Monomorium species

More than a dozen 2,5-dialkylpyrrolidines have been identified in the venoms of Solenopsis and Monomor ium species (J7) AH of these compounds are of the trans configuration. Whereas Solenopsis species may produce only one compound in their poison glands, the venoms of Monomorium species generally consist of mixtures of these alkaloids. 

A variety of Monomorium species in the subgenus Monomor ium produce these alkaloids (I) (6, 12, 12), ... 

Monomorium species also produce dialkylidenepyrrolidines containing a terminally... 

Several N-methylpyrrolidines have been identified in the venoms of Monomorium (Monomorium) species. M. latinode, an Old World species, is distinctive in producing an alkaloidal-rich venom containing two N-methylpyrrolidines with saturated side chains (IV) (6J. On the other hand, the poison gland secretions of several North American species contain N-methylated compounds in which one (V) or both side chains (VI) are terminally unsaturated (6 ) they are accompanied by the corresponding norpyrrolidines. 

Both possible isomers of the 2,5-dialkyl-1-pyrrolines have been identified in the venoms of Solenopsis and Monomorium species. These compounds generally accompany the corresponding dialkylpyrrolidines as venom constituents. The venom of 3. punctaticeps, an African species, contains both 61- and -pyrrolines (VII) (j3) as do the venoms of three North American Monomorium species (12 ). The latter dialkylpyrrolines (VIII) are distinguished by the presence of two terminally unsaturated side chains. The pyrrolines in the venom of M. latinode are distinctive in constituting the only 5-pyrrolines (IX) in ant venoms that are not accompanied by the 1-pyrrolines (6). 

The disubstituted pyrrolidines and piperidines have been demonstrated to be excellent repellents for ants under field conditions. Workers of Monomorium pharaonis effectively repel other species of ants with venom droplets which accumulate on the tip of the sting (37), a strategy that is used with equal success by workers of North American Monomorium species ( 38.) and the European thief ant, Solenopsis fugax (37). The venom of the latter species contains a single alkaloid, trans-2-butyl-5-heptylpyrrolidine (I, m=3, n=6) (1 ), and the... 

Queenright (queen-containing) colonies of 10 species of ants, belonging to two major subfamilies, were utilized for repellency studies. Members of the subfamily Myrmicinae included Solenopsis invicta, Crematogaster ashmeadi. Pheidole dentata, Monomorium minimum. M. viridum and pharaonis. The subfamily Dolichoderinae was represented by Iridomyrmex pruinosus, I. humilis. Tapinoma sessile, and T melanocephalum. Whereas S. invicta and the Monomorium species have been demonstrated to synthesize alkaloid-rich venoms (36, ), these nitrogen... 

Several species pertaining to the sub-family Myrmicinae (e.g., Solenopsis spp., Monomorium spp.) are characterized by a venom rich in dialkylated saturated nitrogen heterocycles (e.g., piperidine, pyrrolidine, indolizidine, pyrrolizidine). Exhaustive lists of these alkaloids have already been published [114-116]. Since then, only a few more of these alkaloids have been reported from a few further species. 

Workers of pharaoh s ant, Monomorium pharaonis, utilize their poison gland secretion as an effective repellent in the same way as that of thief ants, Solenopsis (Diplorhoptrum) species, in order to steal brood from the nests of other... 

Indolizidines have been detected as poison gland products of both Monomorium and Solenopsis species. Monomorine-1, 3-butyl-5-methyloctahydroindolizidine (XVIII), is a major constituent in the venom of M. pharaonis and is accompanied by its congener,... 

Workers of Monomorium minimum rapidly kill termite workers (ReticuTTtermes species) with their poison gland secretions (35). The venom of this species is primarily fortified with 2,4-dialkyl-pyrrolidines (12) which must function as contact insecticides since the venom is applied topically rather than being subdermally administered. The same results have been reported for European species of Monomorium attacking termites (36). 

The first compound identified as a natural product of thrips was V-decalactone (I), a product of Bagnalliella yuccae (8). The anal exudate, which is discharged when the thrips are disturbed, does not contain any other detectable volatiles. Both laboratory and field studies demonstrated that the secretion effectively deterred ant workers either as a topical irritant or by repellency per se. Workers of Monomorium minimum quickly withdrew after contact with the anal fluid and avoided sites at which the exudate had been released (8). The repellency of the anal exudate was clearly identified with T-decalactone, two thrips equivalent of this compound evoking 50% repellency for minimum workers. Similar results were obtained with pharaonis and hvimilis, two other species of predatory ants. The results of field studies corroborated the laboratory findings (8). 

Ants in the myrmicine genera Solenopsis and Monomorium are distinctive in producing venoms that are dominated by alkaloids rather than proteins (15). Fire ants (Solenopsis spp.) in the subgenus Solenopsis characteristically synthesize poison gland secretions that are dominated by the cis- and trans-isomers of 6-alkyl- or 6-alkylidene-2- methylpiperidines ( ). On the other hand, species in the subgenus Diplorhoptrum frequently produce... 

In view of the reported deterrent activities of Solenopsis and Monomorium venoms under field conditions (1, IJ., 12), it seemed worthwhile to evaluate the comparative repellencies to ants of some of these venom-derived alkaloids. In this investigation, the deterrency of these nitrogen heterocycles to a variety of ant species was determined by using a feeding bioassay in which the reactions of hungry ant workers to alkaloid-treated food were quantified Selection of a variety of aggressive ant species... 

Some ants make products reminiscent of the coccinellid alkaloids. Three indolizidines are known from the venom gland of Monomorium pharaonis (Figure 9.10), and a pyrrolizidine from a Solenopsis ant has been known for some time. They would appear to be formed from polyketides or fatty acids as in the case of the coccinellines. More pyr-rolizidines and indolizidines with two alkyl and alkenyl groups have been found in Monomorium and Solenopsis species. Tetraponerine ants smear the venom of their poison glands onto prey. The venom consists of tricyclic alkaloids called tetraponerines (Figure 9.10). They are divided... 

Figure 9.10 More complex alkaloids from ants The indolizidines where R is butyl, hexyl and 3-hexenyl have been known from the venom o/Monomorium pharaonis, pharaoh s ant, for some time. The 2-heptyl-8-methyl-pyrrolizidine is from a Soienopsis ant. The keto-indolizidine is from an African Myrmicaria ant. There are eight of the tetraponerines from Tetraponera species from New Guinea...

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