Migratoria Manilensis Research Articles

Diversity of Bacillus thuringiensis strains from soil in China and their pesticidal activities

A large number of Bacillus thuringiensis (Bt) isolates have been obtained from soil samples in China. The flagellar antigen serotypes, cry genes and crystal proteins of 570 Bt isolates were determined, and the pesticidal activity was assayed against the insects, Plutella xylostella, Heliothis armigera, Phaedon brassicae and Locusta migratoria manilensis, and the snail, Oncomelania hupensis. The results indicated that the Bt isolates were distributed within 35 H-serotypes, in which isolates of H3 were the most abundant (20%) followed by H5 (13%), H7 (9%) and H4 (8.7%), whereas isolates of other H-serotypes were less than 6%. The percentage of isolates containing the genes cry1Ac, cry1Aa/ cry1Ac, cry1Aa/cry1Ac/cry1Ab, and cry1Aa/cry1Ac/cry1C was 14.7%, 6.6%, 5.6%, and 7.0%, respectively, while 265 isolates, representing 46.5% of the 570 Bt isolates, did not show any amplification product for the genes cry1Aa, cry1Ac, cry1C, cry2, cry3, cry4, cry7Aa. Some of the 570 Bt isolates caused high mortality of the assayed pests with 14.9%, 6%, 1.6%, 1.1%, and 0.2% of the isolates killing more than 90% of P. xylostella, H. armigera, P. brassicae, O. hupensis, and L. migratoria manilensis, respectively. The remaining 76.2% of the 570 isolates caused no mortality or less than 90% mortality against the tested insect and snail species.

Relationship between oriental migratory locust plague and soil moisture extracted from MODIS data

Locust plagues have been the source of some of the most severe natural disasters in human history. Soil moisture content is among the most important of the numerous factors influencing plague onset and severity. This paper describes a study initiated in three pilot locust plague monitoring regions, i.e., Huangzao, Yangguanzhuang, and Tengnan in Huanghua county, Hebei province, China, to examine the impact of soil moisture status on oriental migratory locust [Locusta migratoria manilensis (L.) Meyen] plague breakout as related to the life cycle, oviposition in autumn, survival in winter, and incubation in summer. Thirty-nine temperature vegetation dryness index (TVDI) data sets, which represent soil moisture content, were extracted from MODIS remote sensing images for two representative time periods: a severe locust plague breakout year (2001–2002) and a slight plague year (2003–2004). TVDI values demonstrated distinctive soil moisture status differences between the 2 years concerned. Soil moisture conditions in the severe plague year were shown to be lower than those in slight plague year. In all three pilot regions, average TVDI value in the severe plague year was 0.07 higher than that in slight plague year, and monthly TVDI values in locust oviposition period (September and October) and incubation period (March, April and May) were higher than their corresponding monthly figures in slight plague year. No remarkable TVDI differences were found in other months during the locust life cycle between the 2 years. TVDI values for September and October (2001), March, April and May (2002) were 0.11, 0.08, 0.16, 0.11 and 0.16 higher than their corresponding monthly figures in 2003–2004 period, respectively.

Thousand-year-long Chinese time series reveals climatic forcing of decadal locust dynamics

For >1,000 years, Chinese officials have recorded the annual abundance of the oriental migratory locust Locusta migratoria manilensis, with the ultimate aim of predicting locust outbreaks. Linking these records with temperature and precipitation reconstructions for the period 957-1956, we show that decadal mean locust abundance is highest during cold and wet periods. These periods coincide with above-average frequencies of both floods and droughts in the lower Yangtze River, phenomena that are associated with locust outbreaks. Our results imply differential ecological responses to interdecadal and interannual climatic variability. Such frequency-dependent effects deserve increased attention in global warming studies.

Evidence that amino-acid residues are responsible for substrate synergism of locust arginine kinase

A series of mutants were constructed to investigate the amino-acid residues responsible for the synergism in substrate binding of arginine kinase (AK). AK contains a pair of highly conserved amino acids (Y75 and P272) that form a hydrogen bond. In the locust ( Locusta migratoria manilensis) AK, mutants in two highly conserved sites can cause pronounced loss of activity, conformational changes and distinct substrate synergism alteration. The Y75F and Y75D mutants showed strong synergism ( K d/ K m=6.2–13.4), while in single mutants, P272G and P272R, and a double mutant, Y75F/P272G, the synergism was almost completely lost ( K d/ K m=1.1–1.4). Another double mutant, Y75D/P272R, had characteristics similar to those of the wild-type enzyme. All these results suggest that the amino-acid residues 75 and 272 play an important role in regulating the synergism in substrate binding of AK. Fluorescence spectra showed that all mutants except Y75D/P272R displayed a red shift to different degrees. All the results provided direct evidence that there is a subtle relationship between the synergism in substrate binding and the conformational change.

Cloning of a novel protease required for the molting of Locusta migratoria manilensis

Molting is required for progression between larval stages in the life cycle of an insect. The essence of insect molting is the laying down of new cuticle followed by shedding of the old cuticle. Degradation and recycling of old cuticle are brought about by enzymes present in the molting fluid, which fills the space between the old and new cuticle. Here, we describe the cloning of a novel protease gene from Locusta migratoria manilensis, designated as Lm-TSP. The cDNA and its deduced protein sequences were deposited in GenBank (accession numbers EF081255 and ABN13876, respectively). Sequence analysis indicated that Lm-TSP belongs to the trypsin-like serine protease family. We show, by RNA interference (RNAi), that silencing of Lm-TSP leads to dramatic reductions in protease and cuticle-degrading activity of a molting fluid, which leads to molting defects from fourth-instar larvae (L4) to fifth-instar larvae (L5), and between L5 and adult stages. These observations suggest that Lm-TSP plays a critical role in L. migratoria manilensis ecdysis.

Trehalose and trehalose‐hydrolyzing enzyme in the haemolymph of Locusta migratoria infected with Metarhizium anisopliae strain CQMa102

AbstractTopical application of the Metarhizium anisopliae var. acridum specialist strain CQMa102 to the locust Locusta migratoria manilensis results in changes of the concentrations of trehalose and glucose in the haemolymph. Micrographs of the locust haemolymph shows Metarhizium anisopliae can effectivly penetrate the external skeleton of locust and after 2 days infection, the hyphae body will appear in the haemolymph of infected insects. The time in decrease of trehalose concentration coincided with that in increase of trehalose‐hydrolysing enzyme activity in the haemolymph of the fungus‐infected insects. Overlay gel analysis indicated there was considerably more trehalose‐hydrolysing activity in the haemolymph of locusts infected by fungus than in controls. A comparable isoform was identified in in vitro culture of the fungus, suggesting a fungal origin for the in vivo enzyme. Haemolymph trehalose decreased significantly during mycosis of locusts by M. anisopliae. All these results suggested that this fungus may take advantage of competing nutrient utilization against the insect by its trehalose‐hydrolyzing enzyme secretion. It may provide fundamental knowledge for fungal pathogenesis.

Chemical modification studies on arginine kinase: Essential cysteine and arginine residues at the active site

Chemical modification was used to elucidate the essential amino acids in the catalytic activity of arginine kinase (AK) from Migratoria manilensis. Among six cysteine (Cys) residues only one Cys residue was determined to be essential in the active site by Tsou's method. Furthermore, the AK modified by DTNB can be fully reactivated by dithiothreitol (DTT) in a monophasic kinetic course. At the same time, this reactivation can be slowed down in the presence of ATP, suggesting that the essential Cys is located near the ATP binding site. The ionizing groups at the AK active site were studied and the standard dissociation enthalpy (Δ H°) was 12.38 kcal/mol, showing that the dissociation group may be the guanidino of arginine (Arg). Using the specific chemical modifier phenylglyoxal (PG) demonstrated that only one Arg, located near the ATP binding site, is essential for the activity of AK.

Cloning, expression, purification, and characterization of arginine kinase from Locusta migratoria manilensis

Arginine kinase (AK) is a phosphotransferase that plays a critical role in energy metabolism in invertebrates. The gene encoding Locusta migratoria manilensis AK was cloned and expressed in Escherichia coli by two prokaryotic expression plasmids, pET-30a and pET-28a. The recombinant protein was expressed as inclusion bodies using pET-30a. After denaturation, the recombinant AK was successfully renatured and confirmed to be enzymatically active. Addition of Tween-20 and SDS to the dilution system led to higher renaturation efficiency. Using another expression plasmid, pET-28a, and changing the expression conditions resulted in a soluble and functional form of AK, which was purified by an improved method using Sephadex G-75 chromotography to a final yield of 358 mg L − 1 of LB medium. Some parameters for the renatured and soluble forms of AK, including K m, K d, specific activity, electrophoretic mobility and isoelectric focusing, were identical with those of AK obtained directly from L. migratoria manilensis leg muscle. Comparison of kinetic constants with those of AKs from other sources indicated that L. migratoria manilensis AKs have the highest k cat and stronger synergistic substrate binding. The first report of a concise purification method enables the enzyme to be prepared in large quantities. This research should enable further detailed investigations of the enzymatic mechanism by site directed mutagenesis techniques.

Genetic Variation and Population Structure of Oriental Migratory Locust, Locusta migratoria manilensis, in China by Allozyme, SSRP-PCR, and AFLP Markers

Allozyme analysis, microsatellite primer PCR (SSRP-PCR), and amplified fragment length polymorphism (AFLP) techniques were used to assess genetic diversity and population structure of the Chinese oriental migratory locust, Locusta migratoria manilensis. A total of 299 PCR markers (67 SSRPs and 232 AFLPs) were detected in eight populations, of which 98.7% were polymorphic markers. The proportion of polymorphic loci (95.5-98.8%) by SSRP+AFLP markers indicated no significant differences between populations, and all populations exhibited a similar level of variability; results of the allozyme analysis demonstrated that 19 loci gave rise to a lower level of polymorphism (55.6-66.7%). The genetic distances between the populations were relatively low. Shannon's index and Nei's gene diversity showed low differentiation among the populations. Allozyme analysis, however, reflected greater similarity and smaller differentiation between the populations than those shown by SSRP and AFLP markers. Neighbor-joining dendrograms derived from both the allozyme and SSRP+AFLP markers showed that the genetic distances among Chinese oriental migratory locust populations were not greatly influenced by geographic distance and breeding habitats.

Role of hunchback in segment patterning of Locusta migratoria manilensis revealed by parental RNAi

In long germ embryos, all body segments are specified simultaneously during the blastoderm stage. In contrast, in short germ embryos, only the anterior segments are specified during the blastoderm stage, leaving the rest of the body plan to be specified later. The striking embryological differences between short and long germ segmentation imply fundamental differences in patterning at the molecular level. To gain insights into the segmentation mechanisms of short germ insects, we have investigated the role of the homologue of the Drosophila gap gene hunchback (hb) in a short germ insect Locusta migratoria manilensi by paternal RNA interference (RNAi). Phenotypes resulting from hb knockdown were categorized into three classes based on severity. In the most extreme case, embryos developed the most anterior structures only, including the labrum, antennae and eyes. The following conclusions were drawn: (i) L. migratoria manilensis hb (Lmm'hb) controls germ band morphogenesis and segmentation in the anterior region; (ii) Lmm'hb may function as a gap gene in a wide domain including the entire gnathum and thorax; and (iii) Lmm'hb is required for proper growth of the posterior germ band. These findings suggest a more extensive role for L. migratoria manilensis hunchback in anterior patterning than those described in Drosophila.

Determination of Trace Level of cAMP in Locusta Migratoria Manilensis Meyen by HPLC with Fluorescence Derivation

A sensitive and rapid method was developed for the determination of cAMP inLocusta migratoria manilensis Meyen by high-performance liquid chromatography withfluorescence detection. The cAMP was derivatized using chloroacetaldehyde and TBASbuffer/methanol was used as the mobile phase. A detection quantification of 40 fmol/mlcould be achieved when using fluorescence detection. An HPLC-MS method using DMHAas an ion-pair agent to analyze cAMP was also demonstrated. We studied the effect ofdopamine and other stimulants on cAMP levels from isolated locust central nervoussystems. The new method is well suited for the analysis of cAMP in small biologicalsamples.

Purification and Characterization of Arginine Kinase from Locust

L-Arginine kinase (AK; ATP:L-arginine N-phosphotransferase; EC 2.7.3.3) catalyzes the reversible transphosphorylation between N-phospho-L-arginine (PArg) and ATP thus buffering cellular ATP levels. AK was purified from the leg muscle of the locust Migratoria manilensis by Sephacryl S-200 HR gel filtration chromatography and DEAE Sepharose CL-6B fast flow anion exchange chromatography to an apparent homogeneity with a recovery of 80%. The enzyme behaved as monomeric protein with molecular mass of about 40 kD, and had a pH and temperature optimum of 8.6 and 30 degrees C, respectively, and a pI of about 6.3. The Michaelis constants for synthesis of PArg are 0.936 and 1.290 mM for L-arginine and ATP, respectively and k(cat)/K(m)(Arg) 174. The activity of AK required divalent cations such as Mg(2+) and Mn(2+). In the presence of Cu(2+) and Zn(2+), AK activity was greatly inhibited. The intrinsic protein fluorescence emission maximum at 330 nm using the excitation wavelength at 295 nm suggested that tryptophan residues are below the surface of the protein and not exposed to solvent.

<strong>ANALISIS HUBUNGAN TINGKAT SERANGAN HAMA BELALANG KEMBARA (LOCUSTA MIGRATORIA MANILENSIS MEYEN) DENGAN CURAH HUJAN</strong><br>(ANALYSIS ON INFESTATION OF LOCUSTA MIGRATORIA MANILENSIS MEYEN BASED ON RAINFALL DATA)

Rainfall has an important role in the incidence of insect pests infestation, such as of locust grasshopper (Locusta migratoria manilensis Meyen). There are some provinces experience of locust grasshopper infestation, i.e. South Sumatera, Lampung, West and East Nusa Tenggara, North and South Sulawesi, West and Central Kalimantan. Generally, cropping season period of April–September and October-March shows a difference influence on the infestation of locust grasshopper. Most of districts in the provinces indicated that locust infestation increases in October–March cropping season, except in South Sulawesi it increases in April–September period. The analysis of correlation between rainfall and locust infestation applied in various timelags. The timelag was determined correspond with the life stage of locust, i.e. egg–hatching–nymphal–early imago–mating–active imago stage. The life stage of locust most influenced by rainfall and correspond with feed availability were active imago stage (in 9 districts) and egg stage (in 6 districts). The increase of rainfall during egg stage tend to suppress the infestation of locust, while during active imago stage the influence of rainfall tend to increase the infestation. The influence of rainfall closely correlated to locust infestation occurs in OKU, Central and South Lampung, West and East Sumba and West Ketawang.

BIOLOGI DAN TRANSFORMASI BELALANG KEMBARA LOCUSTA MIGRATORIA MANILENSIS MEYEN (ORTHOPTERA: ACRIDIDAE) PADA BEBERAPA TINGKAT KEPADATAN POPULASI DI LABORATORIUM

Biology and Transformation of the Migratory Locust Locusta migratoria manilensis Meyen (Orthoptera: Acrididae) at Several Laboratory Population Density Levels. The migratory locust, Locusta migratoria manilensis Meyen (Orthoptera: Acrididae) is one of insect pests in Indonesia that undergoes a unique polymorphic biology. The locust develops a transformation phase which is triggered mainly by high population density. Its recent outbreaks in several regions of Indonesia cause major concern and control strategies must be developed to strengthen control efforts in the future. Its unique polymorphic phenomenon, therefore, must be investigated thoroughly for the basis of management of the outbreak. Due to its agility and its long range flying ability, the most realistic technique to study behavioral and morphological change of the locust is in controlled condition at a laboratory or a green house facility. The experiment was aimed to study effects of colony densities on the biology and transformation process of the migratory locust. More specifically, the experiment was to study effects of population density on the feeding activity, mortality rate, and the ratio of F/C and E/F of the migratory locust L. migratoria manilensis. The population densities were simulated in colonies at 2, 5, 10, 20, dan 30 couples per cage (cage size: 45x45x90 cm) reared in a green house. Results of the experiment show that, in general, higher densities of the migratory locust colonies tended to feed more rigorously than those of the less dense colonies. The locust remained in solitary phase at the density of 2-5 couples per cage whereas the transient phase occured at the density of 10-20 couples per cage. The colonies transformed to gregarious stage when their densities were 30 couples per cage or higher. Mortality percentage tended to be higher at colonies with higher density, especially for the third instar of the migratory locust.

Laboratory and field trials of Green Guard® (Metarhizium anisopliae var. acridum) (Deuteromycotina: Hyphomycetes) against the oriental migratory locust (Locusta migratoria manilensis) (Orthoptera: Acrididae) in China

Abstract In laboratory and field trials in China, the Australian isolate (FI-985) of the fungus Metarhizium anisopliae var. acridum caused high mortality of nymphs of the oriental migratory locust, Locusta migratoria manilensis. In the laboratory, various dilutions of Green Guard®, the commercial M. anisopliae var. acridum product, caused 70 to 80% mortality of 4th instar nymphs. In field trials conducted at Tianjin and in Henan province, backpack sprayers were used to treat 40 ha (2002) and over 160 ha (2003) with an ULV formulation of Green Guard®.The spray was applied at a rate of 50 to 125g spores in 1125 to 1500 mL of oil/ha and, 8 to 11 d later, field populations had declined by 65 to 97%.

Use of MODIS data to monitor the oriental migratory locust plague

Outbreaks of the oriental migratory locust Locusta migratoria manilensis are a serious problem in China. This study evaluated the potential of MODIS data to monitor locust outbreaks in a heavily damaged area in Nadagang State Farm, Hebei Province. Two cloud-free MODIS images of the study area, taken before and during peak damage, were compared to determine the geographical extent and severity of the 2002 locust plague. Ground survey data were used to evaluate locust damage indicated by the normalized difference vegetation index (NDVI) derived from the MODIS data. The results showed that the NDVI reliably distinguished between before and peak damage situations for each category of damage. NDVI values were calculated pixel by pixel and changes at the same sites were compared. Areas where NDVI decreased could be clearly mapped and classified into light, moderate, and heavy damage categories according to the decrease in their NDVI value. Compared to extensive ground surveys, locust damage could be identified with 88.8% accuracy from MODIS data obtained before and during peak.

Disruption of aggregation behaviour of oriental migratory locusts (Locusta migratoria manilensis) infected with Nosema locustae

Abstract: The effect of Nosema locustae infection on the aggregation behaviour of the oriental migratory locust, Locusta migratoria manilensis, was studied using a two‐choice arena olfactometer and electroantennography (EAG). Infected locusts had low antennal sensitivity and aggregation responses to faecal extracts and to locust body volatiles. Infected fifth instar nymphs had significantly lower aggregation index than the uninfected nymphs, although with fourth instars the effect on aggregation behaviour only occurred in infected females. With regard to antennal receptor sensitivity, infected adult locusts had significantly lower EAG amplitudes in response to extracts from faeces of the adult males. The effect was most pronounced in female locusts. In contrast, there was no significant difference in the EAG responses between the fifth instar male and female nymphs. Further analysis revealed that EAG responses of fifth instar nymphs and adults infected with N. locustae to the faecal extract and volatiles from fifth instar solitary‐reared nymphs were not significantly affected. In contrast, infected nymphs and adults had remarkably low EAG amplitudes for the remaining stimuli.

Characterizations of general esterases in relation to malathion susceptibility in two field populations of the oriental migratory locust, Locusta migratoria manilensis (Meyen)

General esterases were characterized and compared from two populations of the oriental migratory locust, Locusta migratoria manilensis, collected from Huanghua and Pingshan Counties, Hebei Province, China. General esterases were most concentrated in the thorax and abdomen, which contained 46.1 and 36.1% of total esterase activity in females, and 42.7 and 36.0% in males, respectively, when α-naphthyl acetate was used as a substrate. There was no distinct difference in esterase banding patterns in different body regions for the substrates α-naphthyl acetate and β-naphthyl acetate on non-denaturing polyacrylamide gel electrophoresis (PAGE). However, the general esterase activities in the Huanghua population were 1.8-fold higher than those in the Pingshan population in both females and males. Increased esterase activity in the Huanghua population appeared to be mainly due to several additional esterase bands detected on non-denaturing PAGE. Inhibition studies of general esterases using four inhibitors, including paraoxon, malaoxon, eserine, and carbaryl, indicated that most general esterases in the two populations were B-type. The increased esterase activity in the Huanghua population appeared to be associated with a 1.8-fold decreased susceptibility to malathion. Such differences may attribute to the difference in control practices for the locust between Huanghua and Pingshan Counties.

Comparative studies of acetylcholinesterases purified from two field populations of the oriental migratory locust ( Locusta migratoria manilensis): implications of insecticide resistance

Acetylcholinesterase (AChE) was purified by affinity chromatography from two populations of the oriental migratory locust, Locusta migratoria manilensis (Meyen), collected from Huanghua and Pingshan Counties, Hebei Province of China. The purification factors and yields were 1661-fold and 19.3%, respectively, for the Huanghua population, and 3897-fold and 39.6% for the Pingshan population. Both the purification factor and yield were significantly lower in the Huanghua population than in the Pingshan population. AChE activity was almost completely inhibited by 10 −6 M eserine and BW284C51, but ⩽5.8% of AChE activity was inhibited by ethopropazine at the same concentration, suggesting that purified AChE from either population was a typical insect AChE. However, AChE purified from the Huanghua population was 62-, 2.0-, and 1.6-fold less sensitive to inhibition by the three organophosphate compounds, chlorpyrifos oxon, demeton- S-methyl, and paraoxon, respectively, than that from the Pingshan population. Significantly lower purification factor and low yield associated with reduced sensitivity of AChE to inhibition by the organophosphates indicated that AChE purified from the Huanghua population was biochemically and pharmacologically different from that of the Pingshan population. Reduced sensitivity of AChE appeared to contribute to organophosphate resistance in the locust from Huanghua County, where insecticides have commonly been used to manage outbreaks of the locust.

HAMA BELALANG KEMBARA (LOCUSTA MIGRATORIA MANILENSIS MEYEN): FAKTA DAN ANALISIS AWAL LEDAKAN POPULASI DI PROVINSI LAMPUNG

Migratory locust (Locusta migratoria manilensis Meyen) : Preliminary facts and analyzes on the population outbreaks in Lampung Province. The migratory locust (locally known as belalang kembara), Locusta migratoria manilensis Meyen (Orthoptera: Acrididae), has become a major insect pest in Lampung in recent years since its outbreak in 1998. Thousand hectares of agricultural fields were severely destroyed by the locust populations during the course of the outbreak. Local as well as national government were caught in surprised by the population upsurge with little information and technology available for controlling the pest. First presence of locust population was recorded in Kecamatan Pakuan Ratu in 1990. Area damage in the first year was ca. 60 ha. The population grew steadily over the years and reached its peak in April-May of 1998 when thousands of corn and rice fields were severely damaged. Country roads and fields were filled with millions of locust nymphs. Records of locust attacks during preliminary outbreaks from 1990 to 1998 also indicated that the insect started its outbreak from the same areas during those years, i.e. North Lampung District and northern Tulang Bawang District (two of the outmost northern of Lampung Province). Insect pest control experts were very concerned that the locust has established its populations in the region and could cause significant loss in the upcoming years. Control strategy and techniques based on the insect biology and population dynamics, therefore, should be explored and developed to manage future outbreaks. This paper discusses and analyzes preliminary facts and information on the migratory locust and possible strategies that could be implemented for managing the locust.