Beetle, ladybird

Hyperaspine alkaloid (1) was isolated from ladybird beetle Hyperaspis campestris. 

Hyperaspine (1), a perhydropyrido[l,2-c][l,3]oxazine alkaloid was isolated from the ladybird beetle H. campestris (01TL4621). 9-Epi-6-epipinidinol (90), a piperidine alkaloid, was prepared from a perhydropyrido[l,2-c][l,3]oxazin-l-one derivative (98T13505). Perhydropyrido[l,2-c][l,3]oxa-zin-l-ones were used to prepare 2,6-disubstituted piperidines (96CJC2434). 

Attractive Compounds. While the defence chemistry of ladybird beetles has been extensively investigated, little is known about intraspecific communication. The role of chemical and behavioural cues has been described in mate recognition in Adalia bipunctata. Cuticular hydrocarbons, especially 7- and 9-methyltri-cosane seem to play an important role [301]. In Coccinella septempunctata, 2-isopropyl-3-methoxypyrazine 158 (see Scheme 17) accounting for the dis-... 

Defensive Compounds. The defensive chemistry of ladybird beetles was treated in the chapter by Laurent et al. in this volume. 

Hyperaspine (23) is the first 3-oxaquinolizidine alkaloid reported so far from ladybird beetles. Its skeleton, however, which is based on a chain of 13 carbon atoms, is biosynthetically related to those of the homotropane and perhydroazaphenalene alkaloid already isolated from ladybirds [38]. 

Monocyclic Carotenoids. Eighteen carotenoid hydrocarbons have been isolated from the ladybird beetle Coccinella septempunctata. Amongst the minor components were detected small amounts of the new y-ring derivatives 3, 4 -didehydro-y.i/f-carotene (6), 7, 8 -dihydro-y,i/f-carotene (7), and 7, 8, 1T,12 -tetrahydro-y,i -carotene (8). 

Aphids extract sap from plant stems, specifically the phloem tissue. They excrete honeydew which still contains plant sugars. Ants collect this honeydew, often by milking the aphids, and use it as food. In return, they protect the aphids against predators. Ants prey on predators of aphids such as ladybird beetles (coccinellids), thus defending the aphids. Ants also shelter aphids by taking them or their eggs into their nests during inclement seasons. In a sense, ants herd aphids like cows. Furthermore, without removal of honeydew, aphid colonies become fouled. 

Some aphid species depend on ants (they are myrmecophilous) while others do not (nonmyrmecophilous aphids). The latter are better at defending themselves They move faster and defend themselves chemically. When attacked by ladybird beetles, they release the alarm pheromone (fj-P-famesene. In response to the pheromone other aphids walk around or drop from the plant. Pea aphids even may grow wings in response to alarm pheromone, allowing them to fly from the host plant. Ants also prey on other herbivorous insects, thus lowering their impact on the host plant. 

Ladybird beetles, obtained commercially or collected in the field... 

Watch for natural aphid predators such as ladybird beetles or housefly larvae on each stem under observation. Record kind and numbers. 

Once again the azaphenalene, Nuphar, and Lythraceae alkaloids are included in this Chapter. Perhaps the most notable achievement of the year is the synthesis of azaphenalenes of ladybird beetles by Ayer and co-workers.Amongst the new alkaloids, the novel pyridone quinoiizidine, mamanine (3) and its tetrahydro-derivative, pohakuline (5) are of special interest. ... 

The defensive substances present in two species of ladybird beetles from Western Canada have been studied/ The known 2a-methylperhydro-9 >-azaphenalenes precoccinelline (38) and its iV-oxide, coccinelline were identified in Coccinella transversoguttata and hippodamine (39) and its iV-oxide convergine in Hippodamia caseyi. The latter species was also shown to contain two new pentahydro-azaphenalenes, hippocasine (40) and hippocasine N-oxide. The structure of the... 

Figure 5 Structure of the dimeric polyacetate alkaloid psylloborine from the ladybird beetle Psyllobora vigintiduopunctata (12).46...

Figure 10 Polyazamacrolides from pupae of the ladybird beetle Epilachna borealis58 and sulfated nucleosides (17) and (18) identified from spider venom.20-21 59...

Adaline (333) was synthesized as described above for euphococcinine [699]. The two-spot ladybird beetle Adalia bipunctata was found to have a considerable investment in defense via its secretion of adaline-rich reflex blood [700]. 

Mono-, di-, and tricyclic alkaloids from ladybird beetles... 

Figure 26 Acyclic alkaloids from ladybird beetles.

Ladybird beetles produce a wide variety of polyacetate or fatty acid-derived alkaloids, many of which closely resemble the ant venom alkaloids described in the previous section. The original discovery of coccinelline (75) and precoccinelline (100) (Figure 32) in blood of the European ladybird beetle, C. 1-punctata had been motivated in part by these beetles aposematic coloration and their tendency to reflex-bleed when molested. Many ladybird beetle species share these characteristics and correspondingly are chemically protected by alkaloids as well. The carbon skeletons of almost all of these alkaloids are based on simple unbranched chains. The structures, biology, and laboratory syntheses of ladybird beetle alkaloids have been reviewed previously by Daloze et al and by Glisan King and Meinwald. ... 

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