Life tables of the processionary caterpillar Ochrogaster lunifer Herrich-Schäffer (Lepidoptera: Thaumetopoeidae) at local and regional scales

A major ongoing debate in population ecology has surrounded the causative factors underlying the abundance of phytophagous insects and whether or not these factors limit or regulate herbivore populations. However, it is often difficult to identify mortality agents in census data, and their distribution and relative importance across large spatial scales are rarely understood. Here, we present life tables for egg batches and larval cohorts of the processionary caterpillar Ochrogaster lunifer Herrich-Schäffer, using intensive local sampling combined with extensive regional monitoring to ascertain the relative importance of different mortality factors at different localities. Extinction of entire cohorts (representing the entire reproductive output of one female) at natural localities was high, with 82% of the initial 492 cohorts going extinct. Mortality was highest in the egg and early instar stages due to predation from dermestid beetles, and while different mortality factors (e.g. hatching failure, egg parasitism and failure to establish on the host) were present at many localities, dermestid predation, either directly observed or inferred from indirect evidence, was the dominant mortality factor at 89% of localities surveyed. Predation was significantly higher in plantations than in natural habitats. The second most important mortality factor was resource depletion, with 14 cohorts defoliating their hosts. Egg and larval parasitism were not major mortality agents. A combination of predation and resource depletion consistently accounted for the majority of mortality across localities, suggesting that both factors are important in limiting population abundance. This evidence shows that O. lunifer is not regulated by natural enemies alone, but that resource patches ( Acacia trees) ultimately, and frequently, act together to limit population growth.     

Molecular Characterization and Virulence of Beauveria spp. from the Pine Processionary Moth, Thaumetopoea pityocampa (Lepidoptera: Thaumetopoeidae)

The pine processionary moth Thaumetopoea pityocampa (Den. & Schiff.) is one of the most harmful pests to pine species in Mediterranean countries including Turkey. Caterpillars of T. pityocampa are not only significantly harmful to forest trees but also responsible for various allergic reactions in humans and animals. In this study, in order to find a more effective and safe biological control agent against T. pityocampa, we investigated fungal pathogens of T. pityocampa in the Black Sea Region of Turkey and tested their pathogenicity on it. Five different fungi were isolated and identified based on their morphological and molecular characteristics including ITS and partial sequence of EF1-[alpha]. Based on these characteristics, four isolates were identified as Beauveria bassiana cf. Clade C (Rehner and Buckley in Mycologia 97:84–98, 2005) and one isolate was identified as Beauveria bassiana. Among these isolates, B. bassiana KTU-24, B. bassiana cf. Clade C KTU-66 and KTU-67 showed the highest virulence with 100% mortality within 10 days after application. B. bassiana isolate KTU-24 produced the highest mycosis value with %100. Consequently, B. bassiana KTU-24 seems to be good candidate for further investigation as a possible biological control agent against this pest.     

The relationship between pheromone trap catch and local population density of the oak processionary moth Thaumetopoea processionea (Lepidoptera: Thaumetopoeidae)

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Efficacy and Persistence of Entomopathogenic Nematodes in Controlling Larval Populations of Thaumetopoea pityocampa (Lepidoptera: Thaumetopoeidae)

A 3-year study was conducted in a Pinus halepensis reforestation of Apulia Region (Southern Italy) injecting IJs (infective juveniles) of Steinernema feltiae , S. carpocapsae and Heterorhabditis bacteriophora in aqueous and gel suspensions (Idrosorb SR 2002 [Nigem ® ], and Compex) into the nests of Thaumetopoea pityocampa caterpillar. This study showed that the gel suspensions do not percolate and that slow release of water from the gels allowed nematodes to survive and complete their life cycle in the host. Results demonstrate the feasibility of reducing overwintering larval populations by injecting gel suspension of S. feltiae . We found no negative effects on the endoparasite Phryxe caudata .     

Characterization of five microsatellite loci in the Pine Processionary Moth Thaumetopoea pityocampa (Lepidoptera Notodontidae Thaumetopoeinae)

Five microsatellite markers were developed for the lepidopteran species Thaumetopoea pityocampa using an enrichment protocol. All loci could be amplified with no evidence of null alleles and will be useful for population genetic studies. The number of alleles ranged from three to 12 for a population of 30 individuals. Observed heterozygosities ranged from 0.53 to 0.80. No significant heterozygote deficiency was detected. Four markers might be of interest for Th. wilkinsoni.     

Effects of Bacillus thuringiensis kurstaki on Malpighian tubule cells of Thaumetopoea pityocampa (Lepidoptera: Thaumetopoeidae) larvae

In this study effects of Bacillus thuringiensis kurstaki (Btk) on Malpighian tubule cells of Thaumetopoea pityocampa (Lepidoptera: Thaumetopoeidae) larvae was investigated by electron microscopy. 3 mg/l Btk was given with food. After Btk administration, the Malpighian tubule cells were investigated and compared with a control group. 3 and 6 hrs after Btk administration swelling in Malpighian tubule cells was observed. Swelling of mitochondria and separation of their cristae was seen after 12 hrs. After 24 hrs dissolution of the basal cytoplasm, swelling and vacuolization of all mitochondria, partial dissolution of the nucleoplasm, and swelling and separation ofmicrovilli was documented. A membrane-body in the nucleus was seen after 48 hrs. The nucleoplasm was completely dissolved after 72 hrs and after 96 hrs large vacuoles appeared in the cytoplasm and shortening of microvilli was observed.     

Thaumetopoein, an urticating protein of the processionary hairs of the caterpillar (Thaumetopoea pityocampa Schiff) (Lepidoptera, Thaumetopoeidae)

The irritating fraction extracted from processionary caterpillar hairs contains soluble proteins which were separated by various electrophoretic and immuno-electrophoretic techniques. Some of these proteins are present also in cuticle and haemolymph. One protein of 28,000 daltons, formed of two subunits (13,000 and 15,000 daltons) is hair specific and causes a reaction in pig skin identical to that produced by hair extract. It is therefore an urticating protein and which we have named "Thaumetopoein".     

Effects of Thaumetopoea pityocampa (Lepidoptera: Thaumetopoeidae) larvae on the degranulation of dermal mast cells in mice; an electron microscopic study

The pine caterpillar Thaumetopoea pityocampa (Lepidoptera: Thaumetopoeidae) is found in pine woods. Hairs of the T. pityocampa caterpillar cause a cutaneous reaction in humans and animals. Mast cells are responsible for allergic reactions in mammals. In this study male swiss albino mice were divided into two groups: 5 mice in the control group and 25 mice in the experimental group. The dorsal skin of mice was shaved. The mice in the experimental group and T. pityocampa larvae (fifth instar, approximately n=100) were put in the same cage. Dermal mast cells of mice exposed to T. pityocampa were examined with a transmission electron microscope and compared to the control group 1, 3, 6, 12 and 24 hours after exposure. Dermal mast cell degranulation in mice was observed 12 and 24 hours after exposure.     

Susceptibility of the pine processionary caterpillar Thaumetopoea pityocampa (Lepidoptera: Thaumetopoeidae) toward δ-endotoxins of Bacillus thuringiensis under laboratory conditions

A series of natural crystal proteins from B. thuringiensis subsp. Alesti 12–25, caucasicus, galleriae 11–67, galleriae 6–96, kenyae, and shondungensis and spore‐crystal preparations from finitimus 11–66 and from a recombinant strain of B. thuringiensis subsp. kurstaki expressing Cry 1 Ga1 only, were assessed as a toxic agent for the pine processionary caterpillar, Thaumetopoea pityocampa. Some preparations had a thoroughly investigated composition and contained Cry1Aa, Cry1Ab2, Cry1Ab7, Cry1D, Cry1F, Cry 1 Ga1, Cry9Aa, Cry26 crystal proteins, whereas crystals of B. thuringiensis subsp. caucasicus, kenyae, and shondungensis harboured predominantly unidentified toxins distant from commonly used prototypes. Bioassays were based on the simultaneous assignment of each treatment to groups of 20 full sibling first‐instar larvae, obtained from broods of a population from North‐western Italy. The toxin was applied to pine needles by the leaf dipping method and the effect was registered in both feeding inhibition and mortality. B. thuringiensis subsp. caucasicus, kenyae, galleriae 6–96, alesti, and galleriae 11–67 gave the best results in terms of both feeding inhibition and larval mortality. Broods tested in B. thuringiensis bioassays showed a substantial variation in susceptibility to the toxins, suggesting the potential development of resistance in the population.     

Efficacy and molecular studies of a Lebanese isolate of Beauveria for control of Thaumetopoea wilkinsoni (Lepidoptera: Thaumetopoeidae)

A Lebanese isolate of a Beauveria species originally isolated from a hymenopterous insect pest was found to be very effective against the pine processionary moth Thaumetopoea wilkinsoni. In laboratory bioassays, high mortality rates of the five larval stages were attained with spore concentrations of about 5000–50,000 spores/larva. The efficacy of kill on the first three larval stages was similar to the growth regulator diflubenzuron, but it was significantly higher on the fourth and fifth larval stages. Sequences of the DNA lyase gene and the EF-1α gene were used for molecular characterisation of this Beauveria isolate. The DNA lyase gene showed more polymorphism than the previously reported ITS region and EF-1α gene. This constitutes the first report on the possibility of using the DNA lyase gene as a molecular tool in fungal taxonomy.     

Sex Pheromone of the Female Large Cabbage-heart Caterpillar,Crocidolomia binotalis Zeller (Lepidoptera: Pyralidae)

Sex pheromone components of the female Crocidolomia binotalis, an insect pest of cabbages in Indonesia, were identified from the ovipositor tip extract of virgin females by analyzing with chromatographic fractionation and capillary GC/MS. In an EAG response and attractivity test with a wind tunnel system, a mixture of synthetic compounds, (Z)-9-tetradecenyl acetate (Z-9- TDA) and (Z)-l 1-hexadecenyl acetate (Z-ll-HDA), in the ratio of 1:7—1:60 and an amount of 1 ~ 50 ng on a filter paper, showed strong activities comparable to the activity of the ovipositor tip extract, which contained the two compounds at a ratio of c. 1:10 (Z-9-TDA : Z-l 1-HDA). The mixture of these two compounds might be the sex pheromone of C. binotalis.     

A review of Polynesian Carposina Herrich‐Schäffer (Lepidoptera: Carposinidae), with descriptions of four new species

Hawaiian Carposina represent over 17% of the known world fauna of Carposinidae. In contrast, only two species are known for all of French Polynesia in the South Pacific. Here we describe four new species: two from the Hawaiian Islands, C arposina urbanae sp. nov. and C . gagneorum sp. nov. , and two from the Society Islands, C . longignathosa sp. nov. and C . brevinotata sp. nov. We further recognize another new Hawaiian species too worn to describe. Additionally, we present the first phylogeny for Polynesian Carposina, including 19 taxa, using one mitochondrial and two nuclear gene regions. The Hawaiian Carposina sampled thus far form a monophyletic clade. Lastly, we provide a framework to better understand the diversification and phylogeography of this group, and provide a summary of currently known host plant associations. Diversification appears to have resulted from interplay between host switching and geographic isolation across the Hawaiian Archipelago.     

The Role of Tactile and Chemical Stimuli in the Formation and Maintenance of the Processions of the Social Caterpillar Hylesia lineata (Lepidoptera: Saturniidae)

Colonies of the social caterpillar Hylesia lineata (Lepidoptera: Satumiidae) form long, single-file, head-to-tail processions as they move between their shelters and distant feeding sites. Although investigations of other processionary species have implicated a silk trail in the processionary process, silk plays little or no role in initiating or maintaining processions in H. lineata. Studies we report here implicate both tactile stimuli and a trail pheromone in the establishment and maintenance of processions. Processionaries elicit locomotion in the individual preceding them in line by brushing their heads against prominent sulci that project from the tips of their abdomens. Caterpillars mark their pathways with a pheromone deposited by brushing the ventral surfaces of their last abdominal segments against the substrate. The persistent pheromone is soluble in hexanes and appears to be secreted from glandular setae found on the proximal regions of the anal prolegs and the venter. In Y-choice tests, caterpillars selected newer trails over older trails and stronger trails over weaker trails. They did not distinguish between trials deposited by newly fed caterpillars and those deposited by starved caterpillars. Despite the unidirectional nature of processions, there is no indication that caterpillars can determine from the trail alone the direction in which the procession advanced. The significance of these findings to the foraging ecology of the caterpillars is discussed.     

Growth inhibitory activity of Millettia pachycarpa (Bentham) extracts against Tobacco Caterpillar,Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae)

Abstract

Millettia pachycarpa (Bentham), a perennial climbing tree, found endemic in north-east India used by tribes for treating various ailments. To ascertain the potential of M. pachycarpa for pest management, the present investigation was formulated against a polyphagous pest, Spodoptera litura (Fabricius). Growth inhibitory activity of various extracts and extract fractions was evaluated against third instar larvae of S. litura through topical as well as diet incorporation method. It was observed that dichloromethane extract showed very good growth inhibition in both topical (GI₅₀ 7.77?ppm) and diet incorporation methods (GI₅₀< 5?ppm). The growth inhibitory potential of this plant is also demonstrated by the presence of various abnormalities and reduction in larval and pupal weight.     

Pine processionary moth (Thaumetopoea pityocampa,Lepidoptera: Thaumetopoeidae) larvae are highly susceptible to the entomopathogenic fungi Metarhizium brunneum and Beauveria bassiana

The larvae of the pine processionary moth (PPM), Thaumetopoea pityocampa, feed on the needles of pine and cedar. The urticating hairs of older instars pose a threat to human and animal health. Strains of the entomopathogenic fungi, Metarhizium brunneum (V275, ARSEF 4556) and Beauveria bassiana (KTU-24), were assayed against first to fourth instar T. pityocampa using doses ranging from 1?×?10⁵ to 1?×?10⁸ conidia mL^?1. The three strains differed slightly in their virulence but caused 100% mortality of all instars at the highest dose. The newly emerged or first instar larvae were extremely susceptible with 100% mortality being achieved 2–4 days post inoculation with V275 at all but the lowest dose. The fourth instar larvae appeared to be less susceptible than earlier instars. There was good horizontal transmission of conidia from treated to un-inoculated larvae. However, mortality was higher in third and fourth instars and where the ratio of inoculated versus untreated larvae was high. This we presume is due to spores being more readily trapped by the urticating hairs found on third and older instar larvae. Injection of the nests offers a simple and environmentally friendly way of controlling the pest with reduced risk to operators.     

Insecticidal Properties of Bistrifluron,Benzoylphenylurea Insecticide,against Cotton Caterpillar,Palpita indica (Lepidoptera: Pyralidae)

In this study, we assessed the insecticidal properties of bistrifluron on the insect life stages of the cotton caterpillar, Palpita indicaa, with the primary emphasis on hatching rate, mortality, and susceptibility to chemicals, in addition to the preoviposition period, longevity, and fecundity. Bistrifluron exerted no effects on the egg. However, the larvae hatching from the eggs evidenced 100% mortality within 24 hrs. The susceptibility of P. indica to bistrifluron evidenced similar results at each larval stage. When bistrifluron was applied to the pupal stage, the chemicals significantly affected the longevity and fecundity of the normally emerging adults. The application of high concentrations of bistrifluron (50 ppm) to young adults delayed their pre-oviposition periods. In addition, the longevity, fecundity and hatching rate were attenuated.     

Caterpillar (Lepidoptera) communities on European Turkey oak (Quercus cerris) in Malé Karpaty Mts (SW Slovakia)

Between 2000–2002, the structure of communities of lepidopteran larvae was studied in leaf bearing crowns of Quercus cerris in the central and northern part of the Malé Karpaty Mts (SW Slovakia). Caterpillars were collected using the beating method in four study plots. In total, 58 species were found. The families Geometridae, Noctuidae and Tortricidae comprised the highest number of species found. The family Geometridae comprised the highest number of pests. The most abundant species for individual plots were Lymantria dispar, Operophtera brumata, Ypsolopha alpella and Cyclophora ruficiliaria. Most of the recorded species belonged to the trophic group of generalists (39 species). Shannon-Wiener’s diversity index and Pielou’s equitability (evenness) value indicated there were marked differences between the Horny háj study plot (an insular forest with ants as the predators of caterpillars) and other plots. The main ecological gradient along DCA-1 related to the host specificity of caterpillars and consisted of three groups: (a) polyphagous species; (b) specialist species feeding chiefly on oaks or exclusively on oaks and (c) species preferring some oak species, mainly Q. cerris. The fragmentation of growth was identified along DCA-2.