Termite Damage Research Articles

Evaluation of chemical control measures for termites in maize

Field trails were conducted from the 1994/95 to 2000/2001 growing seasons to evaluate various insecticides for preventative and corrective control of the fungus-growing termites, Microtermes sp., Odontotermes sp. and Allodontermes sp. in maize. The incidence of lodged maize plants was used as criteria for insecticide efficacy. Carbofuran GR, imidacloprid WS, chlorpyrifos GR and fiponil GR were evaluated as preventative treatments. Corrective treatments in the form of spray applications of the systemic insecticides carbosulfan EC, benfuracarb EC and imidacloprid SL were also evaluated. Treatments were applied to the basal 25 cm of maize stems and to the soil surface surrounding plants. Imidacloprid spray applications generally provided good control of termites. The optimum plant growth stage for imidacloprid application was during the pre-flowering stage, 6 to 10 weeks after plant emergence. Pre-flowering applications were usually more effective in limiting damage than post-flowering applications. The granular insecticide, fipronil, showed promise for termite control. Chlorpyrifos granules, applied as a side dressing four weeks after plant emergence, significantly reduced lodging. Two novel control methods (fishmeal and diesel fuel) on the soil surface resulted in suppression of termite damage and subsequent reduction in lodging of plants. In the majority of trials total yields (lodged and upright plants) did not differ over insecticide treatments. However, the proportion of the total yield that had to be hand-harvested from lodged plants ranged from 0 to 41%, and was significantly higher in ineffective treatments. This resulted in increased production costs and uneconomic maize production.

Effects of maize–legume intercrops on termite damage to maize, activity of predatory ants and maize yields in Uganda

Field experiments during two cropping seasons at Namulonge Agricultural Research Institute, Uganda assessed the effect of intercropping maize with soyabean, groundnut and common beans on termite damage to maize, activity of common predatory ants and maize yields. Intercropping caused a significant ( P<0.01) reduction in termite attack, reduced loss in grain yield of maize and increased the nesting of predatory ants in maize fields. In many instances, termite attack was significantly lower ( P=0.05) in the maize–soyabean intercrop than in maize intercrops with groundnuts and beans. Species of the genera Myrmicaria and Lepisiota were the dominant ant predators recorded. The study revealed that soyabean and groundnut are more effective in suppressing termite attack than common beans, suggesting the necessity to identify suitable legumes for each cropping situation. Overall, intercropping might form a component of an integrated management strategy for termites in smallholder cropping systems in East Africa.

Effect of Placement Method and Rate of Application of Crushed Fish Bones on the Activity of Predatory Ants and Impact on Termite Damage to Maize

Field experiments were conducted to investigate the attractiveness of fish bones to predatory ants in a maize agroecosystem. The fish bones were applied crushed in shallow furrows together with dry maize stalks, or broadcast on the soil surface at 3 application rates: 0, 40 and 80 kg/ha; subsequent reduction in termite attack on maize plants was then assessed. Burying the fish bone powder caused higher ant nesting (102–78 %) than surface broadcasting (122–39 %). Attractiveness of the fish bones and the predatory efficiency of the ants against termites in maize was also highest with a dose of 80 kg/ha (1.0 kg/plot) causing higher nesting of ants (>90 %) and 54 % lower termite damage to maize plants compared to control plots. Dose responses indicated significant relationships between amount of fish bone powder applied and termite activity and also between termite damage and maize yield. The mechanism by which the ants are able to protect maize against termite damage may be twofold: direct kill as a result of their predatory action and termite avoidance of maize plants with ant nests. Further studies are required to assess the potential benefits of an integrated use of this technique with other non-chemical options for termite control in maize, such as intercropping.

Bioefficacy of imidacloprid against termites in sugarcane

Imidacloprid 70 WS and imidacloprid 200 SL were evaluated for their efficacy against termites in sugarcane as sett dip and spray over setts in furrows in two field experiments. Sett dip of imidacloprid 70 WS at 0.1 and 0.15 per cent and spray over setts of imidacloprid 200 SL at 250 and 375 ml/ha-1 resulted in increased germination of setts. These treatments protected the crop from termite damage and were equal to chlorpyriphos 20 EC at 5 lit./ha/t-1 in the efficacy. They also resulted in increased cane yield. There was no effect on the quality of juice and the residue was at below detectable limit in juice at harvest in these treatments.

Farmers' opinions and influence of cultural practices on soil pest damage to groundnut in West Africa

Farmers in the groundnut belts of Mali, Burkina Faso, Niger, Nigeria and Benin in West Africa were interviewed for their ability to identify economically importanct soil pests infesting their groundnut (Arachis hypogaea L.) crops, and to obtain information on farm histories and cultural practices which may influence soil pest infestation and spread in a field. Termites, whitegrubs and millipedes were recognised by the farmers as being the most important soil pests, with termites being the most damaging group. A negative correlation (P < 0.05) was found between the number of years a farm was cultivated and the frequency of termite occurrence in it. Information on cultural practices obtained from interviews and field visits indicated that practices such as late harvesting and the leaving behind of residues of previous sorghum, millet and maize crops increased termite infestation. The cutting down and burning of the vegetation in a farm before planting significantly (P < 0.05) reduced the percentage of plants attacked by termites. The cultivation of short-duration (< 100 days) varieties to escape drought at the end of the cropping season did not significantly reduce termite damage, due to late harvest. Other farmers' practices which are likely to have contributed to soil pest damage are also discussed.

The potential of protein- and sugar-based baits to enhance predatory ant activity and reduce termite damage to maize in Uganda

Traditional farmers’ practices of using dead animals, meat bones and sugar cane husks to “poison” Macrotermes mounds were adapted to develop baits for ant species predatory on termites. The impact of sugar and protein-based baits on activity of ants in maize fields was evaluated in trials both on-station and in farmers’ fields over three cropping seasons. Powdered fish, broadcast or buried with maize stalks, was compared with molasses painted onto the stems of maize plants and bagasse spread as mulch. Ants were rapidly attracted into plots of maize and fed upon the baits. The protein-based baits attracted significantly larger number of ants compared to molasses and bagasse and resulted in greater ant nesting near maize plants. In both on-station and on-farm experiments, termite damage was significantly reduced and yield of maize increased in plots with protein-based baits. These results suggest that ants could be used in an integrated management strategy for termites in smallholder maize cropping systems.

The effect of maize stover used as mulch on termite damage to maize and activity of predatory ants

We investigated the effect of different quantities of stover applied as mulch on damage to maize plants by termites (principally species of Microtermes, Macrotermes and Pseudacanthotermes) and on the incidence of predatory ant species (Lepisiota sp. and Myrmicaria sp.) over two cropping seasons at Namulonge, Uganda. Termite damage to maize plants was significantly (P

Descripción de la biología, daño y control de las termitas: especies existentes en Chile

Termites are one of the main insects responsible for damaging wood. Although they are considered very destructive, they have an important role in nature in breaking down organic matter. In this study, the main characteristics of termites, such as morphological and biological aspects, are described. A classification of termite damage is carried out according to the humidity content of the wood. The termites present in Chile belong to the families Kalotermitidae, Termopsidae and Rhinotermitidae. Different strategies of control, preventives and curatives are commented on in relation with the current pest problems.

Termite Damage Assessment in a five year old Date palm Plantation in Dutse, Jigawa state, Nigeria

The termites, Odontotermes sp.nr. pauperans and O. smeathmani (Fuller) were found destroying young date palm trees during this study. Messor galla (Mayr.) (Hymenoptera) was often found in association with these termites. A total annual damage of 36.1 % of the palms out of which 19.8 % were damaged beyond survival, was recorded at Dutse date palm Sub – station in 1986. Rainfall and relative humidity were negatively correlated with severity of damage ( r = 0.902 and – 0.887). These correlations were significant at 5 % level. The partial correlation values obtained when rainfall, relative humidity and temperature were variously correlated with grades of damage, indicated that termite damage was more severe with increase in mean monthly temperature. Destruction of termitaria and removal of queens and treatment with insecticides are suggested to reduce incidence of termite damage in date palm plantings.

Prospects for the biological control of subterranean termites (Isoptera: Rhinotermitidae), with special reference to Coptotermes formosanus

Costs associated with subterranean termite damage and control are estimated to approach $2 billion annually in the United States alone. The Formosan subterranean termite, Coptotermes formosanus Shiraki, is one of the more economically important subterranean species. In recent years, the shortcomings associated with conventional chemical control methods have prompted policymakers and scientists to evaluate the potential for biological control of subterranean termites (C. formosanus in particular), that is, to determine the potential for natural enemies - predators, parasitoids and pathogens - to suppress termite populations. Ants are the greatest predators of termites, and may have a considerable local impact on termite populations in some areas of the world. A few parasitoids of termites are known, but their potential for regulating termite populations seems negligible. Characteristics of the colony, such as a protected, underground location (and, for the C. formosanus nest, its modular and dispersed nature), are likely to limit the impact predators and parasitoids have on subterranean termites. Thus, there seems little potential for use of these agents for subterranean termite control. For various reasons, pathogenic organisms, such as viruses, bacteria, Protozoa, nematodes and most fungi, have shown little promise for use in biological termite control. However, research suggests that strains of two well-studied, endoparasitic fungi, Beauveria bassiana and Metarhizium anisopliae, when employed in baiting schemes, may offer the potential for at least some measure of subterranean termite control, although their successful use is compromised by a number of inherent biological limitations and logistical problems that have yet to be solved. Although not strictly in the realm of classical biological control, recent studies suggest that natural products, such as ant semiochemicals and fungal metabolites (siderophores), or their synthetic analogues, eventually might find a use in termite control programmes as repellents or insecticides in wood treatments or soil applications if stable formulations can be developed.

Aspergillus Species Colonization of Termite-Damaged Peanuts in Parts of West Africa and Its Control Prospects

Abstract A survey of farmers' peanut fields in Benin showed that Aspergillus flavus Link ex Fries infection was influenced by Microtermes (Isoptera: Termitidae) damage. Field trials conducted at the ICRISAT station and a farmer's plot in Mali on termite damage and Aspergillus spp. infection showed that peanut plots treated with carbofuran at planting and supplemented with chlorpyrifos at 40 days after planting (dap), or treated with only chlorpyrifos at 40 dap, significantly reduced pod damage by the termite M. lepidus Sjöstedt. and colonization by A. flavus. The cultivar ICG 10946 which had significantly more A. flavus (P &amp;lt; 0.05) also had a higher percentage of damaged pods compared with the other cultivars at the on-station trials. The least infected cultivar in all the trials was 47–16 which also had a comparatively lower percentage of termite-damaged pods, although this was not significant. However, termite damage was correlated with A. flavus percentage colonization.

Effects of termite damage to maize of seed extracts of Azadirachta indica and Piper guineense in farmers' fields

The efficacy of insecticides derived from two local plants was tested on termites infesting maize in maize–cassava–‘Egusi’ melon intercrops in two farmers' fields in south-western Nigeria during the 1989/90 and 1990/91 cropping seasons. The intercrops consisted of 40000, 20000, and 10000 maize plants/ha, with a fixed population of 10000 plants/ha of both cassava and melon. The insecticides were aqueous extracts of ripe seeds of neem (Azadirachta indica A. Juss) and the crude seed oil of Piper guineense Schum And Thonn, each at 10% concentration at the rate of 390 litres/ha and 18 litres/ha, respectively. On the plots treated with these natural insecticides, damage by termites [Microtermes spp., Macrotermes bellicosus Smeathman = nigeriensis Sjostedt and M. subhyalinus Rambur (Isoptera: Termitidae)] was significantly lower and maize yields higher than on the control plots. The mean percentage of maize stems attacked by termites (considering all categories of termite damage) in untreated plots during the trials ranged between 0–22% in 1989 and 2–46% in 1990. Planting densities did not significantly influence termite attack on maize. Cassava and melon plants or cassava tubers were not attacked by termites in any of the trials and their yields were not affected by insecticide treatments or planting density of maize.

Boron addition to non- or low-formaldehyde cross-linking reagents to enhance biological resistance and dimensional stability of wood

and Coriolus versicolor, which are the representative test fungi of brown- and white-rot in Japanese Industrial Standard (JIS) A-9201-1991, respectively. PBA had somewhat less contribution to decay resistance of GX most possibly due to chemical complexation. GA proved superior in decay resistance to the other two reagents. Mass loss due to the Formosan termite Coptotermes formosanus attack could be reduced to a minimum with total inactivation of termites by PBA addition. BA retention did not suffice to impart complete termite resistance after ten cycles of severe weathering of the specimens. Thus, BA was found appropriate to be added to the used cross-linking agents in such service conditions where decay risk is high while PBA combinations should be preferred if termite damage prevailes.

Termite distribution and damage to crops on smallholder farms in southern Malawi

Termite damage to annual crops on smallscale farms was surveyed in eight areas in southern Malawi during 1989/90 to 1991/92. The most frequently grown crop was maize, followed by pigeonpeas, Phaseolus beans, cotton, cowpea and groundnuts. Twenty-seven species of termites were found attacking crops. The most numerous and widely distributed were several species of the Macrotermitinae, including Ancistrotermes latinotus, four species of Macrotermes, four species of Microtermes, three species of Odontotermes and Pseudacanthotermes militaris. All species damaged maize but only a few damaged bambara, cassava and banana. The damage appeared to be more frequent in dry areas than in wet ones.

Anti-termitic efficacy of the resin and rubber in fractionator overheads from a guayule extraction process

Antitermitic properties were evaluated for a mixture of resin and rubber obtained by solvent extraction of guayule. Pine ( Pinus strobus L.) sapwood was impregnated with fractionator overheads consisting of resin and low-molecular-weight rubber. The impregnated wood was exposed for 71 months at two sites in the Panama rain forest and for 67 months at a site in the Arizona desert. None of the treated wood sustained any termite damage at either site, whereas untreated baitwood was routinely destroyed. The impregnant mixture acted as a termite antifeedant rather than a repellant. Almost no loss of resin or rubber was sustained by specimens exposed in Arizona, whereas significant losses occurred at both sites in Panama. Environmental factors, including microbiological activity, may have contributed to the loss of both resin and rubber in the rain forest environment. Enough impregnant did remain in the wood to protect it from termite attack throughout the exposure period.

Termite Abundance and Damage in Traditional Maize–Cassava Intercrops in Southwestern Nigeria

During surveys conducted in 40 maize-cassava intercrops in the humid forest zone of southwestern Nigeria, the following termite species were identified from soil samples: Microtermes spp., Macrotermes nigeriensis (Sjostedt), Macrotermes subhyalinus (Rambur), Amitermes evuncifer (Silvestri) and Anoplotermes quietus (Fr. Muller). High incidence of Microtermes and Macrotermes spp. was observed. The population density of predominant species was generally higher in the rainy seasons than in the dry seasons, indicating the role of moisture in their spread. The soil texture of surveyed farms did not influence the presence of the subterranean species Microtermes. The level of weeds in the surveyed farms also did not affect the population density of termites. However, Microtermes population increased significantly (P < 0.05) with increase in crop residues and its presence in farms partly depended on the presence of maize in such farms. Microtermes and Macrotermes species inflicted most of the damage observed on maize crops, while that caused by Amitermes evuncifer waslow. No termite attack was observed on growing cassava during the surveys. The presence of live cassava in the intercrop did not influence damage by termites. Nasutitermes and Microcerotermes species which attack economic trees such as cocoa, citrus, oil palm, and forest trees did not attack cassava or maize.

Protection of southern pine from fungal decay and termite damage with N,N-naphthaloylhydroxylamine

The design of environmentally benign methods for preserving wood in service requires an understanding of the precise sequence of the biochemical events that occur as wood is colonized. We hypothesize that in-situ precipitation of existing calcium ions in association with pectin in wood may prevent the cascade of biochemical events involved in fungal colonization. Preliminary experiments showed that pretreatment of wood blocks with the selective water-soluble calcium-precipitating agent N,N-naphthaloylhydroxylamine (NHA) inhibited decay caused by brown-rot and white-rot fungi as well as damage caused by eastern subterranean termites.

A New Subterranean Termite Introduced to Florida: Heterotermes Froggatt (Rhinotermitidae: Heterotermitinae) Established in Miami

On 3 January 1995, we were asked to identify termites collected on 30 December 1994 from a house in Miami. The sample, a termite-infested board and attached nest material (carton) contained thousands of workers and hundreds of soldiers and young brachypterous nymphs. We were struck by their small size and recognized the soldiers as Heterotermes which are characterized by their slender and straight mandibles in contrast to the relatively thick, curved mandibles of the native Reticulitermes spp. [Fig. 1; also see Mathews (1977) for character diagnosis of Heterotermes]. The specimens more or less fit the brief description of H. convexinotatus (Snyder 1924), a widely reported northern Neotropical species (Araujo 1977). However, the taxonomic status of Heterotermes in this region is vague and in need of revision, therefore, we have not as yet assigned a species name to this find. On 12 January 1995, we inspected the infested property, a small, older single-family house located 0.6 km east of Interstate Highway 95 and 0.3 km north of Interstate Highway 195 in the Little Haiti district of Miami. The Heterotermes infestation was centered in a room addition which was under construction on the north side of the house. The addition consisted of concrete-block walls opening without a ceiling to a covered wood-truss roof. We observed extensive drywood termite damage to the roof rafters of the original house. The floor area of the addition was unfinished, consisting of fill sand on bare soil. The sand completely or partially buried numerous plywood and solid lumber scraps. Additional scraps were scattered or stacked near the former north wall of the original house. Although conditions were dry, nearly all wood scraps were under some degree of Heterotermes attack. Foraging tubes criss-crossed the surfaces of some of the wood. Fist-size pieces of carton were attached to the older damaged wood. No foraging tubes were observed on any of the structure itself. The condition of the infestation and large numbers of brachypterous nymphs indicated that it had been active for years and had likely undergone one or more annual reproductive dispersal cycles. Our suspicion that additional colonies were established in the neighborhood were confirmed on 30 March 1995 when several soldiers and workers were collected by a pest control operator from a warehouse located about 300 m ENE from the original site. Unlike the original site, the warehouse showed many signs of above-ground for-

Rigid Board Insulation in South Carolina: Its Impact on Damage, Inspection and Control of Termites (Isoptera: Rhinotermitidae)

A total of 225 pest control companies was randomly selected from the 315 members of the South Carolina Pest Control Association to determine their opinion on the impact of rigid board construction on termite control. Of those surveyed, 77% conducted inspections and/or treatments for subterranean termites (Isoptera: Rhinotermitidae, Reticulitermes and Coptotermes spp.) in South Carolina. The focus of survey questions was on demographics, occurrence of rigid board insulation, prevalence of rigid board insulation damage and structural damage, and treatment of structures when rigid board insulation was present. Results indicated termite infestations associated with rigid board insulation are not uncommon; 34% of the companies reported the presence of rigid board insulation on structures that have been treated or inspected for termites. Companies chose not to treat structures with rigid board insulation 43% of the time. Twenty-five percent (25%) of the companies reported damage to rigid board insulation due to insects other than termites. In addition, 12% of the respondents have been sued because of termite damage hidden by rigid board insulation. The primary recommendation to solve these problems is to remove a small gap of insulation, a vision strip, just above the soil level along the perimeter of a structure.

Resistencia natural de trece maderas mexicanas al ataque de termitas subterráneas

Se evaluó la resistencia natural del duramen de trece especies forestales (seis de selva alta perennifolia y siete de bosque de pino-encino) al ataque de termitas subterráneas Heterotermes sp. mediante micropruebas de campo. Bloques pequeños (2.5 × 2.5 × 5 cm) de cada especie se colocaron en cuatro rejillas de madera susceptible siguiendo un diseño de cuadrado latino. Las rejillas se colocaron en el suelo de una selva tropical caducifolia, en el Centro de Investigaciones Costeras, La Mancha, Veracruz, México. La duración total de la prueba fue de 15 meses; los resultados se estimaron visualmente de acuerdo con la magnitud del daño sufrido, estableciéndose cinco categorías. En general las maderas de la selva alta perennifolia fueron mas resistentes que las del bosque de pinoencino. Para algunas especies se observaron diferencias en el grado de ataque que sufrieron entre las cuatro rejillas; se discuten las posibles causas de esta variabilidad. Las clasificación de las maderas fue la siguiente: Muy Resistentes: Guarea chichon, Swietenia macrophylla (Meliaceae); Quararibea funebris (Bombacaceae). Resistentes: Pinus patula var. longepedunculata (Pinaceae); Lysiloma acapulcensis (Leguminosae). Poco Resistentes: Pinus patula, Pinus aff. pseudostrobus (Pinaceae); Quercus acatenangensis (Fagaceae). Susceptibles: Ninguna. Muy Susceptible: Quercus crassifolia (Fagaceae); Alnus jorullensis (Betulaceae). Para Pinus teocote (Pinaceae); Schizolobium parahibum (Leguminosae) y Licania platypus (Rosaceae) no se obtuvieron resultados concluyentes.