Revista Colombiana de Entomología

Spatial behavior of the leaf miner, Leucoptera coffeella (Lepidoptera: Lyonetiidae) in coffee plantations of Temascaltepec, State of México, Mexico

2023-11-27T21:38:44-05:00

The production and commercialization of coffee in Mexico and in the international market is of great importance for the economy of millions of human beings on the planet. In
Mexico, one of the main pests that causes economic damage is the leaf miner, Leucoptera coffeella (Lepidoptera: Lyonetiidae), which, if not adequately controlled, can cause serious defoliation that in turn could translate into economic losses. Controlling this pest effectively generates a high cost due to the purchase of agrochemicals. Therefore, knowing the spatial distribution of the insect is of great importance since control actions can be directed towards specific areas of infestation so that uniform applications will be reduced. The objective of this work was to determine the spatial distribution of leafminer populations in coffee plantations, based on the information collected, maps of leafminer density were made using the kriging method of spatial statistics. The populations of the pest insect presented an aggregate type distribution and it was reaffirmed with the density maps. The distribution of this pest is well defined in the different areas of the crop, which is useful for proper control in specific areas, thereby reducing the volume of agrochemicals to be used.

Population fluctuation of Scolytinae (Coleoptera: Curculionidae) in avocado (Persea americana Mill.) orchards in Michoacán, México

2023-09-01T13:07:55-05:00

This study aimed to determine the population fluctuation of Scolytinae (Coleoptera: Curculionidae) in orchards of avocado Persea americana var. Hass, located in the municipalities of Nuevo San Juan Parangaricutiro (SJ), Uruapan (UR), and Ziracuaretiro (ZR), Michoacán, México. The study was carried out from July 2016 to June 2018. The insects were captured using α-copaene, ethanol and querciverol + ethanol lures, which were placed in bottle traps. The population fluctuation of Scolytinae, during both years and sampling sites, presented its maximum peak during July and August. In ZR, the highest abundance of Scolytinae were recorded during July and October in the 2016-2017 cycle, and during September and October in the 2017-2018 cycle. The population abundance of Scolytinae was higher during the 2016-2017 cycle in SJ and UR, and in ZR the highest population abundance corresponded to the 2017-2018 cycle. The most abundant species of Scolytinae in SJ were Microcorthylus invalidus (43.28 %), Araptus schwarzi (28.68 %) and Corthylus detrimentosus (23.02 %), in UR, were A. schwarzi (41.40 %) and M. invalidus (14.75 %) and ZR were Premnobius cavipennis (26.04 %), Hypothenemus crudiae (17.75 %) and Corthylus flagellifer (16.17%). At the three sites, the maximum population coincided with the periods with higher rainfall and higher relative humidity percentages, conditions that favored a greater availability of food resources at the sites, which were used by the species for their establishment.

Synergists for agave weevil Scyphophorus acupunctatus (Coleoptera: Dryophthoridae) trapping on Agave angustifolia (Asparagaceae), in Guerrero, Mexico

2023-08-16T18:11:32-05:00

Scyphophorus acupunctatus (Coleoptera: Dryophthoridae) attacks several species of native agaves and it is the most important insect pest of cultivated agaves in Mexico. The management of this insect is difficult due to its feeding habits on agave stems and leaves. Recently, a trapping system based on a synthetic aggregation pheromone and food bait has been developed to monitor and capture adult S. acupunctatus. However, it is important to know some alternatives that can synergize the response of S. acupunctatus to the synthetic pheromone. In this study, two consecutive field trials were carried out where diverse synergists were evaluated in traps placed in a plantation of Agave angustifolia (Asparagaceae), in Quetzalapa, Guerrero, Mexico. The synergists evaluated were the following: plant tissue of A. angustifolia, ripe fruits of pineapple (Ananas comosus), and banana (Musa paradisiaca) as well a synthetic synergist (Sinergium®). In all the experiments, a completely randomized design was used, with four repetitions for each treatment. The synergists evaluated had no effect on the captures of S. acupunctatus. The capture averages of S. acupunctatus/trap/day in the experiments did not differ, which is why it is suggested that in plantations with initial or low infestations (up to 5 weevils) it is not required to add synergists, while at high densities (more than 5 weevils) it is advisable to use a plant or synthetic synergist (Sinergium®) to make synergy with the synthetic pheromone. In addition, more female (192) than male (137) were captured in traps, which may impact future pest density populations of the weevil, plant health, and agave producer economics.

Effect of Metarhizium robertsii Associated with Lufenuron on the Mortality of Nezara viridula (Hemiptera: Pentatomidae)

2023-10-19T19:27:43-05:00

The compatibility, pathogenicity, efficiency, and interaction of Metarhizium robertsii (formerly M. anisopliae) with lufenuron on Nezara viridula control were evaluated. Two bioassays were conducted in the laboratory. The first bioassay tested the effect of two concentrations of lufenuron on germination, colony forming units (CFU), vegetative growth and conidia production of M. robertsii. In the second bioassay, the pathogenicity through lethal concentrations (LC) and lethal time (LT) on M. robertsii as well as their efficiency and interaction associated with lufenuron on the mortality of N. viridula was determined. The results indicate that M. robertsii and lufenuron, in lower concentrations are compatible, however, high concentrations of the insecticide may reduce the germination and CFU number. Higher concentrations of M. robertsii increase the percentage mortality of N. viridula nymphs and reduce the lethal time. The interactions of M. robertsii with lufenuron are efficient with additive effects and show potential for use in integrated management of N. viridula nymphs.

Floral characteristics in five landraces accessions of pumpkin (Cucurbita argyrosperma) related to the attraction of insect visitors

2023-01-27T09:42:45-05:00

Pollination is extremely important for agriculture, with insects being the main pollinators. Plants have developed attraction strategies in their flowers to ensure visits from pollinators; therefore, knowing the floral characteristics that influence visits to crops could lead to improvements in yield. The floral attributes of five landraces accessions of pumpkin (Cucurbita argyrosperma) were compared: RRS004, RRS006, RRS005, RRS008 and RRS010. The experiment was carried out in a family orchard in Baca, Yucatan, Mexico. Evaluations were carried out in the period of maximum flowering, the size and area of the corolla, the height of the flower, floral display, volume and concentration of sugar in nectar, pollen production and its viability were recorded; and also, floral visitors. The results showed that there are differences in terms of floral traits between evaluated accessions, as well as the pollen and nectar floral area was associated with floral visitors. Similarly, a greater number of illegitimate visits was observed compared to legitimate visits, of which all were identified as chrysomelids (Acalymma sp.), bees (Partamona sp.), drosophilids (Drosophila sp.), thrips (Frankliniella sp.), ants (Solenopsis sp.) and wasps (Polybia sp.). Our study shows that the variation recorded in floral traits between accessions impacts the attraction of visiting insects, which demonstrates an important intraspecific variation in Cucurbita sp.

Insecticidal and antifeedant bioactivities of Melaleuca alternifolia essential oil on Ascia monuste orseis

2023-07-28T22:29:52-05:00

This study evaluated the bioactive effects of Melaleuca alternifolia essential oil on the behavior and mortality of Ascia monuste orseis caterpillars. The experiment was conducted at the laboratory under controlled conditions using a completely randomized design with six treatments, represented by A. monuste orseis caterpillars fed collard leaves treated with 0 (control), 5, 10, 20, 30, or 40 mg mL⁻¹ essential oil. Each treatment consisted of five replicates of four third-instar caterpillars. Mean daily intake of collard leaves, feces production, mortality, and behavioral changes were assessed for 15 days after the beginning of the experiment. Data on leaf intake and feces production were subjected to analysis of variance by the F-test; when significant differences were found, data were subjected to regression analysis. Corrected mortality rate was calculated and subjected to analysis of variance by the F-test followed by Tukey’s test at the 5% significance level for comparison of means. The median lethal dose (LD₅₀) was also evaluated. Two very clear feeding behaviors were observed, one in caterpillars exposed to essential oil concentrations of 5, 10, and 20 mg mL⁻¹, which showed little difference in feed intake from the control, and the other in caterpillars exposed to the highest concentrations (30 and 40 mg mL⁻¹), which showed a decrease of 76 to 93% in feed intake compared with the control. Lower leaf intake resulted in a decrease in feces production, and the negative effects increased linearly with essential oil concentration. The mortality curve showed a linear and positive response to essential oil concentration, reaching 100% in insects exposed to the highest concentrations. The LD₅₀ was 13.93 mg mL⁻¹.

Effect of different photoperiods on the biology of immatures and adults of Anopheles darlingi (Diptera: Culicidae)

2023-12-01T18:22:01-05:00

Studies on the mosquito Anopheles darlingi Root (Diptera: Culicidae) are essential since it is the main vector of human malaria in the Brazilian Amazon. Photoperiod affects several biological variables of mosquitoes including motor, e.g., mating behavior, and oviposition and behavioral, e.g., consuming sugar and blood diets, activities, therefore, this work investigated the effect of different photoperiods on the biology of this species. Mosquitoes were reared under three different treatments: (i) 12 L:12 D, (ii) 24 L:0 D (constant light), and (iii) 0 L:24 D (constant darkness). Fifty larvae per tray were reared under different light periods and fed ground fish food. Survival and larval development times, emergence and pupation rates, the male-to-female ratio, and adult longevity were recorded. The use of different photoperiods affected several biological parameters of A. darlingi. The 24 L:0 D and 0 L:24 D treatments resulted in higher mortality, whereas constant light increased larval development time. The male-to-female ratio was greatly reduced under constant light conditions, but adult longevity was not affected by the photoperiods used. Thus, unnatural light conditions (complete light or complete darkness) result in suboptimal mosquito rearing.

Occurrence of natural parasitism in Euschistus heros (Heteroptera: Pentatomidae) eggs by Telenomus sp. aff. podisi in soybean in Amambay, Paraguay

2023-11-30T20:05:20-05:00

Euschistus heros (Hemiptera: Pentatomidae) is the main pest of soybean in Amambay, Paraguay; the intense damage to the pods results in decreased production and economic losses for farmers. Parasitoids that naturally control their populations are important agents to include in integrated pest management. In this investigation, the occurrence of natural parasitism of E. heros eggs by Telenomus sp. aff. podisi (Hymenoptera: Scelionidae) in soybean was determined. The parameters evaluated were: The number of parasitized eggs, parasitism index, and percentage of emerged parasitoids. Photographic images of the parasitoids were also produced to describe their main morphological characteristics. The research was carried out in six districts of the department of Amambay, Paraguay. E. heros eggs were randomly collected from 50 soybean plants, transferred to the laboratory, and conditioned in a climate chamber. After the emergence of the parasitoids, they were placed in a freezer to produce death and in 70 % alcohol for preservation. For the identification of specimens, the parasitoid samples were sent to the laboratory of the Biological Institute of Campinas, Sao Paulo, Brazil. Additionally, photographic images of the recovered adult parasitoids were prepared to describe their main morphological characteristics. Only the parasitoid T. sp. aff. podisi was identified. The number of parasitized eggs was 683, the parasitism index was 92.67 %, and the percentage of emerged parasitoids, was 22.55 %. This is the first report of the natural occurrence of T. sp. aff. Podisi in E. heros eggs in Paraguayan soybean crops, an important biological pest control agent.

Testing Opuntia ficus-indica genotypes for resistance against Dactylopius coccus (Hemiptera: Dactylopiidae)

2023-11-21T08:20:03-05:00

Besides being a beneficial insect when it is cultivated for the production of carminic acid, the cochineal

insect (Dactylopius coccus) is also a threat to the prickly pear cactus (Opuntia ficus-indica), a plant that is extremely important as a source of food, cattle feed, income, and soil and water conservation. A crucial component of an integrated pest management approach is the use of resistant varieties. In a greenhouse, a test for resistance of four cactus pear genotypes to cochineal insects was conducted at the University of Guadalajara, Center of Sciences for Biology and Agriculture. Three of these genotypes (‘Punto 1’, ‘Punto 2’, and ‘Sandate 2’) were shown to be non-hosts for D. coccus. These genotypes can be used for further research and development purposes of prickly pear cactus.