The origins and relatedness of multiple reproductives in colonies of the termite Nasutitermes corniger

Colonies of the termite Nasutitermes corniger often contain multiple reproductive queens and kings. We used double-strand conformation polymorphism (DSCP) analysis of mitochondrial DNA (mtDNA) to determine the probable origins of co-occurring reproductives. Colonies differed in queen and king number, in the number of nests containing reproductives, and in the genetic relationships among reproductives. Most of the 44 colonies contained a single pair of maternally unrelated reproductives. In the two single-nest colonies with a pair of queens, the two queens differed in mtDNA haplotype, suggesting nest-founding by unrelated queens. In the seven single-nest colonies with larger numbers of reproductives (11–49), all reproductives shared the same haplotype, a pattern consistent with replacement of a single pair by several offspring. As predicted by theory, the number of coexisting queens was greater for replacement reproductives than for co-foundresses. Several complex colonies contained multiple queens of two or more haplotypes distributed among several interconnected nests. This indicates that several matrilines can persist within a colony through one or more generations of budding and replacement, a hypothesis confirmed by orphaning experiments. The various modes of termite colony formation rival the diversity seen in ant species and demonstrate the remarkable convergence of behaviours between the two groups.     

Light and electron microscopic study of the bacterial adhesion to termite flagellates applying lectin cytochemistry

Summary Many of the flagellates inhabiting the hindgut of lower termites are associated with ectobiotic, rod-like bacteria or spirochetes. Different types of attachment sites are present. Electron dense material underlies, e.g., the plasma membrane ofJoenia annectens at the contact site, whereas other attachment sites do not show any visible specializations. The host cell's glycocalyx may, however, be reduced at the attachment sites as it is the case inDevescovina glabra. The thick glycocalyx ofStephanonympha nelumbium is not changed at the sites where bacterial rods attach, but spirochetes penetrate to a certain extent. Bacteria which colonize the extracellular surface structures ofMicrorhopalodina multinucleata express their own glycocalyx to mediate a contact. In this study we focussed on the examination of one common mode of interaction between bacteria and their host cells, i.e., adhesion via lectins and sugars. The sugar composition was analysed by light and electron microscopic labelling experiments using the lectins Con A, WGA and SBA. In general, only the posterior body surface ofJoenia which is colonized with bacteria is labelled. The demonstrated sugars are found in fibrous glycocalyx portions surrounding the attachment sites of the bacteria. Such glycocalyx fibres in combination with the electron dense material supporting the attachment sites seem to be the prerequisites for bacterial attachment. InD. glabra, however, a role for sugars in mediating the attachment could not be demonstrated. Removal of the ectobiotes using antibiotics revealed that the specialized contact sites ofJoenia are present in the absence of bacteria and thus possibly serve to attract bacteria. Nothing, however, remains of the former attachment sites in bacteria-freeDevescovina cells. Attachment sites in this case could be induced by bacterial contact. There is not one general mechanism for bacterial attachment to termite flagellates; rather, adhesion seems to follow different strategies.Abbreviations Con A concanavalin A - DAB 3,3-diaminobenzidine tetrahydrochloride - DAPI 4,6-diamidino-2-phenylindole - DIC differential interference contrast - FA formaldehyde - FITC fluorescein isothiocyanate - GA glutaraldehyde - PB Soerensen's phosphate buffer - PC phase contrast - pen/strep penicillin and streptomycin - SBA soybean agglutinin - SEM scanning electron microscope - TBS Tris buffer saline - TEM transmission electron microscope - WGA wheat germ agglutinin Dedicated to Prof. Dr. Dr. h.c. Eberhard Schnepf on the occasion of his retirement     

Caste developmental potentialities in the termite Nasutitermes novarumhebridarum

The normal development pathway and caste system of Nasutitermes novarumhebridarum (N. & K. Holmgren) (Isoptera; Termitidae) conform to the general Nasutitermes pattern. Queen-removal experiments in N. novarumhebridarum resulted in the production of replacement reproductives derived from workers (ergatoids), but never from the sexual brood (nymphs and alates). Three moults are necessary to complete the tranformation from the worker to the ergatoid. This pathway is longer than those previously konwn in other termites, in which two moults are sufficient. In a colony with functional ergatoids, some nymphs gave rise to worker-like individuals. The caste potentialities of N. novarumhebridarum differ from those of the sympatric species, N. princeps and N. polygynus, in which imaginal replacement reproductives are easily obtained. Colony reproduction in N. novarumhebridarum seems to be accomplished exclusively by independent alate founders, which colinize massive, but finite and widely spaced resoures such as dead or damaged tree trunks. N. princeps and N. polygynus societies abundantly use colony budding to expand their territory, and exploit various sources of dead wood scattered over their foraging range. We suggest that N. novarumhebridarum caste potentialities are adapted to channelling a maximum of resources into the production of dispersing alates that can colonize new nest sites.

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Résumé Les voies de développement et le système de castes chez Nasutitermes novarumhebridarum sont conformes au schéma général du genre Nasutitermes. L'enlèvement expérimental de la reine chez N. novarumhebridarum entraîne le développement de sexués de remplacement à partir d'ouvriers (ergatoïdes), mais jamais à partir de la lignée sexuée (nymphes et ailés). La transformation de l'ouvrier en ergatoîde fonctionnel nécessite trois mues. Ce développement est plus long que ceux décrits précédemment chez d'autres termites, où deux mues sont suffisantes. Dans une société où se sont développés des ergatoïdes fonctionnels, quelques nymphes se sont transformées en individus rappelant les ouvriers. Les potentialités des castes de N. novarumhebridarum diffèrent de celles des espèces sympatriques N. princeps et N. polygynus, chez lesquelles des sexués de remplacement imaginaux pauvent être obtenus aisément. La reproduction des sociétés de N. novarumhebridarum semble s'effectuer uniquement par des ailés essaimants, qui colonisent des sources de nourriture massives, mais limitées et largement espacées, tels les troncs d'arbres morts ou endomagés. N. princeps et N. polygynus étendent fréquemment leurs territoires par le bourgeonnement de nouvelles sociétés, et exploitent des sources de bois mort variées, dispersées dans leur champ d'exploitation. Nous suggérons que les potentialités des castes chez novarumhebridarum sont adaptées pour diriger un maximum de ressources vers la production d'ailés qui se dispersent et peuvent ainsi coloniser de nouveaux sites favorables.

     

Mixotrophy in the termite gut acetogen,Sporomusa termitida

Cell suspensions of H₂/CO₂-grown Sporomusa termitida catalyzed an H₂-supported synthesis of acetate from CO₂ at rates of about 1 mol acetate x h^-1 x mg protein^-1. Cells pre-grown on methanol, mannitol, lactate, or glycine also displayed H₂-supported acetogenesis from CO₂, although at rates 5–85% that of H₂/CO₂-grown cells. With methanol-grown cell suspensions: the presence of methanol greatly stimulated the rate of H₂-supported conversion of ¹⁴CO₂ to ¹⁴C-acetate (which became labeled mainly in the COOH-group); and like-wise the presence of H₂ stimulated the conversion of ¹⁴CH₃OH+CO₂ to ¹⁴C-acetate (which became labeled mainlyan the CH₃-group). Analogous stimulatory effects were observed for cell suspensions pre-grown on methanol + CO₂+H₂. Furthermore, when H₂ (+CO₂) was included as a growth substrate with either methanol or lactate: both substrates were used simultaneously; there was no diauxie in the growth of cells or in acetate production; and the molar growth yield of S. termitida was close to that predicted from summation of the yields observed when grown with each substrate alone. These data indicated that S. termitida can grow by mixotrophy, i.e. by the simultaneous use of H₂/CO₂ and organic compounds for energy. Results are discussed in light of the ability of H₂/CO₂ acetogens to outprocess methanogens in H₂ consumption in the hindgut fermentation of wood-feeding termites.     

Bioassay design and length of time in the laboratory affect intercolonial interactions of the Formosan subterranean termite (Isoptera, Rhinotermitidae)

This study examined the effect of diet, experimental design, and length of time in the laboratory on intercolonial agonism among Formosan subterranean termite, Coptotermes formosanus Shiraki, colonies. In pairings of 12 C. formosanus Shiraki colonies collected in an urban forest, there was no significant reduction in survival of termites in 30 out of 59 colony pairs compared to colony controls, but there was <50% survival in 18 colony pairs and <10% survival in six colony pairs. There was no correlation between the level of aggressive behavior and the laboratory diet of the termites. Effect of bioassay design and length of time in the laboratory was evaluated in three colony pairs where tests were first conducted on the day of field collection, then colony pairs were retested every 7 days. Aggressive behavior decreased over time in both bioassays, but it tended to decrease more rapidly in the Petri dish tests. The rapid loss of agonism in groups of termites kept in the laboratory demonstrates that changes in environmental factors affect intercolonial agonism. This article presents the results of research only. Mention of a commercial or proprietary product does not constitute endorsement or recommendation by the USDA.     

Bacterial adhesion to different termite flagellates: Ultrastructural and functional evidence for distinct molecular attachment modes

Summary The attachment modes of rodlike ectobiotic bacteria to the surface of two different termite flagellates were studied.Devescovina glabra was covered by laterally attached bacteria. Treatment with chemicals that disturb hydrophobic interactions and solubilize proteins removed the ectobionts. Freeze-fracture and freeze-etching electron microscopy revealed rows of intramembrane particles that occurred exclusively along the attachment sites. The adhering Gram-negative bacteria possessed an S-layer (surface layer) composed of globular protein particles. The S-layer could be removed by protein-solubilizing chemicals, e.g., urea, as shown by ultrathin-section electron microscopy. Therefore, it seems plausible that the attachment was mediated by hydrophobic interactions between the flagellate's plasma membrane and the S-layer of the bacteria. The bacteria of the second flagellate,Joenia annectens, adhered by their tips. The attachment was extremely strong. Chemicals disturbing ionic or hydrophobic bindings or solubilizing proteins did not detach the ectobionts. Globular intramembrane protein particles were preferentially found in a ringlike array at the external fracture face of the flagellate's contact sites.Abbreviations DIC differential interference contrast - EGTA ethylene glycol-bis(-aminoethyl ether) N,N,N,N-tetraacetic acid - TEM transmission electron microscope - Tween 20 polyoxyethylenesorbitan     

Relationship of queen number and worker size in polygyne colonies of the fire antSolenopsis invicta

Summary We examined the relationship between queen number and worker size in colonies of the fire antSolenopsis invicta. Worker size in monogyne colonies was significantly greater than in polygyne colonies; furthermore, polygyne colonies snowed a strong negative linear relationship between queen number and worker size. Higher queen pheromone level and/or decreased food availability accompanying an increase in queen number likely play important roles in producing the observed patterns.     

Turnover rate of metallothionein and cadmium in Mytilus edulis

The results demonstrate the first attempt to determine metallothionein turnover in the whole soft tissues of mussels Mytilus edulis exposed to cadmium. Half-lives for metallothionein and cadmium are 25 and 300 days, respectively. As metallothionein degrades the released cadmium induces further synthesis of the protein, to which the metal becomes resequestered. The slow metallothionein turnover rates (compared with mammals) and the lack of significant cadmium excretion testify to the relatively stable nature of the cadmium-metallothionein complex in these invertebrates and supports the view of a detoxifying role for metallothionein in the mussels.     

Genetic instability in mass-rearing colonies of a sex-linked translocation strain of Lucilia cuprina (Wiedemann) (Diptera: Calliphoridae) during a field trial of genetic control

Summary Genetic breakdown occurred in a strain of Lucilia cuprina constructed for the purpose of genetic control of this pest. The strain incorporated autosomal recessive eye colour mutations linked in repulsion with a translocation involving the Y chromosome (male-determining) and two autosomes. In the original strain females had white eyes and males were wild type. The spontaneous breakdown involved a failure of the sex-limited inheritance of the eye colour mutations. Characteristically the frequency of white-eyed males increased rapidly in the strain, whereas the frequencies of the three other phenotypically recognizable breakdown products did not. This suggested that the white-eyed males had a selective advantage over both the wild type males and the other breakdown products. Genetic analysis revealed that recombination, which is normally rare in L. cuprina males, is considerably more frequent in the presence of a Y-autosome translocation, but that recombination alone was insufficient to account for the rate of increase of the white-eyed males in the colony. Genetic and cytological analysis of the breakdown products revealed that reversion of the multi-break translocation also occurred, and that many of the white-eyed males had either only a Y-single-autosome translocation or no translocation at all; thus these males were more fertile than the wild type multi-translocation males. In addition, under colony cage conditions the white-eyed males may have had a behavioural advantage in competition with the wild type males.     

Isolation of cockroach Phe-Gly-Leu-amide allatostatins from the termite Reticulitermes flavipes and their effect on juvenile hormone synthesis

Immunoreactivity to cockroach Diploptera punctata allatostatin-7 (Dippu AST-7) has been demonstrated previously in axons innervating the corpora allata of the termite Reticulitermes flavipes. This peptide and Dippu AST-11 inhibited juvenile hormone (JH) synthesis by corpora allata (CA) of brachypterous neotenic reproductives (secondary reproductives) of termites. The present study shows that R. flavipes CA are also inhibited by Dippu AST-2, AST-5, AST-8, and AST-9 at approximately the same rank order of potency as demonstrated in D. punctata. Another allatostatin from Periplaneta americana (Peram AST-12) also inhibits JH synthesis by R. flavipes CA. Sensitivity to the allatostatins is higher in glands with low rates of JH synthesis than in those with relatively high JH synthetic rates as has been demonstrated in CA from male and female secondary reproductives as well as in those from non-egg-laying and egg-laying females. The identical inhibitory effects of R. flavipes brain extract on CA from both D. punctata and R. flavipes and the isolation and identification of five cockroach allatostatins (Dippu AST-1, AST-2, AST-5, AST-8, and Peram AST-12) from termite brain extract reflect the close relationship between cockroaches and termites.     

Queen replacement in the termiteMicrocerotermes papuanus

In experimentally orphaned field nests ofMicrocerotermes papuanus Holmgren, 1911, large numbers of workers develop into replacement reproductives (ergatoids) in only one moult. The females become functional egg-layers after approximately two months. Nymphs normally reach the last instars in August–September; at that time, in the orphaned nests, some nymphs moult to nymphoid replacement reproductives. Over long time periods, these nymphoids completely replace the ergatoids and the females become physogastric. Although time-efficient, queen replacement seems energetically expensive for the society, suggesting that this process is under weak selective pressure inM. papuanus, compared with sympatric species such asNasutitermes princeps.

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Le remplacement de la reine chez le termiteMicrocerotermes papuanus

Résumé Dans les nids deM. papuanus rendus expérimentalement orphelins, un grand nombre d'ouvriers se transforment, en une seule mue, en sexués de remplacement ergatoïdes. Les femelles se mettent à pondre au bout d'environ deux mois. Les nymphes atteignent normalement leurs derniers stades en août-septembre. A ce moment, dans les nids orphelins, certaines d'entre elles se différencient en sexués nymphoïdes. Dans les expériences de longue durée, ces nymphoïdes remplacent complètement les ergatoïdes et les femelles deviennent physogastres. Bien que rapide, le remplacement de la reine paraît coûteux pour la société du fait du grand nombre d'individus, ouvriers et nymphes, impliqués. Ceci suggère que la pression de sélection sur ce phénomène est faible chezM. papuanus, par comparaison avec des espèces sympatriques telles queN. princeps.

     

Taxonomy of an anamorphic xylariaceous fungus from a termite nest found together with <Emphasis Type="Italic">Xylaria angulosa</Emphasis>

Two xylariaceous fungi were isolated from a nest of a termite, Odontotermes formosanus, that was incubated in a laboratory after collecting from Iriomote Is., Okinawa Pref., in Japan. One of the two fungi was identified as Xylaria angulosa on the basis of the morphology of branched stroma produced on medium, tiny asci, and ascospores having a germ slit. Another fungus is an anamorphic fungus that produces synnemata up to 50 mm long from which dendritic conidiophores branch out. Unicellular conidia are holoblastically produced on a sympodially proliferating conidiogenous cell. Such morphological characters resemble those of the genus Geniculosporium. However, its distinctive synnema formation and dendritic conidiophores do not assign the fungus to Geniculosporium or other known genera and warrant establishment of a new genus. The phylogenetic tree based on the ITS regions of rDNA shows that the fungus is nested in the cluster of the genus Nemania (Xylariaceae), whose species have mainly Geniculosporium-like anamorphs. We describe here the present anamorphic fungus as Geniculisynnema termiticola gen. et sp. nov., and discuss its phylogenetic and ecological relationships to xylariaceous fungi, especially termiticolous species.     

Loss of genetic variation in laboratory colonies of Phormia regina

Genetic variation of laboratory and wild Phormia regina was examined by gel electrophoresis of enzymes. The two old laboratory stocks studied possessed much less genetic variation than wild flies.

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Zusammenfassung Die genetische Variabilität in Kulturen von Laboratoriumstämmen oder wilden Fliegen von Phormia regina wurde mittels Gel Elektrophoresis von 6 Enzymen studiert. Vier verschiedene Stämme wurden untersucht: wilde Fliegen, die F₁ Nachkommen der wilden Fliegen, ein rot-äugiger und ein weiss-äugiger Laboratoriumstamm. Die wilden Fliegen waren genetisch sehr variabel (mittlere Heterozygosität = 0.157). Die geringste Variabilität war in den weiss-äugigen Fliegen (mittlere Heterozygosität = 0.009). Die Laboratoriumstämme sind genetisch dem wilden Fliegenmaterial nicht ähnlich.

     

Polymorphism in the giant cocoa termite,Neotermes papua (Desneux)

Summary The direct development ofNeotermes papua (Isoptera: Kalotermitidae) comprises four larval and three nymphal instars before the alate. The first five instars can be easily characterized. The second stage nymphs come morphologically close to the pseudergates, characterized by reduced wing buds. These nymphs can moult stationarily, i.e. with little morphological change, or to presoldiers, or proceed to the alate via the third nymphal stage. Pseudergates originate through a late and reversible deviation from the straight development to the alate. Presoldiers may derive from several stages, up to the last nymphal one; their production is subject to an inhibition by extant soldiers. This developmental schema is congruent with those described in other Kalotermitidae and the Termopsidae. By pinpointing the existence of a large pool of pluripotent individuals, in which the penultimate nymphal stage mingles with pseudergates, the present study also reveals a great similarity betweenNeotermes andProrhinotermes, and suggests that this developmental schema might be generally applicable to termites devoid of a permanent worker caste.King Léopold III Biological Station, Laing Island, Papua New Guinea, contribution No. 235     

Protein Turnover in Response to Transient Exposure to Exogenous Auxin is Necessary for Restoring Auxin Autotrophy in a Stressed Arachis hypogea Cell Culture

An auxin autotrophic Arachis hypogea cell culture was sensitive to stress treatments leading to water loss whereas the growth of its auxin-supplemented counterpart was unaffected under similar conditions. Here we show that an hour of transient auxin treatment in the post stress period was sufficient for restoring the auxin autotrophic growth potential of the stress driven quiescent Arachis cells. Qualitative proteome analysis revealed protein turnover to have a role in mediating auxin-originated signals in these cells. In consonance, MG132 a cell permeable inhibitor of the ubiquitin mediated protein turnover completely inhibited the auxin dependent growth restoration of the stressed Arachis cells. Thus protein turnover is a necessary downstream event in exogenous auxin mediated stress tolerance in Arachis cells.     

Characterization of termite lipophorin and its involvement in hydrocarbon transport

The transport of lipids constitutes a vital function in insects and requires the plasma lipoprotein lipophorin. In all insects examined to date, cuticular hydrocarbons are also transported through the hemolymph by lipophorin, and in social insects they play important roles not only in water proofing the cuticle but also in nestmate recognition. High-density lipophorin (HDLp), isolated from Reticulitermes flavipes plasma by KBr gradient ultracentrifugation, contains 66.2% protein and 33.8% lipids; hydrocarbons constitute its major neutral lipid (20.4% of total lipids). Anti-lipophorin serum was generated in rabbit and its specific association with lipophorin, and not with any other plasma proteins, was verified with Western blotting. Immunoprecipitation also confirmed that this antibody specifically recognizes lipophorin, because all hemolymph hydrocarbons of the termites R. flavipes and R. lucifugus and the cockroach Supella longipalpa, which associate only with lipophorin, were recovered in the immunoprecipitated protein. Cross-reactivity of the antiserum with lipophorin from related species was investigated by double immunodiffusion with 10 termite species in the genera Reticulitermes, Coptotermes, Zootermopsis, and Kalotermes, and with five cockroach species. Involvement of lipophorin in hydrocarbon transport was shown by injecting HDLp antiserum into Zootermopsis nevadensis and then monitoring the de novo biosynthesis of hydrocarbons and their transport to the cuticular surface; the antiserum significantly disrupted hydrocarbon transport. ELISA revealed a gradual increase in the lipophorin titer in successively larger R. flavipes workers, and differences among castes in lipophorin titers were highest between nymphs and first instar larvae.     

Turnover and transport of agglutinins in conjugatingChlamydomonas gametes

Summary During gamete-gamete adhesion in the unicellular green algaChlamydomonas eugametos, the sexual adhesion molecules or agglutinins that are located on the flagella are subject to tip-oriented migration and rapid inactivation. It is demonstrated that sexual adhesiveness is maintained by incorporation of additional agglutinins, recruited from a cellular pool. The location of this reservoir is unknown but, as indicated by its insensitivity to the chaotropic agent guanidine thiocyanate, it appears to be distinct from the large amount of agglutinins on the plasma membrane of the cell body. By viewing flagella of conjugating gametes in a confocal scanning laser microscope after immuno-labelling of the agglutinins, evidence was obtained for a linear arrangement of the agglutinins in two rows on the flagellar surface. This suggests that after insertion at the base of the flagellum, the agglutinins follow linear tracks to the tip and that the transport system is confined to two longitudinal domains. It is estimated that the half-life of flagellar agglutinins drops from 1–2 h in nonconjugating gametes to 1 min during conjugation, which suggests that after incorporation at the flagellar base, the agglutinins migrate to the tip with a velocity of 100 nm/s. Presumably after arrival at the tip, the molecules are inactivated. It is postulated that rapid turnover and transport of agglutinins are required for optimal signalling between partner gametes.Abbreviations BSA bovine serum albumine - CHI cycloheximide - CSLM confocal scanning laser microscope - GA glutaraldehyde - GTC guanidine thiocyanate - GAM-IgG goat-anti-mouse immuno-globuline - mAb monoclonal antibody - mt mating type - PBS phosphate-buffered saline - SDS sodiumdodecyl sulphate - TRIS tris-(hydroxymethyl)-aminomethane     

Fine Root Production and Turnover in a Norway Spruce Stand in Northern Sweden: Effects of Nitrogen and Water Manipulation

Fine root length production, biomass production, and turnover in forest floor and mineral soil (0–30 cm) layers were studied in relation to irrigated (I) and irrigated-fertilized (IL) treatments in a Norway spruce stand in northern Sweden over a 2-year period. Fine roots (<1 mm) of both spruce and understory vegetation were studied. Minirhizotrons were used to estimate fine root length production and turnover, and soil cores were used to estimate standing biomass. Turnover was estimated as both the inverse of root longevity (RTL) and the ratio of annual root length production to observed root length (RTR). RTR values of spruce roots in the forest floor in I and IL plots were 0.6 and 0.5 y⁻¹, respectively, whereas the corresponding values for RTL were 0.8 and 0.9 y⁻¹. In mineral soil, corresponding values for I, IL, and control (C) plots were 1.2, 1.2, and 0.9 y⁻¹ (RTR) and 0.9, 1.1, and 1 y⁻¹ (RTL). RTR and RTL values of understory vegetation roots were 1 and 1.1 y⁻¹, respectively. Spruce root length production in both the forest floor and the mineral soil in I plots was higher than in IL plots. The IL-treated plots gave the highest estimates of spruce fine root biomass production in the forest floor, but, for the mineral soil, the estimates obtained for the I plots were the highest. The understory vegetation fine root production in the I and IL plots was similar for both the forest floor and the mineral soil and higher (for both layers) than in C plots. Nitrogen (N) turnover in the forest floor and mineral soil layers (summed) via spruce roots in IL, I, and C plots amounted to 2.4, 2.1, and 1.3 g N m⁻² y⁻¹, and the corresponding values for field vegetation roots were 0.6, 0.5, and 0.3 g N m⁻² y⁻¹. It was concluded that fertilization increases standing root biomass, root production, and N turnover of spruce roots in both the forest floor and mineral soil. Data on understory vegetation roots are required for estimating carbon budgets in model studies.     

Evaluation of decay and termite resistance of wood treated with copper in combination with boron and N′-N-(1, 8-naphthalyl) hydroxylamine (NHA-Na)

This study evaluated the relative ability of various combinations of copper sulfate with either boric acid or calcium-precipitating agent, N′-N-(1, 8-naphthalyl) hydroxylamine (NHA-Na), to inhibit fungal degradation and attack by Formosan subterranean termites (Coptotermes formosanus Shiraki). Wood specimens were treated with either 1%, 0.5%, or 0.1% concentrations of copper sulfate, boric acid, NHA-Na, copper sulfate + boric acid, or copper sulfate + NHA-Na mixtures. Treated specimens were subjected to laboratory decay-resistance tests by using petri dishes inoculated with the Basidiomycetes fungi Tyromyces palustris and Trametes versicolor for 12 weeks. Treated wood specimens were also subjected to termite-resistance tests under laboratory conditions. Increased efficacy of copper sulfate against the brown-rot fungus T. palustris was observed when either boric acid or NHA-Na was added. The most effective treatments against the fungi tested were NHA-Na only treatments at 1% and 0.5% concentration levels. Boric acid treatments were not able to protect wood against decay after leaching because of excessive leaching of boron. Similar results were obtained in termite-resistance tests in comparison with decay-resistance tests. These results indicate that the efficacy of the treatments in preventing fungal and termite attack is a function of the type of preservative.