立菌根真菌分子数据库成为可能。 种群遗传结构的研究包括种群中个体的空间分布和亲缘关系等方面，有助于加深我们对种群的生殖和传播方式，菌根真菌与风、雨、动物等生态因子的关系等方面的理解。第二章主要以两个外生菌根真菌种群为例，对种群遗传结构中空间距离与遗传相似性的关系、种群结构的年度变化等方面进行了探讨。正红菇（Russula vinosa）种群具有较高的遗传多样性，每个子实体来自不同的克隆。空间距离-遗传相似性关系和空间格局分析的结果均表明，这一正红菇的种群结构可能是由短距离孢子传播产生的，而不可能是无性生长或长距离孢子传播形成的。在对隐花青鹅膏菌（Amanita manginiana）连续两年的种群结构进行了研究中，种群的每一个子实体也均来自不同的克隆。遗传相似性分析、AMOVA、遗传相似性-空间距离关系的结果均显示，这两年的种群在遗传相似性和种群结构上均具有显著差异。对此的一个合理的解释就是，这一外生菌根真菌种群来说，其个体由有性孢子发育为子实体的时间可能超过一年，因而2001和2002年的个体并非同一种群的连续世代。 外生菌根真菌群落可以定义为在一定地理范围和时间尺度内不同外生菌根真菌种群的组合。对外生菌根真菌群落的研究有助于揭示森林生态系统中菌根真菌与植物、菌根真菌与环境因子、以及菌根真菌之间的相互关系。在第三章中，我们应用点格局的分析方法和二元逻辑回归分析对外生菌根真菌的主要类群，即鹅膏菌科，牛肝菌科和红菇科，的空间格局及其与周围（5×5米样方）树种组成的关系进行研究。结果表明，某些树种与特定类群菌根真菌的子实体出现有负相关，而三个类群的外生菌根真菌在克隆生长上的差异并不是子实体空间分布的决定因素。而在较小尺度上（450平方米样方）研究也表明，三个主要外生菌根真菌类群的空间分布为聚集半径不等的集群分布，并且其空间分布不依赖于木本植物的分布。外生菌根真菌主要类群在空间分布上具有相互抑制的特点，而抑制能力的大小可能与菌根真菌地下菌丝体的分布范围及连续性有关。 外生菌根真菌的盆栽接种实验通常用来验证菌根真菌-宿主植物的相互关系，不但有理论意义，也是大田实验和大规模生产应用的基础。第四章中进行了两个实验，对外生菌根真菌多样性与宿主植物生长的关系以及菌根真菌与植物之间竞争平衡的关系进行了初步研究。在外生菌根真菌多样性对马尾松生长影响实验中，菌根真菌接种并未显著促进马尾松幼苗的生长和生物量积累，不同的菌种与地上、地下生物量的积累存在不同（正或负）的相关关系。外生菌根真菌的多样性水平与马尾松幼苗的针叶数量存在显著的正相关，并且随接种时间的延长相关关系更为显著。外生菌根真菌多样性水平还与马尾松幼苗地下生物量的累积呈显著的正相关关系。在外生菌根真菌对三种植物的竞争平衡和共存的影响实验中，外生菌根真菌接种没有显著促进马尾松幼苗的生长，但对漆树和枹栎幼苗的生长有显著影响。外生菌根真菌接种能够在两个外生菌根真菌宿主植物竞争中降低枹栎对马尾松的优势，在马尾松和漆树的竞争中降低马尾松的优势，并促使枹栎与漆树（一个外生菌根真菌宿主和一个非宿主植物）的竞争处于不稳定状态。 本文首次通过生态学的角度对外生菌根真菌的物种多样性、种群结构、群落中的空间格局、以及外生菌根真菌与植物生长的关系进行了较为全面的研究。在大型真菌的多样性方面，菌根和木生真菌比例的引入可以完善森林生态系统的健康评价体系，而分子数据库的建立使对大型真菌尤其是外生菌根真菌多样性的长期监测成为可能;在种群遗传结构方面，本文验证了红菇属和鹅膏菌属克隆较小的特点，以及红菇属菌根真菌以短距离孢子传播为主的繁殖特性，并首次从生活史特点的角度解释菌根真菌的种群结构的年度差异;在菌根真菌群落的空间格局方面，本文首次应用二元逻辑回归和点格局分析的方法研究外生菌根真菌的空间分布及菌根真菌－植物关系，并发现三个类群的外生菌根真菌在子实体分布上具有相互排斥的特点;在控制实验中，本文首次研究了菌根真菌接种的多样性水平对宿主植物的影响，首次研究了外生菌根真菌接种对三个物种之间竞争与共存的影响。虽然这些研究在很多方面都仅得到初步的结果，但我们希望这些探索可以为今后对外生菌根真菌的生态学研究提供有益的启示。

Experimental warming causes large and rapid species loss, dampened by simulated grazing, on the Tibetan Plateau

We investigated the independent and combined effects of experimental warming and grazing on plant species diversity on the north-eastern Tibetan Plateau, a region highly vulnerable to ongoing climate and land use changes. Experimental warming caused a 26-36% decrease in species richness, a response that was generally dampened by experimental grazing. Higher species losses occurred at the drier sites where N was less available. Moreover, we observed an indirect effect of climate change on species richness as mediated by plant-plant interactions. Heat stress and warming-induced litter accumulation are potential explanations for the species' responses to experimental warming. This is the first reported experimental evidence that climate warming could cause dramatic declines in plant species diversity in high elevation ecosystems over short time frames and supports model predictions of species losses with anthropogenic climate change.

Review of the genus Bursaphelenchus Fuchs, 1937 (Nematoda, Aphelenchida) with some conclusions on the host-parasite and vector-parasite evolution.

INTRODUCTION AND GOALS: Genus Bursaphelenchus includes several pests of the world importance for the rural economy, the most dangerous are the Bursaphelenchus xylophilus (the pinewood nematode caused decline of the pine trees in south Asia and in one spot area in Europe, Portugal, Peninsula de Setubal) and the Bursaphelenchus cocophilus, causing the decline of coco-palm plantations in Carribean and Latin American regions. The peculiarity of the host-parasite association of the genus that the nematode life cycle includes three trophic components: plant (mostly a tree), insect vector and a fungus. Goals of the presentation is to list all species of the world fauna and all efficient diagnostic characters, then create the identification tool and analyze the similarity of species and possible ways and causes of the host-parasite evolution of the group. RESULTS: Complete list of species with synonymy and a catalogue of all efficient diagnostic characters with their states, selected from papers of the most experienced taxonomists of the genus, are given for the genus Bursaphelenchus. List of known records of Bursaphelenchus species with names of natural vectors and plants and their families is given (for world pests the most important groups of trees and insects are listed). The tabular, traditional and computer-aided keys are presented. Dendrograms of species relationships (UPGMA, standard distance: mean character difference) based on all efficient taxonomic characters and separately on the spicule characters only, are given. Discussion whether the species groups are natural or purely diagnostic ones is based on the relationships dendrograms and the vector and associated plant ranges of Bursaphelenchus species; the xylophilus species group (B. xylophilus, B. abruptus, B. baujardi, B. conicaudatus, B. eroshenkii, B. fraudulentus, B. kolymensis, B. luxuriosae; B. mucronatus), the hunti group (B. hunti, B. seani, B. kevini and B. fungivorus) are probably the natural ones. CONCLUSIONS: The parasitic nematode association includes three trophic components: plant, insect vector and fungus. The initial insect-plant complex Scolytidae-Pinaceae is changeable and only in rare occasions the change of the preferred vector to Cerambycidae (the xylophilus group), Hymenoptera (the hunti group) led to formation of the natural species-groups. From the analysis it is clear that although the vector range is changeable it is comparatively more important for the evolution of the genus Bursaphelenchus than associations with plants at the family level. Data on the fungi species (3rd component in natural Bursaphelenchus associations) are insufficient for the detailed comparative analysis.

Changes of a mutualistic network over time: reanalysis over a 10-year period

We analyzed the structure of a multispecific network or interacting ants and plants bearing extrafloral nectaries recorded in 1990 and again in 2000 in La Mancha, Veracruz, Mexico. We assessed the replicability of the number of interactions found among species and also whether there had been changes in the network structure associated with appearance of new ant and plant species during. that 10-year period. Our results show that the nested topology of the network was similar between sampling dates, group dissimilarity increased, mean number of interactions for ant species increased, the frequency distribution of standardized degrees reached higher values for plant species, more ant species and fewer plant species constituted the core of the more recent network, and the presence of new ant and plant species increased while their contribution to nestedness remained the same. Generalist species (i.e., those with the most links or interactions) appeared to maintain the stability of the network because the new species incorporated into the communities were linked to this core of generalists. Camponotus planatus was the most extreme generalist ant species (the one with the most links) in both networks, followed by four other ant species; but other species changed either their position along the continuum of generalists relative to specialists or their presence or absence within the network. Even though new species moved into the area during the decade between the surveys, the overall network structure remained unmodified.

Ecologia alimentar de aves insetívoras de um fragmento de mata decídua do extremo norte da Mata Atlântica

The diet study of birds has contributed historically as a model for use to understanding ecological patterns and strategies used by several other groups of vertebrates, which are observed in season patterns and temporal availability of resources, and other. This study has as objective generate information concerning the diet of insectivorous birds during rainy season and dry season, as well as analyze Index food importance, niche overlap, niche breadth, electivity, and seasonal availability of prey. The study was conducted in a fragment of about 270 ha (center coordinates and 5 º 53'S 35 ° 23'W). The sampling of birds occurred between March 2008 and December 2009 in three pre-established trails. Catches of birds were performed using 10 mist nets placed in line, where each trails was sampled once a month. Samples of pellets were obtained by means of tartar emetic. Sampling of availability of prey occurred between February 2009 to December 2009. We used two methods of sampling (pitfall traps and Shake cloths). We captured 269 individuals of 21 species of insectivorous birds. We collected 4116 invertebrates of which 3259 in the rainy season and 857 in the dry season. We obtained 174 samples stomach, where 10 species were exclusively insectivorous diet, nine fed on insect/plant material, an insect/plant material/vertebrate and one for insect/vertebrate. During the rainy season was observing difference between the consumption of items with higher food importance. The Coleoptera was item with higher food importance (73%), followed by Formicidae (7%) and Araneae (6%). During the dry season, no difference was found difference between the consumption of items with higher food importance. The Coleoptera was item with higher food importance (34%), followed by seeds (29%) and Formicidae (18%). The highest levels of niche overlap occurred during the rainy season, while the dry season was characterized by high levels of niche 11 segregation. This indicates that the local insectivorous birds community was structured differently between periods. No was found correlation between the values of niche breadth to the mean weight of the body size. We observed seasonal patterns in prey availability, with the peak availability of invertebrates observed seasonal patterns in rainy season. The insectivorous birds selected the same species richness during both periods, showing a specialized diet. Thamnophilus pelzelni was the only species that had their diet influenced by seasonality. Regarding the overall diet of insectivorous birds, observed a high consumption of prey, whose food availability caused the birds could invest and increase their food resources

Sugarcane response to two biotic stressors: Diatraea saccharalis and Mahanarva fimbriolata

In a field experiment in 2007/08 in São Paulo state, Brazil cane was exposed to sugarcane borer (Diatraea saccharalis) and spittlebug (Mahanarva fimbriolata) alone or in combination. Plots comprised 2 m(2) caged and uncaged sugarcane stalks. Compared with the caged (un-infested) control, spittlebug nymphs decreased cane yield by 17.6%, whereas infestation from spittlebug nymphs + sugarcane borer combined and sugarcane borer alone, decreased cane yields by 15.5% and 6.9%, respectively. There was no significant difference among the treatments in levels of soluble solids and cane sucrose content.