Majority Of Moths Research Articles

The Impact of the Leopard Moth Zeuzera pyrina L., (Lepidoptera: Cossidae) Infestation in Casuarina Trees on the Neighboring Pear Orchards in Egypt

The impact and relative susceptibility and monitoring of the Leopard moth Zeuzera pyrina L., (Lepidoptera: Cossidae) infestation in pear orchards neighboring and non-neighboring to casuarina trees were evaluated at Borg el-Arab district, Alexandria Governorate , Egypt, during the two successive years 2015 and 2016. The mean rate of Z. pyrina infestation in pear trees neighboring to casuarina trees were 15 – 21% (mean, 18%). However, pear trees far away and not neighboring to casuarina trees showed significantly lower rate of the borer infestation (7 - 9%, mean 8%). On the other hand, the rate of Z. pyrina infestation in casuarina trees neighboring to pear trees 13 – 18% (mean, 15.5%). The degree of Z. pyrina infestation in casuarina trees surrounding pear trees was high (0.42 – 0.57, mean 0.5 moths / tree / year). The degree of infestation in pear trees surrounded by casuarina wind break trees was high (0.55 – 0.77, mean 0.66 moths / tree / year). The degree of infestation in pear trees not-surrounded by casuarina wind break trees was almost half degree (0.28 – 0.37, mean 0.325 moths / tree / year). In all cases, and during the two years of study, moths started to emerge in April and sometimes in May and continued mostly until November sometimes in October. Peaks of moths’ emergency were mostly in August. Summer months showed that, the majority of moths’ activity. Less mean numbers of emerged moths / tree were noticed in spring months, while autumn showed few numbers, and moths stopped emergence during winter months. The seasonal cycle of Z. pyrina moths consisted of 7 – 8 months of moths’ activity in casuarina trees and pear orchards. Generally, infestation in pear orchards rabidly multiplied and increased more than twice at the end of only two years. These rapid increases impose the urgent need of control Z. pyrina in casuarina trees as well as in pear orchards especially when they are surrounded by infested casuarina wind break trees.

Discovery of a disused desaturase gene from the pheromone gland of the moth Ascotis selenaria, which secretes an epoxyalkenyl sex pheromone

Female Ascotis selenaria (Geometridae) moths use 3,4-epoxy-(Z,Z)-6,9-nonadecadiene, which is synthesized from linolenic acid, as the main component of their sex pheromone. While the use of dietary linolenic or linoleic fatty acid derivatives as sex pheromone components has been observed in moth species belonging to a few families including Geometridae, the majority of moths use derivatives of a common saturated fatty acid, palmitic acid, as their sex pheromone components. We attempted to gain insight into the differentiation of pheromone biosynthetic pathways in geometrids by analyzing the desaturase genes expressed in the pheromone gland of A. selenaria. We demonstrated that a Δ11-desaturase-like gene (Asdesat1) was specifically expressed in the pheromone gland of A. selenaria in spite of the absence of a desaturation step in the pheromone biosynthetic pathway in this species. Further analysis revealed that the presumed transmembrane domains were degenerated in Asdesat1. Phylogenetic analysis demonstrated that Asdesat1 anciently diverged from the lineage of Δ11-desaturases, which are currently widely used in the biosynthesis of sex pheromones by moths. These results suggest that an ancestral Δ11-desaturase became dysfunctional in A. selenaria after a shift in pheromone biosynthetic pathways.

Factors influencing adult male Grapholita molesta dispersal in commercial Malus and Prunus host crops

AbstractThe oriental fruit moth (OFM), Grapholita molesta (Busck) (Lepidoptera: Tortricidae), has been an economic pest of apples (Malus spp.) and peaches (Prunus spp.; both Rosaceae) in the eastern USA since the 1930s. Successful management of G. molesta with insecticides requires careful timing of these products based on sex‐pheromone trap captures of male moths. In Pennsylvania, apple and peach orchards are often planted adjacently. Factors such as trap distance from release points, host crop, and wind were considered in relation to male moth movement within and between hosts. Our practical objective was to understand male G. molesta dispersal within and between these two hosts to achieve better management. Recapture of moths decreased over distance; the majority of moths were recaptured 50–100 m from the release point regardless of crop type. Male G. molesta released into commercial apple and peach orchards were most likely to remain in the crop of release and to not exhibit host shifts over the season, even after peach fruit were harvested. Our analyses of wind direction data with respect to recapture showed that the likelihood of recapture was similar regardless of the orientation of the traps relative to the mean wind direction at peak flight times. The apple and peach host crops appeared to affect male G. molesta dispersal to the extent that wind in orchards affects their perception of pheromone. Crop effects were most likely due to the traps closest to the release points being in the same crop as the release points.

Countryside Biogeography of Moths in a Fragmented Landscape: Biodiversity in Native and Agricultural Habitats

Abstract: Studies of fragmented landscapes, especially in the tropics, have traditionally focused on the native fragments themselves, ignoring species distributions in surrounding agricultural or other human‐dominated areas. We sampled moth species richness within a 227‐ha forest fragment and in four surrounding agricultural habitats (coffee, shade coffee, pasture, and mixed farms) in southern Costa Rica. We found no significant difference in moth species richness or abundance among agricultural habitats, but agricultural sites within 1 km of the forest fragment had significantly higher richness and abundance than sites farther than 3.5 km from the fragment. In addition, species composition differed significantly between distance classes ( but not among agricultural habitats), with near sites more similar to forest than far sites. These results suggest that (1) different agricultural production regimes in this region may offer similar habitat elements and thus may not differ substantially in their capacities to support native moth populations and (2) that the majority of moths may utilize both native and agricultural habitats and move frequently between them, forming “halos” of relatively high species richness and abundance around forest fragments. Correlations between species richness and the amount of nearby forest cover, measured over circles of various radii around the sites, suggest that halos extend approximately 1.0–1.4 km from the forest edge. The extent of these halos likely differs among taxa and may influence their ability to survive in fragmented landscapes.

Flight Thresholds of the Armyworm (Lepidoptera: Noctuidae)

Flight initiation threshold temperatures for agitated and undisturbed adult armyworms, Pseudaletia unipuncta, were measured. A predefined sequence of disturbances was applied to individual moths in an empty environmental chamber at various constant temperatures. With this agitation, the minimum flight threshold observed was 4°C, and the majority of moths could initiate flight at 10°C or above. A linear trend was noted between the log of duration of preflight wing shivering and ambient temperature. There were no detectable interactions with the sex or age of moths. Undisturbed moths were placed on oat seedlings at various constant temperatures under the photoperiodic conditions of rearing and left overnight. The presence of wing scales on a surface coated with Tanglefoot indicated flight. Flight was indicated at a minimum of 8°C. Flight maintenance thresholds were determined by lowering the temperature in a small tubular enclosure containing a single flying moth. Thresholds averaged 5.0°C for females and 3.9°C for males, with a minimum observed threshold of −l°C. No significant interactions with moth age or relative humidity at testing were noted.

Low–Frequency Sodar 1 Device that Counts Flying Insects Attracted to Sex Pheromone Dispensers 23

A low-frequency, sodar (sound detecting and ranging) set was designed, constructed, and tested in cotton fields to detect flying tobacco budworm moths attracted at night to sex attractant dispensed from the sonic transmitter site. Counts made by the sodar set were compared with numbers of male budworms caught in traps baited with either synthetic pheromone or live female moths. Peak sonic transmission power was <25 W/2 ms at a 1.2% transmit-receive duty cycle. With sensitivity set at an effective range of 1 meter, the majority of moths counted by the battery-powered sodar set were tobacco budworms when their synthetic sex attractant was used as bait.