Termite Foraging on Plants of a Brazilian Savanna: the Effects of Tree Height

Termites play an important role as ecosystem engineers in many tropical environments, acting as herbivore-detritivore organisms and strongly influencing vegetation structure and composition by modifying soil properties, providing nutrients by recycling the organic matter, and direct feeding on plants, notably in the Cerrado (Savanna) of Brazil. To evaluate the intensity of termite foraging on Cerrado plants, we recorded plants higher than 25 cm, which exhibited termite activity along nine transects (2 x 50m), at the Estação Ecológica de Pirapitinga (EEP), in the State of Minas Gerais, Brazil. We recorded the height, basal area, and identified the species of each plant. Simultaneously, we used cellulose baits disposed at each 10 m along six transects of 100 m to sample termites in this area, which was protected from fire for at least 40 years. Twelve species of termites were recorded. Termite foraging on Cerrado plant species varied considerably and it was influenced by several factors including plant height and host species. Taller plants presented more termites than smaller plants, probably due to the amount of available resources (for nesting and feeding) for the termites

Morfofisiologia das castas e forrageamento do cupim de cerrado Velocitermes heteropterus (Isoptera: Termitidae)

Os cupins são insetos eussociais que apresentam divisão em castas entre os componentes das colônias. As castas apresentam adaptações morfofisiológicas para o melhor desempenho de determinadas funções e atividades comportamentais. A presente pesquisa objetivou analisar, do ponto morfológico, fisiológico e comportamental, as castas ápteras do cupim Velocitermes heteropterus que participam ativamente do forrageamento. No capítulo 1 deste volume é apresentado o estudo do polimorfismo da casta operária de V. heteropterus com duas subcastas, operários pequenos e grandes, baseado em caracteres morfométricos. Além disso, no capítulo 1 a rede de túneis escavadas por estes insetos foi caracterizada e as redes formadas por operários pequenos comparadas àquelas formadas por operários grandes e por grupos mistos dos dois tipos de operários. No capítulo 2 são apresentados os dados morfométricos dos outros componentes da linhagem áptera, ou seja, larvas e soldados, e também constam os dados de expressão gênica das celulases, os quais foram quantificados para ambos operários (pequenos e grandes) e soldados. Adicionalmente, no capítulo 2 é apresentado o sistema de desenvolvimento pós-embrionário da linhagem áptera de V. heteropterus. No capítulo 3 são apresentados dados sobre a dinâmica das trilhas de forrageamento de V. heteropterus. O fluxo de cupins saindo do ninho e retornando do alimento, a velocidade média individual e o número de colisões, bem como a distribuição espacial dos indivíduos nas trilhas, foram analisados durante as três primeiras horas desde o início do processo de forrageamento. A linhagem áptera de V. heteropterus apresenta um polimorfismo que está intimamente vinculado ao sexo e aos ínstares dos indivíduos. O polimorfismo dos componentes desta linhagem está relacionado...Termites are eusocial insects that exhibit a division in castes among the members of the colonies. The current research had the aim to analyze, on the morphological, physiological and behavioral points of view, the apterous castes of the termite Velocitermes heteropterus that actively participate in foraging. The castes show morpho-physiological adaptations to develop certain functions and behavioral activities. In the chapter 1 of this volume it is presented the study of the polymorphism in the worker caste of V. heteropterus with two subcastes, major and minor workers, based on morphometric characters. In addition, in the chapter 1, the tunnel network excavated by these insects is characterized and the networks excavated by minor workers are compared to those excavated by major workers and mixed groups containing the two types of workers. In the chapter 2, the morphometric data on the other apterous individuals are presented, i. e., larvae and soldiers, and it is shown the cellulase gene expression, which were quantified for both workers (minors and majors) and soldiers. Additionally, in the chapter 2, the post-embryonic developmental system of the apterous line in V. heteropterus is presented. In the chapter 3, it is exhibit data on foraging trail dynamics of V. heteropterus. The flow of termites leaving the nest and returning from the food, the individual speed and the number of collisions, as well as the spatial distribution of the individuals in the trails, were analyzed for the first three hours from the beginning of the foraging process. The apterous line exhibit a polymorphism intimately related to the sex and instars of the individuals. The polymorphism of the members of this line is related to a differential contribution of the subcastes in tunneling and foraging processes, but does not seem to influence the... (Complete abstract click electronic access below)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Record of mimetism between mites and eggs of the neotropical termite Cornitermes cumulans (Isoptera : Termitidae)

Cornitermes cumulans (Isoptera: Termitidae) is a mound-building termite nests provide suitable conditions for the development of associated organ isms. The present stud), describes the occurrence of them ire Caloglyphus sp. (Astigmata: Acaridae) associated with this termite species in laboratory colonies. Mite adults were found among the egg batch of C cumulans and they showed the same shape and color of the termite eggs. This mimicry may represent an adaptation of this organism for survival in termite colonies, and egg-mimicking mites have not yet been recorded in any termite colony. Further studies will help to clarify the ecological aspects of this relationship.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Labral gland in soldiers of the neotropical termite Cornitermes cumulans (Isoptera: Termitidae: Syntermitinae)

Cornitermes cumulans is a termite species of the subfamily Syntermitinae with a nasute mandibulate soldier caste, members of which are morphologically equipped with structures and organs specialized for the defence of the colony. We investigated the labrum of soldiers of C cumulans and described the labral gland, an exocrine structure present in this appendage. The labrum of C. cumulans soldiers presented two distinct regions, the hyaline tip and the proximal region connected to the head. The hyaline tip exhibited a thick cuticle composed of a loose endocuticle involving an epithelium of class 1 cells, which synthesize the glandular product into a subcuticular space that function as a reservoir prior to release the final secretion. The proximal region of the labrum had an epithelium composed of class 1 and class 3 cells, which released the secretion onto both ventral and dorsal surfaces. The ultrastructure showed abundant smooth endoplasmic reticulum and glycogen in the class 1 cells, whereas the class 3 cells had many electron-lucent vesicles that varied in size. We associated the labral gland with the production of toxic substances that may act inside enemy wounds made by the soldiers' mandibles. Other possible functions for the labral secretion are also discussed. (C) 2014 Elsevier Ltd. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

MRT Letter: A Novel Tegumental Gland in Female Imagoes of the Neotropical Termite Cornitermes cumulans (Isoptera, Termitidae, Syntermitinae)

In general, the exocrine glands of social insects are structures involved in the chemical communication associated with social life. Here, we report the discovery of an unknown tegumental gland that is present in the female imagoes of Cornitermes cumulans and occurs next to the well-developed tergal glands that have previously been described. The tegumental glands release their secretion in the intersegmental membrane and are composed of bicellular units, a secretory cell and a canal cell, that are closely located to the epidermal cells in the inferior part of the eighth and ninth tergites. The ultrastructure of the glandular cells showed abundant smooth endoplasmic reticulum, suggesting that the secretion may be pheromonal, although its function is still unknown. These exocrine structures are facing the tergal glands, and we hypothesized that they act synergistically with the tergal glands to generate short-range attraction during tandem behavior. Microsc. Res. Tech. 73: 1005-1008, 2010. (C) 2010 Wiley-Liss, Inc

A Glycoproteinaceous Secretion in the Seminal Vesicles of the Termite Coptotermes gestroi (Isoptera: Rhinotermitidae)

Coptotermes gestroi is a subterranean termite with colonies generally headed by a pair of primary reproductives, although neotenics may occur. In this study, the male reproductive system was compared during different life stages of nymphs, alates, neotenic reproductives, and kings of C. gestroi, focusing on the modifications of this system along the maturation of these individuals. The structure of the male reproductive system follows the pattern described for insects, although C. gestroi males do not exhibit conspicuous penises and differentiated accessory glands. In kings, each testis consisted of about seven lobes, significantly increased in size as compared to younger males. The spermatogenesis begins in third-instar nymphs, which already presented spermatozoa in the testes. The seminal vesicles are individualized in C. gestroi and have a secretory distal portion and a proximal portion with a role in spermatozoa storage. The secretion of the seminal vesicles is strongly periodic acid Schiff (PAS)-positive, whereas the xylidine Ponceau test revealed proteins that increase in quantity while the males become older. This is the first record of glycoproteins in the lumen of seminal vesicles in termites. Further studies will clarify how they are produced and interact in the physiology and nutrition of the non-flagellate spermatozoa of C. gestroi

Tergal glands in termite soldiers of the subfamily Syntermitinae (Isoptera: Termitidae)

The subfamily Syntermitinae comprises 14 genera of termites that are exclusively neotropical. The present study reports morphological data about mandibulate nasute soldiers from termite species belonging to three different genera within this subfamily. We describe tergal glands that were present under all tergites of soldiers of the following species: Cornitermes cumulans, Procornitermes araujoi, Syntermes nanus, and Syntermes wheeleri. The tergal glands were composed of class 2 and class 3 cells. Class 2 cells never reached the cuticle and were located below a flat layer of epidermal cells. Class 3 cells, composed of secretory cells and canal cells, were sporadic, whereas class 2 secretory cells were abundant. Secretory cells of class 3 were narrow and their cytoplasms were filled with several clear, oval-shaped vesicles with limiting membranes. The ultrastructure of class 2 cells showed well-developed smooth endoplasmic reticulum, Golgi apparatus, elongated mitochondria, several electron-lucent vesicles, and electron-dense granules that contain paracrystalline structures in S. nanus. Scanning electron micrographs displayed pores, campaniform sensilla and hairs in the outer cuticle of the soldier tergites. We hypothesize that soldier tergal glands may be involved in the production of defensive compounds, which occur in similar glands of certain cockroaches, or of primer pheromones, that might act in the regulation of soldier differentiation in the termite colony. To date, tergal glands have only been described in termite imagoes, and their occurrence in these soldiers of basal Syntermitinae implies a specific role in this caste that is still speculative and needs to be clarified. (C) 2011 Elsevier Ltd. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

The size of excavators within a polymorphic termite species governs tunnel topology

International audienc

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

Nutrients affecting food choice by the pest subterranean termite Coptotermes gestroi (Isoptera: Rhinotermitidae)

Coptotermes gestroi is a subterranean termite from Asia, introduced accidentally to Brazil, where it is responsible for substantial damage in urban areas. The foraging range of this species frequently overlap with that of Heterotermes tenuis, a native termite also considered to be a severe pest. The greatest challenge in controlling these termites is to develop baits suitable for both species. A critical issue is to select compounds that act as common phagostimulants. We examined whether the feeding preferences of C. gestroi for some nutrients were similar to those already reported for H. tenuis. A double choice design was used. Consumption was evaluated by change in the dry mass of paper discs after termite feeding. C. gestroi fed preferentially on discs treated with a solution of sucrose+yeast. However, insects did not choose urea at 0.015g/ml, one of the preferred solutions for H. tenuis. These results indicate that the two termites have different feeding preferences, and we suggest future use of sucrose+yeast in baits for management of C. gestroi.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq