Oviposition preference of swallowtail butterfly, Papilio polytes （Lepidoptera Papilionidae） on four Rutaceae （Sapindales） host plant species

Oviposition preference and egg deposition site selection by the butterfly, Papilio polytes L. （Lepidoptera： Papilionidae） on four rutaceous host plants, Citrus aurantofolia （Christm.） Swing., Citrus hystrix DC., Citrus reticulata Blanco, and Murraya koenigii （L.） Sprengel, were assessed in field cages measuring 2 × 2 ×2 m. Simultaneous two-choice and four-choice oviposition tests of whole host plants were conducted. The mean total number of eggs laid per plant on C. reticulata in the two-choice test was significantly higher （P 〈 0.01） than those on C. aurantifolia, C. hystrix, andM. koenigii. Among the three other host plants, C. aurantifolia was preferred over C. hystrix, and M. koenigii （P 〈 0.01） and C. hystrix was preferred over M. koenigii （P 〈 0.01）. In the four-choice test, C. reticulata was highly preferred and significantly different from C. hystrix and M. koenigii. However, no oviposition preference was detected with C. aurantifolia. Among the various plant parts in the two- and four-choice tests, eggs on leaves of each plant were the highest, followed by numbers on stems, and negligible numbers on pots. These numbers on leaves of C. reticulata and C. aurantifolia were not significantly different （P 〉 0.05）, but differed significantly （P 〈 0.01） from those on leaves of C. hystrix and M. koenigii. The quantitative trend of egg-laying on stems was very similar to that observed for the leaves. Papilio polytes showed strong preference to lay eggs on the underside of leaves of all host plants than on the upper side or on the petiole. More eggs were laid on the upper side of each host plant than on its petiole. The four host plants in descending order of preference were C. reticulata 〉 C. aurantifolia 〉 C. hystrix 〉 M. koenigii. Although M. koenigii was the least preferred, it has the potential to serve as an alternative host plant for P. polytes which can be manipulated when necessary, to alleviate the infestation of this pest to the citrus industry.

Oviposition preference and larval performance of Epiphyas postvittana （Lepidoptera： Tortricidae） on Botrytis cinerea （Helotiales： Sclerotiniaceae） infected berries of Vitis vinifera （Vitales： Vitaceae）

In this paper we tested the behavior of gravid Epiphyas postvittana in select- ing the most-appropriate site for oviposition thus benefitting offspring performance. Our hypothesis was built on Jaenike＇s preference-performance hypothesis （also referred to as the ＂mother-knows-the-best＂ hypothesis）. To test this, we used the interacting Epiphyas postvittana, its host Vitis vinifera, and the pathogenic microbe Botrytis cinerea system. Populations ofE. postvittana and B. cinerea often exist concurrently on 14. vinifera in Aus- tralasia and their interaction and mutual influence are currently being explored, although the suggestion presently is that the relationship between E. postvittana and B. cinerea is mutualistic. We tested the effect of volatiles from B. cinerea-infected berries and unin- fected （control） berries of V. vinifera on the oviposition behavior of E. postvittana. We also characterized the effects of B. cinerea infection on the berries of V. vinifera on the growth and development of E. postvittana. Contrary to the preference-performance hy- pothesis, oviposition choices made by gravid E. postvittana did not result in the best offspring survival, development, and performance. The preference for oviposition by E. postvittana was strongly influenced by the olfactory and tactile cues. She laid fewer eggs on B. cinerea-infected berries compared to uninfected berries of V. vinifera. The larvae of E. postvittana showed no preference to uninfected berries of V. vinifera. The larvae fed on B. cinerea-infected berries of V. vinifera showing greater survival rate, shorter time to pupation, greater pupal mass, and on becoming adults they laid more numbers of eggs than the larvae that were enabled to feed on uninfected berries. The larvae of E. postvittana transport the conidia of B. cinerea and transmit grey-mould disease to uninfected berries of V. vinifera.