Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Doctorat → États-Unis → 2004 → Studies on two Homalodisca species (Hemiptera : Cicadellidae) in southern California : Biology of the egg stage, host plant and temporal effects on oviposition and associated parasitism, and the biology and ecology of two of their egg parasitoids, Ufens A and Ufens B (Hymenoptera : Trichogrammatidae)

UNIVERSITY OF CALIFORNIA (2004)

Studies on two Homalodisca species (Hemiptera : Cicadellidae) in southern California : Biology of the egg stage, host plant and temporal effects on oviposition and associated parasitism, and the biology and ecology of two of their egg parasitoids, Ufens A and Ufens B (Hymenoptera : Trichogrammatidae)

Al-Wahaibi, Ali Khalfan

Titre  : Studies on two Homalodisca species (Hemiptera : Cicadellidae) in southern California : Biology of the egg stage, host plant and temporal effects on oviposition and associated parasitism, and the biology and ecology of two of their egg parasitoids, Ufens A and Ufens B (Hymenoptera : Trichogrammatidae)

Auteur  : Al-Wahaibi, Ali Khalfan

Université de soutenance : UNIVERSITY OF CALIFORNIA, RIVERSIDE

Grade : Doctor of Philosophy (PhD) 2004

Résumé
This dissertation examined the morphometrics of the egg stage, embryonic development, and non-parasitic mortality of eggs of the glassy-winged sharpshooter, Homalodisca coagulata (Say), and smoke-tree sharpshooter, H. liturata Ball. Degree-day models for H. coagulata and H. liturata were produced. Hatching was reduced at extreme temperatures (13 and 35°C). Five stages of embryonic development of H. coagulata were described and three types of abnormal development were noted. 1n the field, non-parasitic mortality varied among host plants due to nymphs dying as they attempted to hatch or due to abnormal development. A two-year field study was conducted to examine the temporal and host plant distribution (10 host plants total) of Homalodisca oviposition and associated egg parasitism in agro-ecosystems at Agricultural Operations, University of California, Riverside and Desert Center, California. Oviposition occurred in two distinct periods during the year. Parasitism was low from late winter to early spring but reached constantly high levels thereafter. Parasitism was due to a total of eight parasitoid species with Gonatocerus ashmeadi Girault, Ufens A, Ufens B, and G. morrilli (Howard) being the most abundant. Ufens spp. were dominant on jojoba while on other plants, Gonatocerus species tended to dominate. Other temporal and host plant patterns relating to oviposition and parasitism were discussed. The basic biology and ecology of two Ufens species was investigated using laboratory experiments and observations in the field and laboratory. Males tended to emerge mostly at or just before dawn. Male to male aggressive behavior was described. Ufens A oviposition per egg mass was done by multiple females and peaked immediately before sunset during summer. There was a strong positive relationship between Ufens A oviposition and Homalodisca female oviposition. Ufens A females were able to rapidly locate freshly-laid egg masses from a relatively long distance, possibly due to attraction to host related-odors. Parasitism was higher on very young egg masses (0 h old) than on moderately-aged (0–6 h old) and old egg masses (12–24 h old). Other aspects of the biology of Ufens A and Ufens B were investigated including : effects of season and host plant on gregariousness, gregariousness versus adult size, field sex ratios, immature development, longevity, and female age and size and their effects on egg load and parasitism.

Mots clés : BIOLOGY, ENTOMOLOGY ; BIOLOGY, ECOLOGY

ProQuest Digital Dissertations

Aperçu 24 pages : ProQuest Digital Dissertations

Page publiée le 26 janvier 2005, mise à jour le 11 janvier 2017