Incidence of two caterpillar species (Lepidoptera: Crambidae) and injuries caused by them in sweet basil grown in Seropédica County, RJ

Ocimum basilicum L. (Lamiaceae) is one of the most popular herbs in the world, given its aromatic, medicinal and insecticidal properties. Its leaves are rich in essential oils, as well as the plant part with the highest economic value in this species. The aims of the current study are to identify the causative agent of injuries observed in sweet basil plants grown in Seropédica County, RJ (Brazil), as well as to feature both their feeding behavior and injuries caused by them. The herein investigated injuries were caused in sweet basil stems and leaves by caterpillars, which were collected with the leaves and grown in laboratory until they reached the adult stage. Two lepidopteran species belonging to family Crambidae were identified, namely: Hyalorista opalizalis (Guenée, 1854) and Pyrausta phoenicealis (Hübner, 1818); approximately 73% of adult individuals obtained in laboratory belonged to the first species. Caterpillars belonging to both species have caused similar injuries to O. basilicum plants. Injuries were featured by the sectioning of stems whose leaves were bundled with silk threads and formed a shelter, where caterpillars ate the leaf limb in. The current study also recorded O. basilicum plants used as hosts by P. phoenicealis insects, for the first time.

Dissections of Larval, Pupal and Adult Butterfly Brains for Immunostaining and Molecular Analysis

Butterflies possess impressive cognitive abilities, and investigations into the neural mechanisms underlying these abilities are increasingly being conducted. Exploring butterfly neurobiology may require the isolation of larval, pupal, and/or adult brains for further molecular and histological experiments. This procedure has been largely described in the fruit fly, but a detailed description of butterfly brain dissections is still lacking. Here, we provide a detailed written and video protocol for the removal of Bicyclus anynana adult, pupal, and larval brains. This species is gradually becoming a popular model because it uses a large set of sensory modalities, displays plastic and hormonally controlled courtship behaviour, and learns visual mate preference and olfactory preferences that can be passed on to its offspring. The extracted brain can be used for downstream analyses, such as immunostaining, DNA or RNA extraction, and the procedure can be easily adapted to other lepidopteran species and life stages.

Identification and comparative expression analysis of odorant-binding proteins in the reproductive system and antennae of Athetis dissimilis

Odorant-binding proteins (OBPs) are prevalent in the antennal transcriptomes of different orders of insects. Studies on OBPs have focused on their role in the insect chemosensory system, but knowledge of their functions in the insect testis is limited. We sequenced the transcriptomes of the Athetis dissimilis reproductive organs and analyzed the expression of AdisOBP genes in different tissues. We identified 23 OBPs in the testis and ovaries and 31 OBPs in antennal transcriptomes. The results of real-time quantitative PCR revealed that 23 of the 54 OBP genes were highly expressed in both female and male antennae, including three that exhibited male-biased expression and 15 that exhibited female-biased expression. A total of 24 OBPs were highly expressed in the testis of A. dissimilis, while expression of OBPs in the ovaries was very low. These findings highlight the functional diversity of OBPs in insects and can facilitate further studies on the OBPs in A. dissimilis and lepidopteran species.

A Guide for Using Flight Simulators to Study the Sensory Basis of Long-Distance Migration in Insects

Studying the routes flown by long-distance migratory insects comes with the obvious challenge that the animal’s body size and weight is comparably low. This makes it difficult to attach relatively heavy transmitters to these insects in order to monitor their migratory routes (as has been done for instance in several species of migratory birds. However, the rather delicate anatomy of insects can be advantageous for testing their capacity to orient with respect to putative compass cues during indoor experiments under controlled conditions. Almost 20 years ago, Barrie Frost and Henrik Mouritsen developed a flight simulator which enabled them to monitor the heading directions of tethered migratory Monarch butterflies, both indoors and outdoors. The design described in the original paper has been used in many follow-up studies to describe the orientation capacities of mainly diurnal lepidopteran species. Here we present a modification of this flight simulator design that enables studies of nocturnal long-distance migration in moths while allowing controlled magnetic, visual and mechanosensory stimulation. This modified flight simulator has so far been successfully used to study the sensory basis of migration in two European and one Australian migratory noctuid species.

Antispilina ludwigi Hering, 1941 (Lepidoptera, Heliozelidae) a rare but overlooked European leaf miner of Bistorta officinalis (Polygonaceae): new records, redescription, biology and conservation

We record Antispilina ludwigi Hering, 1941 newly for France: Massif Central and Jura, Belgium: Ardennes and Switzerland: Jura and Alps, from many localities at middle elevations. All records were based on leafmines, often with larvae, in Snake-root, Bistorta officinalis Delarbre (Polygonaceae) and adults were reared from several localities. The species inhab its poor grasslands, moor habitats and heathland with relatively large hostplants. As the habitat is declining, and also other lepidopteran species feeding on this host are in decline, we expect that despite the new findings, this species is also declining and should preferably be monitored together with host specialist butterflies, such as Boloria eunomia (Esper, 1799) and Lycaena helle (Denis & Schiffermüller, 1775). During the period that the mines are present, the species is easy to record, even after the larvae have left the mines. The species is redescribed and diagnosed.

Is Aporia crataegi unsuitable host of Wolbachia symbionts?

The Black-veined White Aporia crataegi (Lepidoptera: Pieridae) is a trans-Palearctic species causing damage to various fruit and berry crops. Here we analyzed Wolbachia infection in A. crataegi populations. Wolbachia bacteria are maternally transmitted intracellular symbionts of many arthropods, including numerous Lepidoptera. We have studied 376 samples of A. crataegi collected in 10 regions of Russia from the Far East to Kaliningrad. Wolbachia prevalence was very low; only eight Wolbachia-positive specimens of A. crataegi were detected in Yakutia, Republic of Buryatia, Sverdlovsk and Kaliningrad Provinces, and no infection was found in other localities. Two Wolbachia haplotypes, ST-19 and ST-109, from A and B supergroups respectively, were identified using the multilocus sequence typing (MLST) protocol. These haplotypes were also previously reported in different lepidopteran species. Both Wolbachia haplotypes were associated with the same mtDNA haplotype (as inferred from the cytochrome oxidase subunit I gene) of A. crataegi, and ST-19 with two mtDNA haplotypes. This incongruence of maternally inherited agents indicates independent cases of the bacteria acquisition in A. crataegi history. The above data suggest that Wolbachia can infect Aporia crataegi but cannot establish in the host populations.

Microsporidian and fungal infections in Lepidoptera and Orthoptera in Bulgaria

Fourteen hundred and sixty three larvae of 10 lepidopteran species collected from trees and bushes in the spring and summer of 2017, 2018 and 2019 from 5 localities in Northwest and South Bulgaria were investigated for presence of microsporidian and fungal pathogens. Also, 77 grasshopper individuals of Poecilimon thoracicus (Orthoptera, Tettiigoniidae) collected from various shrubs and perennial plants in the spring and summer of 2017 were examined. Conducted microscopic analyses showed the presence of microsporidian infection caused by Endoreticulatis poecilimonae in P. thoracicus and fungal infection in the larvae of mottled umber, Erannis defoliaria caused by Entomophaga auliciae. The studies showed that the average infection rate with the microsporidium E. poecilimonae was 57.1%. The prevalence of the fungus Entomophaga auliciae was 100% during the observed epizootic. E. auliciae is an efficient fungal pathogen which causes strong epizootics and can be used as classical or augmentation biological agent.

Electrical signalling on Bt and non-Bt cotton plants under stress by Aphis gossypii

Plants have developed various mechanisms to respond specifically to each biotrophic attack. It has been shown that the electrical signals emitted by plants are associated with herbivory stress responses and can lead to the activation of multiple defences. Bt cotton is a genetically modified pest-resistant plant that produces an insecticide from Bacillus thuringiensis (Bt) to control Lepidopteran species. Surprisingly, there is no study–yet, that characterizes the signalling mechanisms in transgenic cotton plants attacked by non-target insects, such as aphids. In this study, we characterized the production of electrical signals on Bt and non-Bt cotton plants infested with Aphis gossypii and, in addition, we characterized the dispersal behaviour of aphids to correlate this behaviour to plant signalling responses. Electrical signalling of the plants was recorded with an extracellular measurement technique. Impressively, our results showed that both Bt and non-Bt cotton varieties, when attacked by A. gossypii, emitted potential variation-type electrical signals and clearly showed the presence of distinct responses regarding their perception and the behaviour of aphids, with evidence of delay, in terms of signal amount, and almost twice the amount of Cry1F protein was observed on Bt cotton plants at the highest density of insects/plant. We present in our article some hypotheses that are based on plant physiology and insect behaviour to explain the responses found on Bt cotton plants under aphid stress.