Lepidoptera genitalia

About: Lepidoptera genitalia is a research topic. Over the lifetime, 10114 publications have been published within this topic receiving 78876 citations. The topic is also known as: Uncus.

Host-Searching Kairomones Alter Behavior of Chelonus sp. nr. curvimaculatus, a Hymenopterous Parasite of the Pink Bollworm, Pectinophora gossypiella (Saunders)

Abstract: This study examines the role of behavior-modifying chemicals in host location for the braconid egg-larval parasite, Chelonus sp. nr. curvimaculatus Cameron (Hymenoptera: Braconidae). The scales of one natural and two factitious lepidopterous hosts were found to contain kairomones that released an intense and stereotyped searching response that included locomotory arrestment, antennation, ovipositor probing, and inverse klinokinesis upon antennal contact in female Chelonus , responsiveness persisting during their entire reproductive life. The chemicals were soluble in hexane and methanol, being perceived by parasites over a range of 0.1 to 0.00004-mg scale equivalents. Scales shed by ovipositing moths around deposited eggs are thought to act as odorous extensions of host eggs for Chelonus , signaling for their presence over a larger area than would be possible by host egg-derived cues alone and leading to concentrated search in probable host-infested areas. When other Lepidoptera cohabiting cotton fields scatter their body scales over a broader area of the cotton plant, the result may diminish the percent parasitization of Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) by Chelonus species.

Male Genitalia of Lepidoptera: Morphology and Nomenclature II. Morphological Significance of Sacculus and Furca

Abstract: The sacculus (named by Pierce, 1909) is a reflected flange of the sclerotized part of the valva, occupying the ventroproximal portion on its mesal surface. Such a morphological element is widely found in the male genital apparatus of most specialized forms of Lepidoptera. However, the degree of development is subject to great variation in individual species, and sometimes even its presence may become obscure. The same situation is also encountered in the male genitalia of more primitive forms. The observation throughout all the lepidopterous families now makes it evident that the development of the sacculus has close relationships to the position of the juxta (Pierce, 1909) in relation to both the bottom of the vinculum and the valva; the association of the sacculus with the juxta is noteworthy as one of general rules in the morphology of male genitalia in Lepidoptera.

INSECTICIDE RESISTANCE AND RESISTANCE MANAGEMENT Bt Maize Seed Mixtures for Helicoverpa zea (Lepidoptera: Noctuidae): Larval Movement, Development, and Survival on Non-transgenic Maize

Abstract: ABSTRACT In 2012 and 2013, field trials were conducted near Rosemount, MN, to assess the movement and development of Helicoverpa zea (Boddie) larvae on non-Bt refuge corn plants within a seed mixture of non-Bt and Bt corn. The Bt corn hybrid expressed three Bt toxins—Cry1Ab, Cry1F, and Vip3A. As the use of seed mixtures for insect resistance management (IRM) continues to be implemented, it is necessary to further characterize how this IRM approach impacts resistance development in ear-feeding Lepidopteran pests. The potential for Bt pollen movement and cross pollination of the non-Bt ears in a seed mixture may lead to Bt toxin exposure to larvae developing on those refuge ears. Larval movement and development by H. zea, feeding on non-Bt refuge plants adjacent to either transgenic Bt or non-Bt plants, were measured to investigate the potential for unintended Bt exposure. Non-Bt plants were infested with H. zea eggs and subplots were destructively sampled twice per week within each treatment to assess larval development, location, and kernel injury. Results indicate that H. zea larval movement between plants is relatively low, ranging from 2–16% of larvae, and occurs mainly after reaching the second instar. Refuge plants in seed mixtures did not produce equivalent numbers of H. zea larvae, kernel injury, and larval development differed as compared with a pure stand of non-Bt plants. This suggests that there may be costs to larvae developing on refuge plants within seed mixtures and additional studies are warranted to define potential impacts.

Incidence of Oscheius onirici (Nematoda: Rhabditidae), a potentially entomopathogenic nematode from the marshlands of Wisconsin, USA

Abstract: In a search for an entomopathogenic nematode to control cranberry insect pests, three Oscheius populations (Rhabditidae) were recovered through the Galleria-bait method from one sample taken in a wild cranberry marsh in Jackson County, Wisconsin, USA. Morphological studies with light microscopy and scanning electron microscopy, as well as molecular analyses of the near-full-length small subunit rDNA gene, D2/D3 expansion segments of the large subunit rDNA gene, internal transcribed spacer, and mitochondrial cytochrome oxidase subunit 1 (CoxI) genes revealed this as Oscheius onirici, a species recently described from a karst cave soil of central Italy. The species belongs to the dolichura-group and is characterized by its DNA sequences; hermaphroditic reproduction; and males not found. A Bacillus-like bacterium appears to be associated with this nematode based on our microscopic and SEM observations; however its identity and persistent association with the nematode has not been confirmed. Nonetheless, this nematode is capable of infecting and killing the sparganothis fruitworm Sparganothis sulfureana Clemens (Lepidoptera: Tortricidae), the brown-banded cockroach Supella longipalpa Fabricius (Blattodea: Ectobiidae), and the cranberry fruitworm Acrobasis vaccinii Riley (Lepidoptera: Pyralidae), under laboratory conditions, and each in less than 72 hr. The mealworm Tenebrio molitor Linnaeus (Coleoptera: Tenebrionidae) and the greater wax moth Galleria mellonella Linnaeus (Lepidoptera: Pyralidae), are also susceptible, but take 3.5 and 5.2 days to die, respectively. This species is a new potential bio-control agent on insects.