Fatty Amines from Little Black Ants, Monomorium minimum, and Their Biological Activities Against Red Imported Fire Ants, Solenopsis invicta

Abstract

Red imported fire ants, Solenopsis invicta, are significant invasive pests. Certain native ant species can compete with S. invicta, such as the little black ant, Monomorium minimum. Defensive secretions may contribute to the competition capacity of native ants. The chemistry of ant defensive secretions in the genus Monomorium has been subjected to extensive research. The insecticidal alkaloids, 2,5-dialkyl-pyrrolidines and 2,5-dialkyl-pyrrolines have been reported to dominate the venom of M. minimum. In this study, analysis of defensive secretions of workers and queens of M. minimum revealed two primary amines, decylamine and dodecylamine. Neither amine has been reported previously from natural sources. Toxicity and digging suppression by these two amines against S. invicta were examined. Decylamine had higher toxicity to S. invicta workers than dodecylamine, a quicker knockdown effect, and suppressed the digging behavior of S. invicta workers at lower concentration. However, the amount of fatty amines in an individual ant was not enough to knockdown a fire ant or suppress its digging behavior. These amines most likely work in concert with other components in the chemical defense of M. minimum.

Update on the defensive chemicals of the little black ant, Monomorium minimum (Hymenoptera: Formicidae)

“…To our knowledge, 9-decenyl-1-amine, N-methylenedecan-1-amine, and Nmethyllenedodecan-1-amine have never been reported as naturally occurring compounds. Two fatty amines, decylamine and dodecylamine, from M. minimum were reported to be insecticidal against the red imported fire ants (Wang and Chen, 2015). Dodecylamine repelled the common house fly, Musca domestica (Ralston and Barrett, 1941) and decylamine repelled the honey bee, Apis mellifera (Atkins et al, 1975).…”

“…Alkaloids are the dominant components of M. minimum venom, including; saturated and unsaturated 2,5-dialkyl-pyrrolidines (Jones et al, 1982;Lange et al, 1989), unsaturated 2,5dialkyl-pyrrolines (Lange et al, 1989), and unsaturated N-methyl-2,5-dialkyl-pyrrolidine (Jones et al, 1982). Two primary amines, decylamine and dodecylamine were recently reported (Wang and Chen, 2015) (see Table 1 for the details of compounds that have been published for M.…”

Naturally Occurring Compounds/Materials as Alternatives to Synthetic Chemical Insecticides for Use in Fire Ant Management

“…Many naturally occurring organic compounds/materials have been assessed for their contact toxicity against fire ants (Table 4), including defensive compounds from other ants [55][56][57], anuran skin alkaloids [58], plant raw materials, plant extracts and essential oils and their individual components [45,[59][60][61][62][63][64][65][66][67]. Soil containing cinnamon leaf debris [62] *: In some studies, the contact and fumigation toxicities of test compounds/materials were not well separated due to the experimental design.…”

“…Tremendous effort has been made in searching for effective and safe repellant alternatives, with numerous compounds/materials being investigated. Many classes of organic compounds have been reported as fire ant repellants (Table 5), such as carboxylic acids, alcohols, carboxylic and dicarboxylic acid esters, ketones [78,79], phthalates [80], terpenes, terpenoids [67,81], phenylpropanoids [64], allylbenzes [63], aminobenzenes [82], alkylamines [57], alkylpyridine (Zhou et al unpublished data), and pyrone derivative [83]. The repellency of many naturally occurring compounds/materials has been tested against fire ants (Table 5), including defensive compounds from other ants [57,84], plant raw materials [62,64], plant essential oils and their individual components [59,60,67,81,[85][86][87][88][90][91][92]94,98].…”

Herbal Plants as Alternatives for the Management of the Red Imported Fire Ant, Solenopsis Invicta (Hymenoptera: Formicidae)

“…However, long-lasting insecticides may reach a lethal amount in species with higher trophic levels through bioaccumulation (Fu et al 2018); the local extinction of these keynote species may break down the entire ecosystem. For reducing the use of synthetic pesticides in pest management projects, it is important to search for more sustainable approaches, such as the phorid y borne pathogen, Kneallhazia solenopsae (Oi and Williams 2003;Oi et al 2008), competitive ant species, Monomorium minimum (Wang and Chen 2015) and costeffective aerial surveillance systems (Spring et al 2017). Among these, plant-based repellents have long been the most attractive alternatives to synthetic insecticides for RIFA management (Chen and Oi 2020).…”