Azimuthal sound localization in the European starling (Sturnus vulgaris): II. Psychophysical results

Small songbirds have a difficult analysis problem: their head is small compared to the wavelengths of sounds used for communication providing only small interaural time and level differences. Klump and Larsen (1992) measured the physical binaural cues in the European starling (Sturnus vulgaris) that allow the comparison of acoustical cues and perception. We determined the starling’s minimum audible angle (MAA) in an operant Go/NoGo procedure for different spectral and temporal stimulus conditions. The MAA for broadband noise with closed-loop localization reached 17°, while the starling’s MAA for open-loop localization of broadband noise reached 29°. No substantial difference between open-loop and closed-loop localization was found in 2 kHz pure tones. The closed-loop MAA improved from 26° to 19° with an increase in pure tone frequency from 1 to 4 kHz. This finding is in line with the physical cues available. While the starlings can only make use of interaural time difference cues at lower frequencies (e.g., 1 and 2 kHz), additional interaural level difference cues become available at higher frequencies (e.g., 4 kHz or higher, Klump and Larsen 1992). An improvement of the starling’s MAA with an increasing number of standard stimulus presentations prior to the test stimulus has important implications for determining relative (MAA) localization thresholds.     

Application of protease from Nocardiopsis sp. as a laundry detergent additive

The application of protease as a laundry detergent additive from a newly isolated Nocardiopsis sp., isolated from a soil sample collected in Northeast Brazil is reported. The optimal pH and temperature for protease activity were pH 10.5 and 50 °C, respectively. The enzyme was stable in a long-term incubation, showed 73.5% of initial activity at pH 10.5 and 61.7% at pH 12.0 for 120 min. Approximately 60% of initial activity remained after 120 min at 50 °C or after 30 min at 80 °C. Almost 87% of enzyme activity was retained in the presence of 10% (v/v) of peroxide at 40 °C, after 1 h. The protease also was stable in the presence of oxidants and surfactants such as SDS, saponin, Tween 20 and Tween 80 after 30 min. In the presence of Omo^®, the enzyme retained 64% of its activity at 40 °C for 1 h. An increase in the proteolytic activity (6–17%) was observed with K⁺, Na⁺, and Mg⁺⁺ ions. At pH 8.0, the protease hydrolysed casein maximally (50 U/mg).     

Hearing in the sea otter (Enhydra lutris): auditory profiles for an amphibious marine carnivore

In this study we examine the auditory capabilities of the sea otter (Enhydra lutris), an amphibious marine mammal that remains virtually unstudied with respect to its sensory biology. We trained an adult male sea otter to perform a psychophysical task in an acoustic chamber and at an underwater apparatus. Aerial and underwater audiograms were constructed from detection thresholds for narrowband signals measured in quiet conditions at frequencies from 0.125–40 kHz. Aerial hearing thresholds were also measured in the presence of octave-band masking noise centered at eight signal frequencies (0.25–22.6 kHz) so that critical ratios could be determined. The aerial audiogram of the sea otter resembled that of sea lions and showed a reduction in low-frequency sensitivity relative to terrestrial mustelids. Best sensitivity was ?1 dB re 20 µPa at 8 kHz. Under water, hearing sensitivity was significantly reduced when compared to sea lions and other pinniped species, demonstrating that sea otter hearing is primarily adapted to receive airborne sounds. Critical ratios were more than 10 dB higher than those measured for pinnipeds, suggesting that sea otters are less efficient than other marine carnivores at extracting acoustic signals from background noise, especially at frequencies below 2 kHz.     

Efficiency of body conduction of underwater sounds in the bottlenose dolphin

Hearing thresholds of the Black Sea bottlenose dolphin Tursiops truncatus for tonal and composite underwater sounds within 50 kHz were ascertained in fully or partly submerged (head out of water) animals (trained by operant conditioning with food reinforcement). Perception of sounds conducted through the body deteriorated in all cases (thresholds for 75%-correct response rose typically by 6-24 dB); the least changes were observed for 10 and 20 kHz tones. The aggregate data also suggested significant individual variations.     

Day and night sounds of the Guiana dolphin, <Emphasis Type="Italic">Sotalia guianensis</Emphasis> (Cetacea: Delphinidae) in southeastern Brazil

Many cetaceans are known to be acoustically active at night. However, for most dolphin species, there is little information about their nocturnal acoustic activities. To study the acoustic repertoire of Sotalia guianensis, diurnal and nocturnal sounds (whistles, burst pulses, low-frequency narrowband (LFN) sounds, and clicks) were identified in the Cananéia estuary (25° 01′ S–25° 13′ S/47° 52′ W–48° 06′ W), south of the state of São Paulo, southeastern Brazil, during April, June, and November of 2012. The emission rate of these sounds was compared between daytime and nighttime using the chi-squared statistical test. The mean values of the acoustic parameters of whistles, burst pulses, LFN sounds, and clicks were compared using the t test. Whistles, burst pulses, and LFN sounds were more frequent at night, as these individuals require greater acoustic communication in the absence of light, mainly for social communication. Echolocation emission rates were similar in both day and nighttime. Dolphin sound structure also varied throughout the day, with dolphins emitting lower-frequency sounds at night. Low-frequency sounds, with longer wavelengths, provide many advantages for dolphins active at night because such sounds propagate greater distances. This study demonstrates that the sounds produced by S. guianensis are dependent on the time of day, with social communication sounds being more influenced by the presence of light.     

Effect of the addition of IGF-I and vitamin E to stored boar semen

The objective of this study was to evaluate the addition of IGF-I to pig insemination doses stored at 15°C, in conjunction with the addition of different amounts of vitamin E (α-tocopherol). Semen samples (n = 12) from four boars were treated by the addition of different concentrations of vitamin E, ranging up to 400 μg/ml. Immediately after processing and after the doses had been stored at 15°C for 24 or 72 h, samples were warmed at 37°C and 30 ng/ml of IGF-I was added. The assessments were made after 10 and 120 min of IGF-I addition. There was a minor effect of the vitamin E added before cooling and IGF-I added after storage on sperm quality. The addition of 400 μg/ml of vitamin E to diluted semen reduced (P < 0.01) the malondialdehyde (MDA) production in boar semen stored at 15°C for 72 h, regardless of the addition of IGF-I as additive during a 120 min incubation period at 37°C. In these conditions, IGF-I also reduced (P < 0.05) the MDA production in semen samples without addition of vitamin E. IGF-I in the presence of vitamin E reduced (P = 0.03) the glucose intake in freshly diluted boar semen samples before cooling. It was concluded that the addition of 400 μg/ml of vitamin E reduces the MDA production in boar semen stored at 15°C for 72 h, regardless of the presence of IGF-I additive. The addition of IGF-I in doses stored for 72 h with vitamin E ensures higher sperm motility after 120 min of incubation at 37°C.     

Involvement of the mechanosensory complex structures of the cricket <Emphasis Type="Italic">Phaeophilacris bredoides</Emphasis> in triggering of motor responses to sound

Using an ethological approach, we studied the possibility of sound perception as well as probable contribution of diverse mechanosensory systems composing the mechanosensory complex to triggering of motor responses to sound stimulation in imaginal crickets Phaeophilacris bredoides lacking the tympanal organs (“deaf”). It was shown that Ph. bredoides imagoes are able to perceive sounds and respond to sound cues by a locomotor reaction in a relatively broad frequency range which becomes narrower as sound intensity decreases [0.1–6.0 kHz (111 ± 3 dB SPL), 0.1–1.5 kHz (101 ± 3 dB SPL), 0.1–1.3 kHz (91 ± 3 dB SPL), 0.1–0.6 kHz (81 ± 3 dB SPL), and 0.1 kHz (71 ± 3 dB SPL)]. Sound perception and triggering ofmotor responses appear to involve the cercal organs (CO), subgenual organs (SO) and, probably, other distant mechanosensory organs (DMO). CO are essential for triggering of locomotor responses to sound within the ranges of 1.6–6.0 kHz (111 ± 3 dB SPL), 1–1.5 kHz (101 ± 3 dB SPL), 0.9–1.3 kHz (91 ± 3 dB SPL), and 0.5–0.6 kHz (81 ± 3 dB SPL). SO and, probably, other DMO provide locomotor responses to sound within the ranges of 0.1–6.0 kHz (111 ± 3 dB SPL), 0.1–0.8 kHz (101 ± 3 dB SPL), 0.1–0.4 kHz (91 ± 3 dB SPL), and 0.1–0.4 kHz (81 ± 3 dB SPL). From this, it follows that “deaf” (nonsinging) Ph. bredoides can perceive sounds using CO, SO and, probably, other DMO, which (as in singing crickets) are likely to compose an integrated mechanosensory complex providing adequate acoustic behavior of this cricket species. Performance efficiency and sensitivity of the mechanosensory complex (specifically, of CO) rely on the thoroughness of grooming. Following self-cleaning of CO, the level of cricket motor activity in response to cue presentation returned to the baseline and sometimes even increased. Whether or not crickets of this species communicate acoustically is yet to be found out, however, we suggest that the mechanosensory complex, which triggers motor responses to a sound, is normally involved in the defensive escape response aimed at rescuing from predators.     

Pupillary dilation response as an indicator of auditory discrimination in the barn owl

The pupil of an awake, untrained, head-restrained barn owl was found to dilate in response to sounds with a latency of about 25 ms. The magnitude of the dilation scaled with signal-to-noise ratio. The dilation response habituated when a sound was repeated, but recovered when stimulus frequency or location was changed. The magnitude of the recovered response was related to the degree to which habituating and novel stimuli differed and was therefore exploited to measure frequency and spatial discrimination. Frequency discrimination was examined by habituating the response to a reference tone at 3 kHz or 6 kHz and determining the minimum change in frequency required to induce recovery. We observed frequency discrimination of 125 Hz at 3 kHz and 250 Hz at 6 kHz – values comparable to those reported by others using an operant task. Spatial discrimination was assessed by habituating the response to a stimulus from one location and determining the minimum horizontal speaker separation required for recovery. This yielded the first measure of the minimum audible angle in the barn owl: 3° for broadband noise and 4.5° for narrowband noise. The acoustically evoked pupillary dilation is thus a promising indicator of auditory discrimination requiring neither training nor aversive stimuli. Accepted: 28 February 2000     

Involvement of Mechanosensory Complex Structures of the Cricket <Emphasis Type="Italic">Gryllus bimaculatus</Emphasis> Larvae (Orthoptera,Gryllidae) in Triggering of Motor Responses to Sound

Using an ethological approach, we studied the possibility of sound perception as well as probable contribution of diverse mechanosensory systems composing the mechanosensory complex to triggering of motor responses to sound stimulation in the cricket Gryllus bimaculatus larvae. It was shown that larvae can perceive sounds and respond to them by a locomotor reaction in a relatively broad frequency range, which becomes narrower as sound intensity decreases [0.1–6.6 kHz (111 ± 3 dB SPL), 0.1–1.4 kHz (101 ± 3 dB SPL), 0.1–0.8 kHz (91 ± 3 dB SPL]. Sound perception and triggering of motor responses appear to involve the cercal organs (CO), subgenual organs (SO) and, probably, other distant mechanosensory organs (DMO). Normal functioning of CO is essential for triggering locomotor responses to sound within the ranges of 1–1.4 kHz (101 ± 3 dB SPL) and 0.1–0.8 kHz (91 ± 3 dB SPL). CO are not necessary for triggering of motor responses to cues with an intensity of 111 ± 3 dB. SO and, probably, other DMO provide locomotor responses to sound within the ranges of 0.1–6.6 kHz (111 ± 3 dB SPL), 0.1–0.9 kHz (101 ± 3 dB SPL), and 0.1–0.3 kHz (91 ± 3 dB SPL). Thus, last instar larvae of G. bimaculatus lacking the tympanal organs can perceive sounds using CO, SO and, probably, other DMO, which (as in cricket imagoes) are likely to compose an integrated mechanosensory complex providing adequate acoustic behavior of this cricket species. Performance efficiency and sensitivity of the mechanosensory complex (specifically, CO) rely on the thoroughness of grooming. After self-cleaning of CO, the level of larval motor activity in response to cue presentation returned to the baseline and sometimes even increased. We assume that under normal conditions the mechanosensory complex, which triggers motor responses to a sound, is involved in the defensive escape response aimed at rescuing from predators.     

Incubation temperature critical to successful stimulation of in vitro zygotic embryo growth in four Australian native Cyperaceae species

Many species of Western Australian Cyperaceae (sedges) are vital components of the indigenous flora but commonly display low seed set, poor seed quality and intractable seed dormancy. We report the effects of incubation temperature and in vitro growth media on whole seed germination compared with extracted zygotic embryo growth in Tetraria capillaris, T. octandra, Lepidosperma drummondii and L. tenue. No germination was observed from intact whole seeds of all test species regardless of the treatment evaluated. In contrast, excised zygotic embryos of all study species exhibited significant increases in growth when cultured at 15°C compared to embryos incubated at 25°C; however, optimal media for embryo growth were genera specific. Extracted embryos of T. capillaris and T. octandra exhibited maximum percentage growth (30 and 40%, respectively) at 15°C on ½ MS medium with no plant growth regulators required. In the case of L. drummondii and L. tenue 1 μM thidiazuron was a necessary addition to the ½ MS medium resulting in 40 and 77% growth of embryos (at 15°C), respectively. Incubation of extracted embryos at 25°C (regardless of medium treatment) resulted in <10% embryo growth for T. octandra and L. tenue, while the remaining two species (L. drummondii, T. capillaris) showed no embryo growth at 25°C on any medium treatment.     

New isolate of Streptomyces sp. with novel thermoalkalotolerant cellulases

A Streptomyces sp. was isolated that produced novel thermoalkalotolerant cellulase activity after growth on crystalline cellulose at 50°C. Three major components of the cellulases (CMCase, Avicelase and cellobiase) were produced with maximal activities (11.8, 7.8 and 3.9 IU/ml) and maximum specific activities 357, 276 and 118 IU/mg protein, respectively, after 120 h growth. Maximum CMCase activity was between 50 and 60°C measured over 3 h. The enzyme also retained 88% of its maximum activity at 70°C and pH 5, and 80% of the activity at pH 10 and 50°C when assayed after 1 h. After incubation at 40°C for 1 h with commercial detergent (Tide) at pH 11, 95% activity was retained. The enzyme mixture produced glucose from crystalline cellulose.     

Changes in searching responses with temperature ofCyrtorhinus lividipennis reuter (Hemiptera: Miridae) on the eggs of the brown planthopper,Nilaparvata lugens (Stål.) (Homoptera: Delphacidae)

The functional response ofCyrtorhinus lividipennis Reuter attacking the brown planthopper(Nilaparvata lugens (Stål.), BPH) eggs on rice was determined at six constant temperatures of 20°C, 23°C, 26°C, 29°C, 32°C and 35°C. Rogers’ (1972) random predator equations were fitted to the data for each temperature separately. The equation model adequately described a Holling’s Type II functional response forC. lividipennis and produced biologically realistic estimates of attack rates and handling times at five experimental temperatures between 20°C and 32°C. However, at 35°C, a negative handling time(Th = - 0.0029) was produced. The effect of temperature was incorporated in to Rogers’ equation by making the attack rate(a) and handling time(Th) functions of temperature within the range 20°C to 32°C. The attack rate and handling time were fitted as hyperbola and reciprocal hyperbola functions of temperature respectively. The temperature incorporating fourparameter composite model fitted the combined data as well as did separate Rogers’ equations based on the parameter estimates.     

Vocal communication in the bicoloured white-toothed shrew<Emphasis Type="Italic">Crocidura leucodon</Emphasis>

Vocal sounds of 15 individuals ofCrocidura leucodon (Hermann, 1780) emitted during agonistic and amicable interactions in male-male, female-female and male-female dyadic encounters, and intraspecific cage groups, were studied. An analysis of spectral properties, along with an examination of context and function, were performed. The sounds registered during agonistic interactions showed an increase, then a decrease in frequency, often followed a complex undulating curve. The dominant frequency (DF) was 10.7±0.05 kHz, and duration (DU) was 104.2±4.4 ms. The calls emitted by shrews at investigation and grooming often ended with chirping notes (DF=4.8±0.2 kHz, DU=23.5±1.1 ms). While clustering and huddling up to the partner, the animals produced calls consisting of short notes with a very low intensity (DF=1.0±0.07 kHz, DU=35.2±0.8 ms). Based on these finding, it can be assumed that threatening sounds, emitted in agonistic encounters, allow shrews to avoid conflicts, while those, emitted when clustering and huddling up to the partner, contribute to maintenance of group cohesiveness. The variability of frequency ranges and intensity of sounds probably reflects the territorial and gregarious behaviour ofC. leucodon and adaptation to communication in variable acoustic environments.     

Biological studies ofDiadegma semiclausum (Hym., Ichneumonidae), a parasite of diamondback moth

Laboratory studies were conducted on certain aspects of biology ofDiadegma semiclausum Hellén, a larval parasite of a crucifer pest,Plutella xylostella (L.). Within the range of 15°C to 35°C, the higher temperature, the shorter was the duration of larval and adult stages. Egg hatching and adult emergence were high at 15°C to 30°C but were significantly reduced at 35°C. The higher the temperature, the higher was the proportion of males produced. Temperature threshold was 5.74°C for eggs, 3.80°C for larvae, 5.91°C for pupae and 6.60°C for adults.D. semiclausum oviposition in the first threeP. xylostella larval instars produced more parasite males than females but oviposition in the fourth instar produced significantly more females than males. Parasite adults tended to emerge from their pupae from 06∶00 to 09∶00 hours although some emerged at other hours during the photophase. Adult longevity and production of eggs increased when adults were provided with a food source (honey) compared with no food or provision of water alone. Parasite adults survived and laid eggs for 28 days when provided with food but for only three days when deprived of food.     

Echolocation by the long-eared bat,Plecotus phyllotis

Summary The echolocating bat,Plecotus phyllotis (Vespertilionidae), uses long-CF/FM and FM sonar sounds in different situations. The CF component in long-CF/FM sounds occurs at 27 kHz and has a duration of 20 to 200 ms. The FM component sweeps down from 24 to 12 kHz, with a prominent second harmonic from 40 to 22 kHz. This second harmonic sweep is interrupted at 28 to 25 kHz, providing a notch in the spectrum of the FM component at the CF frequency. This notch probably permits isolation of CF and FM components in echoes for separate processing, thus avoiding mutual interference with the different kinds of target information the two components convey. The FM component is also used without the CF component as a sonar sound. Two other FM orientation sounds are used when the bat is in a confined space such as a room. One contains only the second and fourth harmonics of the 24 to 12 kHz fundamental sweep, while the other contains only the fifth harmonic. This bat's repertoire of sonar sounds closely matches the hearing capacities of the genus.We thank P.H. Dolkart and W.A. Lavender, of Washington University, and the Nevada State Parks Department for their assistance. This research was supported by Grant # BMS-72-02351-A01 from the National Science Foundation.     

Metarhizium spp. isolates from madagascar: Morphology and effect of high temperature on growth and infectivity to the migratory locust,Locusta migratoria

Five strains ofMetarhizium anisopliae (Metsch.) Sorokin and one strain ofMetarhizium flavoviride Gams &; Rozsypal originally isolated in Madagascar were studied. Measurements of conidia and, for the first time, also of blastospores produced in a liquid medium were used for species and variety determination. Blastospores ofM. flavoviride were more homogenous in their size than those ofM. anisopliae. Growth at high temperatures between 25° and 40°C showed that 4 isolates ofM. anisopliae grew at 36°C andM. flavoviride grew at 38°C. Using alternating day/night temperatures (8/16 h) the three strains tested could also tolerate 40°/25°C. In bioassays, fiveMetarhizium spp. isolates were tested against third and fourth instar larvae ofLocusta migratoria (L.) at two alternating day/night temperatures of 30°/25°C and 36°/25°C. In the cooler regime, all strains caused a mortality of 50% within 5.9 to 8.5 days (median lethal time), while in the 36°/25°C treatment only the thermophilicM. flavoviride and oneM. anisopliae strain isolated from a soil sample gave comparable results with median lethal times of 6.8 and 7.3 days, respectively.     

Saccharomyces cerevisiae strains from traditional fermentations of Brazilian cachaça: trehalose metabolism, heat and ethanol resistance

Nine indigenous cachaça Saccharomyces cerevisiae strains and one wine strain were compared for their trehalose metabolism characteristics under non-lethal (40°C) and lethal (52°C) heat shock, ethanol shock and combined heat and ethanol stresses. The yeast protection mechanism was studied through trehalose concentration, neutral trehalase activity and expression of heat shock proteins Hsp70 and Hsp104. All isolates were able to accumulate trehalose and activate neutral trehalase under stress conditions. No correlation was found between trehalose levels and neutral trehalase activity under heat or ethanol shock. However, when these stresses were combined, a positive relationship was found. After pre-treatment at 40°C for 60 min, and heat shock at 52°C for 8 min, eight strains maintained their trehalose levels and nine strains improved their resistance against lethal heat shock. Among the investigated stresses, heat treatment induced the highest level of trehalose and combined heat and ethanol stresses activated the neutral trehalase most effectively. Hsp70 and Hsp104 were expressed by all strains at 40°C and all of them survived this temperature although a decrease in cell viability was observed at 52°C. The stress imposed by more than 5% ethanol (v/v) represented the best condition to differentiate strains based on trehalose levels and neutral trehalase activity. The investigated S. cerevisiae strains exhibited different characteristics of trehalose metabolism, which could be an important tool to select strains for the cachaça fermentation process.     

Egg laying and host stage preference at constant temperatures inEncarsia tricolor [Hym.: Aphelinidae]

Encarsia tricolor Foërster is a facultative autoparasitoid that develops on the important pestTrialeurodes vaporariorum (Westwood) in outdoor crop conditions, which makes this aphelinid species promising for biological control programs in regions where field and protected crops coexist. In this paper we report the results obtained in the study of daily and totalE. tricolor egg laying and of adult female preference for different host stages in which to lay eggs at constant temperatures in the range 10 to 32 °C. Only whitefly nymphs were present in the searching arena (tomato leaflets). The mean number of eggs laid per female in one day ranged from 4.0 (10 °C and 32 °C) to 15.2 (24 °C). The mean total number of eggs increased with temperature from 10 to 28 °C, reaching a maximum of 123 eggs per female at 28 °C, and decreased sharply from 28 to 32 °C. The relation between the intrinsic rate of increase (r_m) and temperature in the range 10 to 28 °C followed a straight line whose equation was r_m=?0.076+0.011*T (R²=0.99). The r_m ofE. tricolor was greater than the r_m ofT. vaporariorum when temperature was higher than 9.2 °C. The preference for any particular host instar in which to lay eggs was not always significant. However, N4 was the host instar preferred whenever preference was statistically significant.     

In vitro production of Indian citrus ringspot virus (ICRSV) free Kinnow plants employing thermotherapy coupled with shoot tip grafting

Indian citrus ringspot virus (ICRSV) is known to cause serious disease problem in Kinnow (Citrus nobilis Lour × C. deliciosa Tenora) plants. This work reports the elimination of ICRSV by using thermotherapy coupled with shoot tip grafting in vitro. Nodal segments from infected mother plants (indexed by indirect ELISA and RT-PCR) were treated both in water bath and moist hot air at different temperatures viz. 40, 45 and 50°C for 30, 60 and 120 min and cultured on MS medium containing 2-iP (1 mg/l) and malt extract (800 mg/l). Shoot tips were excised from the nodal sprouts and grafted on to rough lemon (C. jambhiri) rootstock under aseptic conditions. Water bath treatment was found to be more effective as compared to moist hot air treatment as maximum number of ICRSV free plants (36.84%) were obtained by grafting the tips (0.7 mm) taken from the nodal segments treated at 50°C in water bath for 2 h. In an alternate treatment regime, 1-year-old infected plants were kept at various temperatures viz.36, 38 and 40°C in a thermotherapy chamber. Maximum of 60% ICRSV free plants were obtained by grafting the tips (0.7 mm) from the plants placed at 40°C followed by the plants placed at 38°C (59.09%) and the least was observed in case of the plants placed at 36°C (40.74%). Only those plants/plantlets were considered virus free, which showed negative reaction both in Indirect ELISA and RT-PCR.     

Trypsin inhibitors in xoconostle seeds (Opuntia joconostle Weber.)

Seed proteins recovered after heating a seed extract from Opuntia joconostle Weber (xoconostle, an acid cactus pear) were screened for different biochemical activities, detecting only trypsin-like inhibitory activity. Two trypsin-like inhibitor forms from seeds were separated by RP-HPLC and partially sequenced and characterized as an enriched mixture. They were evaluated for inhibition on several serine proteinases, but only trypsin-like inhibition was detected by the inhibitor extract. The two isolated forms, OjTI 1 and OjTI 2 showed low molecular weights of 4.26 and 4.17 kDa as determined by mass spectrometry. An enriched inhibitory fraction showed a high thermal stability by retaining the activity after heating the sample for 1 h at 90 °C, as well as after heating for at 120 °C under 1 kg/cm² for 15 min at different pH values. Partial sequence of the two forms was determined by mass spectrometry indicating that they were similar and after alignments analysis they showed the highest similarity with the trypsin inhibitor from O. streptacantha and to a lesser extent to other trypsin inhibitors of the MEROPS database families. The inhibitory spectrum was evaluated against several digestive enzymes from pests and beneficial insects from several taxonomic orders.