The first representative of the trap-jaw ant genus Anochetus Mayr, 1861 in Neogene amber from Sumatra(Hymenoptera: Formicidae)

The ponerine ant Anochetus miosumatrensis Ngô-Muller, Garrouste & Nel, n. sp. is described from a fossil alate female preserved in amber of Sumatra which is reputedly of Miocene age. On the basis of the general morphology, the fossil could be attributed to the extant Sumatran species group risii Brown, 1978. By comparing with the living environment of the extant species, this ant probably lived in a warm humid forest where it was trapped in dipterocarpacean resin during nuptial flight. Until now, the known Cenozoic distribution of the genus Anochetus was restricted to the Neotropical region. Thus A. miosumatrensis Ngô-Muller, Garrouste & Nel, n. sp. brings the first record of the genus from Indomalaya biogeographic region.

Not the Honey Bee (Apis mellifera L.) Queen, but the Drone Determines the Termination of the Nuptial Flight and the Onset of Oviposition - The Polemics, Abnegations, Corrections and Supplements

This paper emphasizes the topics concerning honey bee (Apis mellifera L.) mating biology, which have not been described in the recently published book of Koeniger et al. (2014). At the beginning of natural mating, the drone becomes paralyzed. However, the muscles in the abdomen continuously contract shrinking the abdomen till mating has ended and the pair have separated. It is not the queen that ends the nuptial flight. The termination of the nuptial flight is determined by the drone, which fails to remove the mating sign of the previous drone from the sting chamber of the queen. The mating sign originates from two or more drones. The queen also does not determine the age at which she starts oviposition. It is the last drone, which tried to mate, but failed to remove the mating sign of the predecessor, that determines the age that the queen starts oviposition. The book of Koeniger et al. (2014), together with this paper, present the current knowledge of the mating biology of honey bees.

Population Dynamics of Acromyrmex crassispinus (Forel) (Hymenoptera: Formicidae) and Attacks on Pinus taeda Linnaeus (Pinaceae) plantations

This work aimed to study the population dynamics of Acromyrmex crassispinus (Forel) in Pinus taeda L. plantations, evaluating the density and spatial distribution of nests over time, inferring about the period of the first nuptial flight of A. crassispinus colonies, and evaluating the levels of attack of this leaf-cutting ant on P. taeda plants. Assessments were performed monthly in the first year after planting, every three months until the third year and every six months until the plantation was six years old. The presence of nests was observed only after 15 months after planting. The nest density gradually increased until the planting completed 30 months, and decreased when the forest canopy began to close (after 54 months). Spatial distribution of A. crassispinus nests was random. Probably, the first nuptial flight of an A. crassispinus colony occurs after the third year of the colony foundation. Pinus taeda plants were not attacked by A. crassispinus throughout the evaluation period. Then, when dealing with a replanting area of Pinus plantation, where the previous forest has not been subject to pruning nor thinning, the problem with A. crassispinus is almost null if the clearcutting and the new planting occur during the winter. In this case, leaf-cutting ants control can be alleviated and it is not necessary to carry out systematic control of ants where A. crassispinus is the predominant leaf cutting ant species. Acromyrmex crassispinus control should be done only if nests are located or if attacked plants by ants are detected.

Flight and Digging Effort in Leaf-cutting Ant Males and Gynes

The nuptial flight and nest digging are high intensity activities which consume body reserves. The flight and digging effort was quantified by measuring the carbohydrate and total lipids content in males and females before and after the nuptial flight, and the queen’s digging effort during the foundation. The digging effort was quantified by experimentally stimulating the queens to dig a nest – one, two or three consecutive times – compared to the queens that did not dig. The colorimetric method was used to determine the soluble carbohydrates and extraction method of immersion was used to determine the total lipids. The results showed significant loss of carbohydrates and total lipids in males and females after the flight. On average the males contained 0.027 mg of soluble carbohydrates before the nuptial flight, and 0.005 mg after the nuptial flight, and the females contained 0.129 mg of soluble carbohydrates before the nuptial flight, and 0.079 mg after the nuptial flight. For the males the percentage of lipids decreased from 5.27±1.07% to 2.60±0.63% and for females from 36.46±4.86% to 32.62% after the nuptial flight. The digging effort of the queen caused a slight reduction in total carbohydrates, it was without digging 0.054 mg, normal digging 0.055 mg, double digging 0.045 mg (decrease of 20,22 %), and triple digging 0.044 mg (decrease of 20 %) per queen. Based on our results we conclude that the carbohydrate content is the main energetic resource used for the nuptial flight and nest digging, for males and gynes of leaf-cutting ants.

Mating Behavior of the African Weaver Ant, Oecophylla longinoda(Latreille) (Hymenoptera: Formicidae)

Mating in most species of ants occurs during nuptial flights. In the African weaver ant, Oecophylla longinoda Latreille, mating has previously been hypothesized to take place within the nest before the nuptial flight. However, several researchers disagree with this supposition particularly with reference to the closely related species Oecopylla smaragdina (Fabricius) whose mating occur during nuptial flights. Understanding the mating strategy of O. longinoda is of importance for its successful application in biological control programs. We conducted field and screen house experiments during two mating seasons to determine whether the mating occur prior to the dispersal flight. We examined winged O. longinoda queens on the nest surface before taking flight, immediately after leaving the nest, up to twelve hours (12h) after leaving the nest and after settling naturally following the dispersal flights. Mating in captivity between different number of males and queens were also assessed. Only eggs produced by queens (N=65) collected after their natural settling hatched into larvae. No eggs hatched from any of the 527 winged queens that were collected prior to their dispersal flights and no mating attempts in captivity lead to viable offspring. Findings from the current study suggest that mating of O. longinoda queens take place during a nuptial flight and does not take place within the nest, as previously suggested.