The influence of male dominance in female Anastrepha curvicauda mate selection.

Males of the papaya fruit fly, Anastrepha curvicauda Gerstaecker (former Toxotrypana curvicauda), defend a papaya fruit from rivals and males release their sex pheromone to attract and mate with females and offer them an oviposition site. While some aspects of the biology of A. curvicauda are known, such as its reproductive biology, its sex pheromone, and host selection, there is currently no information on the species mate selection process. This paper describes the precopulatory mating behavior of A. curvicauda and elucidates how intrasexual selection affects the mate selection process. We studied the precopulatory mating behavior of dominant and subordinate males and ethograms were devised. The effect of hierarchy was studied in non-choice and choice experiments. Male's repertoire includes 15 behavioral elements, 12 precopulatory, one mating, and two postcopulatory (tandem and encounter). In non-choice experiments, dominant and subordinate males were accepted by females, but when females had the opportunity to choose among males, dominant males were significantly preferred over subordinate ones. The presence of a rival male modified the courting behavior of males and agonistic behavior among males was observed before and during mating.

Copitarsia decolora Guenée (Lepidoptera: Noctuidae) females avoid larvae competition by detecting larvae damaged plants.

Herbivory insects can discriminate the quality of a host plant for food or oviposition, by detecting the volatile organic compounds (VOC's) released by the plant, however, damaged plants may release a different VOC's profile modifying the insects' response. We tested if the VOC's profile from damaged plants affected the response of Copitarsia decolora as these moths oviposit preferably around undamaged host plants. We assessed the response in wind tunnel conditions of C. decolora mated females to volatiles collected by dynamic headspace from 30-40 d old cabbage undamaged plants and mechanical and larval damaged plants. Headspace volatile compounds from undamaged cabbage plants were more attractive to mated females than those from larval and mechanical damaged cabbage plants. Moths stimulated with headspace volatiles from undamaged plants performed more complete flight and ovipositor displays than those moths stimulated with headspace volatiles from damaged cabbage plants. A mixture of synthetic compounds identified from undamaged cabbages elicited similar antennal and wind tunnel responses in mated females as headspace volatiles from undamaged cabbage plants. C. decolora females may discriminate between damaged and undamaged host plants by detecting their VOC's profiles as a strategy to avoid unsuitable plants for their offspring increasing their fitness.

Influence of host fruit and conspecifics on the release of the sex pheromone By Toxotrypana curvicauda males (Diptera: Tephritidae).

The release of tephritid sex pheromones depends significantly on the age of the male, the social context (presence of conspecifics) and chemical context (host volatiles). In this study, the influence of host fruit and conspecific (males and females) on the emission of the pheromonal compound 2-methyl-6-vinylpyrazine (2,6 mvp) by Toxotrypana curvicauda (Gerstaecker) males was investigated under laboratory conditions. Males were divided into one control group (nonexposed to treatment) and five experimental groups were placed 1 hr before volatile collection with: 1) host fruit (unripe papaya), 2) two females, 3) two males, 4) host fruit plus two females, and 5) host fruit plus two males. The volatiles were sampled by means of solid phase microextraction and analyzed with gas chromatography-mass spectrometry, with a focus on 2,6 mvp. Males emitted volatiles from the first day after adult emergence. The maximum peak and the temporal pattern of 2,6 mvp release were modified by the presence of host fruit and conspecific males or females. On day 5, males in the presence of fruit maintained a constant release of 2,6 mvp while the presence of conspecific caused a decrease of pheromone release. The release of 2,6 mvp was increased significantly in males exposed to both types of stimuli simultaneously. The stimuli (fruit and conspecifics) modified the release of 2,6 mvp, however the effect depended on male age.

Extraction with SPME and synthesis of 2-methyl-6-vinylpyrazine by a 'one pot' reaction using microwaves.

A synthesis of 2-methyl-6-vinylpyrazine was carried out by way of a 'one pot' reaction. In order to establish the efficiency of this synthesis the extraction of the volatiles released by male papaya fruit flies was performed by SPME (solid phase micro-extraction). The compound was separated and identified using GC/MSD (gas chromatography/mass spectrometry detector).

Two low-cost food attractants for capturing Toxotrypana curvicauda (Diptera: Tephritidae) in the field.

Adults of the papaya fruit fly, Toxotrypana curvicauda Gerstaecker, living in wild vegetation in Yautepec, Morelos, Mexico, were captured using McPhail traps baited with pineapple juice or brown sugar. Maximum capture peaks occurred during August and November in the afternoon. Baits were most effective when aged over a 4-d period. Traps baited with brown sugar captured the highest number of adults, and both baits were more attractive to females than males. Potential use of these baits for pest management and research is discussed, considering that this is the first report of pineapple juice being attractive to the papaya fruit fly.