Identifying factors determining the altitudinal distribution of the invasive pest leafminers Liriomyza huidobrensis and Liriomyza sativae

Abiotic and biotic factors that change with altitude can influence the distribution of herbivorous insects. We examined factors influencing the distribution of the generalist leafminers Liriomyza sativae Blanchard and Liriomyza huidobrensis Blanchard (Diptera: Agromyzidae), two pests of agricultural crops, in the tropical Dieng mountainous area of Central Java, Indonesia. Liriomyza huidobrensis predominated at altitudes above 700 m a.s.l. and was the only species collected above 1 400 m a.s.l. In contrast, L. sativae predominated below 600 m a.s.l. and was not found above 1 200 m where the average temperature was 20.7 °C. Parasitoid diversity decreased with altitude, but parasitism did not change. The distribution of neither species was affected by parasitoids; L. huidobrensis predominant at high altitudes was preferred by Opius parasitoids common at these altitudes. Intra‐ and interspecific competition was detected in laboratory experiments where larval density was high, but led to coexistence rather than species displacement. No competition was detected in a field experiment when larval density was low. However, L. sativae failed to reproduce at the highest altitude, whereas L. huidobrensis established at all altitudes. Host composition varied with altitude and one host (faba beans) preferred by L. huidobrensis was common at high altitudes. By relating published data on the performance of the leafminer species to altitudinal temperature changes, we were partly successful in predicting the altitude at which the dominant species switched. Temperature plays an overriding influence on the altitudinal distribution of leafminers.     

Role of altitude and water temperature as regulating factors for the geographical distribution of Tetracapsuloides bryosalmonae infected fishes in Switzerland

The role of water temperature and altitude of the river sites on distribution, prevalence and infection intensity of Tetracapsuloides bryosalmonae infected salmonids was investigated. The study is based on a 6 year survey of salmonids, mainly brown trout, Salmo trutta from 2000 to 2006 at 287 sampling sites across Switzerland. Almost 7000 fishes were tested for the presence of T. bryosalmonae by histological and immunohistochemical techniques. A good correlation between altitude and water temperature in Swiss rivers could be demonstrated. Therefore, the relation between altitude and sites tested for T. bryosalmonae infected fishes was investigated since water temperature values from these sites were not available. Percentage of sites with positive (infected) fishes was identical for altitudes between 200 and 800 m above sea level (m a.s.l.), while above 800 m a.s.l. only three sites with infected fishes were recorded. Site‐specific prevalence values ranging from 0 to 100% and infection intensities from 0 to 6 were found over the whole altitude range from 200 to 800 m a.s.l., and no correlation with altitude was found. Conditions at altitudes >800 m may not be favourable for the establishment of the infection in fishes. With rising temperatures due to climatic changes, however, the prevalence of T. bryosalmonae infected fishes in altitudes >800 m a.s.l. could increase.     

Abundance and nightly activity behavior of a sylvan population of Triatoma dimidiata (Hemiptera: Reduviidae: Triatominae) from the Yucatan,México

Triatoma dimidiata is the vector of Trypanosoma cruzi in the Yucatan Peninsula (YP). Earlier studies have shown that domestic and peri‐domestic populations of the vector originated from the sylvan stock and that effectiveness of insecticide‐spraying was affected by re‐infestations of houses from the sylvan T. dimidiata population. In addition, in the YP most previously published reports have focused on domestic and peri‐domestic populations and very little is known about the nocturnal behavior of the sylvan populations. The main aim of our study was to determine the nightly activity patterns of adult T. dimidiata in a selected location in the YP. Secondly, we sought to document the reproductive status and infection rate of active females. During eight sampling nights spaced from late March to late July, 2007, we collected 544 adult T. dimidiata. We found that square‐cloth illuminated white traps were effective to attract the sylvan individuals and that T. dimidiata adults exhibited a unimodal activity pattern throughout the night. The accumulated mean of captured bugs also showed a non‐linear distribution for females and males. Furthermore, we found that male and female catches were significantly correlated with the means of temperature and humidity recorded during the sampling period. Out of 46 dissected females, we observed that 43.5% of females had fully‐formed eggs in their abdomens, and only two females (4.4%) had sperm within the spermatheca. The infection rate of T. dimidiata harboring T. cruzi was found to be 3.7%. The implications of the light attraction to bugs and potential dispersal capabilities are discussed in the paper in the context of infestation/re‐infestation of rural houses by sylvan T. dimidiata flying adults.     

NEW DISTRIBUTION RECORD FOR CHILOGLANIS BIFURCUS JUBB AND LE ROUX, 1969 IN A TRIBUTARY OF THE CROCODILE RIVER,MPUMALANGA PROVINCE,SOUTH AFRICA

Summary

A new distribution record for the South African Red Data fish species Chiloglanis bifurcus was found in the Nels River at an altitude of 830 m a.m.s.l. in the Mpumalanga province, South Africa. Previously this species was known to occur between altitudes 900 m and 1200 m a.m.s.l. in the Elands and Crocodile Rivers of the Inkomati River system, as well as in tributaries of these rivers, namely the Gladdespruit, Stadspruit and Ngodwana River. It was also found to occur in the Komati River of the same river system.     

Endemic gypsophytes composition delimitated by soil properties and altitude: From calciphytes to halophytes in the south–central Alborz Ranges

Specialized plant species have long served as geobotanical tools for locating mines and ores. Despite their importance, not much research has been dedicated to studying the ecology of endemic specialized plant species, such as those of gypsum or calcareous habitats. Here we describe and analyze the occurence of endemic plant species in gypsum habitats of the south–central Alborz Ranges (Semnan), Iran, in relation to altitude and soil properties. Ecological data and soil samples were collected from 120 plots along along an altitudinal gradient correlated with differences in soil properties. Forty seven plant species, including 6 species endemic to the Semnan area and 20 species endemic to Iran, were identified. The occurrence of the species were analyzed using canonical correspondence (CCA) and detrended correspondence Analysis (DCA), and based on the results the species were categorized as gypsophytes G₁ (1600–2245 m a.s.l.), calciphytes (1500–1700 m a.s.l.), gypsophytes G₂ (1300–1600 m a.s.l.) and halophytes (1100–1300 m a.s.l.). Gypsum content, elevation and salinity (Na content) were identified as the environmental factors having the largest effects on vegetation compositon. Endemic Semnan plant species included Astragalus fridae, Euphorbia gypsicola and Gypsophila mucronifolia at higher altitudes, and Astragalus semnanensis, Centaurea lachnopus and Nepeta eremokosmos at lower altitude gypsic soils. More frequent Iranian endemic plant species included Moltkia gypsaceae at higher altitudes, Echinops nizvanus and Acantholimon cymosum at lower altitude gypsic soils, Astragalus glaucacanthos, A. podolobus and A. microcephalus occurring mainly in calcic carbonate soil, and halophyte species such as Artemisia sieberi dominating at lower altitudes with more saline–alkaline soil.     

Altitudinal variation in life‐history traits in the lawn ground cricket,Polionemobius mikado

It has been reported that the lawn ground cricket, Polionemobius mikado (Orthoptera: Trigonidiidae), shows variations in voltinism and life‐history traits along latitude in Japan, but whether it shows variations along altitude has not been examined. The present study aims to determine whether there is variation in voltinism, body size and the incidence of embryonic diapause among populations of P. mikado at different altitudes in Kyoto, Japan. Six populations collected from 70 to 800 m a.s.l. showed a positive relationship between the adult head width and the altitude of sampling locality. This body size cline is attributed to the increasing proportion of larger univoltine individuals from low to high altitude. The incidence of diapause of the strain from altitude 800 m was approximately 100% when reared under natural photoperiods and temperatures from spring to summer at an altitude of 70 m, and was significantly higher than that of the strain from 70 m. These differences in life‐history traits suggest that the population of P. mikado at a higher altitude has adapted to a shorter length of the season available for growth.     

Species composition of termites of the Nyika plateau forests, northern Malawi, over an altitudinal gradient

Termites were surveyed at three altitudes (Brachystegia woodland at 1676 m and 1905 m, and Juniper woodland at 2210 m) in forests within the Nyika Plateau, northern Malawi. Sampling was by a standardized 100 m transect protocol. Termite diversity was highest in the mid‐altitude site and lowest in the Juniper forest. The assemblages were dominated by soil‐feeding termites in the Termitidae subfamilies Apicotermitinae and Termitinae, and included one new soldierless Apicotermitinae genus. The structure of the assemblages was clearly due to a mixture of altitudinal and site history factors. This was especially true of the lowest altitude forest where burning and other anthropogenic disturbance factors appear to have reduced termite diversity relative to the mid‐altitude site. The Nyika plateau shows a much higher diversity at mid‐altitudes than similar SE Asian sites, probably due to the larger area of highland in Africa than in SE Asia. In addition, the clade composition of the Nyika assemblages differs completely from that found at similar altitudes in SE Asia. This preliminary study supports the hypothesis that mid‐ to high‐ altitude assemblages in both SE Asia and Africa appear to be derived from depauperated random subsets of the lowland fauna rather than from clades specifically adapted to higher altitudes.     

Altitudinal Zonation of Pteridophytes on Mt. Banahaw de Lucban,Luzon Island,Philippines

Five altitudinal pteridophyte zones are established along the northeastern altitudinal slopes of Mt. Banahaw de Lucban, Quezon, Luzon Is., Philippines using cluster- and ordination analyses, namely: Zone 1, Cyathea contaminans – Dicranopteris–Nephrolepis–Diplazium patches at 700–800 m a.s.l.; Zone 2, Sphaerostephanos hirsutus var. hirsutus – Selaginella delicatula patches at 750–900 m a.s.l.; Zone 3, Cyathea philippinensis – Selaginella patches at 900–1200 m a.s.l.; Zone 4, Cyathea philippinensis – Cyathea callosa–Asplenium cymbifolium–Selaginella cumingiana patches at 1200–1550 m a.s.l. and; Zone 5 which is further divided into Sub-zone 5A, Cyathea callosa – Cyathea loheri-Hymenophyllaceae patches at 1550–1800 m a.s.l. and Sub-zone 5B, Cyathea loheri – Cephalomanes apiifolia patches at 1800–1875 m a.s.l. These pteridophyte zones coincide with the woody species zones of Mt. Banahaw de Lucban but differ significantly with the altitudinal fern zones of Mt. Makiling. Stepwise multiple regression analysis reveals that altitude exhibits a linear relationship with pteridophyte species distribution. Altitude and soil pH influence 65% of the variation in principal component 1 [PC1 = 0.0839 + 0.0010(altitude) − 0.2072(soil pH); r = 0.8058] and 27% of the variation in principal component 2 [PC2 = 2.0453 − 0.0005(altitude) − 0.2560(soil pH); r = 0.5206]. Thirty-three (33) species are preferential to specific microenvironments along the altitudinal gradient, making them effective altitudinal zone markers and biodiversity conservation indicators for the forest ecosystem of Mt. Banahaw de Lucban.     

Estimating the genetic structure of Triatoma dimidiata (Hemiptera: Reduviidae) and the transmission dynamics of Trypanosoma cruzi in Boyacá, eastern Colombia

Chagas disease is considered a public health issue in Colombia, where many regions are endemic. Triatoma dimidiata is an important vector after Rhodnius prolixus, and it is gaining importance in Boyacá, eastern Colombia. Following the recent elimination of R. prolixus in the region, it is pivotal to understand the behavior of T. dimidiata and the transmission dynamics of T. cruzi. We used qPCR and Next Generation Sequencing (NGS) to evaluate T. cruzi infection, parasite load, feeding profiles, and T. cruzi genotyping for T. dimidiata specimens collected in nine municipalities in Boyacá and explored T. dimidiata population genetics. We found that T. dimidiata populations are composed by a single population with similar genetic characteristics that present infection rates up to 70%, high parasite loads up to 1.46 × 10⁹ parasite-equivalents/mL, a feeding behavior that comprises at least 17 domestic, synanthropic and sylvatic species, and a wide diversity of TcI genotypes even within a single specimen. These results imply that T. dimidiata behavior is similar to other successful vectors, having a wide variety of blood sources and contributing to the circulation of different genotypes of the parasite, highlighting its importance for T. cruzi transmission and risk for humans. In the light of the elimination of R. prolixus in Boyacá and the results we found, we suggest that T. dimidiata should become a new target for vector control programs. We hope this study provides enough information to enhance surveillance programs and a future effective interruption of T. cruzi vector transmission in endemic regions.     

Seasonal flight activity of Platycerus caprea (Coleoptera, Lucanidae) in the Moravskoslezské Beskydy Mts (Czech Republic)

The seasonal flight activity of Platycerus caprea was studied at two sites in the Moravskoslezské Beskydy Mts in 2002–2004 using bark beetle pheromone traps of Theysohn® type. Platycerus caprea occurred at altitudes of 400 m up to 1200 m a.s.l. Seasonal flight activity in both males and females started at the beginning of May and continued until mid-June. At lower altitudes (up to ca 900 m a.s.l.), adults flew in the first half of May, at altitudes about 1000 m a.s.l. in the second half of May and in the highest sites more than 1200 m a.s.l. in the first half of June.     

Alien seedling recruitment as a response to altitude and soil disturbance in the mountain grasslands of central Argentina

Climate and disturbance are considered key factors in explaining plant invasion, mainly by their effect on alien seedling recruitment. We tested whether soil disturbance by digging and altitude, as a sub-set of climate, affected the seedling recruitment of two alien species (Cirsium vulgare and Melilotus alba) in the mountain grasslands of central Argentina. We performed a seed-addition factorial experiment with altitude as a fixed factor co-variable (6 levels), time since sowing (6 levels) as an autoregressive co-variable, and soil disturbance by digging (two levels) and seed addition (two levels) as fixed factors. Seeds of the studied species were sown in replicated undisturbed and disturbed soil plots, in grassland stands located every 200 m from 1200 to 2200 m a.s.l. The number of emerging seedlings at each plot was recorded during a period of 8 months, at intervals of 30–60 days. Seedlings of both alien species emerged at all the studied altitudes, but only the recruitment of C. vulgare increased linearly with altitude. Moreover, the time window of seedling recruitment for this species increased with altitude. Soil disturbance produced a significant decrease in overall seedling emergence of both species; however, an increase in emergence was observed for C. vulgare at an altitude over 2000 m a.s.l. Natural emergence inside control plots without seed addition was only observed for Cirsium vulgare, which indicates that this species was not seed limited. Our results show that altitude and the absence of disturbance do not restrict the recruitment of C. vulgare and M. alba in these natural mountain grasslands. Moreover, these alien species seem to be tolerant to and even favoured by conditions occurring at higher altitudes and in absence of micro-site soil disturbances in the Córdoba mountain grasslands.     

Altitudinal gradients in seed dynamics of Calluna vulgaris in eastern Scotland

Abstract. Relationships between seed deposition, size of soil seed banks and some of the environmental factors affecting them were assessed for Calluna vulgaris throughout its altitudinal range (150–960 m a.s.l.) in eastern Scotland. Seed rain was assessed using pitfall traps, collected every 5–10 wk for 3 yr; germinability was determined by laboratory incubation. Seed bank size was estimated, once only, by counting seedlings emerging from soil cores kept for 50 wk in a glasshouse. Seed deposition varied annually, was related to parent plant cover but always declined with altitude, falling sharply above 600 m a.s.l. Seed bank size was more closely correlated with the proportion of organic matter in the soil than with the amount of seed rain. Seed bank sizes declined gradually with altitude but did not differ significantly between four altitudinal zones. The mean density of buried seeds was less than half the mean annual seed rain at sites below 300 m a.s.l. but was over 200 × greater than annual seed rain above 800 m, suggesting that seeds buried at high altitudes remain viable for much longer than those at lower altitudes.     

Carabid life-cycle strategies and climate change: a study on an altitude transect

Abstract.

• 1 There was little overlap in the species composition of carabid beetle assemblages sampled below 450 m and above 800 m on an altitude transect and the first axis of a DECORANA ordination was closely correlated with altitude (r₁₁= 0.93, P < 0.001), probably reflecting the differing temperature requirements of different species.
• 2 Life-cycle strategies of two low-altitude species, found predominantly below 600 m, and two species caught above 600 m a.s.l., have been determined, using mandible wear to identify whether the females breed in the calendar year that they emerge as adults or in the year following.
• 3 Nebria salina has an annual cycle at 630 m. Pterostichus madidus and Calathus fuscipes were both biennial at altitudes above 300 m although predominantly annual at low altitude. N.gyllenhali was biennial above 600 m and it is not known whether it is able to switch to an annual cycle at low altitude.
• 4 Both N.salina and N.gyllenhali ceased activity soon after emergence, an adaptation which preserves their mandibles from wear.
• 5 At altitudes of 305 m and 430 m, P.madidus and C.fuscipes entered the breeding season with 33% and 56% reduction in mandible tip length, possibly reducing their reproductive output.
• 6 The necessity for relatively sharp mandibles on entry into the breeding season may restrict the capacity of carabids to respond to a temperature change by switching from annual to biennial cycles, and vice versa, adding support to the suggestion that carabids are more likely to respond to climate change by shifting distributions than by physiological adaptation.

     

Altitude affects the distribution and abundance of two non‐native insect pests of the common walnut

The leaf miner Coptodisca lucifluella and the carpophagous Rhagoletis completa, of American origin, are two non‐native walnut (Juglans spp.) pests in Italy. For the Friuli Venezia Giulia region (FVG) (N‐E Italy), C. lucifluella is not yet listed, while R. completa has been present for over 25 years. During 2015, samples of leaves and fruits were collected from 219 single old common walnut trees (Juglans regia) placed at different altitudes (0–1,073 m a.s.l.) in FVG to detect the distribution and abundance of both pests. Samples of leaf miner larvae and their parasitoids were subjected to mitochondrial DNA analysis for identification. C. lucifluella has been found in 55 out of 219 sites. The species has been identified by typical leaf symptoms and by its DNA barcode. This is the first report of the species for FVG. The leaf miner distribution was negatively correlated with altitude. The species has not been observed at sites over 600 m a.s.l. Larvae were parasitized by native parasitoids identified as belonging to the genus Chrysocharis by morphological features and by DNA barcode. R. completa has been found in 89 out of 165 sites on walnut trees with fruits. The infestation level was very high in lowland localities. At sites over 700 m a.s.l., no infestation was found. Both species are widespread in the region, and their occurrence is significantly affected by altitude. Data suggest that walnut trees could be cultivated in some mountain areas without the need to control R. completa with insecticides.     

Effects of temperature on phenological synchrony and altitudinal distribution of jumping plant lice (Hemiptera: Psylloidea) on dwarf willow (Salix lapponum) in Norway

Summary.

• 1 The geographical distributions of three species of jumping plant lice (psyllids) along an altitudinal transect (988–1300 m a.s.l.) in southern Norway were restricted within the range of their host plant Salix lapponum. One species, Cacopsylla propinqua, occurred at all sampling locations between 988 and 1222 m, whereas C.palmeni was confined to higher altitudes (1153–1222 m) and C.brunneipennis was more abundant at lower altitudes (988–1101 m).
• 2 C.brunneipennis and C.palmeni developed only on female catkins. Development times of catkins and psyllids were similar (approximately 50 days) and successful psyllid development depended on close phenological synchrony with catkins.
• 3 Thermal requirements for development of female catkins were greater at low altitude (988 m) compared with higher altitude (1222 m), showing local adaptation of S.lapponum to altitude. In general, thermal requirements of psyllids were less than those of catkins at the same location. C.brunneipennis had higher thermal requirements than C.palmeni.
• 4 Field experiments, using polythene enclosures to elevate temperatures at two sites at different altitudes (by 0.6–1.4 deg. C), showed that insects had an enhanced relative rate of development under elevated temperatures compared with their host plants.
• 5 Indices of phenological synchrony were calculated from thermal requirements of psyllids and catkins. Under elevated temperatures, phenological synchrony decreased at both sites. This resulted in the subsequent development of smaller adult insects at low altitude, although at higher altitude, insects developing under elevated temperatures were larger and had a higher survival rate compared with controls.
• 6 Effects of temperature on phenological synchrony may explain the limits to the geographical range of psyllids. The consequences of climate change on psyllid populations will depend on the effects of decreased phenological synchrony on insect development and this may differ within the insect's geographical range.

     

Nucleotide polymorphisms related to altitude and physiological traits in contrasting provenances of Norway spruce (<Emphasis Type="Italic">Picea abies</Emphasis>)

Variation of sequences of six EST-derived markers was investigated in three Norway spruce (Picea abies [L.] Karst.) provenances originating from different altitudes growing at two contrasting trial plots in Slovakia (Veľky Lom 450 m a.s.l., Mútne-Zákamenné 1,250 m a.s.l.) within a spin-off experiment of the IUFRO 1964/68 Inventory Provenance Experiment with Norway spruce. Single nucleotide polymorphisms (SNP) were identified and differences in allele frequencies at polymorphic sites were tested against altitude or associated with physiological and growth traits (chlorophyll a fluorescence, frost resistance, height, diameter, budburst phenology).     

Physiological and morphological leaf trait variations in two Apennine plant species in response to different altitudes

Morphological and physiological traits of Crepis pygmaea L. subsp. pygmaea and Isatis apennina Ten. ex Grande growing at different altitudes in the Gran Sasso Massif (Abruzzo, Italy) were analyzed. The two populations of C. pygmaea and I. apennina growing at the highest altitude (C _p2 and I _p2 at 2,310 m a.s.l. and 2,350 m a.s.l., respectively) had a lower leaf mass area (LMA) than the two populations growing at the lowest altitude (C _p1 and I _p1 at 2,250 m a.s.l. and 2,310 m a.s.l., respectively). Leaf tissue density (LTD) had the same LMA trend, decreasing 23 and 10% in C. pygmaea and I. apennina, respectively, from the highest to the lowest altitude. C. pygmaea and I. apennina had the highest photosynthetic rates (P _N) in July decreasing on an average 17 and 30%, respectively, in August and 50 and 38%, respectively, in September. Leaf respiration (R) in I _p1 and I _p2 had the same trend as C _p1 and C _p2, showing the highest rates in September. Global warming could drive C. pygmaea and I. apennina toward higher altitudes in the Gran Sasso Massif. Nevertheless, C. pygmaea with the higher plasticity index (PI) both at physiological and at morphological levels (0.50 and 0.35, respectively) might have a competitive advantage over I. apennina over the long term.     

Changes in plant form and function across altitudinal and wetness gradients in the wetlands of the Maloti-Drakensberg,South Africa

A survey of 93 wetlands in six catchments across the Maloti-Drakensberg is used to assess the distribution of plant functional types across altitudinal and wetness gradients. Altitudes range from 1,000 to 3,200 m a.s.l. Within each catchment, the wetlands were selected to cover the complete range in altitude and wetland types. In each of the selected wetlands, vegetation was sampled in 3 by 3 m quadrats covering the entire range of wetness represented in the wetland, from temporarily wet to permanently inundated soils. Plant species were allocated to one of 11 different functional types (examples are C₃ grasses, C₄ sedges, rosette plants, and shrubs), and the proportion of the vegetation in each sample occupied by each functional type was calculated from the species’ abundances. Canonical Correspondence Analysis shows that “wetness” clearly has the highest impact on the distribution of functional types, followed by altitude. The most important plant functional types in wetlands are grasses and sedges, however, at higher altitudes, forbs (especially rosette plants) and bulbous plants become a more prominent feature in the wetlands. The total amount of graminoids gradually decreases with altitude. The general trend is that sedges tend to increase with increasing wetness and C₃ plants (grasses and sedges) increase with increasing altitude, but these effects are not independent. The distributions of C₄ sedges and C₄ grasses along an altitudinal gradient are quite different, and C₄ grasses grow abundantly at much higher altitudes than C₄ sedges. C₄ sedges are very scarce at the altitudes represented in the Maloti-Drakensberg area, whereas C₃ grasses occur in the permanently wet parts of the wetlands, especially at higher altitudes (normally mostly occupied by sedges). Shrubs are rare in wetlands and tend to be an indication of disturbance. This study complements previous studies on the distribution of grasses and sedges at the lower altitudes within KwaZulu-Natal, which found that at altitudes below 1,000 m a.s.l. C₄ sedges were much more prominent, while forbs and rosette plants were largely absent. This confirms that C₄ as an adaptation to hotter and warmer climates is sometimes a less favorable metabolism in wet high altitude areas. At high altitudes, rosette plants and bulbous plants become more competitive in wetlands, probably because grasses and sedges present at these altitudes generally grow smaller than they do in low altitude wetlands.     

Parasitism of Hypothenemus hampei (Coleoptera: Scolytidae) in different farming systems and altitudes of Mount Elgon,Uganda

Altitude and farming system play a vital role in modifying the niche for arthropods, by directly influencing microclimatic conditions, the quality and quantity of vegetative cover, which act variably on the behaviour of the pests, and their natural enemies. The objective of the study was to determine their effect on the abundance and parasitism of the Coffee berry borer (Hypothenemus hampei) in the Mount Elgon region. Altitude was categorized as: low (1,400–1,499 m.a.s.l); mid (1,500‐1,679 m.a.s.l); and high (1,680–2,100 m.a.s.l), and farming system was categorized as: Coffee monocrop; Coffee + annual; Coffee + banana; and Coffee + banana + shade trees. For each altitudinal range, each farming system was represented three times. The study was in two districts of the Mt. Elgon, covering a total of 72 Arabica Coffee study sites. The work involved field pest infestation inventories, followed by laboratory rearing for the abundance and parasitism studies. The results revealed highly significant interactions between altitude and farming system in influencing the abundance of the pest and its four parasitoids: Phymastichus coffea, Cephalonomia stephanoderis, Prorops nasuta and Heterospilus coffeicola. C. stephanoderis was highest in the mid‐altitudes within Coffee + banana+shade tree system; P. nasuta was highest at high altitude within Coffee + banana system; P. coffea was most abundant at mid‐altitude within Coffee + banana system, whereas H. coffeicola was highest at high altitude within the Coffee + annual cropping system. H. hampei counts were highest at low altitudes, especially in the Coffee + annual system. Some of these trends can be explained by the condition of the microclimate in the Coffee fields. There was a negative relationship between temperature and abundance of all the four parasitoids. Only C. stephanoderis had a relationship (+) with semi‐natural vegetation species counts. And only H. coffeicola had a relationship (+) with light intensity. These contrasted with H. hampei, which was positively related to temperature and negatively to light intensity.     

Metarhizium anisopliae (Deuteromycetes: Moniliaceae) Pr1 activity: biochemical marker of fungal virulence in Rhipicephalus microplus (Acari: Ixodidae)

In the present study, the subtilisin-like protease Pr1 activity of five Metarhizium anisopliae s.l. isolates was evaluated together with their virulence against Rhipicephalus microplus females. Bioassays were performed with engorged females, and Pr1 activity was evaluated with the chromogenic substrate N-succinyl-Ala-Ala-Pro-Phe ρ-nitroanilide. All isolates were virulent to R. microplus, although the isolates CG 629, CG 148 and CG 32 caused higher mortality (P ≤ 0.05) than isolates CG 112 and CG 347 after eight days. No mortality was observed in the control group. Enzymatic assays revealed that the protease activity was greater in isolates CG 629, CG 148 or CG 32 than in isolates CG 112 or CG 347 after cultivation for 48 and 72 h. Based on these results, we suggest that the Pr1 activity may be used as a biochemical tool for screening the virulence among M. anisopliae s.l. isolates, and then selecting promising candidates for biocontrol of R. microplus ticks.