Subcoccinella Research Articles

Ultrastructural Organization and Metal Elemental Composition of the Mandibles in Two Ladybird Species.

The mandibles are among the most important appendages of insects' mouthparts. Their morpho-functional organization is correlated with the variation in dietary preferences. In this study, we investigated the ultrastructural organization and metal composition of the mandibles of two ladybird species with different dietary habits: Harmonia axyridis (an entomophagous species) and Subcoccinella vigintiquatuorpunctata (a phytophagous species). The ultrastructural organization was studied using Scanning and Transmission Electron Microscopy, whereas the metal composition was investigated using Energy-Dispersive X-ray spectroscopy (EDX). Significant differences were observed in the general organization and metal enrichment pattern between the two species. The mandibles of H. axyridis are large and present a molar part with two teeth, with the apical one showing a bifid apex. In contrast, S. vigintiquatuorpunctata exhibited a molar region with several teeth on its apical part. The study revealed significant differences in metal content between the teeth and the prostheca of H. axyridis. Mn was the most abundant element in teeth, whereas Cl was more abundant in the prostheca. In the case of S. vigintiquatuorpunctata, Si was the most abundant element in the prostheca, while Mn was more present in the teeth. A comparison between the two species revealed that both teeth and prostheca showed significant variation in the elemental composition. These findings underscore the role of dietary preferences in shaping the structural and metal composition variations in the mandibles of these two ladybird species.

Age-Stage, Two-Sex Life Tables of the 24 Spot Ladybird [(Subcoccinella vigintiquatuorpunctata (Coleoptera: Coccinellidae)

HIGHLIGHTS Subcoccinella vigintiquatuorpunctata is one of the main pest on alfalfa. Age-specific life table and survival rate for each life stage was calculated by using TWOSEX-MSChart. This study suggest the life table can be used for the biology and control of the alfalfa pest.

A new microsporidium, Vairimorpha subcoccinellae n. sp. (Microsporidia: Burenellidae), isolated from Subcoccinella vigintiquatuorpunctata L. (Coleoptera: Coccinellidae).

A new microsporidium was isolated from Subcoccinella vigintiquatuorpunctata L. (Coleoptera: Coccinellidae), a pest of Galega officinalis L. in Turkey. Infection in larval and adult stages was systemic with mature spores produced in the midgut, gonads, Malpighian tubules and, most extensively, fat body tissues. The microsporidium was polymorphic with two sporulation sequences producing two types of spores, binucleate spores with 13-15 coils of the polar tube, and uninucleate spores with 7 coils of the polar tube that developed within a sporophorous vesicle (SPV) to form meiospores. The 16S small subunit rRNA (SSU rRNA) gene of the microsporidium was sequenced and compared with twenty-seven microsporidian sequences from GenBank. Based on the phylogenetic analysis of the SSU rRNA sequence, this microsporidium is unique within the Vairimorpha group. Morphological and genetic characters indicate that the described microsporidium is dissimilar to all known Vairimorpha species, and so is named here as Vairimorpha subcoccinellae n. sp.

Beetle Communities of Alfalfa (Medicago sativa L.) in the Republic of Moldova

This article reports on the beetle diversity and abundance study conducted during 2009 and 2010 in three alfalfa fields located near Lozova, Ivancea and Trebujeni in the central part of the Republic of Moldova. All insects were collected using pitfall traps and sweeping techniques. In total, 843 beetle specimens were collected, representing 63 species from 49 genera and 12 families. The largest family was Curculionidae, followed by Scarabaeidae, Carabidae, Coccinellidae, Silphidae, Cerambycidae, Dermestidae, Staphylinidae, Tenebrionidae and Trogidae. Weevils (Curculionoidea) also, represented the greatest proportion in terms of number of individuals. During the present study captured beetles from all three localities were compared and Shannon indices were calculated as a measure of diversity within the habitat. The Shannon diversity index has been found maximum (1.035) in Trebujeni, moderate (1.017) in Ivancea and low (0.936) in Lozova. Five of the recorded species are known to feed on alfalfa (Medicago sativa) and cause serious damage in the Republic of Moldova: Sitona lineatus, S. inops, Hypera postica, Protapion trifolii, Subcoccinella vigintiquatuorpunctata. Of these, S. inops is thought to represent the greatest potential threat based on adult abundance at all three sites and the negative impact of this species. A significant number of beetles collected during this study are adventive species associated with forest ecosystems of the Republic of Moldova.

What constitutes optical warning signals of ladybirds (Coleoptera: Coccinellidae) towards bird predators: colour, pattern or general look?

Most ladybirds (Coleoptera: Coccinellidae) possess chemical protection against predators and signal its presence by less or more conspicuous coloration, which can be considered as a warning. Most ladybirds possess a dotted pattern, althougn the number, shape, and size of the spots, as well as their colour, varies considerably. Almost all ladybirds have a characteristic general appearance (body shape). We considered these traits to be used in ladybird recognition by avian predators. In the present study, we compared the reactions of avian predators (Parus major) caught in the wild, to four differently coloured ladybird beetles (Coccinella septempunctata, Exochomus quadripustulatus, Subcoccinella vigintiquatuorpunctata, and Cynegetis impunctata) and two artificial modifications of C. septempunctata; the first was deprived of their elytral spotted pattern by painting it brown, the other had their elytra removed (i.e. altering their general ladybird appearance). Ladybirds with a spotted pattern were attacked less frequently than unspotted ones. Ladybirds with removed elytra were attacked much more often than any ladybird with a preserved general appearance. The results obtained in the present study suggest the high importance of the spotted pattern as well as general appearance in the ladybird recognition process. Additional experiments with naive birds (hand-reared P. major) demonstrated the innateness of the aversion to two differently spotted ladybird species (C. septempunctata and Scymnus frontalis). © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98, 234–242.

GLANDULAR HAIRS: PUPAL CHEMICAL DEFENSE IN A NON-NATIVE LADYBIRD BEETLE (COLEOPTERA: COCCINELLIDAE)

Subcoccinella vigintiquatuorpunctata, an herbivorous coccinellid beetle of Eurasian origin, is now established in New England, as evidenced by the persistence of two central Connecticut populations from 1997–2001. The beetle's pupal surface bears glandular hairs that produce a secretion known to consist principally of three polyazamacrolide alkaloids. We demonstrate that the secretion serves as a potent antipredator defense: contact with it elicited pronounced cleaning activity by the predatory ant Crematogaster lineolata. Additionally, application of the secretion to palatable food items rendered them unacceptable to the ant. This is one of few studies to examine the chemical defense of an introduced animal vis à vis a predator native to its new environment.

Synthesis of Unsaturated Polyazamacrolides from the Ladybird Beetle Subcoccinella vigintiquatuorpunctata

The pupal defensive secretion of the ladybird beetle Subcoccinella vigintiquatuorpunctata consists of a mixture of macrocyclic polyamines (polyazamacrolides, PAMLs) dominated by three dimeric, 30-membered bislactones (1, 2, and 3), which represent the three possible head-to-tail combinations of the two building blocks (S)-(Z)-11-(2-hydroxyethylamino)-5-tetradecenoic acid (4) and (S)-(5Z,8Z)-11-(2-hydroxyethylamino)-5,8-tetradecadienoic acid (5). We now report the synthesis of these three alkaloids via a route involving the nucleophilic opening of a chiral aziridine as a common step.

Polyazamacrolides from ladybird beetles: ring-size selective oligomerization.

The pupal defensive secretion of the 24-pointed ladybird beetle, Subcoccinella vigintiquatuorpunctata, consists of a mixture of macrocyclic polyamines, dominated by the three dimeric, 30-membered macrocycles 11-13, derived from the two building blocks 11-(2-hydoxyethylamino)-5-tetradecenoic acid (9) and 11-(2-hydoxyethylamino)-5,8-tetradecadienoic acid (10). Smaller amounts of the four possible cyclic trimers of 9 and 10 were also detected, corresponding to 45-membered macrocycles. Structural assignments were based on NMR-spectroscopic investigations and HPLC-MS analyses. In addition, the all-S absolute configuration of the S. vigintiquatuorpunctata macrocycles was determined by comparison of derivatives of the natural material with enantiomerically pure synthetic samples. Comparing this alkaloid mixture with that of the pupal defensive secretion in related ladybird beetle species indicates that the degree of oligomerization of the 2-hydroxyethylamino carboxylic acid building blocks can be carefully controlled by the insects.

Host Specificity Tests of Coccipolipus epilachnae , 1 a Mite Parasitic on the Mexican Bean Beetle 2

Tests of the host specificity of Coccipolipus epilachnae Smiley, a mite parasitic on the Mexican bean beetle, Epilachna varivestis Mulsant, suggested that hosts are limited to the members of the subfamily Epilachninae. Coccinellid species tested that were not suitable hosts included: Chilocorus stigma Say, Coccinella septempunctata L., Cycloneda munda (Say), Hippodamia parenthesis (Say), Hippodamia convergens Guerin-Meneville, Coccinella undecimpunctata L. and Coccinella novemnotata Herbst. C. epilachnae did complete its life cycle on Subcoccinella vigintiquatuorpunctata (L.), another epilachnine.