Urticating hairs of "brown-tail" moth (Euproctis chrysorrhoea L.) (Lepidoptera): preliminary studies in urban and laboratory

Urticating hairs of the brown-tail moth (Euproctis chrysorrhoea L.) are detectable in the air using apparatus designed for the collection of airborne microorganisms and pollen research studies. The hairs are produced by caterpillars and are distributed by air currents or via moths. They were collected in Bordeaux. In the laboratory a nycthemeral cycle of hair emission is observed and is correlated with the biological activities of these species.     

The brown-tail moth of Bombyx Euproctis chrysorrhoea L. (Lepidoptera) responsible for lepidopterism in France: biological interpretation

A scanning electron microscope study has enabled an explanation as to why the brown-tail moth provokes Lepidopterism. The brown-tail moth only provokes Lepidopterism via a transmission of the urticating hairs of its caterpillar. Urticating moths (genus Hylesia and Anaphae) protect their eggs and young caterpillars with urticating hairs, thus it is very ambiguous to label erucism as the contact dermatitis produced by caterpillar production or Lepidopterism as the contact dermatitis caused by moth urticating hairs.     

Thigmotaxis maintains processions of late‐instar caterpillars of Ochrogaster lunifer

Processionary behaviour is a distinctive feature of the dispersal of caterpillars of a number of Lepidoptera, including Ochrogaster lunifer Herrich‐Schäffer (Lepidoptera: Notodontidae) from Australia. By cutting hairs on either the first or last three segments of the bodies of caterpillars and re‐introducing them into processions of normal caterpillars, the present study provides strong evidence that thigmotaxis is the mechanism that maintains single‐file, head‐to‐tail movement of groups of individuals. The inclusion of caterpillars whose posterior hairs have been cut results in the breakage of processions, whereas the inclusion of caterpillars whose anterior hairs have been cut rarely results in the breakage of processions. The breakage of processions occurs because caterpillars whose posterior hairs had been cut are difficult to follow and they will not stop when those behind became detached. The speed of movement of processions incorporating caterpillars whose hairs on the posterior segments of their bodies have been cut also has a significant effect on the likelihood of maintaining processionary movement; faster‐moving processions are more likely to break than are more slowly‐moving processions.     

Atmospheric pollution of animal origin: the urticating hairs of the processionary caterpillar (Thaumetopoea pityocampa Schiff.) (Insects, Lepidoptera)

Urticating hairs of pine processionary caterpillars are detectable in air using techniques designed for airborne microorganisms and pollen's research. As with pollens, abondance of hairs is correlated with distance of production zone and with local meterological conditions. Collected in Bordeaux, urticating hairs will be considered for allergists as pollens and other allergic particles.     

Breeding success and lutein availability in great tit (Parus major)

The relationship among temporal variation in the availability of carotenoid-rich food, tissue carotenoid levels and breeding success are poorly known. We studied how diet quality and quantity affect the carotenoid profile and fledging success of great tit (Parus major) nestlings along a pollution gradient. We found declining seasonal trend in lutein concentration of caterpillars, which may be the explanation for the declining trend in nestlings' lutein concentration of plasma with season, despite the increase in caterpillar biomass. This may be because the biomass of most lutein-rich caterpillars (autumnal moths) decreased and less lutein-rich caterpillars (sawflies) increased during the breeding season. The temporal difference in occurrence of different caterpillar species means that peak lutein availability does not coincide with peak caterpillar abundance. However the positive association between total larval biomass and the number of great tit fledglings may suggest that fledging success depends more on total caterpillar availability than on lutein concentration of caterpillars.     

The inhibitory effects of rose powdery mildew infection on the oviposition behaviour and performance of beet armyworms

In this study, we investigated whether the oviposition behaviour and performance of the beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), on the rose cultivar Rosa chinensis Jacq. (Rosaceae) were affected when the plants were infected by rose powdery mildew, Podosphaera pannosa (Wallr.: Fr.) de Bary (Erysiphales). The bioassays revealed that the moths significantly avoided ovipositing on mildew‐infected rose leaves when compared to healthy leaves. Pupal weights, emergence rates, and fecundity decreased when the caterpillars were fed mildewed rose leaves. Further laboratory bioassays aimed to elucidate the effects of two volatile headspace extracts (separately collected from healthy and mildewed rose plants) on the oviposition behaviour and performance of the moths. The moths clearly preferred to oviposit on healthy rose leaves that were not sprayed with additional volatiles rather than on healthy leaves sprayed with the volatile extracts from mildewed plants. The mean number of eggs laid on the former leaves was more than six times higher than that laid on the latter leaves. Olfactory bioassays demonstrated that ovipositing moths were significantly more attracted to volatiles emitted by healthy rose leaves than to those emitted by mildew‐infected leaves. Similar results were obtained when comparisons were made between the volatile extracts collected from healthy and mildewed rose plants. Thus, volatiles from mildew‐infected roses have a strong inhibitory effect against the moths. These results indicated that rose volatiles play a role in the oviposition behaviour of the moths, and that the volatiles induced by powdery mildew might be used for insect control.     

Effect of defoliation by checkerspot caterpillars (Euphydryas phaeton) and sawfly larvae (Macrophya nigra and Tenthredo grandis) on their host plants (Chelone spp.)

Summary The effect of defoliation by herbivores, checkerspot caterpillars (Euphydryas phaeton) and sawfly larvae (Macrophya nigra and Tenthredo grandis), on the reproductive output of turtlehead (Chelone spp.) was examined. Defoliation prior to development of flower buds reduced the number of reproductive stalks, flower buds, flowers and seed capsules. Severe herbivory, after flower buds appeared, decreased the final number of seed capsules and seeds per capsule. The availability of the host plants to the herbivores was a function of prior defoliation and environmental conditions. Sawfly larvae, by defoliating the plants in midsummer, forced prediapause checkerspot caterpillars to wander in search of food plants. Decimation of these perenials by postdiapause checkerspot caterpillars in a dry spring retarded growth of turtlehead and, consequently, most of the plants were not available for egg-laying by sawflies and checkerspots.     

“Balloon hairs” of gipsy moth larvae (Lep., Lymantriidae): morphology and comparative chemistry

The “balloon hairs” of L₁ caterpillars of Lymantria dispar (Lep., Lymantriidae) are jointed, hollow and filled with a fluid. Detection of nicotine in the balloon hairs as well as feeding-deterrent effects of whole larvae and nicotine on ants indicate that these setae serve for defense against predatory arthropods and parasitoids but not for soaring of the larvae. Titers of nicotine and other components were determined for several developmental stages of L. dispar and compared.     

Larval Sociality in Three Species of Central-place Foraging Lappet Moths (Lepidoptera: Lasiocampidae): A Comparative Survey

We studied three species of Lasiocampidae with social, tent-building caterpillars in Northern Bavaria, viz. Eriogaster lanestris, Eriogaster catax, and Malacosoma neustria. We used key life-history data (number of larval instars, sizes and weights of eggs, caterpillars, and moths, size of egg clutches) as well as behavioral data (activity patterns, tent-building behavior, trail following behavior) for a comparative study. Although larvae of all three species are active only in spring, show overlapping habitat requirements, and use the same major host-plant (Prunus spinosa) with only minor differences in phenology, they show markedly different life-history and behavioral strategies.E. catax lays comparatively few but large eggs while E. lanestris lays more but smaller eggs. M. neustria lays the smallest eggs but large clusters. E. lanestris caterpillars build a large tent with an accessible interior while those of E. catax build a small tent that is only used as a resting and molting platform. M. neustria shows a flexible behavior, may abandon the primary tent and build a new one several times. M. neustria colonies also subdivide and reunite regularly while Eriogaster colonies stay together until larvae become solitary. In E. lanestris all tentmates of a colony are highly synchronized while foraging or resting. Instead, in E. catax small subgroups leave the tent for foraging while at every time the majority rests on the tent. M. neustria caterpillars forage more or less individually and only synchronize by night. Results are discussed in relation to other species of the genera Eriogaster and Malacosoma and with regard to the evolution and diversification of caterpillar sociality.     

Reduced antennal sensitivity, behavioural response, and attraction of male codling moths, Cydia pomonella, to their pheromone (E,E)-8,10-dodecadien-1-ol following various pre-exposure regimes

The effects of pre‐exposing male codling moths, Cydia pomonella (L.) (Lepidoptera: Tortricidae), to their pheromone (E,E)‐8,10‐dodecadien‐1‐ol (codlemone), in static and moving air, under laboratory and field conditions, on subsequent antennal sensitivity, behavioural responsiveness, and attraction to codlemone were investigated. In flight tunnel experiments, the percentage of moths wing fanning and taking flight were mostly unaffected, but upwind flight to, and contact with, pheromone sources known to elicit responses of both were shown to depend on the intensity and duration of previous exposure to codlemone and recovery time between exposure and assessment. Ten to 30‐min pre‐exposures to codlemone in static air (≈ 35 µg l^?1) not only caused a 99% reduction in attraction, but also significantly reduced electroantennogram response to codlemone. Recovery of full antennal sensitivity to codlemone took more than 1 h, but recovery of attraction took over 4 h, suggesting that habituation is also partially involved in reduced behavioural responsiveness following pre‐exposure. Seventy‐five min exposures to codlemone in moving air (5–10 cm s^?1) at rates of 0.9, 4.5, and 18 µg h^?1 from Celcon fibres caused 75, 86, and 99% disruption, respectively. However, 30–34‐h exposure of caged moths to air moving through an orchard treated with 1000 Isomate‐C® dispensers ha^?1 releasing approximately 20 µg h^?1 per dispenser during tests, had no impact on moth response in flight‐tunnel assays 30 min after removal from the orchard. In this treated orchard, catches of free‐flying moths in pheromone‐baited traps were completely inhibited. If observed mechanisms such as long‐lasting antennal adaptation or habituation of the central nervous system contribute to the disruption of pheromone communication among codling moths under field conditions, it seems unlikely that they occur following exposure to the average atmospheric concentrations of codlemone. For these effects to be important, codling moths may require close contact with pheromone sources for extended periods, or repeated close encounters.     

Changes in the fecundity of tent caterpillars: a correlated character of disease resistance or sublethal effect of disease?

Over the fluctuation in population density of tent caterpillars, Malacosoma californicum pluviale and M. disstria, fecundity changes from being high at peak density to low for several years during the decline. During the increase phase, fecundity rapidly returns to moderately high levels with a further increase occurring to-ward the end of the increase phase. Two hypotheses which might explain these shifts are that (1) mortality from viral disease which is common during population declines selects for resistant individuals with low fecundity as an associated characteristic, and (2) sublethal viral disease reduces fecundity of moths during population decline. In this study we observed rapid shifts in the frequencies of large and small egg masses and in the mean fecundity between different phases of the population fluctuation. Viral disease was more common in caterpillars from small egg masses of the forest tent caterpillar. These observations are consistent with the hypothesis that sublethal effects of virus reduce the fecundity of moths during the population decline, but high fecundity is quickly restored when disease is rare during the population increase.     

Ligularia zhengyiana sp. nov. (Asteraceae) from the Hubei Province,China

The new species Ligularia zhengyiana from the Hubei Province, China, is described and illustrated. It is characterized by dense blackish purple pilose hairs on the stems and by coarsely triangular‐dentate leaves. Ligularia zhengyiana is similar to L. fischeri (Ledeb.) Turcz., but L. zhengyiana has dense long blackish purple hairs on stems, while L. fischeri is glabrous or has short yellowish‐brown hairs on stems. In addition, the pappus of L. zhengyiana is white, while that of L. fischeri is yellowish‐brown.     

A single lycaenid caterpillar gets an ant‐constructed shelter and uninterrupted ant attendance

Ant‐lycaenid associations range from mutualism to parasitism and the caterpillars of some species of lycaenids are reported to enter ant nests for shelter, diapause, or pupation. The present study aimed to examine the nature of the association between Euchrysops cnejus (Fabricius) (Lepidoptera: Lycaenidae) and Camponotus compressus (Fabricius) (Hymenoptera: Formicidae) worker ants on the extrafloral nectary‐bearing cowpea plant, Vigna unguiculata (L.) Walp. (Fabaceae). The abundance patterns of the ants and the lycaenid caterpillars together with the spatial patrolling patterns of the ants on the plants revealed that ant abundance increased with the occurrence of the lycaenid caterpillars and the ants preferred the lycaenids over the extrafloral nectar. Camponotus compressus worker ants constructed a shelter at the cowpea plant base after interaction with one or more lycaenid caterpillar(s) and tended the caterpillars and pupae till the emergence of the butterfly. The ant‐constructed shelters (ACSs) inhabited by the minor caste workers (13 ± 1.3 ants per ACS), were utilized by the caterpillars to undergo pupation. The ants confined their activities predominantly to tending the pod‐feeding caterpillars and the solitary pupa within each ACS. It appears that the behavior of the tending worker ants is modulated by the lycaenid vulnerable stages.     

n-Butyl (E)-7,9-decadienoate: sex pheromone component of the nettle caterpillar, Darna pallivitta

The nettle caterpillar, Darna pallivitta (Moore) (Lepidoptera: Limacodidae), is an invasive pest on the island of Hawai’i, causing defoliation of ornamental nursery stock and posing a human health hazard due to their urticating hairs that can cause painful stings. Wind tunnel and field tests with 2–3‐day‐old moths revealed behavioral responses of males to caged females, which is indicative of a female‐released sex pheromone. Coupled gas chromatography‐electroantennogram detection (GC‐EAD) analysis of female abdominal tip extracts revealed two male electroantennographically active compounds produced by female D. pallivitta. Mass spectral analysis and subsequent synthesis identified the active compounds as n‐butyl (E)‐7,9‐decadienoate (major component) and ethyl (E)‐7,9‐decadienoate (minor component), both structurally similar to sex pheromone components previously reported from related Darna spp. Additionally, methyl (E)‐7,9‐decadienoate was identified from female abdominal tip extracts and a strong EAD response was elicited by the synthetic compound. n‐Butyl (E)‐7,9‐decadienoate was the only component detected by solid phase microextraction (SPME) collections from single calling female moths, however, the apparent absence of minor components may be a result of their lower abundance. Field trials showed significant attraction of male moths to all lures containing the n‐butyl ester, while the methyl and ethyl esters did not increase trap captures at the levels and ratios tested. Synthetic pheromone lures (2.5 mg) outperformed virgin moths as attractant baits and could be used for monitoring D. pallivitta populations of the island of Hawai’i and detection on other Hawai’ian islands and at ports and nurseries that receive plants from Hawai’i (e.g., California and Florida).     

Adoption of lycaenid Niphanda fusca (Lepidoptera: Lycaenidae) caterpillars by the host ant Camponotus japonicus (Hymenoptera: Formicidae)

Caterpillars of the parasitic lycaenid butterfly are often adopted by host ants. It has been proposed that this adoption occurs because the caterpillars mimic the cuticular hydrocarbons of the host ant. This study aimed to examine whether caterpillars of the Japanese lycaenid butterfly Niphanda fusca induce adoption by mimicking their host ant Camponotus japonicus. Behavioral observations conducted in the laboratory showed that most second‐instar caterpillars were not adopted, whereas most third‐instar caterpillars were successfully adopted by host workers. A chemical comparison detected no characteristic differences in the cuticular hydrocarbon profiles between second‐ and third‐instar caterpillars. However, morphological features of the caterpillars differed between the second and third instars; third‐instar caterpillars developed exocrine glands (ant organs) such as tentacle organs and a dorsal nectary organ. These results suggest that multiple chemical signatures, not only cuticular hydrocarbons, may be important for invasion of the host ant nest.     

Interactions between Chromolaena odorata (Asteraceae) and Pareuchaetes pseudoinsulata (Lepidoptera: Arctiidae)

Feeding of Pareuchaetes pseudoinsulata caterpillars caused the leaves of Chromolaena odorata to turn yellow. Leaf yellowing could not be induced either by artificial removal of leaves or by drenching the plant with a solution of excreta from P. pseudoinsulata caterpillars. Yellow leaves appeared tougher but had the same energy level as that of green leaves. The amount of nitrate-nitrogen was significantly higher in yellow leaves than green leaves. P. pseudoinsulata caterpillars prefer to feed on green leaves. When forced to feed on yellow leaves, they exhibit slow growth and high mortality. Defensive factors in plants attacked by insects seemed to prevent further infestation of plants. In the field, caterpillars on the yellow plants were found during both day and night whereas on green plants they appeared to feed at night and hide in the ground at daytime.     

Host-ant trail following by myrmecophilous larvae of Liphyrinae (Lepidoptera,Lycaenidae)

In this study we report a case of ant-trail following by lycaenid caterpillars. Euliphyra mirifica and E. leucyana caterpillars are involved in a commensal association with the weaver ant Oecophylla longinoda. The host nests are made with leaves which over the course of time dry out or are broken open by storms, forcing the ants to migrate and build a new nest elsewhere. Euliphyra caterpillars are stimulated by recruitment behaviour which triggers the migration of their host. They then follow the host trails leading to the new nesting site. Laboratory experiments showed that these caterpillars are able to follow host trails under varied conditions: (1) fresh trails actually used by workers, (2) fresh trails in the absence of workers, (3) heterocolonial, 2-month-old trails, and (4) fresh trails washed with water (to simulate the effect of tropical rains). They can also bridge trail gaps of more than 1 cm. Under natural conditions, the trails are frequently situated along thin twigs. The forward progress of the ants in such a situation is not impeded by the presence of large Euliphyra larvae. Workers just climb over the caterpillars, even on larger trails where there is enough room to pass alongside them. This suggests that an allomone is secreted on the dorsal part of the caterpillars. When crawling along heterocolonial trails, the caterpillars are not attacked, even if about 21% of the workers from the new colony spread their mandibles when encountering them. They are then adopted and are admitted to the nest of the new host colony of O. longinoda.     

Hair anatomy inPlantago subg.Psyllium (Plantaginaceae)

The hairs of seven representatives ofPlantago L. subg.Psyllium were studied. Three types of headless hairs and three types of headed hairs were observed. Clavate hairs and hairs with several-celled stalk and unicellular head are characteristic of subg.Psyllium and provide evidence for the distinctness of this taxon. Based on our studies it can be assumed thatRahn's idea of enlarging subg.Psyllium by six sections from subg.Plantago sensuPilger is incorrect.     

The Fine Structure of a Sensory Organ of a Cladocop Ostracode (Crustacea) Belonging to the Organ of Bellonci (Sensory Pore) Complex

Andersson, A. 1980. The fine structure of a sensory organ of a cladocop ostracode (Crustacea) belonging to the organ of Bellonci (sensory pore) complex. (Department of Zoology, University of Lund, Sweden.) — Acta zool. (Stockh.) 61(1): 51–58. The organ of Bellonci, a complex of cephalic receptors, has previously been reported from two ostracode groups. On morphologic grounds, a cephalic receptor of a third ostracode group (Cladocopa) is believed to be an organ of Bellonci. The organ is situated on the forehead above the first pair of antennae and consists of two feathered hairs. Two nerves, each formed by one dendrite, run from the protocerebrum into the hairs where they terminate with ramose cilia. The dendrites, as well as the cilia and ciliary branches, are enveloped by glial cells. Distally, these cells form cavities around the ciliary branches. The ciliated neuronal connection and the glial cavities, together with other morphologic characteristics of the organ, support a homologization with the organ of Bellonci of other myodocopid ostracodes.     

Artificial light at night causes diapause inhibition and sex‐specific life history changes in a moth

Rapidly increasing levels of light pollution subject nocturnal organisms to major alterations of their habitat, the ecological consequences of which are largely unknown. Moths are well‐known to be attracted to light at night, but effects of light on other aspects of moth ecology, such as larval development and life‐history, remain unknown. Such effects may have important consequences for fitness and thus for moth population sizes. To study the effects of artificial night lighting on development and life‐history of moths, we experimentally subjected Mamestra brassicae (Noctuidae) caterpillars to low intensity green, white, red or no artificial light at night and determined their growth rate, maximum caterpillar mass, age at pupation, pupal mass and pupation duration. We found sex‐specific effects of artificial light on caterpillar life‐history, with male caterpillars subjected to green and white light reaching a lower maximum mass, pupating earlier and obtaining a lower pupal mass than male caterpillars under red light or in darkness. These effects can have major implications for fitness, but were absent in female caterpillars. Moreover, by the time that the first adult moth from the dark control treatment emerged from its pupa (after 110 days), about 85% of the moths that were under green light and 83% of the moths that were under white light had already emerged. These differences in pupation duration occurred in both sexes and were highly significant, and likely result from diapause inhibition by artificial night lighting. We conclude that low levels of nocturnal illumination can disrupt life‐histories in moths and inhibit the initiation of pupal diapause. This may result in reduced fitness and increased mortality. The application of red light, instead of white or green light, might be an appropriate measure to mitigate negative artificial light effects on moth life history.