Solenopsis species

Stractures of 3-alkyl-5-methylindolizidines, found in thief ants, Solenopsis species (Table II), arrived at by gas chromatographic and mass spectral analysis were confirmed by coinjection and direct comparison with the synthetic sample. Indolizidine 15a from S. conjurata exhibits characteristic peaks at miz 152 (M — CHj) and 138 (M — C2H5, a base peak) as well as a parent peak at m/z 167 in the mass spectram. It corresponds to an isomer of 3-ethyl-5-methylindolizidine (15) which was prepared as a mixture of four stereoisomers by reductive amination of triketone 391 with ammonium acetate-sodium cyanoborohydride and sodium borohydride (Scheme 47). 

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. 

The dialkylpyrrolidines (I) contain unbranched side chains in which one alkyl group is even-numbered whereas the other group is odd-numbered. These compounds have been identified in the venoms of a variety of Solenopsis species ( , 9, 1J ), all members of the subgenus Diplorhoptrum. 

Alkyl-6-methylpiperidines have only been detected in the venoms of Solenopsis workers and their queens (16, 17, 18). These compounds, which are sometimes referred to as solenopsins, are consistent poison gland products of Solenopsis species in the subgenus Solenopsis, the fire ants ( T7, 3J3J. In addition, some species in the subgenus Diplorhoptrum (thief... 

The cis-trans isomers of four 2-alkyl-6-methylpiperidines, in which the alkyl groups consist of relatively long alkyl chains (C9-Ci5), have been identified in fire ant venoms (XI) (15, 17) members of each Solenopsis (Solenopsis) species group appear to produce characteristic alkaloids. The presence of a fifth 2-alkyl-6-methylpiperidine, 2-hepytl-6-methylpiperidine, in the venom of queens of S. richteri is indicated by mass spectral data (20). ... 

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,... 

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... 

The queen is usually reproductively dominant within the colony and uses chemical cues as both primer and releaser pheromones to suppress the production or fecundity of other sexuals, inhibit reproduction by worker castes, modulate reproductive behaviors (e.g., inhibit swarming and orient swarms), attract males, regulate worker tasks and worker ontogeny, and produce host repellents in slave-making species. Considering the importance of queen semiochemicals in social hymenoptera, few queen pheromones have been chemically identified. The queens of most social hymenopteran colonies are attractive to workers, allowing them to be properly tended as well as to facilitate the dissemination of other pheromone cues. However, the retinue pheromone has been chemically identified in very few species. In the 1980s, queen pheromone components were identified in the fire ant, Solenopsis invicta [91,92], and in the Pharaoh s ant, Monomoriumpharaonis [93]. 

Although many queen-produced pheromones are actively being studied in ants, particularly in the fire ant (Solenopsis invicta) [10,105-110], chemical identifications remain elusive. However, there have been a few recent advances in ants. The queen of the slave-making species Polyergus rufescens produces de-cyl butanoate 60 that repels host workers when upsurping a colony [111]. Males of Formica lugubris are attracted to alate queens by undecane 61, tridecane 62 and (4Z)-tridec-4-ene 63 [112]. 

Sodium molybdate and other molybdenum compounds in toxic baits have potential for termite control (Brill et al. 1987). Baits containing 1000 mg Mo/kg were fatal to 99% of the termite Reticu-litermes flavipes in 48 days. After 8 to 10 days, termites became steel-gray in color, but appeared otherwise normal. Mortality began only after day 16. Termites did not avoid the poisoned bait, even at concentrations of 5000 mg Mo/kg. Yoshimura et al. (1987) reported similar results with another species of termite sodium molybdate killed 100% of the workers in a colony of Copotermes formo-sanus within 24 h after eating filter paper treated with a 5% solution. Some other species of insects — including fire ants (Solenopsis sp.) and various species of beetles and cockroaches — were not affected when exposed to baits containing 5000 mg Mo/kg for 48 days (Brill et al. 1987). 

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. 

In an effort to identify possible sources of the 16 alkaloids found in the skin of the Panamanian poison frog Dendrobates auratus, ants from a total of 61 terrestrial nests were analyzed [124]. The alate queens of one species of myr-micine ants (Solenopsis (Diplorhoptrum) sp.) collected at Cerro Ancon were found to contain the decahydroquinoline (-)-ds-195A (112) which was also present as a minor alkaloid in the skin of the microsympatric population of D. auratus. Moreover, from wingless ants of two nests collected at Isla Taboga and identified as Megalomyrmex silvestrU the same workers isolated the stereo-isomeric 3,5-disubstituted pyrrolizidines rfs-251 K (117) and trans-251 K (118) in the same ratio 3 1 that was present in the skin of a microsympatric population of D. auratus (Fig. 20) [124]. 

Laboratory studies have indicated that ozone at l%Mg/m (0.10 ppm) was lethal to adult houseflies Musca domestica L.) and caused them to lay fewer eggs. Two cockroach species Paraplaneta americana L. and Nauphoeta cinerea Oliver) and the red fire ant Solenopsis invicta Buren) were exposed to ozone at SSSug/m (0.30 ppm) for up to 10 days. There was no unusual mortality or evidence of direct injury to individual insects. The fire ant workers were stimulated to migrate inside their nest initially, but further observations indicated no disruption of social behavior. These reports do not suggest that free-ranging insects would be directly affected by ambient concentrations of ozone in natural ecosystems or agroecosystems. 

Thirdly let ns consider ants. They are a social gronp and may forage across snbstantial distances as a group. Ants lay down a molecnlar trail for other ants to follow. The molecnles involved are termed trail pheromones. Now there are many species of ants and they nse different trail pheromones for the obvions reason of being able to follow the right trail as opposed to that of some other species. That for the hre ant, Solenopsis invicta, is a hydrocarbon of moderate complexity ... 

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... 

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